A kind of technology of preparing potassium sulfate and potassium magnesium fertilizer with polyhalite

Abstract

A process for preparing potassium sulfate and potassium-magnesium fertilizer from polyhalite includes the following steps of 1, ore grinding, wherein polyhalite is subjected to ore grinding until the content of 120-mesh ground polyhalite is 85wt% or above; 2, washing, wherein sodium chloride in polyhalite is washed away with water; 3, roasting, wherein the washed ore is roasted at a high temperature; 4, leaching, wherein potassium and magnesium in polyhalite are leached; 5, solid-liquid separation, wherein ore pulp obtained through leaching is subjected to solid-liquid separation, and mother liquor containing potassium sulfate and magnesium sulfate can be obtained; 6, evaporation, wherein the mother liquor is evaporated to separate out potassium sulfate, filtering separation is carried out to obtain a potassium sulfate product, the mother liquor continues to be evaporated to a certain concentration, and filtering separation is carried out to obtain a potassium-magnesium fertilizer product. The process is simple, the raw material source is wide, and the cost is low; sodium chloride in polyhalite can be effectively removed, the K+ leaching rate is high, the water consumption for leaching is small, the K+ concentration in the leaching mother liquor is high, the energy consumption for evaporative crystallization at the later stage is lowered, the K+ utilization rate is high, and the product grade is high.

Description

technical field [0001] The invention relates to a process for preparing potassium sulfate and potassium-magnesium fertilizer from potassium-containing minerals, in particular to a process for preparing potassium sulfate and potassium-magnesium fertilizer with insoluble polyhalite. Background technique [0002] Polyhalite (K 2 SO 4 · MgSO 4 2CaSO 4 2H 2 O), is a kind of insoluble potassium ore, which is widely distributed in sulfate-type potassium ore, and its theoretical potassium content (K 2 O) reaches 15.6%, which is an important potential potassium resource. The world's polyhalite resources are very rich, and the research on the development and utilization technology of polyhalite is of great significance for alleviating the situation of the world's potash resources, improving the status of the potash industry, and increasing the strategic resource reserves. [0003] Due to the stable structure of polyhalite and poor water solubility, it needs certain treatment to ...

AI Technical Summary

Problems solved by technology

[0003] Due to the stable structure of polyhalite and poor water solubility, it needs certain treatment to dissolve the potassium and magnesium in it, which contains K + and Mg 2+ The solution is mostly used to prepare potassium sulfate or potassium-magnesium fertilizer. Some literatures have reported the method of using polyhalite to prepare potassium sulfate or potassium-magnesium fertilizer. However, preparing potassium sulfate with polyhalite is not only a complicated process, but also K + Utilization rate is low, and potassium magnesium fertilizer is prepared with polyhalite, although K + High utilization rate, but poor economic benefits