Deployment of Continuous Miner-Based Mass Production Technology from Shallow to Deeper Depths: Challenges and Mitigation Strategies

Abstract

Extraction of coal using Continuous Miner (CM) technology in Indian coalfields has been found to be satisfactory up to 300 m depth under easy-to-difficult caveable overlying strata. However, the presence of geological discontinuities remains one of the major challenges for the safe development of unsupported cut-out distance by CM. The CM technology is also deployed at depths exceeding 300 m in a few mines (Churcha RO underground mine, SECL; VK-7, VKP Mine, and Shantikhani, SCCL), where strata mechanics issues affect the performance of underground structures, including loss of life and natural energy resources. At the greater depths, redistribution of in-situ stresses impacts the efficiency of the bord and pillar (B&P) method of mining. Around 128 billion tons of coal are available at depths of 300-600 m in different Indian coalfields, which require suitable technology and methodology for safe and efficient extraction. The CM technology has been successfully deployed at depths of up to 600 m in Australia to extract coal using an alternative method to the B&P method. An attempt has been made to alleviate the challenges associated with CM workings. This paper also presents a possible novel mining method for deeper cover at an SCCL mine using CM technology.