Producing method of calcium hydrogen phosphate

A technology of calcium hydrogen phosphate and production methods, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc., can solve the problems of medium and acid-base cycle efficiency reduction, meet the requirements of simple raw materials, improve the efficiency of ammonia distillation, and improve the efficiency of hydrochloric acid The effect of cycle efficiency

Inactive Publication Date: 2012-09-12
INST OF PROCESS ENG CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] However, only half of the magnesium that is hydrolyzed to hydroxymagnesium chloride has ammonia distillation activity, and only half of the hydrogen chloride is released, which will greatly reduce the efficiency of the medium and acid-base circulation

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] 1) Put 1600mL of 25% hydrochloric acid into a 2000mL beaker, add 660g of phosphate rock powder under stirring, the fineness of phosphate rock powder is 80% and over 100 mesh, P 2 o 5 The CaO content is 27.8%, the CaO content is 39.0%, and the MgO content is 3.2%. After acidolysis at 45-50°C for two hours, filter and wash, the recovery rate of phosphorus in the acidolysis solution is 99.2%;

[0032]2) Add a compound defluorinating agent to the acid solution and neutralize it with ammonia water until the pH is 1.6-2.2, then separate and dry the precipitate to obtain a fertilizer calcium hydrogen phosphate product (which contains 3.2-3.6% nitrogen and 18.6-24.2% phosphorus, which can be used as compound fertilizer raw material);

[0033] 3) The above-mentioned filtrate is neutralized with ammonia water in the second stage until the pH is 4.2 to 4.8, and the feed grade calcium hydrogen phosphate product is obtained after separation, washing and drying (the yield in terms ...

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Abstract

The invention relates to a producing method of calcium hydrogen phosphate. The producing method includes firstly, utilizing hydrochloric acid to decompose phosphorite powders to obtain a mixture of phosphoric acid and calcium chloride, subjecting the mixture to defluorination purification, and using ammonia to neutralize the phosphoric acid to obtain a calcium hydrogen phosphate product; secondly, after the phosphoric acid is separated, using the ammonia and carbon dioxide to convert redundant calcium to a calcium carbonate product, using magnesium oxide to distill the ammonia out of remaining ammonium chloride in a solution in a boiling state, circulating the distilled ammonia to a neutralization procedure, subjecting remaining a magnesium chloride solution after ammonia distillation to evaporation concentration to obtain magnesium chloride-water (1 / 6), subjecting magnesium chloride hexahydrate to dehydration at the temperature of 120 DEG C to obtain magnesium chloride-water (1 / 2), then subjecting the magnesium chloride-water (1 / 2) to pyrogenic decomposition at the temperature between 550 DEG C and 600 DEG C to release hydrogen chloride, subjecting the hydrogen chloride obtained by the pyrogenic decomposition to water absorption, returning to the process of acid hydrolysis of phosphorite, and finally subjecting the magnesium oxide to returning to the process of the ammonia distillation. The producing method of the calcium hydrogen phosphate has the advantages that the resource utilization ratio is high, large-scale production of the phosphorite by means of a hydrochloric acid processing method can be achieved, acid-base media can be completely circulated, phosphorous gypsum or calcium chloride are prevented from discharging, and the like.

Description

technical field [0001] The invention relates to a production method of calcium hydrogen phosphate, in particular to a method for preparing calcium hydrogen phosphate by treating phosphate rock with hydrochloric acid, belonging to the field of chemical production. Background technique [0002] Phosphate rock refers to the general term of phosphate minerals that can be used economically, and is an important chemical mineral raw material. It can be used to produce phosphate fertilizer, and can also be used to produce yellow phosphorus, phosphoric acid, phosphide and other phosphates for use in medicine, food, matches, dyes, sugar, ceramics, national defense and other industrial sectors. Phosphate rock has been used in industry for more than 100 years. [0003] At present, the preparation of phosphoric acid or phosphate is generally obtained by treating phosphate rock with sulfuric acid, and the solid waste residue phosphogypsum (its main component is calcium sulfate) produced ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/32
Inventor 谢渝春刘会洲安震涛魏雪团
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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