Process for optimizing phosphoric acid reaction and separation by using active silicon dioxide

Abstract

The invention discloses a process for optimizing phosphoric acid reaction and separation by using active silicon dioxide. The process comprises the following steps: adding active silicon dioxide, which is a byproduct of an enterprise for producing anhydrous hydrogen fluoride by a fluosilicic acid method, into a phosphoric acid digestion tank, mixing phosphogypsum with the active silicon dioxide and an extremely small amount of flocculant at 80 DEG C, and aging to form a co-crystal, so that the phosphogypsum crystallization rate of the digestion tank is improved, filtering by a phosphoric acidvacuum drum filter, so that the filter cake is uniformly distributed, the formed filter pore size is uniform and fine, the filtering speed is greatly improved, and the total phosphorus and fluorine content of the phosphogypsum are both at a lower level, and carrying out dilute phosphoric acid concentration, separation and water washing to prepare fluosilicic acid for fluorine hydride production. According to the invention, the process achieves harmless treatment of fluorine-containing silicon dioxide, and the recovery rate of fluosilicic acid in phosphorite is increased, and after the auxiliary agent is mixed into the phosphoric acid digestion tank, efficient separation of phosphogypsum and dilute phosphoric acid is achieved, so that the process is a new process of resource recycling, byproduct comprehensive treatment and efficient phosphoric acid separation and purification.

Description

technical field [0001] The invention relates to the technical field of silicon dioxide production, in particular to a process for optimizing phosphoric acid reaction and separation of activated silicon dioxide. Background technique [0002] Silica has many uses. The relatively rare crystals in nature can be used to manufacture important components of the electronics industry, optical instruments and handicrafts. Silica is an important raw material for the manufacture of optical fibers. Silica is used in the manufacture of flat glass, glass products, foundry sand, glass fiber, ceramic glaze, sand blasting for anti-rust, sand for filtration, flux, refractory materials, and the manufacture of lightweight air bubble concrete; recovery of fluorine resources associated with phosphate ore The obtained fluorosilicic acid can further produce hydrogen fluoride and silicon dioxide products, which have high added value, realize the efficient utilization of fluorosilicon resources in f...

AI Technical Summary

Problems solved by technology

Silica is used in the manufacture of flat glass, glass products, foundry sand, glass fiber, ceramic glaze, sand blasting for anti-rust, sand for filtration, flux, refractory materials, and the manufacture of lightweight air bubble concrete; recovery of fluorine resources associated with phosphate ore The obtained fluorosilicic acid can further produce hydrogen fluoride and silicon dioxide products, which have high added value, realize the efficient utilization of fluorosilicon resources in fluorosilicic acid, and increase the new way of fluorine resource source, but the by-product silicon dioxide is effective Taking advantage of the problems in the industry; Fujian Wengfu Lantian Fluorine Chemical Co., Ltd. uses fluosilicic acid (H2SiF6) as a raw material to produce anhydrous hydrogen fluoride. Due to the production of hydrogen fluoride by fluosilicic acid, silica will be produced, and the current environmental protection situation Serious, there are great safety and environmental protection problems in the storage of silica

Phosphoric acid rapid extraction technology and ideas have become the core technology for tapping potential and refurbishing factories, greatly reducing production costs and effectively improving the competitiveness of enterprises; at present, the by-products obtained from the production of anhydrous hydrogen fluoride from fluosilicic acid are difficult to handle , Fujian Wengfu Lantian Fluorine Chemical Co., Ltd. is the exclusive unit to realize the industrial application of fluosilicic acid to anhydrous hydrogen fluoride technology, but the difficult problem of silica treatment largely limits the continuation of the co-deterioration application of this technology. It is beneficial to the comprehensive utilization of phosphoric acid by-product fluosilicic acid, and the effective utilization of silicon dioxide is a common problem in the industry. At present, there is no other effective solution except for the production of silicate, silicon micropowder and white carbon black with silicon dioxide. At the same time, the essence of phosphoric acid rapid extraction technology is to choose the operation mode of "big in and big out". In addition to hard factors such as equipment and filter cloth, the crystallization state of calcium sulfate is an important factor affecting filtration separation; adding filter aids is another important means to increase filtration speed

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