Device and method for extracting refined salt from waste liquid generated during wet ISS-J desulfurization

Abstract

The invention discloses a device and a method for extracting refined salt from waste liquid generated during wet ISS-J desulfurization. The device comprises a coarse salt drying assembly, a sodium thiocyanate separating and refining assembly, a sodium thiosulfate separating and refining assembly, a sodium sulfate separating and refining assembly and a solvent recycling assembly. The coarse salt drying assembly comprises a desulfurization waste liquid tank, a heat exchanger, an evaporation kettle, a crystallization kettle and a centrifugal machine; the sodium thiocyanate separating and refining assembly comprises a dissolving kettle, a filter-press kettle, an evaporation kettle, a crystallization kettle, a centrifugal machine, a drying machine and a packaging machine; the sodium thiosulfate separating and refining assembly comprises a dissolving kettle, a condensate tank, a filter-press kettle, a crystallization kettle, a centrifugal machine and a packaging machine; the sodium sulfate separating and refining assembly comprises a dissolving kettle, a concentrate sulfuric acid elevated tank, an evaporation kettle, a centrifugal machine, a drying machine and a packaging machine. The device and the method have the advantages that the waste liquid which can originally pollute environments and is generated by desulfurization systems can be thoroughly treated by the aid of the device and the method, industrial-grade products can be produced from the waste liquid, accordingly, wastewater emission can be truly prevented, and waste can be truly turned into wealth.

Description

technical field [0001] The invention belongs to the technical field of coal chemical industry, in particular to a device and method for extracting refined salt from waste liquid produced by wet ISS-J desulfurization. Background technique [0002] Under the increasingly stringent exhaust gas emission standards, the discharge of desulfurization waste liquid will become larger and larger, and the burden on environmental pollution and environmental governance will also become heavier. How to effectively solve the problem of desulfurization waste liquid discharge has become an important issue in the chemical industry. major issues. [0003] In wet ISS-J desulfurization, while hydrogen sulfide and hydrogen cyanide in coke oven gas are removed, side reactions inevitably occur, and inorganic substances such as sodium thiocyanate, sodium thiosulfate and sodium sulfate will be generated. Salt; when the inorganic salts accumulate to a certain level (generally the total content is grea...

AI Technical Summary

Problems solved by technology

However, there are not many companies currently using salt extraction equipment, and the domestic desulfurization waste liquid salt extraction system has almost no advanced treatment, only extracting mixed salt or sodium thiocyanate, sodium thiosulfate, and the remaining wastewater still needs to be discharged, so will cause some environmental pollution

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