Regeneration method and system for hydrochloric acid waste liquid

Abstract

The invention relates to a regeneration method for hydrochloric acid waste liquid. According to the method, a spray roasting process is adopted, and at least part of the hydrochloric acid waste liquid entering a Venturi preconcentrator is preheated hydrochloric acid waste liquid. The invention further relates to a regeneration system for the hydrochloric acid waste liquid. The regeneration system for the hydrochloric acid waste liquid comprises a roasting furnace, the Venturi preconcentrator, an absorption tower and at least one stage of washing mechanism which are sequentially connected through flue gas pipelines. At least one of the flue gas pipelines is provided with a heat exchange mechanism. The hydrochloric acid waste liquid enters the heat exchange mechanisms to serve as a refrigerant for heat exchange with flue gas, and refrigerant outlets of the heat exchange mechanisms are all connected with the Venturi preconcentrator. By preheating the hydrochloric acid waste liquid, the heat needed for heating concentration of the hydrochloric acid waste liquid in the Venturi preconcentrator is reduced, and thus more hydrochloric acid waste liquid can be heated by the same quantity of roasting flue gas in the Venturi preconcentrator, the processing efficiency of the Venturi preconcentrator is effectively improved, and meanwhile the energy consumption of the roasting furnace can be reduced.

Description

technical field [0001] The invention relates to a hydrochloric acid waste liquid regeneration method and regeneration system. Background technique [0002] For the waste hydrochloric acid pickling produced by iron and steel or chemical enterprises, the spray roasting method is generally used to regenerate the waste hydrochloric acid. The problems with this method are: [0003] (1) The hydrochloric acid waste liquid enters the Venturi pre-concentrator for heating and concentration, and sprays it into the roaster for chemical reaction after reaching a certain concentration. This process requires a large amount of heat to be realized; this part of heat is mainly provided by the roaster. The system provides a large amount of fuel to realize, which does not meet the requirements of energy saving and consumption reduction. [0004] (2) The temperature of the mixed flue gas discharged from the roaster and Venturi pre-concentrator is still as high as 95-100°C. After conventional c...

AI Technical Summary

Problems solved by technology

[0003] (1) The hydrochloric acid waste liquid enters the Venturi pre-concentrator for heating and concentration, and sprays it into the roaster for chemical reaction after reaching a certain concentration. This process requires a large amount of heat to be realized; this part of heat is mainly provided by the roaster. Provided by the system, it takes a lot of fuel to realize it, which does not meet the requirements of energy saving and consumption reduction

[0004] (2) The temperature of the mixed flue gas discharged from the roaster and Venturi pre-concentrator is still as high as 95-100°C. After conventional cooling and dust removal treatments such as absorption tower and washing equipment, the temperature of the flue gas discharged from the chimney remains As high as 80 ~ 85 ℃, under normal ambient temperature conditions, the exhaust gas is generally white, misty water vapor mixture, the sensory effect is poor, especially in autumn and winter

If the above-mentioned hydrochloric acid waste liquid regeneration unit is close to the residential area, the "white smoke billowing" exhaust gas discharged from the chimney will often become the object of complaints from residents in the surrounding residential areas of the hydrochloric acid waste liquid regeneration unit, which will bring great harm to steel or chemical companies. pressure

Images