Innovative solutions to improve the efficiency of coarse crushing in iron ore mining and processing plants

The need to increase the capacity of crushing and processing facilities of mining and concentrating operations plants that develop deposits of hard and abrasive ores, most of which are concentrated within the Kursk Magnetic Anomaly, required solving a number of technological challenges in the crushing process. For this purpose, requirements were formulated as a result of analyzing characteristics of coarse, medium and fine ore crushing, based on which Uralmashplant JSC executed research and development activities aimed at upgrading the KKD-1500/180-2P crushers. As the result of this upgrade, the crushing chamber profile for hard and highly abrasive ores has been optimized to achieve an 8-10% increase in coarse crushing throughput capacity and a 29% increase in the reduction ratio. Due to the increased vertical adjustment of the mantle, more stable gradation of the KKD crushing product was ensured, while the time between relining was increased by 92% with a 48-50% reduction of repair and maintenance costs for relining of the KKD crushers. In addition, a 25% reduction in the number of the crusher blockages was noted, which further ensures the stability of the ore feed to the subsequent crushing and grinding stages. Field tests of the upgraded KKD-1500/180-2P crushers proved the following technical and economic effects in the medium and fine crushing stages: an increase in the volume of undersized material in scalping, a reduction in the product size in secondary crushing as a result of decreasing the crusher's closed side settings (CSS), a reduced cycle time of tertiary (fine) crushing with a decreased circulating load in secondary and tertiary crushing stages, which helped to increase the medium and fine crushing throughput capacity by 3-5%. The savings in maintenance and operating costs for the coarse, medium and fine crushers are estimated to be around 20%.