Steel hydrochloric acid pickling wastewater treatment device

Abstract

The invention relates to a steel hydrochloric acid pickling wastewater treatment device which comprises a negative pressure evaporator, a steam condenser, a gas absorption tank, an aeration oxidation precipitation tank, a regulating tank and a flow-deflection aeration filter tank, wherein the negative pressure evaporator comprises a negative pressure evaporator water inlet pipe, a negative pressure evaporator water outlet pipe, a heating and pressure regulation device and a gas outlet pipe; the steam condenser comprises a steam inlet, a hydrochloric acid receiving tank, a cooling liquid inlet, a cooling liquid outlet and a steam outlet; a hydrochloric acid gas absorbent is arranged in the gas absorption tank; the gas absorption tank is provided with an upper cover; the upper cover of the gas absorption tank is in a conical structure; the top end of the conical structure is provided with a gas collection pipe; the aeration oxidation precipitation tank comprises an aeration mixing region and a precipitation range; the bottom of the aeration mixing region is provided with an aeration tray; an aeration oxidation precipitation tank water distribution branch pipe is arranged above the aeration tray; the middle upper part of the flow-deflection aeration filter tank is cylindrical, and the lower part is a conical structure; and the flow-deflection aeration filter tank comprises a downstream region, an upstream region and a sludge region.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a treatment device for steel hydrochloric acid pickling wastewater. Background technique [0002] Pickling is a method of cleaning metal surfaces, and it is also a necessary process for steel production and processing. Its purpose is to remove oxides on the metal surface. During the pickling process, the acid cleaning agent contacts and reacts with the metal surface. With the decrease of the concentration of hydrogen ions and the increase of the concentration of metal ions in the acid solution, the pickling efficiency of the acid solution is also continuously reduced, and it becomes necessary to discharge of pickling waste. For ordinary steel, the pickling effect of hydrochloric acid is more significant than that of sulfuric acid, and the stripping effect of hydrochloric acid pickling makes the loss of base iron less, so hydrochloric acid has gradually become the ma...

AI Technical Summary

Problems solved by technology

The process includes neutralization, flocculation, sedimentation, filtration and other processes. The treatment effect is average, and a large amount of alkali and flocculant are needed. There are problems such as lengthy process, unstable effluent quality, large floor area, etc., and a large amount of sludge is dehydrated. Difficult, so it is gradually eliminated in the process of practical application

Large-scale enterprises generally adopt high-temperature roasting method, which has the advantage of high recovery rate of regenerated acid and iron salt, but the investment is huge, the equipment requirements are high, the operating conditions are strict, and the operation and maintenance costs are also high, which has an impact on the large-scale promotion of the process restricted by

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