Method of producing potassium sulfate by reaction, extraction and crystallization one-step method

Abstract

The invention relates to the new process for producing lemery by a one-step method of reaction-extraction-crystallization, which takes dilute sulphuric acid and potassium chloride as the raw material and adopts the one-step reaction of a complex extracting agent to extract and crystallize to prepare the lemery under normal temperature; the three processes of reaction, extraction and crystallization are simultaneously carried out in a same device, and the solid lemery can be obtained without heating and compression. The used extracting agent can be effectively recovered by the back extraction of ammonia so as to be reused. The whole process is a closed cycle, which ensures zero discharge of three wastes.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a method for producing potassium sulfate by reaction extraction crystallization-one-step method. Background technique [0002] Potassium sulfate is the main variety of chlorine-free potassium fertilizer, especially suitable for cash crops such as tea, tobacco, sugar, and fruits that avoid chlorine. At present, the production ratio of nitrogen fertilizer and phosphorus fertilizer in our country can basically meet the needs of agricultural production development, but the gap of potassium fertilizer is getting bigger and bigger, especially potassium sulfate. At present, there are three methods for producing potassium sulfate from potassium chloride in industry: metathesis method, establishment method and the Mannheim method introduced by Taiwan Qingshang Company. Among them, the transformation rate of metathesis method is low and the product quality is difficult to control; less, l...

AI Technical Summary

Problems solved by technology

At present, there are three methods for producing potassium sulfate from potassium chloride in industry: metathesis method, establishment method and the Mannheim method introduced by Taiwan Qingshang Company. Among them, the transformation rate of metathesis method is low and the product quality is difficult to control; less, low cost, and high product quality, but it is easy to form salt and clog during industrial production, making continuous production very difficult; as for the Mannheim method, it needs to be carried out at high temperature, and the whole set of equipment is imported, making localization difficult. The equipment is severely corroded, and the investment is large (about 35 million yuan for a 10,000-ton unit), which is high in cost, and a large amount of hydrochloric acid is produced by-product, and waste residue and waste acid are difficult to handle