A high-recovery production process for extracting potassium chloride from carnallite ore

Abstract

A high-recovery production process for extracting potassium chloride from carnallite ore: the fresh water required for carnallite decomposition is added to the back end of the process for washing crude potassium and tailings to obtain KCl with high content and MgCl 2 Unsaturated low-magnesium and high-potassium mother liquor, the low-magnesium and high-potassium mother liquor produced at the back end of the process is returned to the front end of the process to decompose carnallite through the dense pool. Utilizing the present invention can effectively improve the control precision of the amount of decomposed fresh water, which not only ensures the quality of potassium chloride products, but also greatly improves the comprehensive recovery rate of potassium chloride in the processing technology, and overcomes the difficulty in controlling the amount of decomposed fresh water and the low comprehensive recovery rate of the traditional process and other shortcomings, significantly improving the utilization rate of potassium resources and the production efficiency of potash fertilizer enterprises. The invention has the advantages of simple technological process, little environmental pollution, low production cost, good quality of obtained potassium chloride product and high recovery rate.

Description

technical field [0001] The invention relates to a production process of potassium chloride, in particular to a high-recovery production process for extracting potassium chloride from carnallite ore. Background technique [0002] The agricultural potassium chloride fertilizer in our country is generally processed by decomposition-positive flotation or decomposition crystallization-positive flotation process. However, these two processes often choose to add fresh water at the front end of the process (i.e. decomposition or crystallization process) to decompose carnallite and then carry out flotation, as disclosed in CN 107739037A, CN 102963912A, and CN 204079502U. The disadvantage of adding fresh water to decompose carnallite at the front end of the process is that the amount of decomposed fresh water is not easy to control. 2 Both the concentration and viscosity increase, the decomposition rate slows down, and the impurity entrainment rate of the flotation foam increases, re...

AI Technical Summary

Problems solved by technology

The disadvantage of adding fresh water to decompose carnallite at the front end of the process is that the amount of decomposed fresh water is not easy to control. 2 Both the concentration and viscosity increase, the decomposition rate slows down, and the impurity entrainment rate of the flotation foam increases, resulting in a significant decrease in the grade of crude potassium (the grade of crude potassium in Chaerhan Salt Lake in Qinghai is generally between 58% and 70%). It is necessary to increase the amount of fresh water for washing during pulping and repulping, otherwise the quality of the final product will not meet the standard, but after increasing the amount of fresh water for washing, the washing recovery rate and output will decrease significantly; Decomposition liquid MgCl 2 Concentration, viscosity, flotation foam impurity entrainment rate will decrease, flotation concentrate grade will increase, but the recovery rate of decomposition process and the whole system will decrease significantly

[0003] In order to ensure the quality of products in production, my country's potash fertilizer production enterprises generally add a large amount of excessive fresh water when decomposing or decomposing crystallization and repulping washing. The consumption rate is getting faster and faster, the production load is getting bigger and bigger, and the equipment failure rate is getting higher and higher, while the resource utilization rate and enterprise production efficiency are constantly declining

At present, when my country uses Yantian carnallite ore to process and extract potassium chloride products, including all processes of decomposition, crystallization, flotation and washing, the comprehensive recovery rate of the processing technology is only 60%. Loss of recovery rate, the recovery rate of potassium chloride in the whole process from the original halogen to the final product of potassium chloride is only about 40%, and the resource utilization rate is very low

[0004] The technical solutions disclosed in CN 107572552A and CN 108862328 are to adopt screening-reverse flotation-cold crystallization mixed process and reverse flotation-cold crystallization process to produce potassium chloride products respectively, although their KCl recovery rate is relatively high, but due to The price of reverse flotation collector is relatively high, which makes the comprehensive chemical cost of reverse flotation-cold crystallization process several times higher than that of decomposition or decomposition crystallization-positive flotation process. Therefore, the market application of this process limited