Method for reduction and detoxification of stainless steel acid pickling sludge

Abstract

The invention provides a method for reduction and detoxification of stainless steel acid pickling sludge, and belongs to the field of metallurgy and environmental protection. The method comprises the following steps that 1, after the stainless steel acid pickling sludge is produced, water can be reduced to 50% after stockpiling and natural drying; 2, the sludge, coke and an adhesive are added into a vertical curing furnace after batching, mixing and pelleting, meanwhile, a proper amount of air is blown in for high-temperature reducing roasting curing, reduction is achieved through the water reduced by 50%, Cr6+ is reduced, decomposed and converted into Cr3+, thorough detoxification is carried out, and a nichrome basic material is obtained and conveyed to a smelting plant for producing nichrome; and 3, smoke generated in the roasting process is subjected to bag dedusting and then is discharged after wet desulphurization and defluorination are carried out to meet the standard, and a small quantity of desulphurization and defluorination byproducts are used as common solid waste to be used as backfill materials of building roadbeds and the like or abandoned. Reduction, detoxification and efficient resource recycling of the stainless steel acid pickling sludge are achieved, and remarkable economic, environmental and social benefits are achieved.

Description

technical field [0001] The invention belongs to the fields of metallurgy and environmental protection, and in particular relates to a method for reducing and detoxifying stainless steel pickling sludge. Background technique [0002] In the production process of stainless steel, in order to improve the corrosion resistance and surface quality of the product, it needs to undergo pickling surface treatment such as sulfuric acid and hydrofluoric acid before cold rolling, resulting in a large amount of pickling waste liquid containing toxic and harmful substances such as Cr, Ni, F, etc. . At present, most stainless steel plants still use lime, carbide slag or calcium hydroxide to neutralize them. Although this method makes the effluent meet the standard, it produces a large amount of toxic and harmful stainless steel pickling sludge, which is a dangerous solid waste and causes secondary pollution. [0003] In recent years, the output of stainless steel in my country has increas...

AI Technical Summary

Problems solved by technology

In fact, this patent still dries the sludge and directly makes cement raw materials, at the cost of consuming H 2 o 2 and KMnO 4 and other resources, while other methods of utilization in the form of powder are difficult to implement because of the impact on ironmaking production, so it is still a low value-added utilization method

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