Production method of potassium dihydrogen phosphate

Abstract

A production method of potassium dihydrogen phosphate comprises the following steps: adding a potassium bisulfate solution and powdery calcium hydrogen phosphate into a potassium dihydrogen phosphate reaction tank for reaction, filtering the material slurry after the reaction, delivering the filter residues to a wet-method phosphoric acid system filter for filtration, delivering to a phosphogypsum stockyard or directly stacking in a stockyard, delivering the filtrate into an evaporation concentration device for concentration; allowing the concentrated supersaturated solution to enter a cooling crystallization tank, filtering the material slurry after cooling crystallization by a centrifugation filter, returning the filtered mother liquor to the potassium dihydrogen phosphate reaction tank and a mixed acid tank of a device for producing sulfur-base composite fertilizer, wherein the crystal obtained from filtration is potassium dihydrogen phosphate, drying to obtain the potassium dihydrogen phosphate finished product. The invention is applicable to all enterprises with a high-concentration sulfur-base composite fertilizer device, and has the advantages of low cost, good product quality, and less equipment investment.

Description

technical field [0001] The invention relates to the technical field of compound fertilizer production methods, in particular to a production method of potassium dihydrogen phosphate. Background technique [0002] Potassium dihydrogen phosphate is a high-quality phosphorus-potassium compound fertilizer. The traditional process generally uses neutralization and double decomposition. The neutralization process is simple, but the raw materials used are expensive and the production cost is high. It is difficult to use dihydrogen phosphate in agriculture and industry. Promotion in the production of potassium; the metathesis method mainly uses potassium chloride and phosphoric acid to carry out the metathesis reaction, and the reaction can be carried out by removing the hydrogen chloride gas generated by the reaction. This method has problems such as high energy consumption and excessive residual chloride ion content in the product. In addition, the production process of potassium ...

AI Technical Summary

Problems solved by technology

[0002] Potassium dihydrogen phosphate is a high-quality phosphorus-potassium compound fertilizer. The traditional process generally uses neutralization and double decomposition. The neutralization process is simple, but the raw materials used are expensive and the production cost is high. It is difficult to use dihydrogen phosphate in agriculture and industry. Promote in the production of potassium; the metathesis method mainly uses potassium chloride and phosphoric acid to carry out the metathesis reaction, and the reaction can be carried out by removing the hydrogen chloride gas generated by the reaction. This method has problems such as high energy consumption and excessive residual chloride ion content in the product.

In addition, the production process of potassium dihydrogen phosphate includes organic extraction method, ion exchange method and direct method, etc., all of which have not been industrialized due to high production costs, substandard product quality, and serious equipment corrosion.

[0003] So far, there is no large-scale potassium dihydrogen phosphate production device, resulting in a shortage of potassium dihydrogen phosphate in the market and high product prices

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