Moscow State Mining University (Moscow, Russia):

Goncharov S. A., Professor, Doctor of Engineering Sciences, phone: +7 (499) 236-71-12

Mechanical crushing and grinding of ore mass, which was broken in open pit by drill and blast method, are the most power-consuming stages of technological process of extraction and concentration of ferruginous quartzites of Kursk Magnetic Anomaly. Multi-year researches established, that, considering the total power intensity of manufacturing of final product (iron ore concentrate), the power intensity of three-stage mechanical crushing (coarse, medium and fine) with following grinding is 60-65%. Considering the cost price of iron ore concentrate, the same power intensity is 50-55%. At the same time, the power intensity of explosive rupture (crushing) of ferruginous quartzites in open pit is 0.5-0.7 kWh for the tone of extracted ore. Power intensity of three-stage crushing is for about 3 kWh per t. Power intensity of grinding is 28 kWh per t. In such a way, the «factory» power intensity of crushing and grinding of ore is about 50 times higher, than the «open pit» power intensity. Due to intensification of drilling and blasting crushing of quartzites in open pit, the power intensity of mechanical crushing and grinding of extracted ore mass was decreased by increasing of explosives consumption rate. The fundamental changes of price parameters for regular industrial explosives, electric power and other material resources have been made for the last 20 years. According to this, the unreasonableness (unprofitability) of decreasing of the foregoing power intensity is explained by the example of open-cast mining and processing of ferruginous quartzites in the region of Kursk Magnetic Anomaly. This article is published in order of discussion.

1. Goncharov S. A. Fiziko-tekhnicheskie osnovy resursosberezheniya pri razrushenii gornykh porod (Physical and technical basis of resource economy during the destruction of rocks). Moscow : Publishing House of Moscow State Mining University, 2007, 211 p.