Editors: | F. Kongoli, J. De Castro, M, Gomez-Marroquin, Y. Gordon, M. Naimanbayev, V. Tsepelev, S. Prakash |
Publisher: | Flogen Star OUTREACH |
Publication Year: | 2022 |
Pages: | 148 pages |
ISBN: | 978-1-989820-36-0(CD) |
ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
Over 140 million tons of copper slag have been accumulated in the Russian Federation and this amount continues to increase. The storage of the copper slag not only requires a large area, but also causes environmental issues. The environmental taxes and landfill maintaining are costly, making it necessary to process the production wastes as completely as possible. At the same time, these slags contain valuable elements, in particular, iron, copper, zinc, selenium, arsenic and some others, which recovery can make the slag utilization profitable. The highest value is represented by iron which content exceeds 40%; it is almost at the level of some iron ores used in the ferrous metallurgy. However, the use of this iron-containing material in the conventional processes of ferrous metallurgy is complicated due to the high content of copper (up to 0.6%) . In addition, the extraction of iron by conventional methods cannot solve the issues with recycling the newly formed slag. Other existing methods of processing of copper-smelting slags are aimed at extraction of certain components, but they cannot solve the issue of their disposal in general.
The purpose of this work was to develop economically feasible methods for the complete utilization of copper-smelting slags and obtain the demanded products.
The object of the study was the dumped slag produced during copper smelting. The slag contains metal particles consisting of copper, iron, antimony and tin. The oxide phase is represented by the iron spinel particles and complex silicates containing iron, zinc and other elements. Spinel contains a relatively high amount of sulfur and the silicate phase contains impurities of non-ferrous metals. According to the XRD analysis, the main iron-containing phases of the sludge are fayalite 2FeO∙SiO2, magnetite Fe3O4, and pyroxene СaFeSiO4.
In this paper, the processing of copper-smelting slags was studied by using solid-phase reduction of iron with carbon from steam coal. At the reduction stage, zinc was extracted into gas phase and during smelting of the reduced semi-finished product the copper-containing cast iron with a high sulfur content and oxide melt were obtained. Afterwards, the grinding media were produced from the obtained cast iron which showed high performance properties, and on the basis of the slag residue proppants were produced that are in demand in the oil and gas industry.