The carbon briquette manufacturing industry has a history of more than 20 years in China. Recently, with the increasing demands of carbon briquette, the carbon briquette is popular. Because of extruder briquette with a hole in the middle then those briquette could be carbonization very well, after carbonization then could get the charcoal. The charcoal in nature could hardly fill the demands. Thus, machine made charcoal began to grow rapid. However, such factors as manifold materials, frequent disassembly and wear and tear of screws extruder and fast wear of formation barrels (mould)which are particular to the industry hinder its development. Besides, they contribute to variation of techniques and complicate the maintenance. Some technical problems still remain unresolved. The plants contain a large amount of lignin and fibrin. As the lignin doesn't have dissolving point but only softening point, when temperature reaches 70 to 110degree, the hot water soluble substance in lignin begins to dissolve and at 200 to 300degree, it begins to soften. At this point, when posed pressure, the lignin can stick together with fibers and cement with adjacent particles. The briquette making technique is to use this features of the plants and through compression to mold.
