Method for recovering stainless steel acid pickling waste sulfuric acid solution

Abstract

The invention discloses a method for recovering a stainless steel acid pickling waste sulfuric acid solution. The method includes steps: pretreating the waste sulfuric acid, and finely removing fine impurities by using a 1-micron-size filter to obtain a pretreated solution; (2) separating and recovering sulfuric acid and a metal salt solution from the pretreated solution by utilizing a periodic reverse pulsed power supply diffusion dialysis-electrodialyzer to obtain recovered acid and residual liquid, respectively; (3) returning the recovered acid to a production line of a workshop for reuse,and after adding a proper amount of sodium phosphate and an alkali agent into the residual liquid to remove heavy metal impurities such as chromium, oxidizing the residual liquid to prepare polyferricsulfate which is a water treatment agent. The periodic reverse pulsed power supply diffusion dialysis-electrodialyzer is utilized for efficient separation of acid from metal ions. The method is low in cost, resources can be fully recovered, and economic and environment protection benefits are good.

Description

technical field

[0001] The invention relates to the technical field of waste liquid recovery and utilization, in particular to a method for recovery and utilization of stainless steel pickling waste sulfuric acid solution. Background technique

[0002] During the production and processing of steel products, in order to make the surface of steel products smooth and free of rust, steel components need to use mineral acid to clean off the metal oxide layer on the surface. The acid solution after cleaning contains a lot of ferrous, chromium, nickel , manganese and other heavy metals to become waste acid, the state has included such waste sulfuric acid in the "National List of Hazardous Wastes". As a big country producing and processing stainless steel, in recent years, China's iron and steel enterprises produce nearly 10 million tons of pickling waste sulfuric acid every year. How to economically, efficiently and cleanly dispose of stainless steel pickling waste sulfuric acid i...

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