Production method of potassium dihydrogen phosphate

Abstract

The production method of potassium dihydrogen phosphate uses the calcium hydrogen phosphate whose impurities of iron, aluminium, fluorine and sulfur are low as raw material, and is implemented by adopting technological processes of potassium hydrogen sulfate preparation, solution extraction, potassium dihydrogen phosphate crystallization and separation ,and its operation includes the following steps: fulfonation, hydrolysis, extraction, filtration, filtrate concentration, crystallization and separation, drying and fractionation. Its reaction condition is moderate, its potassium yield is high,at the same time the quality of potassium dihydrogen phosphate and phosphoric acid can be ensured.

Description

technical field [0001] The invention relates to a production method of potassium dihydrogen phosphate, and at the same time relates to the industrial-grade phosphoric acid or phosphate produced in conjunction with the production method of potassium dihydrogen phosphate. Background technique [0002] Potassium dihydrogen phosphate [KH 2 PO 4 ] Contains two nutrients, phosphorus and potassium, with high purity and high concentration. It is an ideal chemical fertilizer variety, which has a significant effect on increasing production of various crops. In recent years, the market for potassium dihydrogen phosphate to make liquid fertilizers is gradually expanding; since the salt index of potassium dihydrogen phosphate is relatively low, it will not increase the salt index of the soil after application, so it is especially favored by vegetable farmers, fruit farmers and horticultural circles. . With the advancement of agricultural technology, potassium dihydrogen phosphate has ...

AI Technical Summary

Problems solved by technology

[0006] 4. Ion exchange method: use ion exchange resin to separate H 2 PO 4 - and K + Potassium dihydrogen phosphate is generated during the adsorption and regeneration process. The biggest disadvantage of this production method is that the amount of evaporated water is too large and the energy consumption is too high

This production method has three problems: one is that the extraction agent is expensive; the other is that the poisoning of the extraction agent is not easy to solve; the third is that the processing of by-products is difficult

The biggest problem with this method is that the phosphate rock powder has a high fluorine content, and insoluble potassium fluorosilicate is formed during the reaction process. In addition, a part of potassium gypsum is formed, and the loss of potassium reaches more than 20%, which is economically impossible to pass.

Also due to the many impurities in the phosphate rock powder, the quality of potassium dihydrogen phosphate is poor

[0009] Due to the drawbacks of the above methods, so far, there is no large-scale production device, resulting in a shortage of potassium dihydrogen phosphate in the market, and the product price has been high.

[0010] In addition, the existing industrial-grade phosphates are all produced using expensive thermal phosphoric acid as raw materials, so the cost of the product is high

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