The lightweight aggregate process is also called clay ceramsite production line, ceramsite sand production line, building ceramic production line, ceramsite production machine, and shale ceramsite production machine. At present, all China's ceramsite production devices are adopting industrial rotary kiln. The main drum kiln is placed inclined on the idler pulley about 3 degrees from the horizontal line. Materials enter the kiln from the upper end and rotate inside the kiln. Then they roll from the upper end (back of the kiln) to the low end (head of the kiln). Meanwhile, at the kiln head, the high pressure fan blows the coal powder (or the natural gas and other fuels) into the kiln and make them burn completely. Then the heat forces the materials to suffer physical and chemical changes. Materials expand and then are cooled to become ceramsite.