Production process of preparing high-quality potassium chloride from carnallite

Abstract

A production process of preparing high-quality potassium chloride from carnallite includes the steps of 1) crushing carnallite ore; 2) adding the crushed carnallite ore to a decomposition crystallizer filled with saturated mother liquid; 3) adding fresh water or a washing mother liquid obtained in subsequent processes into the decomposition crystallizer; 4) stirring the slurry so that a quasi-closed loop circulation flowing status that the ore slurry flows from bottom to top in a flow guide cylinder and flows from top to bottom in an annular chamber being adjacent to the external side of the flow guide cylinder is formed, and during the flowing process, the carnallite is decomposed and the potassium chloride is crystallized; and 5) sieving a bottom flow in the decomposition crystallizer, wherein the oversize substance serves as tailings while the undersize substance is filtered then; and 6) feeding a filtrate to the next process to perform evaporation crystallization to recycle the KCl, and washing, filtering and drying a filter cake. The production process is simple, is low in mechanical loss and energy consumption, is low in production cost, is free of any chemical reagents and is environment-friendly. The potassium chloride product has good quality and large granularity.

Description

Technical field [0001] The invention relates to a production process of potassium chloride, in particular to a production process of preparing high-quality potassium chloride by using carnallite ore. Background technique [0002] Potassium chloride is mainly obtained by processing and purifying potash or carnallite. Potash salt is generally a mixed salt of impurities such as potassium chloride, sodium chloride, a very small amount of magnesium chloride and silt. The crystal particles of potassium chloride and sodium chloride are both large, and the raw ore does not have crystal water, and the grade of potassium chloride is high , Good flotation performance, high-quality potassium chloride can be obtained through direct flotation. Carnallite is a compound salt containing potassium chloride, magnesium chloride and crystal water, the molecular formula is KCl·MgCl 2 ·6H 2 O, usually said carnallite is actually carnallite mine, which is a mixed salt of carnallite and sodium chloride ...

AI Technical Summary

Problems solved by technology

However, the underground primary carnallite ore (that is, the solid carnallite ore mined) has good crystallization degree, high strength, and large particle size. It needs to be crushed to -2mm in front of the device to make carnallite ore decompose and crystallize smoothly in the crystallizer. For example, the invention patent application with the publication number CN102963912A, but because carnallite is very easy to absorb water and deliquescence, it is necessary to crush carnallite to -2mm. Industrial production brings great difficulties. In addition, the patented decomposing crystallizer needs to circulate mother liquor during production and operation, which is inconvenient to operate

In short, whether it is hot melt recrystallization process, granulation process or cold decomposition crystallization process, there are some technical deficiencies