Method for producing potash magnesium sulphate fertilizers with unsaturation brine serving as flotation medium

Abstract

The invention relates to a method for producing potash magnesium sulphate fertilizers with unsaturation brine serving as a flotation medium. The method comprises the following steps of: (1) crushing potassium magnesium mixed salt raw materials with an SO4<2-> / K<+>mass ratio of 1.0-3.5 into a grain size smaller than a 40-mesh taylor sieve to obtain crushed raw materials; (2) adding the raw materials in a floating machine, adding a reverse flotation agent for flotation, respectively obtaining low sodium potassium magnesium mixed salt with a sodium chloride content lower than 10% and flotation froth; and conducting floating adjusting slurry through a low-selection medium to obtain floating slurry with a mass concentration of 10-50%; (3) putting the floating slurry in the floating potassium magnesium mixed salt, filtering and transporting to a reaction tank; and discharging the flotation froth to a tail salt pond for sedimentation to obtain flotation tail liquid; (4) adding water in the low sodium potassium magnesium mixed salt in the reaction tank for stirring to obtain potassium sulphate magnesium fertilizer slurry; and (5) conducting centrifugal filtration on the potassium sulphate magnesium fertilizer slurry to respectively obtain filter cakes and secondary transformed mother liquor, drying the filter cakes to be constant weight to obtain the potash magnesium sulphate fertilizers, and recycling the second turning mother liquor. The method is less in energy consumption, low in cost and good in product crystallinity.

Description

technical field [0001] The invention relates to the field of salt chemical industry, in particular to a method for producing potassium magnesium sulfate fertilizer using unsaturated brine as a flotation medium. Background technique [0002] Magnesite is an intermediate raw material for the production of potassium sulfate, and it is also a high-quality chlorine-free potassium-magnesium sulfate compound fertilizer. The shortage of medium elements such as sulfur and magnesium is a common problem in the world's agricultural production. The results of field application research It shows that the application of potassium and magnesium sulfate fertilizer can significantly improve the yield and quality of economic crops such as rice, vegetables, tobacco, and fruits. It is known as the "golden partner" of crop fertilization and has broad market application prospects. my country is a large agricultural country, which consumes a large amount of potassium fertilizer every year. Potassi...

AI Technical Summary

Problems solved by technology

[0004] Potassium-magnesium mixed salt mine adopts the technical route of "transforming first and then floating". From the perspective of production and operation, there are two main technical problems that need to be solved urgently: First, the conversion conditions of the first stage of the method are harsh. In order to ensure complete conversion, it must pass The ball mill performs ball milling on the raw ore. It is required that the 60-mesh Taylor sieve after the conversion is completed must not exceed 15%, and the energy consumption is relatively high. The loss of dust during drying is 15~20%, and the total yield of potassium is low

In addition, the product has fine particles and is easy to agglomerate, and it needs to be rolled and granulated, which further increases the cost