VNII Galurgii, Perm, Russia:

D. N. Shkuratsky, CEO, Candidate of Engineering Sciences, vniig@uralkali.com
M. V. Skopinov, Project Director

Uralkali, Berezniki, Russia:

E. V. Smirnov, Chief Technical Officer

Mining Institute, Ural Branch, Russian Academy of Sciences, Perm, Russia:

A. A. Baryakh, Research Manager, Academician of the Russian Academy of Sciences

Potash mining obligatory includes protection of mines from fresh water inrushes. It is for the first time that the method for closure of a mine site potentially hazardous in terms of fresh water inrush is proposed and being implemented. The potentially hazardous site is isolated with the help of special partitions and is then filled with fairly pregnant brines. The density of fresh water is lower than the density of the brines, and fresh water is incapable to enter mined-out voids even in case of discontinuity of waterproof strata. Closure of a hazardous site includes construction of isolating partitions in grouped accessing openings in a hydroisolating solid block, and the mined-out space is then filled with brines. The brines are additionally saturated with NaCL and KCL in the course of closure. The integrated numerical modeling of permeation, flow and geomechanics allows assessment of the adverse effects because of salt dissolving and the related extra deformations in the waterproof strata. From the implemented calculations, a zone is localized in the down-dropped western area where mining operations can add to the manmade load applied to the waterproof strata and can invite danger of the waterproof strata fracture. For minimizing the risk of the waterproof strata discontinuity, it is recommended to fill the mined-out voids in this area with the pregnant brines. Implementation of these activities can help reduce dissolvability of salt rocks and, thereby, mitigate the manmade load on the waterproof strata.
The study within the Section Geomechanical Analysis of Waterproof Layer Fracture Risk in Potential Hazard Elimination was supported by the Ministry of Science and Higher Education of the Russian Federation, Topic: Deformation and Fracture Research in Quasiplastic Rocks under Complex Loading.

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