Potassium dihydrogen phosphate prepared by agricultural ammonium phosphate and water-insoluble phosphorus recovery method thereof

Abstract

The invention relates to potassium dihydrogen phosphate prepared by agricultural ammonium phosphate and a water-insoluble phosphorus recovery method thereof; the method is characterized by comprising the following steps: dissolving the agricultural monoammonium phosphate or the diammonium phosphate by utilizing the circulatory potassium dihydrogen phosphate crystal mother liquor to prepare ammonium salt solution of phosphoric acid, filtering the solution, processing ammonium phosphate residues to recover all the phosphorus pentoxide and potassium oxide contained in the residues by utilizing hydrocarbonate, carbonate and/or hydroxide; adding alkaline substances into the ammonium phosphate solution, evaporating and recovering ammonia, meanwhile, obtaining sodium dihydrogen phosphate solution or potassium dihydrogen phosphate solution, after reacting with potassium chloride, filtering the solution to remove sodium chloride, adjusting the pH by phosphoric acid, cooling to obtain potassium dihydrogen phosphate. The steps also comprise: preparing ammonium sulfate by absorbing ammonia by using sulfuric acid, preparing sewage water or water treatment drug by utilizing the residues after recovering phosphorus and potassium. With the method of the invention adopted, any inferior quality ammonium phosphate and the potassium chloride with use value can be used, and phosphorus and potassium has high coefficient of recovery, good quality products, low raw material consumption, low energy consumption, low production cost, removal pollution, and has great technological economic and social benefits.

Description

technical field [0001] The invention belongs to the field of fine phosphate production, and relates to a production method of using agricultural ammonium phosphate (monoammonium phosphate, diammonium phosphate) and potassium chloride (or potassium carbonate, potassium hydroxide) to produce potassium dihydrogen phosphate and the water therein Conversion recovery method of insoluble phosphorus. It is suitable for producing fine phosphate (potassium dihydrogen phosphate, sodium dihydrogen phosphate, etc.) using agricultural ammonium phosphate and agricultural potassium chloride (or potassium carbonate, potassium hydroxide). Background technique [0002] In the prior art, the production of fine phosphate generally adopts hot process phosphoric acid or wet process phosphoric acid. At present, the production technology of fine phosphate generally uses thermal phosphoric acid. Because wet process phosphoric acid inevitably contains various impurities, such as alumina, iron oxide,...

AI Technical Summary

Problems solved by technology

These impurities, under the operating conditions for the manufacture of phosphate, generate AlP0 4 , FeP0 4 , CaHPO 4 , MgHPO 4 , MgNH 4 PO 4 , Ca 3 (PO 4 ) 2 , Mg 3 (PO 4 ) 2 and other precipitates, causing a large loss of phosphorus pentoxide and seriously deteriorating the separation process and product quality

At the same time, the concentration of wet-process phosphoric acid is generally very low. The phosphorus pentoxide content of common commercial wet-process phosphoric acid is generally about 20%. In addition to the loss of phosphorus pentoxide in the production process, the concentration of the phosphate solution obtained after processing is even lower. , which brings a large workload of evaporation and concentration, which not only greatly increases energy consumption, but also seriously affects the efficiency of equipment, making it difficult to receive better economic benefits

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