Fluosilicic production of hydrofluoric acid is actually using a sulfuric acid decomposition method of fluosilicic acid, concentrated sulfuric acid is added to the fluoro-silicate solution was concentrated, and the decomposition of fluorosilicic acid into hydrogen fluoride and silicon tetrafluoride gas, most of the sulfuric acid hydrogen fluoride is absorbed. The silicon tetrafluoride is difficult to absorb, gas evolution was washed with diluted fluorine acid solution needed to absorb this silicon tetrafluoride, produced white carbon and thicken dilute hydrofluoric acid, fluorosilicic acid enriched and went concentrated sulfuric acid, and so forth cycle. Sulfuric acid hydrogen fluoride absorbed through desorb hydrogen fluoride, anhydrous hydrofluoric acid can be obtained by refining. The process does not consume other auxiliary materials, but produce large concentration of 60% to 70% sulfuric acid; the process has a certain economic rationality, but more complex process control, low-fluoride per pass conversion efficiency, a large amount of recycled material, equipment, infrastructure large investment and long payback period; and because a large amount of sulfuric acid produced, there can only be applied fertilizer companies superphosphate production plant and therefore has great limitations. Now the domestic dozens of hydrofluoric acid production lines, the smallest only 3000 tons / year, the largest reached 25,000 tons / year. Most of the production line is between 10,000 tons / year to 15,000 tons / year. National Policy Provisions: from 2002 onwards, a single set of device production scale new AHF production line must be greater than 10,000 t / a, which is an indicator of China in line with the truth. It is understood that the annual sales of AHF prices vary widely, from March to September is the peak season, the price is relatively high, from December to February is the off-season, it is basically guaranteed sales. Therefore, reducing the consumption of enterprises to reduce costs and improve competitiveness plays a significant role; and the production scale of more than 10,000 t / a production plant, consumption is relatively low.
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