Potassium sulfate producing process

Abstract

A potassium sulfate producing process includes the reaction of sodium sulfate or mirabilite, potassium chloride and system mother liquor in the weight ratio of (1.7-2.15) to (0.08-0.20) to (8.19-10.76) and solid-liquid separation to obtain glaserite and salt making mother liquor, the reaction of glaserite, potassium chloride and water in the weight ratio of (1.1-1.2) to (0.65-0.95) to (1.6-1.9) on potassium sulfate and potassium other liquor; and the three-effect inverse evaporation of salt making mother liquor at 75-140 deg.c to separate sodium chloride and post-evaporation liquid. The present invention has the advantages of short technological process, short reaction period, low power consumption, high product yield and quality, and no "three waste" discharge.

Description

[0001] Field: [0002] The invention relates to a production process of potassium sulfate. Background technique [0003] Sodium sulfate or Glauber's salt (Na 2 SO 4 10H 2 (O) and KCl conversion in the production technology of preparing potassium sulfate, its production process has two stages of transformation mother liquor evaporation method and one stage of transformation once evaporating once washing and two stages of transformation mother liquor freezing and separating out miscellaneous salt and then evaporation method. [0004] Such as " the production technique of potassium sulfate " (patent application number 97107952) is to be raw material with mirabilite or sodium sulfate and Repone K and prepare potassium sulfate with two-stage transformation mother liquor evaporation method. The main problems are: sodium chloride is produced from the salt-making mother liquor in a system where multiple salts coexist, and the by-products often contain sodium sulfate and potassium c...

AI Technical Summary

Problems solved by technology

The main problems are: sodium chloride is produced from the salt-making mother liquor in a system where multiple salts coexist, and the by-products often contain sodium sulfate and potassium chloride, and a part of the salt is not precipitated. After evaporation, the liquid enters the reaction system and circulates, resulting in the conversion of the reaction system The rate is low, potassium sulfate can only reach the first-grade product of the national standard, and the raw material consumption is high. The conversion rate of potassium chloride can be ≥ 90% based on a shift, and based on a cycle or continuous stable monthly production, the conversion rate ≤ 83%

[0005] In order to avoid the above defects, some foreign production enterprises directly drain the mother liquor of salt making. Of course, the consequences of doing so are high raw material consumption, high product cost, and the conversion rate of potassium chloride is ≤57%.

[0006] The known technology of producing potassium sulfate by converting once, evaporating once and washing once can be seen in the production method of Patent No. 98112323.6. The quality of the product potassium sulfate obtained after one reaction is generally inferior. However, although washing with potassium sulfate solution improves product quality, it brings more water to the system and increases evaporation, and the production process discharges a certain amount of useful ionized water to ensure system stability, making High raw material consumption and low conversion rate, the conversion rate of one shift can be ≥80%, while the conversion rate of one cycle can be ≤60%