ESEARCH INTO THE COMMINUTION AND MAGNETIC BENEFICIATION CHARACTERISTICS OF UNDERGROUND-MINED HEMATITE QUARTZITES

Abstract

The processing of underground-mined iron ores is driven by a complex of geological, economic, and technological factors, making this issue critically important for the metallurgical industry. The beneficiation of underground-mined hematite quartzites is a complex, multi-stage process that requires a deep understanding of the ore's mineralogy and the selection of an optimal processing method and equipment. The article establishes that ores from the underground horizon are characterized by high strength, specific mineral composition, and fine mineral dissemination, which complicates their processing. Efficient and economically viable processing of such ores is impossible without preliminary fundamental research into their beneficiation properties, which is a relevant scientific and practical task. Furthermore, the global iron ore market demands high-quality concentrate with an iron content of no less than 64% and minimal content of harmful impurities such as sulfur, phosphorus, and silica. Without deep beneficiation, such ores cannot meet these standards or compete with higher-quality raw materials. The aim of this work is to establish the patterns of influence of the mineralogical and technological properties of underground-mined hematite quartzites on their comminution and subsequent beneficiation indicators. The conducted research allows for establishing the influence of hematite quartzite properties on the efficiency of comminution and subsequent separation. It was found that to achieve high separation indicators, the raw ore must be ground to a fineness of 65% passing 0.071 mm. At this size, the maximum percentage of ore grain liberation is achieved. The optimal ore grinding time was also determined experimentally. Subsequent beneficiation of the ground ore using high-intensity magnetic separation with a magnetic induction of 1.0 T allows for the effective separation of the mineral raw material. Despite the challenges associated with the energy intensity and fine dissemination of the ore, modern technologies, such as high-intensity magnetic separation and efficient comminution, enable the production of high-quality iron ore concentrates.