Prospects for application of mining systems with caving in stoping blocks with manmade bottoms at deep levels in Donskoe Chromite Mine

Abstract

The main and constitutive criteria in selecting methods and engineering plans for ore mining are the geological conditions of ore bodies and enclosing rocks, their structure, strength, deformability and stability. After these criteria are scrutinized, the geotechnical behavior of rock mass during mining is assessed, the parameters of engineering procedures with the assumed mining system are determined, as well as the issues of mining safety, reliability and efficiency are addressed. In this respect, it is required to reveal the nature of possible implications, reveal geotechnical patterns in the course of mining, select processes flow charts and their designs to avoid accidents and to ensure sound subsoil use. Thus, justification of engineering solutions for deep-level chromite-bearing ore mining in difficult geological conditions by Donskoe GOK is a relevant scientific problem. Stoping operations form underground enclosed areas which need to be dealt with at the preserved efficiency of the mining technology and economy. In this regard, the most promising geotechnology involves creation of artificial bottoms at the intersections of drift pillars in the zone of ore drawing and haulage. These manmade floors should be capable to sustain extremely high overburden pressure. From the accomplished calculations of strength of a vertical and square reinforced concrete column–support 7–9 m high, its factor of safety is assumed as 1.51. By the estimates, the proposed technology of stoping in extraction blocks with manmade bottoms can save up 1,347,2 million Kazakhstani tenge per block.The study was supported by the Ministry of Education and Science of Kazakhstan, Grant No. AR05131352. The authors appreciate participation of PhD A. T. Abakanov, Researcher at the Integrated Subsoil Management Laboratory of the Kunaev Institute of Mining, and Doctoral Student B. K. Bektrur from the Satbayev University in this study.