Historical legends garnet

Garnet in the Bronze Age has become a very popular gemstone , garnet was the ancient Egyptians also to beautify their costumes. The first four centuries of ancient Greece has been decorated with garnet bracelet . In 1842 , France Aube Pouan find treasures (Treasure of Pouan) , we found a five- century garnet and Germanic warriors buried with the bones . Leicestershire , UK Gold Garnet Charm found a 5th century . In a 6th century Frankish graves , found a hair clip decorated with garnet pin (Hairpin). In the 16th century, garnet is thought to protect the heart against the effects of toxins and plagues . In the Renaissance to the Victorian era produced by the Bohemian pyrope garnet as the main source was , but in the late 19th century , decorated with garnet bracelet and brooch (brooches) particularly widespread .
garnet supplier is the allegation that the first high priest of ancient Israel (High priest) Aaron wearing one color chest pocket (Hoshen) twelve jewels, on behalf of the tribe of Judah (Tribe of Judah). In Greek mythology, Kazakhstan at the end of Sri Lanka when Persephone returned to her eating pomegranate seeds , so she must return to the underworld within a certain time . Therefore Garnet represents loyalty, true and faithful . Besides, garnet in the " Koran" lit up the fourth heaven argument. Maintenance : the need for short-term defense salt per flooding filtered raise one day . If you pray with defense declared wish to write on , on both INCREDIBLE bowl , the long-term use can occur on the roots look like a bowl of strange phenomenon .
European Bohemian Garnet Museum : a sleeping centuries garnet red , her owner is black dew Juliet , then , Wu Lu Juliet is wearing While every stone of love , and her Goethe dating lover , she then convinced : garnet to bring good luck and happiness for their eternal love .

The crystal structure of garnet

garnets is a generic formula X3Y2 (SiO4) 3, silicate minerals (Silicate_minerals).
Garnet necklace
Garnet necklace
X where normally bivalent (divalent) of positive ions (Ca, Mg, Fe) occupy , and Y is where is a trivalent cation (Al, Fe, Cr) occupies , with a regular octahedron or the [SiO4] provided tetrahedral framework. Garnet crystal dodecahedron habit (crystal habit) most commonly found, but there is also a common habit recipe three octahedral (trapezohedron) (note here the "recipe three octahedral " in the main mineral literature will be called kite -shaped three-dimensional geometry THH (Deltoidal icositetrahedron)). They crystallize in the isometric crystal system , there are three equal -length axis and perpendicular to each other . garnet suppliers and will not appear cleavage (Cleavage), so when they burst under pressure will produce significant irregular pieces , a powerful natural crystal energy can bring unlimited inspiration and vitality.
On the market so-called " green garnet Bi " and garnet nothing to do , in fact, prehnite . Prehnite not green garnet , two completely different concepts . The grapes on the market take the side of the stone and green garnet , is nothing more than for financial gain . Value Demantoid very expensive diamond bid , the market is extremely rare.

Comparison of aluminum and silver

which can be adjusted to reduce the amount of silver to the background and modulated gray , silver and blue phase effects of different hues , adding a very small amount , convection flat with good role in promoting. Applied to the film material in the mill together , can not be directly applied , will produce satellites plus direct silicon carbide manufacturers , such as white spots , R01 best, direct dry mix without particles .
2, the sheet structure leafing aluminum extrusion in the grinding process will be damaged ( deformed or crushed ) , resulting in the color gray, it is generally a dry mix method .
Non- floating silver
Uniformly distributed parallel to the non- silver coating in the float , and thus the resin package, and therefore have good oxidation resistance and wear resistance , good weather resistance acid , no fingerprints , glossy surface , and colors can be adjusted from the bottom powder, but adding a large amount of silver compared to floating , floating silver metallic effect without strong whiter . 2, PCR \ DIS aluminum powder especially suitable for outdoor products , because there are inorganic coating layer , with good water resistance, weather resistance, chemical resistance ; though coated with silicon and other materials, but in the natural environment of exposure to Alumina Abrasive powder in the light and humidity conditions will soon change chemical Physics oxidation , thus weakening the metal sense , the film is dark gray , gray leaf spot , etc. appear . In order to solve such problems and abrasions and other problems, we recommend using transparent powder varnish . 3 , cover the bottom with a transparent bottom powder dosage test , the addition of silver flash can reach up to about 10% ; mixed with spraying process directly affects the spray and cover the results, please note the consistency of mixing and spraying , the more coarse particle flashes better. 4, due to the differences in the shape of silver particles , the density and the amount of charge with respect the powder will cause separation and impact of the powder. Using bonding techniques for bonding the powder and silver powder , the powder and the effect of greatly improved. 5 , aluminum can not change color temperature of 600 degrees .

The introduction of various aluminum products

Silver Aluminium hydroxide powder
Floating silver superfine large surface area , when it is exposed to air , its surface can be rapidly generated in a passive protective film , i.e., black oxide , sealing measures to be good , floating silver case not recommended for applications requiring alkali- 2 large , silver between batches have some differences , and by the process , spraying effects , in addition to need to try to maintain the stability of the production process , but should first test of reproduction , so ; , if required may be considered white pearl powder expand loss. 3 , ultra-fine silver amount 1-2% of the bottom cover , with the addition of a high wax AW500B 0.6% -1.5 % and the bottom of the cover can produce a strong metallic luster , the more the addition amount of silver white, the smaller the amount of blue , there is insufficient amount of black spots black silk added , or commonly known as the fly feces , overall blackish . 4 , floating silver flaky , always floating in the outermost layer of the coating , so the hardness and antioxidant properties blackened somewhat less , plus Indian consumer to get better hardness required to increase the hardening agent AS501, plus additional silver hard agent POL16, POL09 , etc., can not be heightening wax , gold and silver aluminum powder arrangement agent, polyethylene wax , mixing the longer the better.
Floating silver
1 , silver metallic , the stronger the smaller the particle size , hiding the stronger ; addition of too easy to produce powder and spit tip clogging phenomenon ; easy enough when you add the amount of black spots , flooding or fine stripes. R18, R01 and other effects of new silver dispersant is used as carrier SIO2 efficient dispersant, unlike ordinary silver dispersants , regardless of how much can be uniformly dispersed silver added no black spots ,

Optical properties of aluminum powder

Aluminium hydroxide by a light color, high- gloss aluminum metal , its smooth surface that reflects visible light, 60% -90% ultraviolet and infrared light , with the object containing aluminum powder paint coating , the surface of silver white light , this is the aluminum light reflection characteristics.
" Color effect" characteristic of aluminum powder
Since aluminum has a metallic luster and a characteristic to be coated parallel to, a vector containing a transparent pigment , a change in the gloss and color shades with aluminum angle of incidence of the incident light and the viewing angle of the light and color change , such feature is called " two-tone effect ." Aluminum in the coating film are arranged at different levels , when the incident light is irradiated to the layers of aluminum flakes , because by passing through the film thickness of the different type of weakening of the light reflected brightness is obviously different . When the inner light into the white fused alumina suppliers -containing layer and a transparent pigment , the pigment particles become incident through the colored light , and then after reflected different levels of aluminum , light metal , and a hue change will occur , and the viewing angle of the incident light gradual angle from the vertical position to move through the different light color and the number of particles of different particle sizes of aluminum , the hue of light reflected light can occur and the metal endless changes . This feature aluminum has been widely used in the paint, as hammer paint or metallic paint .
Floating aluminum powder characteristics
Pigment with a large variety of aluminum and aluminum paste is floating type , which is characterized by scaly film floating on the surface .
5 Application
Applications
Because aluminum has a silver-white metallic luster, so called aluminum silver or silver , its chemical composition is indeed " aluminum" , not " silver ." Applications: powder coating , ink, plastic masterbatch , printing, paper imitation gold , imitation Gold, gold film , textiles, but the use of water-based paints and paint with a pH of oxidized black. Not recommended for applications requiring a combination of acid rain and the occasion .

The development of aluminum industry

Chinese brown fused alumina price industry since the 1950s started, has been 50 years of history . Subsonic air atomized aluminum powder atomization method are used , the pressure water atomizing method is started into the production sequence , both products of irregular shape , also being spherical. In terms of ball milling of aluminum and aluminum manufacturing pulp , dry process and wet process have manufacturers use . Products are leafing aluminum powder and aluminum paste , aluminum and non- leafing aluminum paste . Suitable for water-based paint water dispersible aluminum paste already available in the form of aluminum alloys such as zinc and aluminum pulp slurry also produced .
4 features
Aluminum silver metal relative mass of 26.98 , a relative density of 2.55 , melting point of aluminum of 99.5% purity was 685 degrees , the boiling point of 2065 degrees, melting endotherm 323kj / g, aluminum reductive easily oxidized in the oxidation process exothermic . When a sharp exothermic oxidation 15.5 kj per gram / ​​g, aluminum is malleable metal , easy processing. Aluminum oxide film on the surface of the transparent and has good chemical stability.
Pigment particles with white fused alumina powder means scaly , and the desirability of treating agent coated aluminum powder pigments do . Aluminum paste is a mixture of aluminum powder pigment and a solvent , and it uses substantially the same characteristics and aluminum , because it is simple to use , and the greater the amount of production . Compared with aluminum pigment and other pigments , but also has its characteristic performance in the following aspects :
A scaly hide characteristics
Scaly aluminum particles , the ratio of diameter to sheet thickness of about ( 40:1 ) - ( 100:1 ) , the aluminum powder dispersed in the carrier in parallel with the substrate having the characteristics of many of the aluminum interconnection , the size filling the particles together to form a continuous metal film covering the substrate , and an outer coating of the light reflected , which is unique to aluminum hiding . Aluminum hiding depends on the surface area of the large and small , which is thicker than the diameter . Aluminum was extended during the grinding process , increasing diameter to thickness ratio , hiding also will increase .
2 , aluminum shielding properties
Aluminum powder dispersed in the carrier floating movement occurs , the result is always that its movement is parallel to its metal carrier coating to form a continuous layer of aluminum , and this aluminum layer is arranged parallel to the carrier film multilayer . Pores are staggered between the layers of aluminum powder , the capillary cut microporous support membrane , the outside water can not reach the gas through the pores of the substrate , which is characterized by good physical aluminum shielding .

Brief aluminum powder

Eight Aid Inhalation : If irritation occurs , so that the eyelids open, with normal saline or slow flush eyes with lukewarm water for at least 10 minutes. Skin contact : In case of irritation, excess pink fused alumina erase or wipe gently . Oral : Do not induce vomiting. Approximately 250 ml of water to the patient . All patients should ask a doctor for treatment.
Nine storage and transport rules storage and transport of flammable substances. Store in a cool, dry, well- ventilated place, avoid dust generation . Package No. 2,6 .
Ten safety and handling only trained personnel to undertake cleaning work. Guarantee to provide good ventilation . Use good protective clothing and respirators . Do not touch the fallout can shovel into clean, dry , and cover the container with the label , rinse the scene. Scattered away from combustible materials , compliance with environmental regulations.
2 Uses
Aluminum pigment particles using a scaly , it is precisely because of this state of scaly particles , it has a metallic luster and aluminum shielding . Industrial production of aluminum metal , long time ago there early production is pounding punch method, the buy brown fused alumina debris on the pound punching machine grooves , rods driven continuously under mechanical punch fight groove aluminum scrap , with ductility of aluminum foil under the impact of becoming and broken, after the aluminum becomes very meager fine filter , remove the aluminum as a desirable product . Productivity pound punch method is very low, the product quality is not easy to master, but a lot of dust in the production process , very easy to fire and explosion . In 1894 , the German Hamtag mill production with aluminum powder, placed in a ball mill , aluminum scrap and lubricants , the use of fly balls move after becoming crushed aluminum scrap aluminum flake in the mill and pipe filled with inert gas , this method is still in use , is called " dry production ." In 1910, the United States J.Hall invented adding petroleum solvent instead of inert gas in the mill , the production of aluminum powder and solvent slurried become pasty aluminum pigment. This method is simple , process safety , the product is easy to use , quickly adopted by countries in the world . The vast majority of modern aluminum pigments are using this method, which is also known as "wet ."

Detailed aluminum powder

Aluminium hydroxide powder, commonly known as " silver " , i.e., the silver metallic pigments , a small amount of lubricant is added to pure aluminum foil , crushed by ramming Chance squamous powder , and then polishing is made . Aluminum is light, floating force, hiding power, light and heat reflective properties are good . After treatment, can also become a non -leafing aluminum . Aluminum can be used to identify fingerprints , you can also do the fireworks . Due to extensive use of aluminum , the demand for large , multi-species , it is a large class of metallic pigments .
1 Introduction
Chemical Formula : Al
Product Name : Aluminum
CAS NO :7429-90-5
MW: 26.9815
EC NO :231-072-3
InChI: InChI = 1/Al
Aluminum
Alumina Oxide
A physical and chemical properties and uses odorless. Silver-white metal powder , self-ignition temperature : 5900 ℃, dust explosion limit : 40g/m3. Used to make : paint, ink, paint and fireworks , also used as an additive porous concrete. Aluminum is also used as treatment and medical supplies , in addition to automotive and aircraft industries.
Two toxicity of the product is non-toxic to the respiratory tract induced pulmonary fibrosis. Maximum allowable concentration : 4mg/m3
Three short-term effects of exposure Inhalation : High concentrations of dust may irritate the respiratory mucosa . Eye contact: tiny dust particles generally no stimulation, a large dust particles will be some friction irritation. Oral: in the workplace without normal access to oral dose toxicity . Dust is a lot to swallow friction irritation of the stomach .
Four long- term effects of exposure or repeated exposure causes lung tissue fibrosis, occurring aluminum pneumoconiosis, symptoms include : cough , shortness of breath , loss of appetite, lethargy. Similar to asthma symptoms had appeared.
Five of the fire and explosion of combustible chemicals , powder and air can form explosive mixtures . Isolate the source of fire and let it burn . With sand, talc , sodium chloride to extinguish a small fire. Absolute ban on water.
Six chemical reactivity untouchable acid or alkali. A lot of dust will naturally generate heat when wet. Aluminum and other metal oxide mixture in a fire occurs violent reaction or fire. Mixed with halogen elements will fire. And halogenated hydrocarbons, heat or friction will react explosively .
Seven personal protective Inhalation : If dust concentration is unknown or exceed the exposure limit should wear dust masks Ⅰ level . Skin : To prevent excessive dust deposition or friction , the use of gloves, coveralls , work shoes . Eyes : Wear chemical safety glasses.

Garnet sand processing technology and uses

Waterjet sand processing
Reference Product Name : 60 mesh - 90 mesh garnet sand ( natural emery ) aka ( waterjet sand, water jet sand )
Processing: Featured content 85.4% garnet rock , artificial drying the moisture content of less than 4.7% , after the mechanical grinding pickling ( removal of impurities ) washing ( to remove sediment dust ) , the second artificial drying ( easy points sieve dust ) , moisture content below 5% . Finally, advanced secondary sieving process ( the particles more uniform ) screening package.
Recommended : 60 mesh silica sand supplier for cutting stainless steel , copper , marble products. 80 mesh sand for cutting glass , ceramics.
Garnet sand main purposes are:
( 1 ) steel hull , bridges and other sand-blasting ;
( 2 ) metal, stone, glass and other water jet cutting ;
( 3 ) chemical, petroleum, pharmaceutical , water treatment filter Alumina Grinding Media ;
( 4 ) polishing marble , optical lenses, glassware , leather and other materials ;
( 5 ) wheel, Whetstone , emery cloth , sandpaper raw materials ;
( 6 ) motorways , runways , wear rubber , non-slip paint and other wear-resistant materials ;
( 7 ) is widely used in the construction industry in the field of high-grade lacquer interior wall decoration elegant temperament . Ideal new non-metallic wear-resistant flooring aggregate.

Details about the garnet abrasive

Garnet is a island structure of calcium silicate, aluminum on mineralogy divided into two categories: department of aluminum oxide and black silicon carbide oxide. The chemical composition of garnet change is bigger, general chemical formula for the A3B2 [SiO4] 3, which represents A divalent calcium, magnesium, iron, manganese and other cations, B on behalf of trivalent aluminium, iron, chrome, manganese and other cations. Garnet generally is the crystallization of the sizes of particles, with moderate hardness, high melting point, good chemical stability, color according to different products and structure, present a different color, a dark red, red, pink, black, brown, etc. Garnet with moderate hardness, good toughness, particle size uniform, it is a good natural abrasive. In the optical industry, electronic industry, machinery industry etc widely used. Such as:
(1) in the high pressure water jet equipment (water knife cutting abrasive;
(2) the sandblasting derusting, cutting, special welding and thermal spraying, manufacturing grinding wheel, oilstone, emery cloth and garnet sand paper raw materials;
(3) used as water treatment filter medium;
(4) of silicon wafer, optical lenses, precision instruments and meters, polishing glass shell, glass, ceramic, stone, leather, plastic, metal parts can improve finish;
(5) can be used as building highway pavement, airport runway, wear-resisting rubber, industrial floor. Antiskid considerations of wear-resistant materials such as paint;
(6) for chemical, petroleum, pharmaceutical, water treatment filter medium and drilling mud weighting agent;
(7) can be used for washing factory jeans with sand sand workshop, etc

Purple garnet can work?

China's jewelry industry, the technology of the Garnet sand"purple tooth wu". "Tooth uri (gu)," derived from Arabic Yakut (gem), and because of garnet is purple red, so named purple teeth.
For thousands of years, garnet is regarded as a symbol of faith, firmness and simplicity. People want to own, and worship it, not only is because of its aesthetic value, more importantly, people believed that gem has a magical magic power, make the person not jeopardized, killed ChengXiang, can keep honor status forever, and has important function of memorial.
Today, January birthstone, garnet, as a symbol of the faithful, love and virtue.

Brown fused alumina major functions

Brown fused alumina with high temperature resistance, corrosion resistance, high strength, such as performance, so use casting steel slide gate, and special alloy smelting rare metals, ceramics, blast furnace lining; Physical and chemical vessels, spark plugs, heat-resistant oxidation coating; Corundum heat preservation material, which are widely used in all kinds of high temperature furnaces furnace wall and furnace top, high temperature resistant and heat preservation.
Brown Corundums sand particle size is by the artificial corundum block, using the equipment such as roller, ball mill, the mark, it is mainly used for polishing, grinding, grinding industry, etc., can also according to customer requirements for water washing, acid pickling treatment methods such as processing, able to meet the different needs of customers.

Garnet bracelet physiological efficacy is what?

1, Garnet sand, help to improve the human blood troubles, can promote the blood circulation, enhance vitality, which can play a beauty to raise colour effect, so it can say garnet is the first choice for ms act the role ofing is tasted.
2, garnet, helps to recover quickly, strengthen the vitality and vigor, for a man who often stay up late, overtime, restores the physical strength can make it active.
3, garnetcan strengthen the wearer's vitality and charm and affinity, garnet wheel at the bottom of the corresponding to the human body, help to improve the reproductive system function, enhance sexual performance. Can strengthen their own cells regeneration ability, and the ability to turn the healing of the wound to get fast. For women, garnet can effectively improve the troubles of department of gynaecology, improve the inner loop.
4, garnet on hormone secretion and blood circulation have certain stimulative effect, good reproductive system and the health of the relevant organ, can put a garnet in the lower spine on the back of the coccyx, can feel the vibration slowly, can purify the spleen, for arthritis are said to be effective, but if allergic or practice was not prepared for the best to avoid doing so, in order to avoid damage. Garnet is said to have also prevent snake bites and food poisoning.

The role of garnet!

Garnetrole 1) helps to improve blood troubles, promoting circulation, enhance vitality, which can take to the effect of hairdressing to raise colour, is the first choice for ladies to love.
(2). Help to improve the function of the reproductive system, and strengthen the regeneration of the body, can accelerate wound healing.
(3). To often stay up late, overtime and fatigue workers, day and night to recover. Wish I could help you!

Purifying quartz sand - chemical method

Quartz purification chemical method is mainly acid leaching method and the complex legal, acid leaching method is to use quartz insoluble in acid (except for HF) and other impurities minerals can be the characteristics of the acid dissolution, which can realize further purification of quartz. Ways is to use quartz powder after pickling, acid and can form a coordination compound and the impurity ions in solution, further to remove the impurity ions in solution.Acid leaching method is divided into single acid leaching method and mixed acid leaching method. Acid leaching is often? With acid with sulfuric acid, Aluminium hydroxideacid, nitric acid and hydrofluoric acid. Complexation is often with acids mainly oxalic acid and acetic acid (more)Crusher andKunming crusher technical details please visit kunming kunming andKun ding ChongJi beneficiation plant network). The acids of metal impurity in quartz mineral has a better removal effect. Various dilute acid on Pe and A1 removal effect is obvious, and the removal is the main use of Ti and Cr relatively concentrated sulfuric acid, hydrofluoric acid and aqua regia. The main factors influencing the effect of acid treatment is acid concentration, temperature, time and washing process, etc. 2.1 single acid leaching method to put a certain amount of quartz sand in a certain concentration of acid solution, heated to a certain temperature, heating time appropriately, the acid solution recycling, quartz sand after washing and drying. Somewhere in sichuan containing silty clayey diatomite l 'oJ, using sulfuric acid as acid infusion, by means of temperature, concentration of sulfuric acid and the study of liquid-solid ratio, it is concluded that when the temperature is 90 ℃, sulfuric acid concentration was 40%, the liquid-solid ratio of 10:1, the leaching rate of diatomite railway, best Fe20, decreased from 3% to 3% to 3%, and the content of A1203 content also decreased from 9.55% to 9.55%, and the diatomite in the SiO: content rise to more than 80%. Zhou Yongheng on acid leaching of quartz purification experiment study, through to the hydrofluoric acid pickling temperature, concentration, time of the study, the results show that when the raw material for vein quartz powder in the temperature of 120 ℃, HF, and the proportion of water in a solution of 0.4-0.5 0.5 6 h acid leaching, the purity can be reached the standard of high-grade quartz glass. 2.2 mixed acid leaching methodBecause each kind of effect of removal of impurities of quartz sand is different, different acid mixed together, produce synergies, impurity removal rate higher in the quartz sand, can obtain higher purity quartz sand. Will be washed after quartz sand to join the acid mixture, at room temperature, agitation leaching, clearance generally time for 24 h, if under the condition of heating, using agitation leaching, time is usually 2-6 h, washing dry can. Zhang Chang use at room temperature, such as 18% hydrochloric acid and silicon powder 1.5:1 the liquid-solid ratio, then with 25% sulfuric acid, sulfuric acid and silicon powder liquid-solid ratio of 2:1 in second acid leaching, acid leaching time were used in the 12 h, after two times of acid leaching purification treatment of micro silicon powder fe content < 60 ug/g. Washing of the quartz sand by 20% - 80% of the solid mass fraction with the slurry release containers of mechanical agitator, then add in hydrochloric acid solution (1% 10%) and fluorosilicic acid solution (1% 10%), quartz sand and solution in 75-100 'C temperature mixing 2 to 3 h, and then remove the slurry solution, washing with water several times, until cleaning solution pH value is close to neutral. Use this method to deal with, can reduce the iron content of quartz sand from 0.0059% to 0.0059% - 0.005%. Shen Jiu proportion of mixed acid used for sulfuric acid, hydrochloric acid, nitric acid, hydrofluoric acid 50% : 25% : 15% : 10%, heated to 80 ℃, the concentration of the leaching pulp is 50% - 55%, the content of the silica and iron impurity content reached the standard of high purity quartz sand (SiO2 99.98% or higher, Fe2O3 0.001% or less). 2.3 complex legal ways is a kind of medium strength of organic acids, react with impurities on the surface of the quartz silica sand, and also with the reaction of impurity ions to form stable coordination compounds, and reduces the concentration of impurity ions on the surface of the particles, as well as prevent ion precipitation in the process of washing, further reduce the impurity content in the quartz sand. Panias etc., 120, the average particle size of 20 LTM iron content is 110 x10 ° of quartz sand, said take a certain amount in oxalic acid solution, under heated to 80 ℃, the processing time is 3 h, can dissolve including iron ore, in acidic solution can only exist in the form of Fe3 ', Fe3 + again with oxalic acid to form stable chelate, the iron removal rate between 80% and 100%, after processing, iron content in the quartz sand below 10 x10 ~. - Hunan province LiuYangShi quartz sand, after dealing with the oxalic acid, the sample of SiO2 content increased from 98.26% to 98.26%, A1203 decreased from 0.18% to 0.18%, and the content of Fe203 content reduced to 0.10%. Acid used in the above are available evaporation, condensation, or other methods to achieve the purpose of regeneration and reuse. When Si02 require high purity, acid cleaning of water must be distilled water or deionized water, avoid tap water contains impurities such as iron cause pollution to the high purity Si02.

Purifying quartz sand - physical method

Physical purification quartz Silica sandis washed and classification desliming, scrub, magnetic separation, flotation and ultrasonic method.
1.1 washing and classification desliming this approach is mainly aimed at containing a large amount of clay minerals quartz sand. Because as quartz sand particles and the grade of the SiO2 decreases, and the grade of iron and Aluminium hydroxideimpurities such as mineral increase, so the rounding out the top of water concentration and classification of quartz sand ore desliming is very necessary, and the effect is also evident in the 18 j. It only as a method of the pretreatment of the ore candidate before application earlier are also common, but for the exist in the thin film on the surface of the quartz sand iron and adhesion impurity minerals, its removal effect is not significant. Scrubbing is 1.2 with the help of a mechanical force and sand grain peel force to remove the film on the surface of the quartz silica sandgrinding impurity iron, bonding and clay mineral and further chopped into single mineral aggregate, then through classification work to achieve the effect of quartz sand further purification. At present, the main two methods have good friction and mechanical scrubbing washing. For mechanical scrubbing, the related mechanical equipment structure, configuration and process flow of scrubbing washing time and concentration are the main factors influencing the scrubbing effect. Due to the factors that affect it too much, make the mechanical scrubbing the recovery rate is very low, only about 40%, so the mechanical scrubbing effect is not ideal. Compared with the mechanical scrubbing, great friction wash effect is much better than it. In great friction washing process, add the appropriate reagents, increase of impurity mineral and quartz particles on the surface of the electric repulsion, enhance impurity minerals and quartz particles mutual separation effect, increase the recovery rate of scrubbing to 80%, great friction wash is almost twice the mechanical scrubbing, but for the purification of high purity quartz sand, it is just a way of ore pretreatment. 1.3 magnetic separation magnetic separation method can remove the quartz sand particles maximum contains some impurities, hematite, limonite and biotite of weak magnetic impurities such as minerals and strong magnetic minerals mainly magnetite. Mineral often choose for weak magnetic impurities in strong magnetic machine more than 100000 e, for strong magnetic mineral impurities often adopt magnetic machine in the weak magnetic machine or magnetic separation. In general, the number of magnetic separation and magnetic field strength has important influence on magnetic separation effect of iron, with the increase of the number of magnetic separation, the iron content gradually reduce; And under a certain magnetic field strength can remove most of the iron, the magnetic field intensity even improve a lot since, in addition to iron rate also do not have changed much. In addition, quartz sand particle size is fine, in addition to iron, the better the results, the reason is that fine particle high mineral content of iron impurities of quartz sand. Tian Jinxing in experimental research progress of the study on the purification technology of high purity quartz sand, the results show that along with the increase of magnetic field intensity, impurity removal rate rise, magnetic field intensity of 100000 e, impurity removal rate increase is not obvious. Therefore appropriate magnetic field strength should be 100000 e. After magnetic separation, 40 mesh Si02 grade can reach 99.05%, with 0.071% Fe203:40-80 mesh Si02 grade is 99.09%, 0.070% Fe203 content; 80-140 mesh Si02 grade is 99.14%, 0.067% Fe203 content: 140-200 mesh Si02 grade is 99.10%, 0.069% Fe203 content. But are too many impurities in the quartz sand, especially containing more weak magnetic or nonmagnetic impurity, with magnetic separation is not only purified into high purity quartz sand. 1.4 flotation
Flotation is to remove the quartz sand in feldspar, mica and other non-magnetic minerals associated impurities. At present there are mainly with fluorine flotation and two methods of fluorine-free flotation. Fluorine flotation is using cationic collector and hydrofluoric acid as activator in the acidic pH range. But given the fluoride waste water serious impact on the environment, people are turning to non-fresno flotation. Use of quartz, feldspar differences in structure, reasonable ratio of ion of Yin and Yang of mixed collector with depth and dosage, using their Zeta potential of different, preferential flotation of feldspar, realize the separation of the two llo,. Have been reported in the neutral condition, join non-fresno flotation reagents, the silica micro powder Si02 content increased from 99.1% to 99.1%, accordingly Fe203 content decreased from 0.081% to 0.081%, a 85% yield at 83%. This indicates that no flotation can significantly improve quality of silica micro powder. Shang Yafei, sodium hexametaphosphate as dispersant and flotation agent, twelve amine collector, can remove the iron impurities from quartz fine powder, Fe2O3 content from 0.09% to 0.02%, the yield reached 85%. 1.5 the ultrasonic method, ultrasonic method is a kind of sound waves, depending on the media to spread it is mechanical energy, in the heart of the communication process will cause interaction with the media, to produce a variety of effects (mechanical effect, thermal effect and the cavitation effect). Using ultrasonic grinding head on the liquid, the liquid internal changes, pressure or tension, when the tension reaches a certain intensity, produce cavitation effect, causing the tiny bubbles, the bubbles with ultrasonic vibration is compressed stress decreased; When the bubble reaches a critical scale (the scale determines the frequency of the ultrasonic wave), the bubble will burst, produce a great pressure, engaged in fierce impact of solid particles in liquid, under the intense impact, trace impurity or water film on the surface of the particles, quickly from the particle surface spalling, suspended solids under the action of dispersant, become a subtle, from quartz sand, after washing the separation, to make the purity of quartz sand is greatly improved. Liao Qing in water and a small amount of dispersant media such as medium, the 0-15 mm depositional quartz sandstone particles, powder by ultrasonic treatment, including Fe2030.12 %, quartz sand to contain Fe2030 S10299.42 %. 01%, 8 i0299. 8%, recovery rate over 99%, reached the standard of optical glass with sand.

Corundum grinding stone have what effect

 Brown Corundums grinding stone for: bicycle, aluminum die casting, zinc die casting, furniture hardware accessories, clothing hardware accessories, luggage hardware accessories, eyewear accessories, accessories, locks, electronic accessories, all kinds of jewelry, jewelry, and powder metallurgy, resin, etc. Dongguan widely suggested corundum grinding stone on the stainless steel, iron, copper, zinc, brown fused alumina, magnesium alloy material such as stamping, die-casting, casting, forging, For wire rod, ceramics, jade, coral, synthetic resin, plastic, porcelain and other material items are all in different cutting and polishing effect, about parts normal chamfering, remove burrs, derusting, coarse grinding, and other issues

Green silicon carbide range of applications and key raw materials smelting

Green silicon carbide range of applications is gradually changing, and it is constantly rising trend in walking , silicon carbide main types of black and green , in today's high-tech refractory materials , silicon carbide is the most widely used products . Can be called emery or refractory sand .
Where: Green silicon carbide is petroleum coke and quality silica as the main raw material, add salt as an additive in electric arc furnace smelting . Green , high hardness and cutting ability, chemical stability , good thermal conductivity . High purity , brittle , microhardness 3280-3400 kg / mm2. It is made of abrasive, suitable for processing high hardness, brittleness of the material , its hardness between corundum and diamond , the mechanical strength is higher than corundum . Mainly used for grinding hard gold-bearing instruments . Green silicon carbide containing SiC99% or more, good self-sharpening , mostly used for machining tungsten carbide, titanium and optical glass , also used for grinding cylinder liners and grinding high-speed steel cutting tools.
Green Silicon Carbide Applications:
Do bonded and coated abrasives , and polishing and so on. Suitable for machining cast iron , tungsten carbide , titanium , high-speed steel. Can grind glass, ceramics, stone , agate and jade and other non-metallic materials, fine jewelry , heating elements and thermal elements . Such as carbide , optical glass, glass and ceramics brittle ma non-metallic materials , can also be used to manufacture high-grade refractory , electric components and electrical component products. There is also cubic silicon carbide, which is based on a special process to take the yellow-green crystals, suitable for the production of abrasive bearing super finishing , make the surface roughness Ra32 ~ 0.16 microns from primary processing to Ra0.04 ~ 0.02 microns.
The physical properties of green silicon carbide is better, in the major industries in the area has a significant role , is very important .

Green silicon carbide powder raw material selection

Green SiC is a high-tech refractory , has been in use in various industries , more and more , and it has many excellent performance in a high-performance products , silicon carbide, green silicon carbide and black can be divided into carbonization silicon , here to introduce you to a green silicon carbide powder of raw material selection , I hope for your help .
Green silicon carbide is quartz sand and coke for raw materials as a good thermal conductivity , high hardness of man-made materials . Silicon carbide powder is widely used in refractory, wear-resistant flooring , ceramic foam , specialty coatings, corrosion-resistant paint, flow separation and environmental protection industries , green silicon carbide even at high temperatures also have high strength , elastic modulus at the temperature reaches its 1600 ℃ , began attenuation. At a temperature of 2815 ° C begin to separate , but it does not melt at atmospheric pressure . Green silicon carbide grain of sand can quartz sand and coke as raw materials, manufacture green silicon carbide powder with a grain of sand , and you can choose as raw materials of sand . Green silicon carbide powder raw materials first look at the color , the second depends on the hardness , the third depends on the content .

Green silicon carbide on the performance and introduces the main purposes

Presumably there are many people in the choice of green silicon carbide does not know when its purpose and performance is what? Hope to explain below, we will further green silicon carbide silica fume for mastery.
At least 70 kinds of green silicon carbide crystal patterns. α-SiC is the most common form of allomorphic matter, in temperatures above 2000 ° C to form, with a hexagonal crystal structure (like wurtzite). β-silicon carbide, cubic crystal structure, and diamonds are similar, below 2000 ° C generated. Although the heterogeneous catalyst carrier body applications, because of its higher than α type of unit surface area and compelling, but until now, there has not been this type of commercial applications.
And a high proportion of its 3.2 sublimation temperature (about 2700 ° C), silicon carbide is suitable as raw materials for high-temperature furnace bearing or objects. Can be achieved at any pressure, it will not melt, and has a relatively low chemical activity. Because of its high thermal conductivity, high breakdown electric field strength and high maximum current density, the recent high-power semiconductor devices in applications, many people try to use it to replace silicon.
Pure silicon carbide abrasive is a colorless, while the industrial production of brown to black iron is due to the impurities. Crystal rainbow sheen is generated on the surface of the silicon dioxide because of its protective layer due.
Green silicon carbide for compound semiconductor materials, lightning, circuit elements, high-temperature applications, UV detectors, structural materials, astronomy, disc brakes, clutch, diesel particulate filter, filament pyrometer, ceramic films, cutting tools , heating elements, nuclear fuel, jewelery, steel, protective gear, catalyst carrier body and other fields.
Through the above and on the performance of green silicon carbide main purpose of introduction, I hope to bring you help.

Corundum brief analysis of the composition and uses

Corundum based on industrial alumina powder as raw material in the arc by melting temperatures above 2000 degrees made. Corundum main chemical ingredient is AL2O3, the content of a 98.65% -99.37 % , and the other a small amount of Fe, Si, Ti and so on. Corundum behalf # "WA" on internationally accepted standards, national standards, most for export, there is a certain amount of supply domestic users . Prominent feature is the small crystal size impact resistance, due to a self- processing mill crushed particles are mostly spherical particles , dry surface cleaning, easy binding agent combination .
Corundum is high-quality aluminum oxide powder as raw material , through the fused corundum sand refining crystal, high purity, good self-sharpening , acid corrosion , high temperature, thermal properties and stability. Slightly higher than corundum corundum hardness , toughness slightly lower , high purity, good self-sharpening , grinding ability , heat a small , high efficiency, acid and alkali resistance , high temperature resistance and good thermal stability . Made with corundum abrasive sand , suitable for grinding high carbon steel , high speed steel and stainless steel fine-grained abrasive . Corundum of sand can also be used for precision casting and high-grade refractory .

What are the methods of making corundum

Corundum structure is very special, and general usage of corundum is different, following a brief introduction about the purpose of corundum .
Corundum high quality bauxite as raw material, anthracite , iron Xiao , in the arc melting temperatures above 2000 degrees by made ??by shaping from the mill grinding , magnetic separation to iron , sieving into a variety of particle size , its dense texture , hardness high formation of spherical particles , for the manufacture of ceramic , resin high abrasive and grinding, polishing , sandblasting, precision casting , etc., can also be used to manufacture advanced refractories .
Corundum with high purity, good crystalline liquidity, low coefficient of linear expansion , corrosion-resistant characteristics. After dozens of proven refractory manufacturer , the product in the application process has not detonate , not powder, not crack characteristics. In particular, its price is much higher than conventional corundum , and more to become the best corundum refractory aggregate and filler.
Particle size in accordance with international standards and national standards of production, processing granularity according to user requirements . General size number of F4 ~ F320, depending on its chemical composition and different particle sizes . Prominent feature is the small crystal size , impact resistance, due to a self- processing mill broken particles are mostly spherical particles , corundum with high purity, dense texture , bulk density, self-sharpening strength , good toughness, magnetic material Features ultra-low levels , with its made of abrasive grinding sharp , low fever , grinding ratio .

Good or bad way to distinguish quality corundum

Corundum as one of the common resistant material , often involved in the manufacture of wear-resistant products . Especially the production of wear-resistant castable . Castable kind of common ways of its production is to corundum powder and bauxite with a certain proportion of the mixer is made in accordance with certain resistant castable . The material can be used as a variety of high-temperature furnace masonry materials can also be made using prefabricated parts or unfired brick . Corundum in industrial applications , there are many , then how to distinguish corundum and the bad?
Corundum is made ??of carbon , Alumina Oxide , iron three kinds of raw material refining , because the color of iron should be presented so that high-quality brown corundum , corundum observed color is a way to distinguish . Three brown fused alumina is the composition of substances. Three alumina content is directly related to how much good or bad quality corundum . Corundum is divided into three , one of the best is a corundum , followed by two and three , corundum quality standards is mainly to see where AL2O3 content , content of more than 95% of a corundum, that is, we often say that the 95 corundum . Two and three corundum corundum content progressively reduced , the quality decreases. You can see the color purity corundum to distinguish , as corundum containing Fe (iron ) elements , Fe element is reddish-brown , tan it rendered as corundum , you can see by looking at the color to identify the level and quality of corundum .

Corundum refractories used in

Brown fused alumina is a high-grade synthetic material. Is the use of high-quality bauxite as main raw material, coke, iron and other auxiliary materials, high-temperature smelting in electric arc furnace purified from.
Generally were brown corundum, Al2O3 ≥ 94.5%, SiO2 ≤ 2.5%, TiO2 ≤ 3.5%, Fe2O3 ≤ 1%, mineral composition to α-Al2o3 main center of the diamond-shaped crystal, slab type and with crack particles have more peripheral silicon oxide, calcium Melt Crystallization, elongated plate, the coarse crystal grains become skeletal-like sheet. Corundum hue is largely dependent on the remnants of the titanium oxide.
Corundum is mainly used as an abrasive. Refractory materials have been widely used in recent years, such as hooks castable, no blisters mud, corundum brick, precast, air brick, ladle brick, magnesia carbon bricks.
Brown fused alumina for refractory aggregate and powder is generally used to do, it has the advantage of high refractoriness, wear resistance, erosion, corrosion, bulk density, high alumina content, mainly for aluminum lines and alumina. When do products have a high load softening temperature and high temperature volume stability. But corundum impurities in the products in the course of life. Since smelting impurities not removed completely, so corundum also contains six calcium aluminate, calcium plagioclase, spinel, rutile and other times crystalline phase and glass phase, ferro alloys and solid solutions. In a large sense, corundum smelting process and smelting time determines the performance and quality of its products.

Corundum and corundum abrasives

By fused corundum sand to produce high-quality bauxite corundum, and used to produce high-quality aluminate powder corundum and corundum. Their natural crystal structure of its high hardness, fast cutting performance. And they are often used as bonded abrasives and coated abrasives raw materials.
Corundum can be recycled many times, cycle times and material grade and the specific processes related to most standard abrasive blasting equipment can be used.
Corundum (aluminum oxide) for a variety of wet and dry treatment process, the workpiece can be any rough surface fine polished, is one of the most affordable abrasive. Such a sharp abrasive synthetic water chestnut has a hardness second only to diamond, iron particularly suitable for use when there are strict requirements pollution. It is used for the rough cutting can also be made to precise dimensions pebble-shaped workpiece is processed to achieve a very low roughness. Due to its high density, sharpness, water chestnut structure, so it is currently one of the fastest cutting abrasive.
Applicable to industrial range: aerospace, automotive, consumer products, casting / die casting, OEM distributors, semiconductor industry and other different fields.
Applicable range of technology: surface plating, painting, glazing and coating Teflon pretreatment; aluminum and alloy products deburring, go to boiler scale; mold cleaning; Metal Blast pretreatment; dry and wet ; precision optical refraction; minerals, metals, glass and crystal grinding; glass sculpture and paint additives.

The use of alumina , alumina is mainly used in what areas

Alumina is a white amorphous powder , commonly known as bauxite , density 3.9-4.0g/cm3, melting point 2050 ℃, boiling point 2980 ℃, insoluble in water, aluminum oxide mainly two kinds of α -and γ variants industrially from bauxite is extracted .
Now a lot of aluminum products such as : aluminum hydroxide, alumina, calcined alumina high temperature alumina purity alumina industrial grade white aluminum hydroxide aluminum hydroxide, aluminum hydroxide toothpaste grade agate grade aluminum hydroxide filler grade aluminum hydroxide and so on. Wide range of applications regardless of alumina products economic development or life has its existence, it has played an unparalleled role.
Specialty alumina refractory varieties: Advanced ceramic refractory products fiber products as well as lightweight insulation products unshaped products , with its main application areas are:
( 1 ) ultra-high temperature kiln lining structural materials.
( 2 ) high purity metal alloys with rare metals smelting crucible purification .
( 3 ) high-temperature tube furnace thermocouple tube heat insulation.
( 4 ) high-temperature kiln sticks and briquetting pressure washers , etc.
( 5 ) Petroleum and Chemical Industrial temperature corrosion-resistant lining material .
( 6 ) do transparent alumina ceramic high-temperature high-pressure sodium viewing glass tube microwave hood .
( 7 ) in the electronics industry to make the circuit substrate voltage ceramic shell and tube seat tube radome spark plugs and so on.
( 8 ) grinding tools and abrasives such as grinding wheel cutting disc Dies La Sita round nozzles textile porcelain pieces and a variety of high-temperature resistant bearing props .
( 9 ) Chemical Industrial Piston Pump Parts sealing ring.
( 10 ) ferrous metallurgy industry molten metal pipe.
( 11 ) in various industrial sectors such as high-temperature energy-efficient materials like alumina hollow ball alumina whiskers, alumina fiber and products .

Recent developments in green silicon carbide

Green silicon carbide as an abrasive, silicon carbide production area in our previous two or three decades was a hero, and later as for export purposes and silicon carbide grinding non-development, production volume relative to the black silicon carbide, gradually relegated secondary position.
But its total production is always rising steadily, especially in the late 1990s, the international wire cutting of green silicon carbide powder application process, our green silicon carbide production and exports have increased, but producing regions and manufacturers also limited to the traditional Northeast Mudanjiang, Hun, etc., the Central Plains, Zhengzhou, Pingdingshan, Shandong Tengzhou, linshu and Hubei Danjiangkou, etc., the Northwest Territories and only Qinghai Guide Haiyan and Blackforge change Green furnace of LAI.
Another turn of the century before, not on the use of Sichuan power grid small hydro electricity low (from the 0.08 to 0.15 yuan / KWH), from Shandong, and Fujian in Lianyungang Miannig, ganluo and Johnson and Yaan, etc., to build a batch furnace capacity 6300KVA ~ 2000KVA green silicon carbide smelter home.
So far, China's annual output of green silicon carbide by the reform and opening up to the time of less than three tonnes to seven or eight tons. But the biggest single furnace capacity still hovering at 5000 ~ 6300KVA, smelting process also follows the formation of the sixties and the East China Sea petroleum coke calcination quartz sand as raw material processes.

Garnet evaluation and appreciation

Garnet in color, transparency, clarity, weight and other aspects of its cut quality evaluation standards, excellent product requires pure color beautiful, clean and transparent interior, flawless crack, cut well and have some weight.
(1) Color: The color to be pure and beautiful. Different varieties, different colors, values ??are different. As rare demantoid, chrome vanadium grossular other green varieties if transparent without cracking, high quality and high quality emerald may equal value; red pyrope, orange spessartine, Hessonite also valuable, and maroon, dark red almandine lower value.
(2) Transparency: high quality person should be transparent and clean. Translucent or color depth are often processed into a concave arc in order to increase transparency. While opaque to translucent varieties to check the internal arrangement of inclusions see if processed into cabochon while showing a starlight effect.
(3) Clarity: To no cracks, flaws, especially a lot of dark red almandine. Complete crystal partakers who pay attention to whether the internal structure or folder with black opaque inclusions agglomerate. Such as Vietnam output intact skin only to garnet crystal thin transparent can be utilized for other mineral impurities within the black heart. At present, high-quality garnet mostly irregular silicon carbide grit.
(4) Weight: raw block the bigger the better, rounded shapes to mix better, which can improve the processing yield. Right Demantoid green grossular other high-grade varieties, the price increases exponentially with the weight, usually more than 0.5ct very valuable; while other species with different weight finished their prices changed little, mainly to see required when making jewelry styles and sizes requirements. But a few rare giant crystal or finished products can be regarded as treasures. (5) Cut: To fashionable, proper proportion, polish well. Different varieties of materials to be designed for different styles. High dispersion Demantoid processed into standard round brilliant, in order to fully reflect its fire color; coloration were processed for the double curved to enhance the body color; color depth are processed in order to lighten the color of the concave arc, increasing transparency; has multiple sets of special needles arranged in the direction of the arc-shaped inclusions processing to display the star effect.

Silicon carbide industry's position in the slice

Crystalline silicon photovoltaic feeder line cutting is cutting the biggest market differentiator, and silicon carbide crystal wafer cutting is very important as an accessory, the market demand with the development of photovoltaic industry has maintained a strong growth momentum. However, since entering in May, silicon carbide market prices began to loosen, product demand dropped, companies have been affected to varying degrees. Henan Green foreign filter water treatment materials industry professionals once said: "silicon carbide powder is a tool in the hands of photovoltaic enterprises, who have the best tools, whoever occupies the best cutting opportunities."
It is obvious from this statement in the slice of silicon carbide powder industry position is pivotal. With the rapid development of photovoltaic industry, the industry's growing demand for wafer temperature, the number is growing, while the production of polycrystalline silicon carbide powder as an important accessory, its natural demand is increasing. Domestic silicon carbide powder is mainly divided into black silicon carbide powder and green silicon carbide powder into two categories, the black silicon carbide powder and green silicon carbide powder technology and ingredients are different, resulting in the market demand for these two products is not the same.
At present, mainly dominated by green silicon carbide powder, because it itself determines its characteristics more suitable for photovoltaic, semiconductor crystal silicon material cutting edge parts, so the use of green silicon carbide powder than black silicon carbide powder. Our country is a major exporter of silicon carbide production and, in 2009 total output of 530,000 tons of silicon carbide and more, accounting for 56.3% of the global total, ranking first in the world. 2010 silicon carbide production reached 700,000 ~ 800,000 tons, as of now, 2011 silicon carbide production has reached 30 million to 40 million tons.

About corundum abrasive characteristics and processing technology introduction

Corundum abrasives, white fused alumina, white fused alumina block, abrasive corundum, white corundum sand (WA)
White fused alumina abrasive is alumina as raw materials, high temperature melting together. White, slightly higher hardness than corundum, lower toughness. Made with corundum abrasive for high carbon steel, high speed steel and hardened steel grinding. Corundum abrasive, white corundum abrasive polishing material can be used, but also for precision sand casting, coating materials, chemical catalyst carrier, special ceramics, advanced refractories.
White fused alumina abrasive chemical composition:
Chemical composition size range AI2O3 (%) Na2O (%)
F12 - F80 ≥ 98.5 ≤ 0.50
F90 - F150 ≥ 98.5 ≤ 0.60
F180 - F220 ≥ 98.2 ≤ 0.70
Physical properties of corundum abrasives: Physical property
Basic mineral crystal size μm really infer g/cm3 Bulk density g/cm3 microhardness g/mm2
α-AI2O3 600 ~ 1400 ≥ 3.90 1.5 ~ 1.95 2200 ~ 2300
Corundum abrasive properties: white, hard and brittle than corundum, strong cutting force, good chemical stability, with good insulation. White fused alumina abrasive Scope: do solid structure and coated abrasives, wet or dry spray sand, suitable crystals, the electronics industry and ultra-fine grinding and polishing production advanced refractory. Suitable for machining hardened steel, alloy steel, high speed steel, high carbon steel and other hard hardness, tensile strength greater material. Corundum abrasives can also be used as catalyst, insulators and precision casting sand.

Silicon carbide is the most widely used and most economical product

Silicon carbide (SiC) with quartz sand, petroleum coke (or coal), wood chips as raw material in electric arc furnace smelting. There are also rare in nature, silicon carbide mineral, Moissanite. Silicon carbide, also known as Moissanite.
In contemporary C, N, B and other high-tech non-oxide refractory raw material, silicon carbide is the most widely used and most economical one. Can be called emery or refractory sand. Silicon carbide is quartz sand, petroleum coke (or coal), wood (green silicon carbide production requires add salt) and other raw materials at high temperature in a resistance furnace smelting. At present, China's industrial production is divided into black silicon carbide and silicon carbide green silicon carbide two kinds, both hexagonal crystal, specific gravity of 3.20 ~ 3.25, microhardness 2840 ~ 3320kg/mm2.
SiC as chemical stability, high thermal conductivity, thermal expansion coefficient, good wear resistance, except for the abrasive used, there are many other uses, for example: a special process the silicon carbide powder coating on the turbine impeller or cylinder block wall, can improve the wear resistance and extended service life 1 to 2 times; made for advanced refractory, thermal shock resistance, small size, light in weight, high strength, good energy saving effect. Low-grade silicon carbide (SiC-containing about 85%) is an excellent oxygen scavenger, it can accelerate the speed steel, and facilitate control of chemical composition and improve the quality of steel.
Silicon carbide is also used extensively for production of silicon carbide heating elements.

Corundum: corundum density related presentations

Corundum density:
Density is divided into two, one corundum bulk density, the second is the true density corundum. 
Bulk density:
1.53 ~ 1.99g/cm3, the bulk density of the abrasive and the abrasive grain size, grain size, species, particle shape and other factors are, in general, coarse abrasive bulk density than the fine-grained abrasive, mix size is greater than the bulk density of the abrasive single particle density.
Particle density:
3.95 ~ 4.0g/cm3, in recent years, special casting corundum true density has reached 4.1g/cm3, the true density of the abrasive is the unit volume (excluding the volume of open porosity) contained within the abrasive quality, primary particle size of as follows: 45% to 55%, corundum can rest assure that more than 50%, the basic effect of particle size is an important indicator to ensure the ground, should be properly controlled in the production, but the production speed may slow down.

 

Silicon carbide and corundum abrasives on the characteristics and performance description

1, brown fused alumina:The main chemical composition AL2O3, the bauxite, iron and anthracite from melting in an electric arc furnace. Corundum abrasive color is brown, its color, the name corundum. The abrasive has a certain hardness and toughness, with the strong grinding ability, able to withstand great pressure. With a high temperature, anti-oxidation, anti-corrosion and chemical stability is good. High tensile strength as it applies to the grinding of the material tensile strength, suitable for general steel, high carbon steel, alloy steel, for the processing of hard wood, other abrasives can be used in substitution is insufficient, a universal Abrasive said, is the most widely used kind of abrasive.2, corundum:The main chemical composition of AL3O2 aluminum oxide powder as raw material in electric arc furnace melting together. Color is white, in terms of its color name corundum. Corundum corundum texture purer than brown. Using aluminum oxide powder material, corundum used by the Department of bauxite processing is made in advance, the main physical components (without grinding capacity) by arc melting from the converted. The conversion has strong grinding force.3, black silicon carbide:The main chemical composition of SiC. From petroleum coke, quartz sand, sawdust as raw materials in the resistor formed by the melting furnace. Black silicon carbide color is black, in terms of its color, named for the black silicon carbide. Black silicon carbide is brittle texture than corundum abrasive, hardness hard, its toughness is also inferior to corundum abrasive, than the end of the tensile strength of the material, such as non-metallic materials (various boards such as wooden plywood, particleboard, high school low-density fiberboard , bamboo board, calcium silicate board, leather, glass, ceramics, stone, etc.) and non-ferrous metals (aluminum, copper, lead) and other materials processing is particularly suitable for hard and brittle materials texture is ideal abrasive machining .4, green silicon carbide:The main chemical composition of SiC used in the manufacture of raw materials such as black silicon carbide plus industrial salt production are substantially the same as the reaction agent and accelerator reaction from the resistance furnace. Terms of their color is green so named for the green silicon carbide . green silicon carbide texture than the more pure black, green silicon carbide powder can be made, even higher hardness than black silicon carbide and silicon carbide which uses the same ground outside is more suitable for fine grinding of materials such as grinding thread, measuring tools, etc. in the grinding mill material is more widely used carbide, diamond products of the workpiece. Because green silicon carbide in the manufacturing cost is higher than the black silicon carbide, such as the use of raw materials is not the same on the ratio, plus a salt auxiliary materials as well as differences in processing power and so on, so green silicon carbide products cheaper than Black silicon carbide is higher. Therefore, the selection of green silicon carbide and silicon carbide in comparison, in the non-metallic and non-ferrous materials generally do not use green silicon carbide, green silicon carbide as the main choice and precision grinding carbide grinding, in belt and other coated abrasives green silicon carbide as grinding on the selection of materials for less.5, microcrystalline corundum:The main chemical components of AL2O3, used the same raw materials and corundum, only in the smelting process using rapid cooling process fine crystals obtained results. Fine crystalline corundum corundum mechanical strength than ordinary higher. Made with microcrystalline corundum abrasives commonly used for coarse grinding steel, high toughness titanium-nickel alloy steel and other difficult to grind materials, but rarely used in the manufacture of coated abrasives.

 

Developments of refractories and corundum, silicon carbide refractories application

Refractories are widely used in metallurgy, building materials, chemicals, nonferrous metals and other high-temperature industrial, which cuts the base material in many fields. Refractories and high temperature industrial interdependence, mutual promotion and common development, China's industrial economic development plays an important supporting role. Of refractory industry has made great progress, in 2010 more than 2,000 enterprises above designated size, yield 28 million tons.
Refractories industry development status of
1 position in the national economy refractories
Refractories are widely used in metallurgy, building materials, chemicals, nonferrous metals and other high-temperature industrial, which cuts the base material in many fields shared. The proportion of high-temperature industrial applications is approximately: 65% steel, building materials, 17%, 4% nonferrous metals, chemicals accounted for 4%, other 10%. Applications involving all sectors of the national economy, the industry and the refractory industry interdependence, mutual promotion and common development, no refractories, there is no high-temperature industrial. Refractory technological advances supporting high-temperature industrial development, the implementation of "energy saving, emission reduction and saving" strategy and "low carbon economy" has played a very important role in promoting.
2 of Refractories Refractories in the international market position
In the iron and steel, nonferrous metals, building materials, chemical industry, electric power and other high-temperature industrial development, driven by the rapid industrial development of refractory materials, production processes, technology, equipment levels rising, continuously improve product quality, variety increasing gradually been recognized by the international market , production and sales has for many years ranked first in the world.
Currently the variety and amount of refractory products not only meet the domestic high-temperature industrial production, development needs, and refractory products export volume increased year by year, the market throughout many countries in Southeast Asia and the Americas, European Union, Russia and other 150 countries (regions). Of refractory industry has been from small to large, from weak to strong, to become the world refractories industry, mainly producing and consuming countries.
As China's industrial structure adjustment and optimization of refractories, asset restructuring, elimination of backward production capacity of the accelerated pace of the strength of some refractory enterprises through the listing and the formation of enterprise groups in the capital and production equipment, has strong technical strength to participate in international competition in the market. The next few years, China will account for a larger refractory international market share, will become a truly world-refractory manufacturing center.
3 of refractories industry development achievements
In recent years, the rapid development of high-temperature industrial technology, driven by strong, China's refractory industry, adhere to scientific development, changing concepts, focus on independent innovation in the optimization and upgrading of industrial structure, product structure adjustment and upgrading of technical equipment as well as in the world refractory industry's competitiveness, etc. have achieved outstanding results for our steel and high-temperature industrial development has laid a solid foundation.
Optimization and upgrading of industrial structure, size and growth. Some refractory enterprises through powerful alliances, mergers and acquisitions, cross-shareholdings and other ways to strategic integration, and promote the refractory industry structure adjustment, optimization and industrial upgrading.
Product structure adjustment, independent innovation ability. In order to meet long-life steel industry blast furnaces to improve converter furnace, refining and efficient continuous casting technology, has developed a special micro-pore structure and the blast furnace process to produce ceramic cup with a slightly corundum brick, Sialon bonded corundum products, blast furnace zone drying strength corundum - nitride - silicon carbide composite castable, non-oxide refractory metal composite oxide containing blast furnace iron runner Si3N4 Si3N4 composite materials and blast furnace gunning, magnesium and calcium brick, tundish ventilation intakes, clean steel casting with carbon-free silicon and thin-slab continuous casting nozzle submerged nozzle and other new products, Baosteel, Anshan Iron and Steel, Wuhan Iron and Steel and other large enterprises to use, and achieved good results. Building materials and other industries for the service, has developed a float glass furnace oxidation no shrinkage casting and regular cast AZS series of cast products, cement kiln directly bonded magnesia chrome brick, magnesia chrome brick semi-combined, the new new dry-process cement kiln tabular alumina castable, National Science and Technology Progress Award of the aluminum reduction cell combined with a silicon nitride nitride brick refractory products, chemicals with a series of high-purity alumina refractory products and other ancillary products in the domestic large-scale enterprises with favorable results, replacing the imported products. Monolithic refractories has been widely applied trough of blast furnace, one pass more than 100,000 tons of iron. Work in the ladle lining life of up to 1000 times. Mixer working lining using all or part of the whole cast replace brick lining, the service life of up to three years. Torpedo using wet jet repair, life expectancy increased by 25% or more. In order to improve construction efficiency and avoiding extreme weather disturbances, ladle castable also adopted a work precast lining. Ladle, ladle, tundish backing by the volume density of 1.6-2.2g/cm3 high strength, low shrinkage semi lightweight castable to reduce heat loss. Large and shaped preform castable used increasingly and exported abroad, such as furnace burners, flue tiles, anchoring brick, brick blast furnace combination, etc., are used castable prefabricated parts. Corundum, silicon carbide materials for the development of these products should play a major role.
Production technology and equipment to accelerate the pace of upgrading. With the rapid development of the refractory industry, refractory production enterprises, key enterprises in particular the level of equipment is constantly upgraded.
4 Refractory Production Status
2010 refractory industry enterprises above designated size was 2,000, yield 28 million tons. Product support, variety, yield higher than the growth rate of fixed assets, the product structure was further optimized to meet the high-temperature industrial and technological progress. Industry on cost control ability level higher equipment levels have significantly improved profitability has been further improved, the industry to promote energy conservation, environmental protection, there is significant progress in the development of refractories industry as a whole more stable.
5 refractory raw resource availability
A wide variety of refractory raw materials, resources are more abundant, which magnesite, bauxite refractory raw materials and other resources called China's pillar, fire clay, silica, dolomite, magnesium olivine, serpentine, zircon and other resources widely distributed, fine texture. These refractory raw material resources for China's refractories industry, providing a reliable foundation conditions.
6 of refractories industry problems
Although our refractories industry has made great progress, but according to the concept and practice the scientific concept of development, the current situation of the development of the industry and the national economy, there are many inappropriate places, the raw material resources, product structure, technology and equipment, consumption levels, energy conservation, environmental protection and industry concentration, there are still some problems with individual products still lags far behind the developed countries.
7 the development trend of refractories
High industry in China will continue to play an important role in the national economy. National development of ten industrial revitalization plan, low carbon development planning and energy saving policies on the development of high-temperature industrial far-reaching significance. Overall control, eliminate backward production capacity, industrial restructuring, technological upgrading and industrial integration is the future direction of development of high-temperature industrial.
Energy saving and recycling economy has become China's high-temperature industrial development of the basic guiding ideology. High-temperature industrial development and direction of the change will be on the development of refractory industry have a significant impact, which will greatly facilitate future sustainable development of stable refractory industry and new technologies, new materials, new technology development and application, which is refractory industry once accelerate technological innovation, the adjustment of product structure rare opportunity for development.
Technological innovation and the development of low-carbon economy will further advance the refractories industry technology innovation, product restructuring and mergers and acquisitions, green, functionality, longevity and other advanced refractory development space and market space increases.
Development of energy efficient refractories, efficient functional refractories, refractory integrated optimization technology systems integration and engineering technology; increase the efficient use of resources and refractory low-grade resource utilization and environmental protection after use eco-refractory refractory material applications; continuously improve the application of refractory technology, give full play to the function of refractories, to achieve consumption and emissions reduction.
Refractory consumption will gradually decline, the total market demand will be maintained at a certain level, the market competition will become more intense. To adapt to the development trend of reduction, refractory enterprises must eliminate backward, the adjustment of product structure, increase the technological upgrading and enhancing service levels to enhance the core competitiveness, but will also increase market integration efforts, improve industrial concentration, and enhance international competitiveness.
Major high industry demand for refractories
Iron and steel industries. The future development of the steel industry: will continue to "control the total elimination of backwardness, mergers and acquisitions, technological innovation, optimize the layout" as the core, control capacity, elimination of backward production capacity, strengthen technological innovation, the development of new materials, iron ore trade norms order to accelerate domestic enterprises to "go out" pace. 2015, construction steel proportion will drop to about 50%, the proportion of steel manufacturing rebound; plates proportion will reach 55%, the key varieties of steel self-sufficiency rate can be increased to about 95%; total production capacity surplus will continue currently half of backward production capacity will be eliminated. Next few years, although the refractory industry will be affected by the presence of iron and steel production by pulling some room for development, but the number used in steel production will continue to decline, it is expected that by 2015, the consumption of refractories will fall 15kg / t steel or so.
Building materials industry. According to China's building materials industry over the past few years the demand for refractories and refractory own development, we can predict the next few years, the building materials industry for refractories demand growth rate will slow down, but the demand will still maintain an upward trend.
The chemical industry. The next few years, the chemical industry will remain above 7% growth, the development of the industry will present different characteristics. According to the World Refractory applications industry statistics, the proportion of the chemical industry use refractory is 4% higher than this level our country. Next few years, the chemical industry will increase total demand for refractories. Large oil refining capacity expansion device and process optimization transformation, will bring some refractory industry development space.
Non-ferrous industries. By 2015, the nonferrous metals industry will further optimize the industrial structure, quality and efficiency improved significantly, significantly enhancing the capability of technological innovation, the main technical and economic indicators have reached the world advanced level, the overall strength jumped to the forefront of the world. Overall, non-ferrous metal smelting industry, the demand for refractories refractory aggregate domestic demand accounted for about 3-5%. Next few years, high-tech, high value-added refractory products demand will increase overall demand for refractory products will continue to maintain about 5%, the growth rate is not too large. Meanwhile, with the non-ferrous metal smelting technology advances and technological progress itself refractory industry, smelting need tons of products also show a downward trend in the amount of refractory material.
Overseas markets. At present, the international refractory products increasingly competitive market, or even to low-disordered unfair competition, export refractory products falling prices. According to statistics, in recent years, ordinary refractory products in the international market prices generally fell by 10%, while the decline of some species can reach 20-30%, as well as by the pressure of RMB appreciation, domestic exports increased the difficulty of refractory products. Refractory products due to the presence of domestic GB market has not yet been fully understood, and some high-end products can not meet the foreign enterprise production technology issues, the next few years, this trend will be maintained within a certain time.
Next few years China refractories overall demand situation. As international and domestic macroeconomic situation for the better, our industry in the next few years will heat usher in a new round of development opportunities, which gives refractories industry has brought opportunities and market space. Can be predicted: the number of refractory market development space is limited, a huge space for adjustment of product structure, service mode conversion will occur, industrial layout adjustment will occur. Refractory aggregate demand will not be much increased, but there will be some increase in high-performance refractory materials, including functional, energy-saving, environment-friendly and other advanced refractories market space will be further expanded, the demand ordinary products decreased.
Basic principles guiding ideology and main objectives
Guiding ideology. To the scientific development as the theme, the main line of independent innovation in order to meet the development needs of high-temperature industrial and international market demand, focusing on promoting industrial restructuring, to create a new model of sustainable development.
Basic principles. Based on domestic resources, and actively explore overseas resources, improve the level of raw material processing equipment, process optimization, rational use of low-grade raw material resources, development of high-grade synthetic refractory raw materials characteristics, the formation of development suited to China's refractory industry, high stability of series refractory raw materials.
Main objective. 2015, achieve significant decline in ordinary products, functional, energy-saving and environment-friendly products such as the proportion of refractory advanced greatly improved to meet the high-temperature industrial and emerging industries for advanced refractory products. Improving product technology content, extend product life and reduce the consumption of refractories, refractory consumption per ton in 2015 to 15 kilograms. Focus on consumption per ton of steel mills close to the international advanced level. Improve industrial concentration, optimize the industrial structure, eliminate backward production capacity to support large enterprises with comparative advantages mergers and acquisitions, foster industrial clusters. By 2015, significantly reduce the number of enterprises to further improve the existing "small, more casual" situation, bred 2-3 home sales reached ,20-30 5-10 billion sales revenue of 10-50 million with strong competitiveness and influence of the refractories business.
Development priorities
The next few years, China's refractory industry is a breakthrough in the development of key industries and key generic technologies, development of new refractory materials, leading the industry development direction. Actively explore special functional refractories, non-oxide composite materials, energy saving refractory materials, environment-friendly refractories, ceramics and other advanced special field of refractories; to China's development of strategic emerging industries, to promote low-carbon economy and high temperature industrial advanced technology as an opportunity , speeding up China's refractories industry, industrial restructuring and industrial upgrading; rational planning, the use of advanced mining and processing technologies, promote the magnesite, bauxite-based refractory materials such as resource utilization development; comprehensively promote the industry energy conservation and clean production; committed to industry standards, and guide the healthy development of industry.
Key development areas
Iron and steel industry new technologies, new processes and major equipment of key development and application of refractories. Steel industry restructuring and technological progress and the acceleration of large-scale equipment in the steel, direct reduction, and other non-coke smelting reduction ironmaking, efficient continuous casting, thin slab casting and other aspects of the refractories industry put forward new requirements and issues . In order to meet the development needs of the steel industry, iron and steel industry to develop refractory to high-performance, long-life, functional refractories and refractory efficient application of technology-based. Focus on research and development of large-scale blast furnace refractories with a long life, clean steel smelting efficient refractories, a new generation of efficient continuous casting refractories function integration, non-refractory coke ironmaking technology key technologies and applications.
Building materials, nonferrous metals, and chemical industries key equipment and key parts of the research and application of refractories. Building materials, nonferrous metals and chemical industry is an important part of our national economy, China's current production of key equipment used in these industries and key parts of the partial refractory Compared with similar products, product quality and performance but also has some gaps , to a certain extent, affected the development of these industries. Focuses on the development of green basic refractories, advanced oxides and fused cast refractories, refractory chrome chrome or low, new non-oxide composite materials, high performance kiln, waste incinerators and ash melting furnace key refractories, foundry porous ceramic filter materials with high technology and applications.
Field of low-carbon energy efficient thermal transfer and the development and application of monolithic refractories. Improve thermal efficiency furnace, reducing energy consumption is to achieve energy saving high temperature industrial focus of development. Research and development of high-temperature insulation refractory material, as well as energy-efficient combustion technology matching, can greatly reduce the energy consumption of industrial furnaces, high temperature industrial energy saving on the whole has a decisive significance. Unshaped refractory materials plays an important role, but also the future direction of development of refractory materials, their production and construction process is simple, can be mechanized construction, environmental protection, high temperature has been widely used in industry. We should vigorously develop, promote the use of a variety of high quality and efficient monolithic refractories, and strive to 2015, the proportion of monolithic refractories around 50%. Focus on research and development of lightweight refractory porous highly fortified industrial technology, super-insulation materials industry prepared nano-technology, high-performance crystal fibers and products of advanced manufacturing technology, high-performance lightweight refractory aggregate production technology, the series monolithic insulating refractory materials, multifunctional monolithic refractories, large and shaped preform preparation techniques, stereotypes of unshaped refractory materials, flame spraying and wet jet technology.
Refractory resource utilization technology development and application. Refractory materials of low resource utilization, waste generated each year iron ore fines, super ten million tons of low-grade ore, a huge amount of revenue and expenditure refractory raw material resources is imperative. Rational use of fine ore, low grade ore is refractory industry limited resources conservation for sustainable development urgent task.
Refractory after use will generate a lot of waste refractories, refractory materials for waste treatment and recycling for environmental protection, clean production and achieving sustainable development of great significance. Focuses on the development and application of low-grade magnesite and bauxite resource utilization of industrial technology, comprehensive utilization of refractory mineral tailings key technologies, high-quality synthetic refractory raw materials, "three stone" (andalusite, sillimanite, kyanite) raw comprehensive and efficient use, recycling and refractory after use and reuse of resource integration technology.
Refractories industry standards and promotion. Existing standards of refractories, refractory industry to promote the development of technology has played an important supporting role. With technological progress, China's refractory industry standard in intellectual property protection, industry development guidance, resource sharing, enterprise participation, standards, international standards, etc., and the reality of our country is not commensurate with the scale of production of refractories, refractory standard system need further improvement to make it more scientific and reasonable. Access standards in the industry, "energy-saving and environment-friendly" standards and refractory products and other new energy standards, the technique should be followed by the development of international standards, to fully absorb the international advanced achievements of refractories, and comprehensively promote to have our intellectual property-based standard system. Focus on the refractories industry access standards (including the energy, environmental protection, scale, variety, etc.) the formulation of new refractory industry testing methods and standards development and promotion of Chinese refractories industry standard internationalization.
Corundum, silicon carbide refractories application
Reform and opening up, high-temperature industrial backward technology and equipment, refractories single species, a large proportion of ordinary refractory materials, corundum, silicon carbide materials rarely, corundum less than 10%, a silicon carbide less than 5%. Technical equipment introduction, digestion, enhance the high-temperature industrial level of technology. High-temperature industrial process equipment technology to improve and enhance the quality of quality refractories made demanding. Corundum, silicon carbide materials resistant to corrosion, slag corrosion, wear resistance, the amount of high-temperature industrial technological progress as needed, with special refractories, unshaped refractories varieties increased the dosage is gradually increased. Such as: iron and steel industry blast furnaces, the iron ditch, Mixer, ladle, continuous casting, electric stove top and other amorphous materials. Such as: cement industry kiln lining material with amorphous silicon Mo bricks. Such as: non-ferrous industrial smelting furnace nitride bonded silicon carbide bricks. Corundum, silicon carbide and other refractory materials to promote the adjustment of product structure.
Market needs, but development is limited. Corundum vigorous market demand, but its supply of raw materials was extremely restricted. Long-term over-exploitation, high alumina refractory clay depleted, if uncontrolled, refractory materials, corundum bauxite resources required, will soon dry up. Since 2010, raising the cost of production factors such as price, make corundum, silicon carbide smelting enterprises have encountered unprecedented difficulties. Currently operating at only 25% of Henan, some companies are forced to move to areas with lower tariffs. Its high cost, high prices, this situation has affected the development of the downstream industry chain.
Future development proposals backward to upgrade equipment. Refractory stable quality performance requirements, need to dump furnace, therefore, in accordance with national policies, the following ordinary corundum phase 3000 kVA and 4000 kVA smelting furnace fixed corundum smelting furnaces. Strictly control capacity expansion, not duplication. Compressed production scale, production efficiency. High alumina refractory clay is already scarce resources, have a plan to protect the refractory materials, corundum use.
High-temperature industrial development is inseparable from refractories, refractory industry's development is inseparable corundum and silicon carbide refractory raw materials!