The Xinjiang Coalfield Fire Extinguishing Department, operating in the Liuhuangghou coalfield, identified 18 main coalfields in an area of 1,830 square kilometres which needed to be extinguished. So far, fires have been put out at 14 of them, and the other four should be extinguished by October this year, Beijing Today reported.
The paper said it was estimated 42 million tons coal had already been lost in Liuhuanggou, more than 1.76 million tons a year. The fact that another 32 million tons of coal in nearby coalfields were also at risk jolted China to attempt to do something about the problem.
Beijing Today said the difficulty authorities faced was the ground in the area remained permanently hot as a result of geological activity in the area, so extinguishing fires had been no easy task. Positive results so far have pointed towards an estimated total eclipse of the problem by 2018.
To put out the fires the Xinjiang department has set up 73 kilometres of water pipe lines. Beijing Today said the department used a process where bulldozers are used to flatten the fire source, water is poured on to reduce the temperature and holes are drilled to inject water and mud. The mud is used to fill the underground cracks and block the fire’s source from air. Lastly the surface is covered with soil to completely separate the coal from oxygen.
Making the project possible has been the department’s close affiliation with German company Deutsche Gesellschaft fuer Technische Zusammenarbeit GmbH (GZT). GZT has supplied equipment and advice free of charge and assisted in detecting the depth of the fires and established a temperature measuring system, Beijing Today said.
The department hoped methods used in their project could be applied across other Chinese provinces.