Phosphorite comprehensive utilization method

Abstract

The invention discloses a phosphorite comprehensive utilization method. The method is characterized by comprising the following steps: a. decomposing phosphorite by using acid; b. purifying an acidolysis solution; c. using raw materials containing ammonia compounds to gradually adjust the pH value of the acidolysis solution, and separating produced phosphate precipitate. d. storing the acidolysis solution containing water-soluble calcium; and e. adding a precipitating agent that generates calcium compound to the acidolysis solution containing water-soluble calcium so as to generate calcium compound precipitation. According to the phosphorite comprehensive utilization method disclosed by the invention, phosphorite can be completely, efficiently and comprehensively utilized, and the method is especially applicable to low grade phosphate and magnesium phosphate; acidolysis can be performed on the phosphorite to turn the phosphorite into phosphate, potassium dihydrogen phosphate, potassium nitrate, ammonium dihydrogen phosphate, feed-grade DCP, calcium dihydrogen phosphate fertilizers, high purity calcium carbonate, industrial calcium chloride, high purity calcium sulfate whisker. The process is simple and high in efficiency; phosphate products and calcium products are excellent in quality, and are free of waste water, exhaust gas and waste residue discharge, and the method can be completely compatible with current phosphorus product technology.

Description

technical field [0001] The present invention relates to a method for comprehensive utilization of phosphate rock, more precisely, to a method for completely comprehensive utilization of raw materials of acid-hydrolyzed phosphate rock, especially suitable for complete comprehensive utilization of low-grade phosphate rock and high-magnesium phosphate rock . Background technique [0002] The present inventor is in the patent document that the patent number is 200510067111.5, promptly " the method for the comprehensive utilization of the raw material of acidolysis phosphate rock and co-production high-purity microsphere nano calcium carbonate ", described technical scheme comprises 4 characteristic steps: 1, phosphate rock React with acid to prepare water-soluble calcium and phosphorus acid solution; 2. Add substances to adjust the pH value of the acid solution, and control the pH value within the range of 0-12; 3. Purify the acid solution; 4. In the acid solution A precipitati...

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Problems solved by technology

[0011] Although this patented technology can obtain highly pure calcium products and excellent Ca(H 2 PO 4 ) 2 ·H 2 Solids of O crystals, but because steps b and c are generating and separating Ca(H 2 PO 4 ) 2 ·H 2 When O is crystallized, the separated Ca(H 2 PO 4 ) 2 ·H 2 O crystals contain more circulating media (chloride ions Cl - or nitrate ion NO 3 - ); at the same time, the acid solution also contains water-soluble Ca(H 2 PO 4 ) 2 , leaving the acid solution of step c contains water-soluble phosphorus, magnesium, iron, manganese, zinc and other metal or non-metallic ions, especially the metal ions in phosphate rock, all of which are essential elements for the growth of crops, because these elements The practical effect of phosphorus-containing fertilizers is reduced due to poor utilization; especially in the repeated circulation of acid hydrolysis solution, the accumulation concentration of magnesium ions increases rapidly, resulting in the influence of the purity of calcium compounds in step f

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