System and method for treating and recycling carnallite in coal chemical industry

Abstract

The invention discloses a system and a method for treating and recycling carnallite in the coal chemical industry. The system comprises a carnallite pretreatment unit, a double decomposition reaction unit, a sodium bicarbonate separation unit, an NH3 and CO2 recovery unit and an ammonium salt separation unit; the carnallite is treated by equipment such as a carnallite pretreatment unit, a double decomposition reaction unit, a sodium bicarbonate separation unit, an NH3 and CO2 recovery unit and an ammonium salt separation unit to obtain ammonium chloride, ammonium sulfate and sodium bicarbonate products. According to the method, the sodium sulfate / sodium chloride waste salt, NH3 and CO2 are used as raw materials, the final products obtained after reaction are ammonium chloride, ammonium sulfate, sodium bicarbonate and other bulk chemical products, the market demand is large, resource utilization of the waste salt is achieved, and economic benefits and environmental benefits are remarkable.

Description

technical field [0001] The invention relates to the technical field of coal chemical miscellaneous salt treatment, in particular to a system and method for coal chemical miscellaneous salt disposal and resource utilization. Background technique [0002] With the rapid development of my country's emerging coal chemical industry and the improvement of environmental protection requirements, coal chemical projects require zero discharge of high-salt wastewater, and a large amount of saline wastewater will be produced under the existing zero-discharge process conditions. According to the "Environmental Access Conditions for Modern Coal Chemical Construction Projects" in the coal chemical industry, "salt mud produced by wastewater treatment that cannot be recycled as a resource is temporarily managed as hazardous waste." According to the "Hazardous Waste Landfill Pollution Control Standard", waste with a total amount of water-soluble salt greater than 10% must be rigidly landfille...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a system and method for coal chemical miscellaneous salt disposal and resource utilization, using coal chemical miscellaneous salt mainly sodium sulfate and sodium chloride to produce sodium bicarbonate and mixed ammonium salt, turning waste into treasure , which not only solves the problem of difficult disposal of miscellaneous salt at the present stage, but also realizes the resource utilization of miscellaneous salt

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