Method and special device for treating lithium hexafluorophosphate synthetic tail gas with simple process flow

Abstract

The invention discloses a method and a special device for treating lithium hexafluorophosphate synthetic tail gas with a simple process flow. The tail gas is pressurized by a booster fan and then sentto a condenser, a condensate is recovered to an anhydrous hydrogen fluoride receiving tank, the mixed gas out of the condenser sequentially passes through a closed first-stage stirring reactor, a horizontal spiral conveying reactor and a second-stage stirring reactor in a material stirring diversion direction, trace HF in the mixed gas reacts with LiCl powder pre-added in a stirring reaction combination device, and the LiCl powder in the second-stage stirring reactor is returned to the first-stage stirring reactor through a material balance pipe; the tail gas out of the second-stage stirringreactor is collected by a dust collector to take away a small amount of powder and then enters a water washing tower to prepare hydrochloric acid, and the gas out of the water washing tower is discharged after alkali washing by an alkali washing tower. The method and the special device provided by the invention effectively remove HF in the mixed tail gas, improve the quality of a by-product namelyhydrochloric acid and broaden the application field.

Description

[0001] This application is a divisional application with application number: 201610000694.8, application date: 2016.1.4, and name "method and special device for treating tail gas of lithium hexafluorophosphate synthesis". technical field [0002] The invention relates to a method and a special device for treating tail gas of lithium hexafluorophosphate synthesis. Background technique [0003] Lithium hexafluorophosphate, as the key material of lithium-ion secondary batteries, is a typical high-tech, high-risk production environment, and high-difficulty production "three high" technology product. At present, the mainstream synthesis process is anhydrous hydrogen fluoride solvent method, and the tail gas produced by it contains HCl and A mixture of HF, of which HF accounts for about 10-15%, the commonly used treatment method is to directly transport it to the tail gas scrubber for washing and absorption, and make a mixed acid containing HCl and HF (the content of HF is more tha...

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Problems solved by technology

[0003] Lithium hexafluorophosphate, as the key material of lithium-ion secondary batteries, is a typical high-tech, high-risk production environment, and high-difficulty production "three high" technology product. At present, the mainstream synthesis process is anhydrous hydrogen fluoride solvent method, and the tail gas produced by it contains HCl and The mixture of HF, of which HF accounts for about 10-15%, the commonly used treatment method is to directly transport it to the tail gas scrubber for washing and absorption, and make a mixed acid containing HCl and HF (the content of HF is more than 10%) ), this treatment method cannot realize the effective separation of HCl and HF, thus limiting the scope of application of its by-product hydrochloric acid

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