Preface:

In solid waste, residential waste is most common along with industrial exhaust, construction sludge, waste grease, acid, alkali, and sealed gas waste. It is not an easy task to collect these wastes of various kinds and monstrous size, let alone to decrease it, make it harmless, and transform it into conducive resources.

With modernization advancing into future and people’s living standard greatly increased, the number of a variety of waste is incremental day by day, posing severe risk to ecological environment. The development of modern industry only aggravated the situation, especially when the advancement of modern electronic information and pharmaceutical chemistry become the main cause of increase in the production of hazardous waste.

Traditional landfill is difficult to continue due to the mounting pressure of the size, want of space, long time period and environment pollution. As a result, burning become a much more desirable method. The public concern nevertheless does not go away but shifts to the cost, burning size, production of dioxin and a second damage to environment.

The technology of waste co-processing in cement kilns is to put qualified waste or qualified waste after pretreatment into cement production to achieve a harmless disposal of the waste by taking advantage of the high temperature, large specific heat capacity, long-term gas retention, good thermal stability, alkaline environment and no exhaust discharge of the cement rotary kiln. Its significant advantages are as following:

High Temperature

Cement kiln co-processing directly uses the high temperature of cement kilns, and the temperature is much higher than that of waste incineration plants. The high temperature can fully and stably burn the solid waste, the heavy metal ions in the solid waste are discharged without waste residue, and the hazardous organic matter such as dioxins will be completely decomposed or effectively controlled.

Cost Effective

Cement kilns have strong adaptability to various wastes, such as residential waste, construction sludge and hazardous waste. The disposal of waste does not affect the quality of cement products. The waste incineration equipment is shared with the cement production equipment, and there is no need to set up a special kiln, saving the investment in the construction of the kiln system.

As co-processing in cement kiln has been promoted and adopted in a broader area, new regulations Environmental Protection Technical Specification for Co-processing of Solid Wastes in Cement Kiln and Technical Specification for Co-processing of Solid Waste in Cement Kiln come out for the normalization of this measure and protection of environment. These two regulations put a certain limit on heavy metal and other hazardous substance content in solid waste used in kiln. Hence cement plant in this project is required to add a heavy metal test in waste to the normal test process. There will be a separate introduction for waste electricity generation in which test for heavy metal is also demanded.

Despite the high precision of ICP, sophisticate pretreatment of the waste is still a problem. Energy Dispersive X-ray Fluorescence Spectrometry (EDXRF) in comparison is quicker and can deliver test result of elements as a whole without loss. EDXRF is the best way to test heavy metal and other inorganic elements content in solid waste. 5E-XRF2500 EDXRF Spectrometer from CKIC therefore is the most desirable choice in achieving these goals.

Process by 5E-XRF2500 EDXRF Spectrometer

Pretreatment

Press dry powder sample into a tablet (in a vacuum, without consumption of helium). Put moist powder sample or slime into Mylar-filmed sample cup and test directly.

Calibration

To use the various standard sample from GSS, GSR, GSD to create a calibration curve in 5E-XRF2500, covering most macroelements and elements in cement kiln.