Method for mining sylvite in underground carnallite ore

Abstract

The invention discloses a method for mining sylvite in underground carnallite ore, which comprises the following steps of: (1) building wells, namely, taking three-pipe structures as well bodies, wherein the three pipes include a technical sleeve pipe, a production sleeve pipe and a central pipe; (2) building a groove on a single well, namely, filling normal-temperature water in annular space of the central pipe and the production sleeve pipe, and discharging dissolved brine from the central pipe; (3) mining by non selective dissolution at normal temperature; (4) selectively mining by hot melting at high temperature, namely, communicating two wells or well groups, pulling out the central pipe, filling a sodium chloride and magnesium chloride containing filler of 75 to 90 degrees centigrade into a well, and discharging the brine for processing from the other well in the well group; and (5) refilling a mother solution into the wells. The method for mining the sylvite in the underground carnallite ore provided by the invention realizes selective mining of potassium chloride; and, the method saves energy resources and reduces production cost; moreover, the refilling process of the mother solution realizes zero discharge of the mother solution and facilitates environment protection.

Description

technical field [0001] The invention relates to a method for mining underground carnallite ore, in particular to a method for mining potassium salt in underground carnallite ore. Background technique [0002] my country is a country with a serious shortage of potassium resources. Potassium deficiency is common in cultivated land, and the contradiction between supply and demand of potassium fertilizer is very prominent. The satisfaction rate of domestic potash fertilizers only accounts for about 30%, and the annual import of potash fertilizers reaches 4000kt (K 2 O) above. With the development and structural adjustment of agriculture, China's potash fertilizer consumption will also have a relatively high annual growth rate. It is estimated that by 2020, China's potash fertilizer consumption will reach 10,000kt (K 2 O), the market space is vast. The vast majority of potash fertilizers in my country are produced in salt lakes. [0003] In recent years, there have been appli...

AI Technical Summary

Problems solved by technology

However, the concentration of brine produced by this method is not high

CN 1987041A discloses a method and device for selective thermal solution mining of potash ore by drilling four-pipe liquid cushion, but the method uses anti-emulsifier to form a liquid cushion, and the investment and production costs of anti-emulsifier are relatively high

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