First Mining Drc-Zambia March -April 2020 digital edition First Mining Drc-Zambia March - April 2020 digital | Page 36

FEATURE TOMRA’s XRT sorting of lumpy chrome ore delivers high recovery rates and cuts costs T he rise in demand for chrome has been driven in great part by the China-dominated stainless steel industry, which represents more than 75% of chromium consumption. South Africa is a dominant global supplier of chrome ore and ferrochrome, and the biggest exporter to China – in 2017, it accounted for 73% of the country’s c h r o m e imports. African chrome mining operations have been facing the challenge of meeting this rising demand while dealing with electricity and price constraints. They have been expanding into larger-scale underground and open-cut operations. These higher-capacity, less selective mining processes produce greater amounts of marginal or lower grade material due to the dilution of the main ore body. South This translates into higher costs, as the traditional methods for separating this low-chromite content material, such as Dense Media Separation, cyclones and spirals, are power and water- intensive or require costly agents. TOMRA’s X-Ray Transmission (XRT) sensor-based ore sorting is an established technology in physical separation that has proved extremely effective in mining operations for a variety of minerals, including chrome. Its benefits are significant: less complexity in the 34 process, considerably lower costs, higher productivity and profitability – and the added advantage of a lower environmental impact. The X-Ray sensor accurately establishes the density of each particle in the feed, and high-speed pneumatic ejectors separate ore with high chromite content from bare or low-grade ore at throughputs between 60 and 200 tonnes per hour. The resulting output is a high-grade product that is ready to sell, with no need for additional comminution. It is a dry process that requires no water or reagents, and is frugal in its energy consumption, resulting in a fraction of the capital expenditure and running costs of traditional methods, as well as a smaller footprint. TOMRA’s XRT technology expectations in LG6 mine. exceeds Engineering and project management company P2E Consulting has first- hand experience of the advantages of TOMRA’s XRT technology in sorting chrome ore at Eastern Chrome mines www.fmdrc-Zambia.com