Acid-regeneration acid tail gas purification system by using spray roasting method and tail gas purification process

Abstract

The invention relates to an acid-regeneration acid tail gas purification system by using a spray roasting method and a tail gas purification process. A tail gas purification system adopting an alkaline tower comprises the alkali wash tower, an alkali preparation tank and an alkali storage tank, wherein the alkali wash tower, the alkali preparation tank and the alkali storage tank are communicated through pipelines; an alkali wash tower circulating pump is arranged on a self-circulation pipeline of the alkali wash tower; an alkali discharge pump I is arranged on a pipeline between the alkali storage tank and the alkali preparation tank, and an alkali liquor spray pump is arranged on a pipeline between the alkali preparation tank and the alkali wash tower. A tail gas purification system adopting an alkali wash circulating tank comprises the alkali wash circulating tank and a concentrated alkali tank, wherein the alkali wash circulating tank and the concentrated alkali tank are communicated with each other through a pipeline; an alkali wash tank circulating pump is arranged on a self-circulation pipeline of the alkali wash circulating tank, and an alkali discharge pump II is arranged on a pipeline between the alkali wash circulating tank and the concentrated alkali tank. Compared with the prior art, the acid-regeneration acid tail gas purification system has the benefits that (1) the acid tail gas is purified in an alkali wash manner through the wash tower, a pH valve approaches 7, and the treated acid tail gas achieves the emission standard of the nation; (2) the system is stable in operation, small in fluctuation and low in alkali consumption; and (3) the system is small in investment and fast in effect and has popularization and utilization values.

Description

technical field [0001] The invention relates to a tail gas purification technology after a washing tower in a regeneration hydrochloric acid process in the metallurgical industry, in particular to a spray roasting acid regeneration acid tail gas purification system and a tail gas purification process. Background technique [0002] Pickling is carried out before steel rolling in metallurgical factories. The waste acid produced in the pickling line is usually regenerated by spray roasting method, and 18-20% of the regenerated acid can be produced and returned to the pickling line for use, and high-quality iron oxide powder can be obtained at the same time. The tail gas produced by this process is washed in three stages in the washing tower, but after washing, it still contains about 50-80mg / m3 of acid 3 , still can not reach the maximum allowable emission concentration of 30 mg / m controlled by my country's current "Steel Rolling Industry Air Pollutant Emission Standard" (GB286...

AI Technical Summary

Problems solved by technology

The tail gas produced by this process is washed in three stages in the washing tower, but after washing, it still contains about 50-80mg / m3 of acid 3 , can not reach the maximum allowable emission concentration of 30 mg / m controlled by my country's current "Steel Rolling Industry Emission Standard of Air Pollutants" (GB28665-2012) 3 index

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