Belaruskali, Soligorsk, Belarus:

L. Yu. Levin, Head of Department, Doctor of Engineering Sciences

O. S. Parshakov, Junior Researcher

Mining Institute, Ural Branch, Russian Academy of Sciences, Perm, Russia:
I. I. Golovaty, Chief Executive Officer

JSC “Trest Shahtospecstroy”, Soligorsk, Belarus:
D. A. Diulin, Chief Executive Officer

The article presents an intelligent system introduced to control condition of frozen walls at the shafting site of Petrikovsky Mining and Processing Plant of Belaruskali. The basic methods to determine temperatures in rock mass under artificial freezing are described. It is shown that the use of the modern innovative technologies and calculation techniques greatly improves quality of freezing and, if required, allows adjustments and optimizations. It is found that for the conditions of shaft no. 1 under construction at Petrikovsky Mining and Processing Plant, on the transition to passive freezing, frozen wall thickness steadily grows. The objective of frozen wall formation optimization is to control freezing equipment of mining shafts under construction at minimized cost of material, financial and human resources, as well as at mining safety. The energy-efficient mode of operation of freezing plants in the shaft under construction is determined analytically so that the project parameters (integrity and thickness) of the frozen wall are preserved till the shaft construction completion with respect to the decrease in the rock mass refrigeration capacity. A nonstationary Stefan problem is solved for the case of a set of freezing wells. It is emphasized that in designs of mining shaft construction with artificial freezing, the choice of cooling plants should be based on the wide-range adjustability of temperature of a cooling agent, which is directly governed by engineering specification of refrigerating units. The authors show that deployment of intellectual monitoring provides both safety of mining and improvement of engineering-and-economic performance of shaft construction.
The study was supported by the Russian Science Foundation, Project No. 17-11-01204.

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