Coal gangue is the largest industrial waste in China, accounting for about a quarter of China's industrial solid waste. According to the materials of relevant departments, China has accumulated about 3.6 billion tons of coal gangue over the years, and there are about 2,600 large coal gangue hills with an area of10.2 million hectares. With the development of China's modernization and environmental protection, the development of clean coal technology and the improvement of coal mining mechanization, the emissions of coal gangue and slime will increase. Shanxi Province, with the largest coal output, has accumulated more than 6543.8 billion tons of coal gangue, forming more than 300 coal gangue hills. In recent years, with the rapid growth of coal output, about 80 million tons of coal gangue are added every year. According to experts in coal processing and utilization, coal gangue with a calorific value of 300 to 1000 kcal can completely or partially replace clay to produce new building materials such as coal gangue hollow bricks and coal gangue cement, and can be used to make bricks without soil and burn bricks without coal. In 2005, the total amount of coal gangue in China was about 65.438+38 million tons. If all these coal gangue are used to make bricks, 42 billion coal gangue bricks can be produced, which can save more than 5,500 mu of land occupied by coal gangue storage, 30,000 mu of land can be destroyed instead of clay bricks (calculated by 3 meters of mining pit), and more than 5.6 million tons of commercial coal can be saved.