Process for purification of hydrochloric acid pickling solution and treatment of sludge

Abstract

The invention belongs to the technical field of pickling production of pickling units, and particularly provides a process for purification of a hydrochloric acid pickling solution and treatment of sludge. According to the process, a high-temperature pickling solution flowing out of an acid solution circulating tank is directly flocculated, and heat exchangers for cooling and heating of the pickling solution are not arranged, so a process flow is shortened, the consumption of steam and cooling water is saved, equipment investment is reduced, and a site area is reduced; a static-pressure sludge discharge mode is adopted at the bottom of a settling tank, and a sludge pump for conveying is not needed, so power cost is saved, disturbance of suction of the pump to the sludge at the bottom of the settling tank is avoided, sludge discharge is stable and good effect is obtained; silicon-containing sludge is neutralized in a workshop, so subsequent waste treatment and transportation are facilitated; and the sludge is further reduced through a vacuum decompression drying machine, the water content of the sludge can be controlled according to actual needs, pollutants are subjected to reduction and harmless treatment in the workshop, and pollution to the environment is reduced.

Description

technical field [0001] The invention belongs to the technical field of pickling production and treatment of pickling units, and in particular relates to a hydrochloric acid pickling solution purification and sludge treatment process. Background technique [0002] In the pickling production line of silicon steel or high-strength steel, hydrochloric acid is usually used as the pickling solution to remove the oxide layer on the surface of the steel strip, and the insoluble silicon-containing particles that are pickled from the surface of the steel strip will be suspended in the pickling solution. If these silicon-containing particles cannot be separated from the acid circulation system in time, these silicon-containing particles will inevitably accumulate in the pipeline of the circulation system, thereby blocking graphite heat exchangers, pipes, nozzles and other pipelines or equipment, As a result, the pickling unit cannot continue to produce, and has to be shut down for a lo...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the problem that a large amount of sludge and concentrated brine will be produced in the treatment of pickling liquid by the existing flocculation-sedimentation method and the problem of large equipment investment

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