China's energy-saving and environmental protection industry ranks first among strategic emerging industries, and its policy is strongly supported. It is estimated that during the “Twelfth Five-Year Plan” period, the investment in environmental protection industry will reach 3.1 trillion. The key environmental protection projects involve solid waste treatment, desulfurization and denitrification, municipal sewage, Sludge, industrial wastewater and many other aspects. In addition, the General Office of the Ministry of Industry and Information Technology issued the "Notice on the Pilot Work on the Construction of Industrial Solid Waste Comprehensive Utilization Bases", stating that by the end of the "Twelfth Five-Year Plan", the comprehensive utilization rate of industrial solid waste in each pilot area will be based in 2010. The project will increase 10-12%, build a group of industrial solid waste comprehensive utilization bases, and form a comprehensive industrial solid waste comprehensive utilization policy system and promotion mechanism to promote the leap-forward development of industrial solid waste comprehensive utilization across the country. China's solid waste treatment industry faces good opportunities for industrial development.

Separation of solid waste is an important means to realize the recycling and reduction of solid waste. The separation can be fully selected and utilized to separate the harmful substances. The other is to separate the wastes of different grain sizes. The basic principle of sorting is to use the difference in certain aspects of the material to separate it. For example, separation is performed by utilizing magnetic and non-magnetic differences in waste; separation by particle size difference; separation by specific gravity difference. According to different properties, various machines can be designed and manufactured to sort solid waste. The sorting includes manual selection, screening, gravity sorting, magnetic sorting, eddy current sorting, and optical sorting.