Method for producing water-soluble calcium nitrate dihydrate and phosphoric acid by decomposing phosphorite through nitric acid

A calcium nitrate, water-soluble technology, applied in the direction of phosphoric acid, calcium/strontium/barium nitrate, phosphorus oxyacid, etc., to reduce the storage space, improve the competitive advantage, and facilitate crop absorption.

Inactive Publication Date: 2013-05-01
云天化集团有限责任公司 +2
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  • Abstract
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  • Application Information

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Problems solved by technology

So far, there is no report on the production of phosphoric acid by decomposing phosphate rock with nitric acid, deep impurity removal, re-evaporation concentr

Method used

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  • Method for producing water-soluble calcium nitrate dihydrate and phosphoric acid by decomposing phosphorite through nitric acid

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Embodiment

[0020] Adopt nitric acid of the present invention to decompose phosphate rock to produce water-soluble calcium nitrate dihydrate and co-produce phosphoric acid, and the specific operations are:

[0021] Table 1 Composition of phosphate rock powder

[0022] project Ore size P 2 o 5 SiO 2 Al 2 o 3 Fe 2 o 3 MgO CaO F content / % 80%≤-200 mesh 28.21 17.10 1.70 1.94 1.98 43.0 2.41

[0023] A), acid hydrolysis

[0024] Nitric acid with a concentration of 60% to 66% is mixed with the washing liquid during the filtration of acid insoluble matter. The concentration of nitric acid is 50% to 55%. The nitric acid solution is added to the acidolysis tank, and phosphate rock powder is added under stirring to carry out the acidolysis reaction. The amount of nitric acid is 95%~110% of the theoretical amount, the temperature of the acidolysis reaction is 50℃~70℃, and the residence time of the acidolysis reaction is 0.5~4h. Then filter the sl...

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Abstract

The invention relates to a water-soluble calcium nitrate production method, and especially relates to a method for producing water-soluble calcium nitrate dihydrate and phosphoric acid by decomposing phosphorite through nitric acid. The method comprises the following steps: decomposing phosphorite by nitric acid to prepare an acidolysis liquid, carrying out freezing crystallization of the acidolysis liquid to separate a calcium nitrate crystal and phosphoric acid, dissolving the calcium nitrate crystal, carrying out deep impurity removal of the obtained calcium nitrate solution, carrying out evaporative concentration of the calcium nitrate solution, removing water from the obtained crystal, and carrying out ammonium nitrate wrapping granulation to prepare calcium nitrate dihydrate having a water solubility of not less than 99.9%. The method avoids the insufficient utilization of sulfate radicals residual in phosphogypsum of sulfuric acid methods when wet phosphoric acid is simultaneously produced, and the production of the high-added-value calcium nitrate dihydrate through the combination of nitrate radicals with calcium ions has the advantages of widening of the product chains of phosphoric acid or nitric phosphate enterprises, economic utilization of the nitrogen element in nitric acid, and improvement of the competition advantages of the enterprises.

Description

technical field [0001] The invention relates to a production method of water-soluble calcium nitrate, in particular to a method for decomposing phosphate rock with nitric acid to produce water-soluble calcium nitrate dihydrate and co-production of phosphoric acid. Background technique [0002] At present, wet-process phosphoric acid mainly uses sulfuric acid to decompose phosphate rock, and a large amount of phosphogypsum is produced while obtaining phosphoric acid. Nitric acid can also be used to dissolve phosphate rock. Nitric acid is widely used to acidify phosphate rock to make nitrophosphate fertilizer. In this method, the acidified material is ammonified and dried to obtain a solid nitrophosphate fertilizer product, which contains part or all of calcium. . Phosphoric acid is thus present at a certain stage (in the acidified solution) and is used to produce phosphate fertilizer. In this respect it can be said that nitric acid is used to make phosphoric acid. However,...

Claims

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Application Information

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IPC IPC(8): C01F11/38C01B25/20
Inventor 张宗凡张必江李德高马洪伟阮永刚周艳
Owner 云天化集团有限责任公司
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