Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
Possibility justification of losses reduction in pillars by backwatering with hardening mixtures
Abstract
The relevance of the research. The problem of mining field development quality is aggravating in new economic management conditions. The need to preserve the earth's surface, reduce ore losses and amount of diluting rocks can be ensured by filling out the space with hardening mixtures. This opportunity is limited by high-value components of hardening mixtures, which can be reduced by using mining waste. The desired effect is achieved by a rational use of properties of natural and man-made arrays. Objectives of the study: to justify the possibility of losses reduction in interchamber pillars while regulating the stress in the array by means of ore pillars backwater with hardening mixtures. The objective is achieved by resolving a problem of geomechanical stress estimation in the array depending on the mining and use of hardening mixtures mechanism for stress regulation. Methods used in the research. The stress state of the array in various phases of its weakening by sewage treatment works is studied with a photoelastic method on the models of optically active polyurethane with a variable coefficient of lateral thrust while maintaining the rest of the model parameters. The results. The authors found that when the stress level is maintained ore pillar losses can be reduced by decreasing the size of pillars by an amount depending on the amount of developed space, physical and mechanical properties of ores and strength of hardening mixtures. Backwater with hardening mixtures reduces the stress level in the vicinity of the stopes by a certain value that comprehensively improves the economic and environmental performance of underground mining, reducing losses in the interior of the earth.