A coalfield fire that has been burning for nearly 100 years in northwest China would be extinguished soon, the Yangcheng Evening News reported Monday.
The fire in the Liuhuanggou Coalfield in Changji, in the Xinjiang Uygur Autonomous Region, the largest coalfield fire in China, will be put out by the end of July, according to Qi Dexiang, an official in charge of extinguishing the fire.
Firemen have extinguished the fire at 14 locations and completed major work for putting it out at four remaining locations, said Qi.
The process of putting out the fire was complicated, said Mr. Miao, an engineer. First, firemen roll the field with bulldozers, and then saturate it with water. When the temperature drops to around 70 degrees Celsius, they drill the field and fill the holes with earth and concrete. Finally, the field will be covered with a thick layer of earth to prevent oxygen from reaching the fire.
“We have to wait for at least 10 years before we can exploit the burned coalmine again,” said Qi. “When the fire is extinguished, the temperature of the coalmine is about 70 degrees Celsius. But a coalmine can not be used unless its temperature drops to under 12 degrees Celsius.”
Qi said if the coalmine were exploited before the temperature drop, the fire would ignite again.
Attempts to put out the fire have been continuing since 2000.
The Liuhuanggou Coalfield is one of the key coal bases in Xinjiang producing 1 million tons of coal a year. The fire spread to 18 locations burning a total area of 1.8 million square meters. Every year, more than 4,000 tons of poisonous gas and harmful dust are released into the atmosphere affecting Urumqi and Changji, both of which are about 40 kilometers from the coalfield.
The fire started back in the Xuantong Period of the Qing Dynasty (1644-1911) and has been burning an estimated 1.76 million tons of coal a year since.
Miao said the coal burned due to years of exposure to air. Media reports said a general accidentally started the fire when he tried to mine coal with backward technology.
(Shenzhen Daily July 29, 2003)