China Shenhua Energy Co, the nation's biggest coal producer, started trial operation of a mine after investing 4.48 billion yuan in the project.
The 20 million metric-ton-a-year Bu'ertai mine in the Inner Mongolia Autonomous Region is the world's largest by capacity, parent Shenhua Group Corp said in a statement on the website of the State-owned Assets Supervision and Administration Commission.
The mine, which covers an area of 193 sq km, has explorable reserves of 1.85 billion metric tons, according to the statement.