Xintai, September 8 - “Now we have enough filling technology to eat off the gangue and directly fill it underground so it does not even need to raise above the ground." Said Li Quanshui, the technic chief of 7402 working face of Zhaizhen coal mine, Shandong Energy Xinwen Mining Group. As the fully mechanized mining machinery eat into the coal seams, chunks of coal fell on the conveyor belt and flew away like water into the underground preliminary washing plant before raised into the fine washing plant on the ground. The separated gangue is transported back to the mining face from the track roadway, and pushed into the goaf in a compacted manner.
"More than 1.8 million tons of gangue has been dealt with in this way." Said Li.
The Xinwen Mining Group was established in 1956, since then it had formed 22 piles of waste rock of 50.33 million tons, covering 92 hectares. Starting from 2004, the company took the lead in the national development of "gangue-coal replacement" technology. By now it had independently developed 6 technologies that were applied in 111 working faces of 15 mines successively, cumulatively reduced 7 piles of wast rock into supporting materials underground, Ever since the Twelfths Five-Year Plan, 13.404 million tons of coal had its original space been replaced by 17.329 million tons of gangue, significantly extended mine service life for more than 10 years.
At present, the Xinwen Mining Group holds 32 patents related to gangue filling. It is also responsible for the formulation of 12 national industrial standards, of which 8 have been promulgated.