A study on utilization of coal gangue and copp.DOC

A study on utilization of coal gangue and copper tailings as clay for cement clinker calcinations QIU Guohua, LUO Zhongyang, SHI Zhenglun*, NI Mingjiang  （State Key Lab of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China） Abstract: In order to avoid environmental pollution from Coal gangue (CG) and copper tailings (CT), a study on utilization of them as clay for cement clinker calcinations was carried out in the laboratory. Low-calcium limestone was also selected as another raw material. The clinker component and microstructure were analyzed by XRD and SEM. The results showed that qualified cement clinker could be generated by substituting CG and CT compound for clay. While mixed with high-calcium limestone and low-calcium limestone, the calcinations temperature were 50 ℃ or 100 ℃ lower than that of clay. CT and CG contain oxygen-rich minerals and potential of geological rock energy. The energy of CG performs functions and drops down sintering temperature. The calcinations time was shortened and the clinker sintering coal consumption reduced while substituting CG and CT for clay, and also served the reutilization of low-calcium limestone, CG and CT. Key words: Coal gangue; Copper tailings; XRD; Oxygen-rich minerals 1 Introduction Coal gangue (CG) is an industrial residue when coal is excavated and washed in the production course of coal mine, and it has become the largest solid waste in China[1-4]. Metal tailing is an industrial waste for metal mine after mining, crushing, flotation. China is abundant in copper tailings (CT) and other metal tailings[5, 6]. However, most of them still not disposed and occupy a great deal of lands[7, 8]. These solid waster materials begin to contaminate soil, water and air in the surrounding areas[9,10]. Therefore, it’s of great significance by applying CG and CT to the production of cement industry so as to protect our environment. 2 Materials and methods The raw materials in this experiment include CT, high