New Mining Methods and Strata Control Techniques for Underground Coal Mining and Its Eco-Friendly Perspective

Abstract

This presentation and panel discussion is related to an overview of the new indigenous mining methods introduced for the first time in Indian and International scenario since 1989 with active association of the author; such as simultaneous extraction of three contiguous seams, thick seam mining with cable bolting, parting stabilisation with underpinning as scientist of CIMFR, NIRM, etc in Indian coal mining industries. These indigenous methods were introduced when some of the imported methods (Hydraulic mining – at BCCL, blasting gallery method at BCCL and ECL, Integral/sublevel caving at BCCL etc, and long wall mining at SECL etc were not successful to the expectations of our Indian coal mining industry, and extraction of pillars in thick seams was in jeopardy since 1980’s. Some of the experiences of scientific evaluation of the long wall mining through international arbitration for Kottadih-ECL mines as an expert from India were also discussed with a view to improve the procedures for design of underground coal mining methods to greater depths up to 1200 m, in near future. Some of the strata control techniques including stress relieving techniques, sacrificial galleries, need of introduction of truss supports to deal with cutter roof failures/guttering, high horizontal stress field areas, design of chain pillars for barriers in long wall mining at greater depths etc., were also discussed. Brief summary of the strata control techniques being followed at greater depths of underground coal mining as per the international experiences in various countries such as USA, China etc is also deliberated. Attempts are also made to present few results of the projects to implement online, real-time monitoring of strata/ground behaviour by the group of scholars/faculty of TTIORA (Transdisciplinary translational industry Oriented Research and Academics) through various Ministry of Coal and Mines and Industry sponsored projects.