Technology for preparing kainite with potassium-containing heptahydrate epsomite raw product

Abstract

The invention relates to a technology for preparing kainite with a potassium-containing heptahydrate epsomite raw product. The technology comprises the following steps: (1) mixing brine according to the mass ratio of the potassium-containing heptahydrate epsomite raw product to magnesium sulfate saturated epsomite mother liquor or old brine being 1:(1-3), then adding in a heating fluid bowl for heating to 60-90 DEG C, preserving the heat for dissolution for 0.5-4 hours to obtain hot brine; (2) preserving the heat and filtering the hot brine obtained in the step (1), wherein the filter residue is crude kainite; (3) adding water with the amount of 1-4 times of the weight of the crude kainite equivalently to the crude kainite obtained in the step (2) and then washing with slurry to obtain high-quality kainite and potassium-containing repulping water; (4) returning the potassium-containing repulping water obtained in the step (3) to the step (1) to replace the epsomite mother liquor or old brine used in the step (1). According to the technology, the flow is simple, the solution temperature is low, the energy consumption is low, the production cost is low and economic benefits are good.

Description

technical field [0001] The invention relates to a preparation process of kainite, in particular to a process for preparing kainite from crude potassium-containing heptahydrate salt obtained by flotation. Background technique [0002] Potassium sulfate is a long-term shortage of chlorine-free potassium fertilizer in my country, and magnesia is an intermediate product for the preparation of potassium sulfate, and its chemical formula is KCl MgSO 4 2.75H 2 O. The langbeinite is processed into langbeinite, and then converted into potassium sulfate by adding potassium chloride through metathesis reaction; or adopting the process route disclosed in the patent application with application number 201080019037.9 to prepare potassium sulfate, ammonium sulfate, etc. by reacting with ammonia. [0003] At present, the main preparation process of kubeinite is that after the sulfuric acid salt lake brine is concentrated by sunlight to precipitate sodium chloride and epsom salt, the mothe...

AI Technical Summary

Problems solved by technology

At present, there is little research on the recovery and utilization of this part of potassium salt. In a small number of reports, the recrystallization method is generally used to purify magnesium sulfate heptahydrate, and potassium ions are made to enter the solution phase, and the solution is returned to the salt field for circulation. High energy consumption, and cannot directly obtain potassium salt products