Metals and hardening mixtures from beneficiation tailings of the Kursk Magnetic Anomaly ores

Abstract

The tailings storage facilities of mining and metallurgical complexes hold approximately 100 billion tons of solid waste, which can serve as raw material for extracting residual metals left after primary processing. The current practice of disposing these tailings into mined-out spaces leads to the loss of valuable components and effectively transforms the region into a natural reactor for metal leaching. This study aims to elaborate the concept of resource conservation specifically for the conditions of the Kursk Magnetic Anomaly (KMA). The paper presents a comprehensive overview involving analysis, systematization, experimentation, modeling, techno-economic calculations, and engineering forecasts. Data on the leaching rates of beneficiation tailings are also provided. The results demonstrate that maximum metal recovery is achieved through mechanochemical activation of the leaching process. Therefore, a waste-free processing flowsheet incorporating this mechanochemical activation is presented. It is recommended that a comprehensive flowsheet be used for the deep processing of technogenic raw materials to extract valuable components. Research has shown that milling tailings into a fine powder allows for the production of backfill mixtures with a strength of 6–10 MPa. After metal extraction, the beneficiation tailings can be used as a component of these mixtures and as binders. The study also confirmed that activation increases the strength of the mixtures. A nomogram was developed to determine the strength of artificial structures. After metal recovery, tailings are suitable for concrete production with reduced cement consumption. The study determined that mechanochemical activation of tailings in a disintegrator allows the mixture to meet required specifications two orders of magnitude faster than agitation leaching. The results of an economic efficiency calculation for processing tailings with mechanochemical activation are presented as well.