Improved process of preparing potassium sulfate with bittern containing potassium and magnesium sulfite

Abstract

The improved process of preparing potassium sulfate with bittern containing potassium and magnesium sulfite includes the following steps: 1. tedding bittern to obtain mixed potassium salt; 2. crushing and milling; 3. mixing the mixed potassium salt with fresh water or slight salty water in the weight ratio of 1 to 0.2-0.5 to prepare the first slurry and the first conversion reaction; 4. mixing the first converted slurry and floating chemical for floating to obtain solid concentrated mineral; 5. mixing the solid concentrated mineral and fresh water or slight salty water in the weight ratio of 1 to 1.0-1.5 to prepare the second slurry and the second conversion reaction; and 6. solid-liquid separation of the second converted slurry to obtain wet potassium sulfate and drying to obtain dry potassium sulfate product. The technological process has high stability, low water consumption, low mineral consumption, high comprehensive potassium ion recovering rate and low insoluble matter content in the product.

Description

technical field [0001] The present invention relates to an improved method for preparing potassium sulfate, in particular to an improved method for preparing potassium sulfate with potassium-containing magnesium sulfate subtype brine. Background technique [0002] Application number is 200410038989.1, and the name is called " a kind of method for producing potassium sulfate with potassium mixed salt " Chinese invention patent application discloses a kind of method that prepares potassium sulfate with potassium-containing magnesium sulfate subtype brine, and this existing method exists The following defects: [0003] 1. The process stability is poor; this existing method has carried out two pilot tests, respectively with the potassium mixed salt made in spring and autumn winter and the potassium mixed salt made in summer as raw material potassium mixed salt, the process index drawn is completely different, the former The indicators are very poor, the comprehensive recovery r...

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Problems solved by technology

[0004] 2. The process consumes a lot of water, and the comprehensive recovery rate of potassium ions is low; because this existing method removes the sodium chloride impurity by adding water chemically, if you want to remove sodium chloride, you only have to add more water. The quality of the potassium sulfate produced in the two-stage conversion reaction process just can't be guaranteed, and this existing method per ton potassium sulfate finished product water consumption is between 9~12 tons, is on average more than 10 tons; In addition, adds water more, It means that there are more potassium ions dissolved in the liquid phase, which will lead to a lower comprehensive recovery rate of potassium ions. When the existing method uses potassium mixed salts made in spring, autumn and winter as raw material potassium mixed salts, the comprehensive recovery of potassium ions The rate is 31.78%, and when the potassium mixed salt made in summer is used as the raw material potassium mixed salt, the comprehensive recovery rate of potassium ion is 41.19%;

[0005] 3. The content of insolubles in the finished product of potassium sulfate is high; this existing method is due to the whole process is completed by adding water to transform the whole process, and there is no physical separation process, so the raw material potassium mixed salt is deposited in the natural beach drying process of the salt field It is impossible to remove the insoluble matter formed by sand and dust, and the content of insoluble matter in the finished product of potassium sulfate in the test is about 2 to 3%.

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