Prediction of thermostabilization of wet slide rocks at the bottom of open pit mine in the permafrost zone using seasonal coolers

The study focuses on safety of underground kimberlite mining under open pit mines in the permafrost zone. The article describes research findings on stability and waterproofing of wet slide rocks on the bottom of an open pit after freezing using seasonal coolers. For the method efficiency evaluation and its implementation optimization, the 3D mathematical model of heat processes in manmade water body and in wet slide rocks on the pit bottom, as well as in the crown pillar under the pit is constructed with regard to the phase transition of moisture and to the influence of seasonal coolers. The mathematical model uses the finite element method, is implemented as Microsoft Windows application and enables long-term prediction of temperature field in slide rocks depending on various process variables of freezing by seasonal coolers. The numerical experiments are carried out as a case-study of Internatsionalny open pit kimberlite mine. The research findings on optimization of seasonal cooling toward enhanced freezing of slide rocks on the pit bottom are presented. The research proves efficiency of seasonal coolers in stimulation of freezing stabilization of wet and salt slide rocks on the bottom of the mined-out pit in the permafrost zone. In the course of time, steady-state negative temperature sets in the frozen rock mass, which allows shutdown of seasonal coolers. Slide rocks on the pit bottom keep frozen in the ensuing years and gradually come into natural temperature regime.

Romanova E. K. Prediction of thermostabilization of wet slide rocks at the bottom of open pit mine in the permafrost zone using seasonal coolers. MIAB. Mining Inf. Anal. Bull. 2021;(12—1):183—194. [In Russ]. DOI: 10.25018/0236_1493_2021_121_0_183.

Romanova E. K., Cand. Sci. (Eng.), Researcher, Chersky Mining Institute of the North, Siberian Branch, Russian Academy of Sciences, Yakutsk, Russia.

Romanova E. K., e-mail: helconst@mail.ru

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