Scientists from South Ural State University have found a profitable solution for recycling copper smelting waste. The remaining slag will be used to produce grinding cast iron balls, which are used to crush ore, coal and other industrial raw materials.
Huge black slag dumps are a problem in all metallurgical cities. Copper smelting waste is stored in millions of tons and is practically not recycled. There is the Karabash Plant in the Chelyabinsk Region, which is surrounded by mountains of slag. SUSU metallurgy scientists are confident that the remaining raw materials can be beneficial. Research has been successfully conducted for more than seven years now.
"At first we found out that iron, which is important for industry, can be extracted from waste, but along with it comes a hazardous impurity – copper," says Pavel Gamov, Head of the SUSU Department of Pyrometallurgical and Foundry Technologies. "We have found an area of production that will not be harmed by copper in iron. It turned out to be the creation of cast iron grinding media."
Cast iron balls used for grinding raw materials are produced all over the world using expensive materials. Chelyabinsk scientists have found a way to make them from slag. To do this, it is necessary first to separate the iron from other substances contained in the waste. Next comes the high temperature. The reducing agent, carbon, takes oxygen from the iron. Metal remains in the furnace, which can immediately be sent for the production of cast iron balls. However, after all procedures, a residue remains.
"It was not very correct to throw away inevitable waste: this does not completely solve the disposal problem," says Pavel Gamov. "It is necessary to develop a technology for obtaining a material from the residue that can be used in industry. Several options are being considered. This year we will select the most promising ones in terms of economics."
The project is being implemented within the frameworks of a grant from the Governor of the Chelyabinsk Region. By the end of 2025, scientists must provide a technology ready for implementation in production. The research is also supported by industrial partner OOO Inzhenernyi tsentr AS Teplostroy engineering centre, a company that creates metal products.