Production method of industrial-grade potassium dihydrogen phosphate coproduced water-soluble fertilizer

Abstract

The invention provides a production method of an industrial-grade potassium dihydrogen phosphate coproduced water-soluble fertilizer. The production method comprises the following steps: by taking wet-process phosphoric acid as a raw material, extracting high-purity nitrogen-phosphorus compound salt intermediate-urea phosphate from wet-process phosphoric acid, purifying the wet-process phosphoric acid, producing master liquor by utilizing the industrial-grade potassium dihydrogen phosphate, and preparing nitrogen-phosphorus-potassium ternary water-soluble fertilizer. Through continuous operation of a production device, high-nitrogen, high-phosphorus and high-potassium type water-soluble fertilizer having constant-quality and high-efficiency products and containing medium and trace elements in uniform and multiple formulas can be produced so as to meet different market demands, the raw materials for production are mainly wet-process phosphoric acid, urea and potassium hydroxide, the cost of the raw materials is low, the technological route is simple, and the industrial-grade potassium dihydrogen phosphate production technology can be effectively coupled.

Description

Technical field: [0001] The invention belongs to the technical field of agricultural fertilizers, and in particular relates to a production method of industrial grade potassium dihydrogen phosphate co-production water-soluble fertilizer. Background technique: [0002] According to the data of the National Agricultural Technology Extension Service Center of the Ministry of Agriculture, my country uses 6% of the world's water resources, 9% of the arable land and 30% of the chemical fertilizers. At the same time, it produces 26% of the agricultural products and feeds 18.84% of the global population. Huge, water shortage is more serious than land shortage. my country's irrigation water is about 3.6×1012m 3 / a, the gap is greater than 3.0×1011m3 / a, and the irrigation water production efficiency is 1kg / m 3 , which is only about 50% of that of the United States, Israel and other developed countries; the annual consumption of chemical fertilizers in my country exceeds 5400wt (pure ...

AI Technical Summary

Problems solved by technology

[0004] At present, the electrolytic method in the traditional production process of industrial grade potassium dihydrogen phosphate is limited by the high cost of ion exchange membranes, low production efficiency, and high energy consumption, making it impossible to carry out large-scale production

In the ion exchange method, the ion exchange resin itself has the disadvantage of small exchange capacity, and the concentration of the exchange solution is low, causing greater pressure on subsequent evaporation, and at the same time, equipment and cost investment are large, so this method is only suitable for small-scale production of industrial and pharmaceutical grade product

The quality of the product KH2PO4 obtained by the double decomposition method is not as good as that of the neutralization method, and it can only be used in the agricultural field, and this method consumes a lot of energy and severely corrodes the equipment. The obtained product contains chlorides, and the added value of the by-product hydrochloric acid or chloride salt is low.

The neutralization method has high requirements on the acid quality, and usually uses thermal acid or wet acid purification, and the production cost is relatively high

[0005] At present, the production process of water-soluble fertilizer is relatively chaotic, and most of them are produced by physical blending of industrial-grade single nitrogen, phosphorus and potassium source raw materials. Mechanical blending of various materials leads to poor material uniformity and high production raw material costs.

Most of the production equipment is intermittent operation and simple and small, and the stability of product quality is not good

Images