Fluoride recycling of quartz raw materials to obtain pure products

In recent decades, there has been an intensive growth in research into areas of science and technology based on the use of various forms of silica. The existing methods of producing amorphous silica are not without their drawbacks, the main ones being the multistage technological processes, their complicated apparatus design, the use of scarce raw materials and the high cost of ensuring environmental safety. At the same time, quartz sand is the most widespread silica-bearing rock, which can be a promising raw material for obtaining amorphous silica and other silica products. Based on these R&D efforts, a fluorination process was proposed using ammonium hydrodifluoride (NH4HF2), which is a fairly inert crystalline powder under normal conditions and poses no significant environmental hazard, but becomes a powerful fluorinating agent when heated. We have developed the technological and apparatus schemes for the production of pure silica products: ammonium hexafluorosilicate, amorphous silica and silicon.