Key problems and countermeasures of precise management and control of hazardous waste in coking industry

A great deal of waste gas, waste water and hazardous waste are produced in the coking process. Coking industry is a heavy pollution industry and key control industry in China. The precise control and safe utilization and disposal of hazardous waste in coking industry can not only improve the ecological environment, but also protect people’s health. The present situation of hazardous waste in coking industry was that there were numerous nodes, multiple kinds, large amount and various kinds of pollutants. There were three main ways of utilization and disposal, which were to extract a variety of chemical raw materials from high temperature coal tar and medium-and-low temperature coal tar, to extract salt and acid from desulfurization waste liquid, and to carry out cement kiln collaborative disposal and incineration disposal of the coking hazardous waste which could not be effectively utilized at present. The main problems existing in the current utilization and disposal methods were analyzed. Some suggestions on improving the utilization rate of coking hazardous waste and strengthening the safe disposal were put forward, which mainly included three aspects: 1) In order to promote the utilization of high temperature coal tar and medium-and-low temperature coal tar, the exemption conditions of utilization link in List of Hazardous Waste Exemption Management should be followed. 2) Through the formulation of pollution control standards or technical specifications, “point-to-point” utilization, development of efficient salt extraction and acid production technology, and park unified planning and centralized utilization, the level of salt extraction and acid production from desulfurization waste liquid could be improved. 3) Under the premise of controllable environmental risk, new dry process rotary kiln technology and scientific compatibility of hazardous waste, the coking hazardous waste which could not be effectively utilized at present could be disposed by cement kiln combined disposal and incineration.