Method for processing and producing potassium chloride by using magnesium sulfate subtype or sulfate chloride transitional-type potassium-containing salt lake brine

Abstract

The invention relates to a method for processing and producing potassium chloride by using magnesium sulfate subtype or sulfate chloride transitional-type potassium-containing salt lake brine. According to the method, the potassium-containing salt lake brine as a raw material contains Na, K, Mg, Cl, SO4 ions, wherein the weight ratio of SO4 to K is (0.5-3.5): 1. The method disclosed by the invention comprises the following steps of: introducing a modifying agent to a halite stage in a brine evaporation process, wherein the weight ratio of SO4 to K in the modified brine is (2.0-0.1): 1; continuously evaporating the modified brine by insolation to obtain sylvine and carnallite; and carrying out potassium chloride flotation on the sylvine and carnallite mixture, and washing and drying flotation concentrate to obtain a potassium chloride product. The method disclosed by the invention solves the problem of processing and producing the potassium chloride by using the potassium mixed salt obtained by the insolation of the magnesium sulfate subtype or transitional-type potassium-containing salt lake brine, is used for processing and producing the potassium chloride from the sylvine and carnallite obtained by using the modified brine and is good in product quality and high in sylvine yield.

Description

technical field [0001] The invention belongs to the technical field of inorganic chemical industry and relates to the chemical separation technology of inorganic salt phases, in particular to a method for producing high-quality potassium chloride by processing magnesium sulfate subtype potassium-containing salt lake brine or sulfate chloride transition type potassium-containing salt lake brine. Background technique [0002] Potassium chloride is an important chemical raw material, which has a wide range of uses in industry; at the same time, it is one of the three major fertilizers of nitrogen, phosphorus and potassium necessary for the growth of crops, and it plays an even more important role in agricultural production. As a large agricultural country in my country, The market demand for potash fertilizer is very large. my country is also a country seriously short of potassium resources. The proven reserves of potassium resources account for about 2% of the world's total pot...

AI Technical Summary

Problems solved by technology

[0003] Magnesium sulfate subtype and chloride transition type potassium-containing salt lake brine are different in composition, and their brine composition points are Na, K, Mg / / Cl, SO 4 -H 2 The phase regions on the metastable phase diagram of the five-component water-salt system are different. Generally, salt lake brines are mostly in the white sodium magnesium vanadium phase region, soft potassium magnesium vanadium phase region, epsom salt phase region or potassium rock salt phase region. Part of the magnesium sulfate subtype or transition type potassium-containing salt lake brine in the soft potassium magnesium vanadium phase area, epsom salt phase area or potassium halite phase area, the potassium mixed salt intermediate product obtained by evaporation and crystallization in salt fields is directly used in production Potassium sulfate, its sulfate group is insufficient, and its sulfate is too high for the production of potassium chloride, the resulting potassium chloride product is of poor quality, and the potassium yield is low

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