Application of Microwave Reduction Roasting for Dezincification of Converter Sludge

Converter dust is a by-product produced in the process of converter steelmaking, also known as converter dust, which is the dust produced in the process of converter steelmaking and collected by the dust removal system. The annual occurrence in China is 8 million t/a~9.5 million t/a.

Due to the high iron content in the dust sludge, at present, most of the converter dust sludge in China is used as raw material to prepare sintering materials, or it is recycled by the iron making and steelmaking methods to return to the steel production process. In recent years, a large number of scrap steel is used in converter steelmaking, and the zinc content in the converter dust sludge increases significantly, which leads to the inability of sintering to be recycled, and the converter dust sludge is forced to be stockpiled in large quantities to accumulate hundreds of millions of tons.

At present, there are rotary kiln, rotary hearth furnace, small blast furnace and other processes to deal with converter dust, but there are problems of environmental protection and high energy consumption.

Therefore, it is necessary to study and explore an efficient, energy-saving and environmentally friendly way to treat converter dust and sludge. The main purpose is to remove and recover zinc from converter sludge, and recycle iron, calcium, magnesium and other substances in converter sludge.

  Microwave processing Features of converter dust and mud technology

Utilizing the microwave selective heating characteristics, zinc oxide and carbon absorb the microwave and quickly rise to the reaction temperature. Zinc oxide is reduced to simple zinc, which becomes zinc vapor at high temperature. The carbon monoxide and carbon dioxide gas generated by the reaction are discharged out of the furnace. The zinc vapor enters the recovery system and is recycled. The iron in the dust is reduced to sponge iron and recycled in the converter to replace some scrap steel. The main purpose is to remove and recover zinc from converter sludge, and recycle iron, calcium, magnesium and other substances in converter sludge.