Improving the technology for obtaining high-grade concentrate at an iron ore plant in Kazakhstan

This article presents the results of a comprehensive set of process studies conducted both in laboratory and industrial settings aimed at improving the grade of magnetite concentrate produced by an iron ore processing plant in Kazakhstan. In order to align with the current global standards for iron ore products, the plant must improve the iron content (Fetot) in its concentrate from 66 % by weight to at least 67–68 % by weight. The technology upgrade proposed is based on a stepwise process that involves replacing conventional hydrocyclone classification with fine screening and substituting wet magnetic separation with magnetic-gravity separation at the final stage. The integration of fine vibration screening and magnetic-gravity separation ensures high separation efficiency, enabling a phased extraction of high-grade concentrate, recognized as a leading method in mineral raw material processing. The implementation of this updated technology at a section of the plant resulted in the production of magnetite concentrate with a Fetot content of 68 % with a recovery rate of 88.8 %. These results significantly exceed those achieved using the previous technology, which produced concentrate with a Fetot content of 65.9 % and a recovery rate of 86.7 %. Adopting this new technology reduces the circulating loads within each process, increases the energy efficiency of the grinding stage, and eliminates the need for PBM series separators, which have low operational efficiency in the concentrate cleaning process. From a financial perspective, the technology proposed increases the market value of the concentrate by an average of 10–12 %, enhancing the competitiveness of the product.