Method for manufacturing industrial phosphoric acid, industrial ammonium phosphate and food-grade phosphoric acid from medium and low-grade phosphorite by one-step extraction of hydrochloric acid method

Abstract

The invention discloses a method for manufacturing industrial phosphoric acid, industrial ammonium phosphate and food-grade phosphoric acid from medium and low-grade phosphorite by one-step extraction of a hydrochloric acid method. The method is characterized by comprising the following steps of: decomposing any phosphorite (the P2O5 of which is more than or equal to 6 weight percent) by using hydrochloric acid, preparing calcium chloride dihydrogen phosphate CaClH2PO4.H2O (P-01 for short), adding dilute phosphoric acid, pulping, filtering and purifying the P-01, pulping and dissolving the P-01 with hydrochloric acid, performing extraction by using tributyl phosphate, performing concentration and decolorization to obtain the industrial phosphoric acid, adding ammonia into the industrial phosphoric acid to obtain the industrial ammonium phosphate, or adding P2S5 into the concentrated industrial phosphoric acid to remove arsenic and heavy metal, performing decolorization by using active carbon and hydrogen peroxide and removing easily oxidized substances to reach the index requirement of the food-grade phosphoric acid.

Description

technical field [0001] The invention belongs to wet-process phosphoric acid and its wet-process phosphoric acid purification technology, and is the technical category of decomposing any phosphate rock with hydrochloric acid to produce hydrochloric acid wet-process phosphoric acid and its phosphates. Background technique [0002] As we all know, so far, most of food-grade phosphoric acid is purified by thermal phosphoric acid. Due to high energy consumption and cost, since the 1970s, sulfuric acid wet-process phosphoric acid has been used as raw material at home and abroad. Solvent extraction method, ion exchange method, ion membrane electrodialysis method and crystallization method have produced industrial and food-grade phosphoric acid. Foreign countries, represented by Israel I.M.I. Mining Company, have carried out extraction tests of hydrochloric acid wet-process phosphoric acid and sulfuric acid wet-process phosphoric acid. Production [1] ,Japan [2] and other countries...

AI Technical Summary

Problems solved by technology

The second extraction agent in this process is diisopropyl ether, which is only suitable for the extraction of high-concentration phosphoric acid and the operating temperature is below 5°C. For this reason, the entire equipment, extractant and extracted solution are required to be cooled below 5°C, so that Need to add a lot of cold exchange equipment, the operation is more troublesome, and the energy consumption is higher

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