Objective :To study on main phase

chemical composition

thermal stability of calamine before and after processing. Method :Analyzed phase and chemical composition of calamine X-ray diffraction (XRD)

infrared spectrophotometry (IR) and titration method;studied thermal stability of calamine by differential thermal analysis. Result: Main phase of calamine after processing changed from monoclinic system of Zn5(CO3)2(OH)6 to hexagonal system of ZnO;Stretching vibration and bending of carbonate obviously weaked; The content of zinc oxide increased from 63.36% to 82.95%; Sample released heat when heated to about 250 ℃ and heat did not change when heated close to 315 ℃. Conclusion : Not only main phase changed of calamine after processing

but also chemical composition changed.Differential thermal analysis (DTA) could regulate calcined temperature of calamine.