Stainless steel cold rolling sludge recovery processing method

Abstract

The invention provides a stainless steel cold rolling sludge recovery processing method. The method comprises the steps that stainless steel cold rolling sludge is dried so as to enable the water content of the stainless steel cold rolling sludge to be 20% to 30% by weight; the dried stainless steel cold rolling sludge is contained into an electric-arc furnace through a feeding basket, and it is required that at most 3 tons of stainless steel cold rolling sludge is added into every 115 tons of steelmaking raw materials; it is guaranteed that the stainless steel cold rolling sludge is contained at the bottom of the feeding basket; the steelmaking raw materials are added into the electric-arc furnace, a production mode is started, and stainless steel cold rolling sludge recovery processing is completed, wherein the electrification amount is 23000 Kwh to 25000 Kwh when oxygen blasting is started. The stainless steel cold rolling sludge recovery processing method has the good environmental protection effect, secondary pollution cannot be generated, the using cost is low, and disadvantages and negative effects cannot be brought to electric-arc furnace smelting.

Description

technical field [0001] The invention relates to a method for recycling and treating stainless steel cold-rolled pickling sludge, which belongs to the field of recycling industrial hazardous waste. Background technique [0002] During the production process of stainless steel, its surface is covered by a dense oxide film formed by Fe, Cr, Mn, etc. In order to enhance the surface finish and corrosion resistance of stainless steel, stainless steel must be pickled to remove the oxide film on the surface of the steel. Commonly used pickling solutions mainly include HF and HNO 3 The mixture, Na 2 SO 4 、H 2 SO 4 etc. The waste water produced by pickling of stainless steel is mainly acidic, with a pH value generally below 4, and must be discharged after neutralization. At the same time, wastewater contains a large amount of ferric ions, ferrous ions, fluoride and certain concentrations of heavy metals Cr and Ni. In industrial treatment, lime is generally used to neutralize and ...

AI Technical Summary

Problems solved by technology

Sanitary landfill is a treatment method with strong adaptability to sludge types. It is characterized by simple operation, but there are also prominent problems: first, sanitary landfill has high requirements on the soil mechanical properties of sludge, and the filling The seepage of the landfill is high-concentration sewage, which must be treated intensively. Harmful elements in the sludge may gradually seep out and pollute the groundwater. Therefore, sanitary landfill is only a temporary stabilization method for sludge treatment.

However, sludge incineration also has obvious disadvantages: high cost, waste gas and noise pollution caused by incineration, etc.

[0005] Before 2016, a steel factory also used sanitary landfill to dispose of stainless steel cold rolling sludge, but the landfill site occupied a large area, and the secondary pollution was also serious. As the national environmental protection requirements became more and more stringent, the sludge The cost of sanitary landfill has also risen by leaps and bounds, from 360RMB / ton to 2600RMB / ton, an increase of more than 600%

For example, the electric arc furnace is directly loaded into the cold-rolled sludge for recycling treatment, but due to the high moisture content of the sludge, an explosion occurred in the electric arc furnace in the second test; after that, the steel mill dried the cold-rolled sludge, It is used in an electric arc furnace, but due to uneven drying, sometimes a large amount of dust will be generated in the factory building, and sometimes small explosions will still occur in the furnace

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