In the past ten years, South Cement Group’s performance in environmental protection has begun to shift further to a major issue of the people’s livelihood that the government is most concerned about—and the disposal of a large amount of domestic waste generated by households every day.
Prior to this, the government’s disposal of "kitchen waste" only included landfills and incineration. But landfills caused soil pollution, and incineration caused air pollution. At present, the use of a cement rotary kiln for co-processing not only effectively prevents soil and air from being polluted, but also makes the treated domestic waste a treasure.
In the cement production process, the cement kiln can generate a large amount of high temperature, waste heat and negative pressure, which has the advantages of high temperature, alkalinity, and perfect and powerful exhaust gas treatment system. These unique resources create good conditions for the harmless disposal of domestic garbage and industrial waste. The method of using cement kilns to co-processing urban domestic waste and realizing co-production not only realizes the detoxification, reduction and resource utilization of domestic waste, but also lays the foundation for the ecological restoration of landfill sites and the conservation of land resources. Therefore, compared with other disposal methods, the use of cement kiln to treat domestic garbage has the advantages of less investment, good effect, residue utilization, and no secondary pollution, etc., and it can effectively solve domestic garbage.
Cement kiln co-processing waste technology, that is, the use of energy and materials recovered from waste during the production of cement to replace certain fuels and raw materials required in industrial production, while the waste is a "secondary pollution-free" disposal process, has been widely used in developed countries such as ones in Europe and the United States, reaching a high level, and has achieved social, environmental and economic benefits.
Technical advantages of co-processing in cement kilns:
(1) The high temperature of clinker production in cement kiln, strong alkali, convection, and vortex environment, is conducive to 100% disposal of waste quality.
(2) Closed-circuit production measures are adopted for the co-processing of cement kiln, and the sorted inorganic slag, secondary derived fuel and dust are all melted into cement clinker.
(3) Trace elements such as heavy metals brought in by waste are solidified in the crystal lattice of cement clinker in the form of solid compounds during high-temperature incineration, which will not adversely affect cement quality and ecological environment.
(4) Natural conditions such as alkaline reduction and sustained high temperature in cement kilns can effectively inhibit the formation of dioxins and reduce the emission of toxic gases; the substitution of secondary derived fuels for coal can help reduce the decomposition of CaCO3 and carbon combustion CO2, thereby reducing CO2 emissions.
