Quartz beneficiation and purification:

Quartz sand, also known as silica sand, is a common non-metallic mineral raw material and has a wide range of applications. Low-grade quartz sand can be used in the construction, glass manufacturing, ceramics, and foundry industry. High-purity and ultra-high-purity quartz sand made by beneficiation and purification have been widely used in aerospace, atomic energy technology, laser, optical cable communication, military, and other high-tech fields.
Quartz sand purification is a difficult separation process to remove impurities from quartz sand and obtain refined quartz sand or high-purity quartz sand (such as electronic grade quartz).

• Washing, grading, desliming : The grade of SiO2 in quartz sand decreases as the grain size of quartz sand becomes thinner, but the grades of impurity minerals such as iron and aluminum increases. This phenomenon is particularly noticeable in quartz sand containing a large amount of clay. Washing, grading, and desliming usually as a pre-processing operation set before the beneficiation.
• Scrubbing : Scrubbing process is referring to removing the thin iron layer, conglomeration, and muddy impurity minerals on the surface of the quartz sand by mechanical force and abrasive stripping force between the sand particles. The scrubbed quartz sand is further classified to achieve further purification.
• Magnetic separation:  The magnetic separation process can remove weak magnetic impurities such as hematite, limonite and biotite. Strong magnetic separation usually uses a wet magnetic separator or a high gradient magnetic separator.
• Flotation: “Fluorine-free and acid-free flotation method” is a new process for flotation separation of quartz feldspar which has been vigorously developed in recent years. This method is based on the difference in the composition of quartz.
• Acid leaching: Acid leaching is the use of quartz insoluble in acid (except HF), other impurity minerals can be dissolved by acid, further purification of quartz. Acids commonly used for acid leaching include sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid; and reducing agents include sulfurous acid and salts thereof.
• Microbial leaching: Thin-film iron or leaching iron on the surface of quartz sand particles by microorganisms is a newly developed iron removal technology. According to foreign research results, it is indicated that aflatoxin, penicillium, pseudomonas, polymyxin, Microorganisms such as bacilli have achieved good results when leaching iron on the surface of the quartz.