This paper presents a series of surface experimental simulations methane-oriented underground coal gasification using hydrogen as medium. The main aim the experiments conducted was to evaluate feasibility methane-rich gas production through in situ hydrogasification process. Two multi-day trials were carried out large scale facilities designed for ex (UCG) different coals investigated: “Six Fee...

Due to the high attenuation of radio frequency (RF) signals in underground mines and the statutory power restriction of communication gadgets especially for coal mines, the wireless communication systems have restricted applications in the underground mines. The paper discusses different radio frequency communication techniques being employed for Indian underground mines. Experiments were condu...

Due to the improvement of production technology and the adjustment of energy structure, as well as the town-ownership and private-ownership coal mines (TPCM) were closed or merged by national policy, the number of underground miner has changed comparing with 2004 in China, so collective dose and normalization collective dose in different type of coal mine should be changed at the same time. In ...