Method for producing calcium phosphate and high-purity gypsum by using hydrochloric acid and phosphate rock

Abstract

The invention belongs to the technical field of feeds, and specifically relates to a method for producing calcium phosphate and high-purity gypsum by using hydrochloric acid and phosphate rock. To solve technical problems, the invention provides the method for producing calcium phosphate and high-purity gypsum by using hydrochloric acid and phosphate rock, comprising the following steps: incompletely decomposing phosphate rock with hydrochloric acid, carrying out solid-liquid separation to obtain a solid 1 and a liquid 1; A. treating the solid 1: carrying out a reaction between the solid 1 andhydrochloric acid, filtering and separating to obtain filter residue and a filtrate 2; mixing the filtrate 2 and phosphoric acid to obtain finely-tuned slurry, heating the finely-tuned slurry for dechloridation, defluorination and dehydration to obtain calcium phosphate; B. treating the liquid 1: (1) removing fluorine in the liquid 1; (2) adding calcium to prepare calcium hydrophosphate; (3) removing magnesium; and (4) adding sulfuric acid to prepare high-purity gypsum. The method has advantages of simple steps and low cost; the prepared calcium phosphate completely meets the national standards; and the gypsum quality is excellent.

Description

Technical field [0001] The invention belongs to the technical field of feed and fertilizer, and specifically relates to a method for producing calcium phosphate salt and high-purity gypsum by using hydrochloric acid and phosphate rock. Background technique [0002] Calcium phosphate salt can be used as fertilizer-grade calcium phosphate salt, which is widely used in agricultural production, mainly used as a raw material for compound fertilizer, and can also be directly applied to farmland; calcium phosphate salt can be used as feed-grade calcium phosphate salt, suitable for Animals such as livestock and aquatic products are feed additives used to supplement calcium and phosphorus nutrition of livestock and aquatic animals. [0003] The industry generally believes that P 2 O 5 24%-28% is medium-grade phosphate rock, and 18%-24% is low-grade phosphate rock. China is rich in phosphate resources, and the total amount of proven resources is second only to Morocco, ranking second in the...

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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