Flotation processing of ultra-white silica sand for photovoltaic glass

 This article introduces in detail the processing technology of supersilica sand for photovoltaic glass. Using ordinary quartz sand as raw material, the Fe2O3 in the silica sand is reduced to less than 90ppm through flotation, which meets the quality requirements of photovoltaic glass raw materials.

Ultra-white glass requires Fe2O3 <0.009% in its composition and high light transmittance. Light transmittance determines the quality of glass. The light transmittance of float glass is 86%, and the light transmittance of ultra-white glass is more than 92%. The glass substrate of the solar photovoltaic power generation system requires the use of ultra-clear glass.

The production of ultra-white glass requires very strict quartz sand, SiO2>99.6%, Fe2O3<0.005%-0.001%, otherwise the quality of ultra-white glass cannot be guaranteed. With the development of photovoltaic power generation, the demand for ultra-white glass has doubled, and the demand for high-purity low-iron quartz sand has also increased. Acid-washed quartz sand was previously used for high-purity, low-iron quartz sand. However, my country’s quartz reserves are small, mining is difficult, processing costs are high, and output is low, which is far from meeting the needs of the photovoltaic industry.

This silica sand treatment provides a quartz sand flotation process, which can promote the production of quartz sand and ensure product quality, thereby solving the current problem that my country's quartz sand production cannot meet the growing market demand.

The specific technical scheme of silica sand flotation processing is as follows:

Put the quartz sand raw materials into the production bin, and then put the quartz sand raw materials into the first conditioning tank for mixing. A permanent magnet is placed outside the regulating tank. Before the quartz sand raw material enters the first conditioning tank, it is removed by the permanent magnet for the first time; add 45% H2SO4 solution or 4-5% H2SO4 and HF solution into the first regulating tank, and adjust the pH value to 3 . Put the quartz sand raw materials into the regulating tank to form a slurry. Then the quartz mortar material is sent to the secondary conditioning tank, and flotation agent is added to the secondary conditioning tank for mixing.

The composition of the flotation agent is as follows:

Fatty Alkyl Propylene Diamine 30-35%

Butyl xanthate 3-4.5%

Fatty acids 30-35%

Diesel 30-35%

Terpineol oil 0.1-0.3%

The quartz sand slurry and flotation agent fully react in the second regulating tank.

Then put the quartz sand slurry into the flotation machine for flotation. The flotation quartz sand concentrate is screened by a high-frequency vibrating screen and flows into the fine sand tank. The slurry in the fine sand tank is then pumped into the desliming cone or spiral washer. A large amount of water-containing agent in the quartz sand concentrate is removed through a slurry pump, and then placed in another desliming cone, rinsed with clean water, and then washed again by a permanent magnet high gradient strong magnetic separator to remove iron and then sent to fine sand cleaning Library.

The flotation process of quartz sand is easy to implement and simple to operate. Through this flotation method and flotation agent, quartz sand can be flotated quickly and effectively, thereby improving the production efficiency of quartz sand, greatly reducing the production cost of quartz sand, and reducing the labor intensity of operators.