Method for improving powder potash magnesium sulphate fertilizer granularity

Abstract

The invention discloses a method for improving the powder potash magnesium sulphate fertilizer granularity. The method comprises the steps that 1, magnesium sulfate subtype potassium-magnesium mixed salt is subjected to rotation and floating to obtain soft potassium concentrate foams containing about 70% picromerite; 2, soft potassium concentrate foams obtained in step 1, fresh water and a mothersolution returned after washing are mixed on the basis of the ratio of 5:1:4 and washed for 30 min; 3, pulp obtained in step 2 is filtered and separated, some filtrate is returned back to normal temperature conversion, and the other filtrate is returned back to a washing tank to regulate the concentration; 4, filter cakes obtained in step 3 enter a high temperature stirring groove, 80 DEG C hot water accounting for 70% of the weight of the filter cakes is added, the conversion temperature is controlled within the range of 50-55 DEG C, and mixing and stirring are performed for 30 min; 5, pulp obtained in step 4 is filtered and separated, filter cakes with the obtained free water content being about 8% and the total water content being about 31% are obtained, and a high temperature mother solution is returned to the high temperature stirring groove for circular pulp regulation; 6, the filter cakes obtained after filtering separation is performed in step 5 are dried under the temperatureof 150 DEG C for 1.5 h, and the first-class potassium magnesium fertilizer is obtained. The defect of the rotating and then floating technology can be effectively overcome.

Description

technical field [0001] The invention belongs to the technical field of salt chemical industry, and in particular relates to a method for increasing the particle size of powdered potassium magnesium sulfate fertilizer. Background technique [0002] The process of producing langbeinite from sulfate-type salt lake brine is relatively mature. First, the brine is evaporated to obtain potassium-magnesium mixed salt, and then potassium-magnesium sulfate fertilizer is produced through the transformation method. Transformation method, including three ways of turning first and then floating, first floating and then turning, and two-stage transformation. First conversion followed by flotation, that is, adding water or mother liquor to convert langbeinite into langbeinite and then flotation, so as to realize the separation of langbeinite from NaCl and epsom salt, and obtain langbeinite product (CN03134289.2 , CN200610008787.1, CN011136421, etc.); the method proposed by the patent CN101...

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Problems solved by technology

[0006] The present invention is based on the production process of "turning first and then floating" potassium and magnesium sulfate fertilizer, and under the premise of ensuring that the potassium yield and energy consumption remain unchanged, the particle size of the semi-finished potassium and magnesium sulfate fertilizer is increased by heating in the latter stage, so as to solve the problem of dust The purpose of a series of issues such as drying, packaging, etc.

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