A method for producing calcium phosphate salt and high-purity gypsum by utilizing hydrochloric acid and phosphate rock

Abstract

The invention belongs to the technical field of feed, in particular to a method for producing calcium phosphate salt and high-purity gypsum by using hydrochloric acid and phosphate rock. The technical problem to be solved by the present invention is to provide a method for producing calcium phosphate salt and high-purity gypsum by using hydrochloric acid and phosphate rock, comprising the following steps: incompletely decomposing the phosphate rock with hydrochloric acid, and separating solid and liquid to obtain solid 1 and liquid 1; 1. Treatment of solid 1: solid 1 is reacted with hydrochloric acid, filtered and separated to obtain filter residue and filtrate 2; filtrate 2 is mixed with phosphoric acid to obtain fine seasoning slurry, and the refined seasoning slurry is dechlorinated, defluorinated, and dehydrated by heating to obtain calcium phosphate; B 1. Treatment of liquid 1: ① remove fluorine in liquid 1; ② add calcium to obtain calcium hydrogen phosphate; ③ remove magnesium; ④ add sulfuric acid to obtain high-purity gypsum. The method of the invention has simple steps and low cost, and the prepared calcium phosphate fully meets the national standard, and the obtained gypsum has excellent quality.

Description

Technical field [0001] The invention belongs to the field of feed and fertilizers, and more particularly to a method of producing phosphate salts and high purity gypsum using hydrochloric acid and phosphate. Background technique [0002] Calcium phosphate salt can be used as a calcium phosphate salt of fertilizer grade, and is widely used in agricultural production. It is mainly used as a raw material for configuring compound fertilizers. It can also be applied to farmland; calcium phosphate salt can be used as a feed grade phosphate salt, suitable for Animals such as livestock and aquatic products are a feed additive for supplementing calcium phosphorus nutrients of livestock and aquatic animal. [0003] The industry is generally considered P 2 O 5 At 24% -28% as the Chinese-based phosphate, 18% -24% is low-grade phosphate. China phosphate ore resources are relatively abundant, and the total amount of resources has been proven to Morocco, ranking second in the world. China's pho...

AI Technical Summary

Problems solved by technology

At the same time, most of the existing processes for producing calcium phosphate salt first convert the calcium in phosphate rock into phosphogypsum (calcium sulfate with high impurities) and remove it as industrial waste. The storage and digestion of phosphogypsum is a difficult point in this industry. It has affected the sustainable development of this industry, and in the process of subsequent production of calcium phosphate salt, it is necessary to add a large amount of calcium carbonate as a calcium source, resulting in a great waste of resources

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