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.