Method for producing potassium chloride by using direct flotation process of third solid sylvinite

Abstract

The invention relates to a method for producing potassium chloride by using the direct flotation process of third solid sylvinite. The method comprises the following steps: third solid sylvinite materials are crushed into particles with the diameter smaller than 10 millimeters, water is added into the crushed materials for decomposition to obtain slurry, and the weight ratio of the materials to water is 3:1 to 3.3:1; a flotation agent and a restraining agent are respectively added into the slurry, after the mixture is mixed evenly, a closed process including one-stage rough flotation, one-stage of scavenging flotation and two-stage fine flotation is carried out to perform flotation, and coarse potassium chloride, fine potassium chloride, tailing potassium chloride and decomposition motherliquid are respectively obtained after filtration; the decomposition mother liquid is evaporated and cooled for two times to fully change into magnesium chloride products; after coarse potassium chloride is washed, filtered and dried, a potassium chloride product the purity of which is more than 90% is obtained. The method can realize the decomposition process under the condition of large granularity, and effectively saves investment and running cost of grinding devices and raises the productivity of potassium chloride.

Description

technical field [0001] The invention relates to a method for producing potassium chloride, in particular to a method for producing potassium chloride by positive flotation of tertiary solid potassium salt ore. Background technique [0002] Potassium resources in the world are extremely rich, with a total of 250 billion tons of resources. Most of them are underground solid potassium salts, and a small part is potassium-containing brine. They are mainly distributed in North America, Europe, South America, the Middle East, Thailand, Laos and other countries in Asia. However, my country's potassium salt resources are scarce, especially the lack of large soluble solid potassium salt deposits. There are 40 proven soluble potassium salt deposits, including 6 large ones, distributed in Qinghai, Xinjiang, Tibet, Yunnan, Shandong, Gansu and other provinces. Among them, potassium-rich salt lakes are concentrated in the Qaidam Basin. The grade of these potassium-rich salt lakes is relat...

AI Technical Summary

Problems solved by technology

[0003] Although the state strongly supports my country's potash fertilizer production and doubled the new output, due to the lack of domestic potash resources, the total annual output of potash fertilizer in China is about 2.5 million tons, and the expansion space is very limited, which cannot meet the domestic market of 10 million. Tons of huge demand, currently about 80% of domestic agricultural potash depends on imports, agriculture is an important foundation for my country's national economic and social development, and the potash problem has become a bottleneck for the sustainable development of my country's agriculture