Study On The Melting Characteristics Of Slag From The Incinerator Of Hazardous Wastes Containing Fluorine And Chlorine

Hazardous waste which has characteristics of toxic, explosive, inflammable, corrosion, chemical reactive, infection, radioactive and harmful contaminate the environment by its unique properties. Incineration has been identified as the best disposal option for hazardous wastes because it is harmless and realizes a large reduction in volume as well as resources recovery. The compositions and characteristics of hazardous waste slag including fluorine and chlorine are important parameters for improving incinerator design, operation and control. Hazardous waste from chemical factories including fluorine and chlorine has rather low fusion temperatures. During incineration in a rotary kiln incinerator, hazardous waste including fluorine and chlorine melts and turns into slag, possibly adhering to the inner wall and leading to unstable operation of the incinerator. In other cases, the molten slag probably tumbles and rolls, bonding to other slag particles; finally large slag agglomerates are formed, blocking the exit of rotary kiln. Therefore, the melting characteristics of fluorine and chlorine contained hazardous waste slag are important for optimizing hazardous waste incineration and preventing slagging of rotary kiln incinerators.The composition and fusion temperatures of fluorine and chlorine contained hazardous waste, collected from hazardous waste treatment center; were analyzed and compared with coal ash, biomass ash and medical glass. The components convertible method is used to investigate the effects of slag component on the melting characteristics of slag of hazardous waste including fluorine and chlorine. Na2O decrease fusion temperatures sharply. Effect of NaF on fusion temperatures of hazardous wastes related to the content of NaF. The melting temperatures of KCl-NaCl-NaF-(SiO2) system decreases when NaF content increases up to12%, and increases when NaF content increases above12%. SiO2, Al2O3and CaO increase fusion temperatures of hazardous wastes. The addition of CaO and coal ash can significantly improve the melting temperature of fluorine and chlorine contained hazardous waste.Regression analysis and neural networks were used to predict the fusion temperatures of fluorine and chlorine contained hazardous waste. The calculated results reveal that predictive values of fusion temperatures agreed well with experimental values. And neural network has higher precision compared with regression analysis.