Experts urged the country on Tuesday to increase its investment in extinguishing and preventing coal fires. Such fires lead to serious coal depletion, pollution and mine explosions.

At least 5 billion yuan (US$625 million) are needed to put out current spontaneous coal seam fires in 62 coal mines nationwide, coal mine expert Guan Haiyan said at the three-day International Conference on Coal Fire Research, which kicked off Tuesday in Beijing.

Guan suggested the bulk of the money should be used to renovate current mining technologies in large coal mines to ensure safety.

"Present methods, such as pouring water into mines and building isolation walls, always fail to prevent coal fires during the extraction of combustible seam (or coal layer)," he said. "We need to develop new methods."

He said that in China, the careless closing of small mines and large mined-out areas is the main cause of coal fires. This occurs when the mine is not closed properly, and the coal is exposed to the air making it flammable.

Guan and his team are going to work on new mining and coal fire extinguishing methods that can use less water and stop re-combustion under a Sino-German coal fire research initiative.

The six-year-long program was started two years ago in Wuda Coalfield in Inner Mongolia Autonomous Region, with designing mining methods with minimal fire risk as one of the aims.

Wuda Coalfield is the largest inflammable mine in the country, covering an area of 35 square kilometers.

Coals are inflammable substances, which are easily oxidized once exposed to air during mining. A belt of spontaneous coal fires extends 720 square kilometers in northern China, bringing 200 million tons of coal reserve each year.

Coal fires are always the main reason behind gas explosions, dust explosions, mine collapses and water leak all of which have resulted in a number of mine accidents in the country.

(China Daily November 30, 2005)