Continuous crystallization process for monopotassium phosphate

Abstract

The invention discloses a continuous crystallization process for monopotassium phosphate. The continuous crystallization process comprises the following specific steps of: introducing a feed liquid to be crystallized into a first-stage continuous flash crystallizer so as to be separated into a primary clear liquid, primary crystal mush and secondary steam; discharging the primary crystal mush from the first-stage continuous flash crystallizer and feeding the primary crystal mush into a second-stage continuous cooling crystallizer, wherein the second-stage continuous cooling crystallizer is composed of an Oslo crystallizer and an external cooler; separating the primary crystal mush into secondary crystal mush and a secondary clear liquid in the Oslo crystallizer; discharging the secondary crystal mush from the Oslo crystallizer, feeding the secondary crystal mush into a thickener and separating the secondary crystal mush into triple clear liquid and triple crystal mush; discharging the triple crystal mush from the thickener, feeding the triple crystal mush into a centrifugal machine, and separating the triple crystal mush into solid monopotassium phosphate and a centrifugal liquid; and discharging the solid monopotassium phosphate from the centrifugal machine. The continuous crystallization process is stable in operation, low in energy consumption and low in labor intensity; and by using the continuous crystallization process, the operation stability and the product quality are greatly improved, the on-site operation environment is improved, and the production cost of the monopotassium phosphate is reduced. A mating device for the process is small in floor area and high in capacity.

Description

technical field [0001] The invention relates to a production method of potassium dihydrogen phosphate, in particular to a crystallization process of potassium dihydrogen phosphate. Background technique [0002] Potassium dihydrogen phosphate is an important chemical, which is widely used in agriculture, chemical industry, medicine and food industries. In the chemical industry, potassium dihydrogen phosphate can be used as a buffer, a culture agent, a raw material for making potassium metaphosphate, a fermentation aid, a culture agent, a strengthening agent, and a leavening agent for brewing yeast; in agriculture, potassium dihydrogen phosphate It is a high-concentration and high-efficiency phosphorus and potassium compound fertilizer; in medicine, potassium dihydrogen phosphate can be used to acidify uric acid, as a nutrient, etc.; in food, potassium dihydrogen phosphate can be used as a flavoring agent for synthetic sake. [0003] At present, the production methods of pota...

AI Technical Summary

Problems solved by technology

However, because most of the crystallization equipment used in this process is a simple stirred tank crystallizer, the crystallization process has the following disadvantages: 1) It is batch crystallization, which is not suitable for continuous operation; 2) The crystallization process takes a long time, The equipment used occupies a large area; 3) The operation requirements of the crystallization process are high, and the temperature and flow of the cooling medium need to be adjusted at any time. The stirred tank crystallizer is prone to local overcooling, which causes the material to be crystallized to condense on the heat exchange surface of the crystallizer, and then This makes the heat transfer effect worse, and eventually leads to an increase in the labor load of the subsequent crystallization process; 4) During the crystallization process, the material is prone to leakage and splashing due to stirring, and the operating environment is relatively harsh; 5) The crystallization operation is mainly completed by a large number of personnel. Higher operating costs; 6) Due to differences in professional quality between personnel, the overall crystallization operation and product stability are poor, and product quality in different batches may vary

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