Justification of design and parameters of mixed mining system for gently dipping low-grade complex ore body

The results of the research on the justification of a safe and effective technology for mining gently dipping body of low-grade complex ore are presented. The main limitations and causes of low efficiency of the traditional mining system by block caving with layered blasting in the conditions of gently dipping ore bodies and stable overlying rocks which require additional caving are revealed. The application conditions and the main design principles are determined for the mixed mining system based on the use of advantages of room-and-pillar mining at its minimized disadvantages. The rational variants of the mixed mining system are found and designed for a medium-thickness and gently dipping ore body. The variants differ in shape (rectangular or trapezoidal) and parameters (width) of rooms and pillars, in arrangement of rooms and pillars (across or along the strike of the ore body), and in mining technology and method of bottom preparation in the rooms (trench or flat). As a result of the geomechanical modeling as well as the technical and economic assessments, it is found that the optimal variant for the discussed conditions is the mixed mining system with rectangular flat-bottom rooms, caving of overlying rocks and extraction of ore reserves from the rib and level pillars arranged along the strike of the ore body by block caving. The efficiency of this variant is ensured by increased extractability of ore reserves up to 1.5-2 times, which allows enhanced value of produced and processed ore by 13.4 % and reduced operating costs per 1 ton of proven reserves by 9.1%.

Sokolov I. V., Antipin Yu. G., Nikitin I. V., Krinitsyn R. V. Justification of design and parameters of mixed mining system for gently dipping low-grade complex ore body. MIAB. Mining Inf. Anal. Bull. 2021;(5—1):88—104. [In Russ]. DOI: 10.25018/0236_1493_2021_51_0_88.

Sokolov I. V., Dr. Sci. (Eng.), full member of the Academy of mining sciences, director;
Antipin Yu. G., Cand. Sci. (Eng.), head of the laboratory of underground geotechnology, е-mail: geotech@igduran.ru;
Nikitin I. V., research worker of the laboratory of underground geotechnology;
Krinitsyn R. V., head of the laboratory of geo-dimamics and rock pressure, е-mail: krin@ igduran.ru;
¹ The Institute of Mining of the Ural branch of Russian Academy of Sciences (IM UB RAS), Ekaterinburg, Russia.

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