Today, 41 years ago, on August 31, 1984 (August 5, 1984), China's first modern outdoor coal mine was built in the Inner Mongolia Autonomous Region. On August 31, 1984, China designed and built its first modern outdoor coal mine - the Hunan Hunan outdoor mine in the Inner Mongolia Autonomous Region. The mine was the first project of the Hunan River large outdoor coal mine, producing 3 million tons of coal annually. The Hunan River coal field is one of the four largest outdoor coal fields in China, with a total area of 540 square kilometers, and a total coal reserve of 12.9 billion tons.