Production method of calcium dihydrogen phosphate

Abstract

The invention relates to the technical field of chemical engineering and in particular relates to a production method of calcium dihydrogen phosphate. According to the method, urea phosphate and calcium hydroxide directly react at 50-70 DEG C for 20-50 minutes under a stirring condition to prepare calcium dihydrogen phosphate. The method has the advantages that since calcium dihydrogen phosphate is prepared by reacting high-purity urea phosphate with calcium hydroxide, the defect in a production technology in which calcium dihydrogen phosphate is directly produced from phosphoric acid is overcome, the production process of calcium dihydrogen phosphate is simplified, and the production cost is reduced; the process conditions are accurately controlled, so that the purity of calcium dihydrogen phosphate is improved and the quality of calcium dihydrogen phosphate is stable and completely reach the standard of feed-grade calcium dihydrogen phosphate.

Description

technical field [0001] The invention relates to the technical field of chemical industry, in particular to a production method of calcium dihydrogen phosphate. Background technique [0002] Calcium dihydrogen phosphate is a colorless triclinic flaky, granular or crystalline powder inorganic compound with a strong sour taste. It does not absorb moisture when it is pure and contains trace impurities. Decomposes, soluble in dilute hydrochloric acid, dilute nitric acid and dilute acetic acid, slightly soluble in water, insoluble in ethanol, widely used as feed additive for aquaculture animals and livestock and poultry animals, as leavening agent, dough conditioner, buffer agent , Nutritional supplements, emulsifiers, stabilizers and other quality improvers can improve the complexation of metal ions, pH value, and ionic strength of food, and can improve the adhesion and water holding capacity of food. my country stipulates that it is used in bread, biscuits, and baking powder, a...

AI Technical Summary

Problems solved by technology

[0003] At present, industrial calcium dihydrogen phosphate is mainly used in feed, food additives, gypsum abrasives, plastic stabilizers and pharmaceutical additives. It is produced by neutralization method and metathesis method; among them, the neutralization method is neutralized by thermal phosphoric acid, food-grade phosphoric acid or wet-process purified phosphoric acid and calcium hydroxide (or limestone), and then washed, centrifugally dehydrated, dried, and pulverized Obtain product, its process production cost is high, energy consumption is high, pollution is big, process route is long, economic benefit is not high, is unfavorable for environmental protection; Mixed solution, then add calcium chloride solution to carry out metathesis reaction, and then neutralize until the pH of the reaction slurry is about 3.0. This method has a long process flow and the incorporation of chloride ions in the middle, so the product quality is unstable.

[0004] For example, the patent No. 01108797.8 "A Production Method of Feed Grade Calcium Dihydrogen Phosphate" is obtained by mixing dilute phosphoric acid and defluorinated tricalcium phosphate, and the material is crushed and aged for 12-24 hours, dried and sieved, because phosphate rock is directly used The tricalcium phosphate obtained by calcination and defluorination of stone is used as raw material to produce calcium dihydrogen phosphate products. During the calcination process, waste gas will be emitted into the air, which is not conducive to environmental protection. long process

[0005] For example, the patent No. 01107215.6 "Production method of calcium dihydrogen phosphate for feed" uses wet-process phosphoric acid as the raw material. The raw phosphoric acid is firstly treated with impurity removal and purification, and then the slurry reaction is carried out, and the reacted slurry is formed into drops through the nozzle. The hot air is sprayed into the hot air to make it crystallize, solidify, and dry into the product calcium dihydrogen phosphate during the hot air falling process. This product can promote uniform dispersion in the feed, but the process requires hot air, which consumes a lot of energy. At the same time, it needs Phosphoric acid is treated for impurity removal, so the process is long and the production cost is high

[0006] For example, the patent No. 01107205.9 "New Feed Grade Calcium Dihydrogen Phosphate and High-Phosphate Production Method, including decomposing phosphate rock with sulfuric acid to obtain filtered phosphoric acid, and neutralizing calcium carbonate to obtain products, but this process will produce a large amount of The carbon dioxide gas is discharged into the air, causing environmental pollution. At the same time, the entire production process is long, the production cycle is long, and the cost is high.

[0007] It can be seen that in the prior art, in the production method of calcium dihydrogen phosphate, there are generally problems such as long process route, high energy consumption, unstable product quality, poor economic benefit and unfavorable environmental protection.

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