The most basic variety of potassium fertilizer is potassium chloride, which is rich in resources, simple in processing technology and high in potassium content. It is the most widely used potassium fertilizer and the basic potassium source of potassium sulfate and potassium nitrate, accounting for about 90% of the total. Potassium sulfate is mainly suitable for use in chlorine resistant crops, which can improve the yield and quality of crops. As an important raw material for the production of compound fertilizer, potassium nitrate is a physiological neutral fertilizer. Therefore, using fertilizer granulator machine to make potash fertilizer into granules is very promising.
The production of potassium sulfate mainly includes double decomposition and production of potassium sulfate with alunite. 1. The raw material of the double decomposition method is to control the concentration and temperature according to the difference of the solubility of the salt produced by the reaction of sulfate such as mirabilite or ammonium sulfate with potassium chloride at different temperatures, to carry out crystallization separation, so as to obtain potassium sulfate. 2. There are reduction pyrolysis, hydrochemistry and ammonia leaching methods to produce potassium sulfate from alunite. The crude potassium product obtained by reduction pyrolysis has high purity, but the consumption of caustic soda and steam is large, and the economic benefit is poor. The hydrochemistry process has the advantages of short process, low investment, low energy consumption, high yield, small pollution and simple special equipment. It is an advanced alunite processing method at present. The process of ammonia leaching is more complicated, but the potassium sulfate and ammonium sulfate produced by the reaction can not be separated into N-K fertilizer. Therefore, from the perspective of fertilizer, it is more advantageous to produce potassium sulfate by ammonia leaching.
Potash fertilizer manufacturing process meets the needs of the market. Extrusion granulation is the most viable method of making granular potassium fertilizer. At present, the most advanced extrusion granulation technology is the use of double roller fertilizer granulator, which has the characteristics of low energy consumption and low investment. In the granulation process, there is no need to add additional binder. The size range of raw materials used is large, the capacity range of double roller fertilizer granulator is wide, and the economic benefit is good.