Experimental Research About Calcination And Decarburition Of Coal Caolin

High quality kaolins resource of China havs been running low and thephenomenon of “good is not much and much is not good” is ubiquitous. Exploratingdifferent application fields for different types of poor quality kaolin ore and thendoing rational development and application is imperative. Therefore, doing theapplication research and industrial adjustment of a coal kaolin with high content of Feand Ti and also high COD value in Xingshan of Yichang Has the practicalsignificance.The chenmical composition, mineral composition, crystal structure and thermaleffect of the coal kaolin of Xing Shan have been studed through the means of XRF、XRD、IR、SEM and TG-DSC. The results indicates that although the content ofkaolinite is about95%and the quality of a material is pure, but the content of Fe andTi is nearly2%of the total, so the whiteness and the quality of direct application ofkaolin is not high.We have studied the calcination temperature, time, atmosphere and whitingauxiliary on the effect of the white of kaolin, and have guided the industrial test withthe laboratory results. It is shown that we can obtain the calcined kaolin with thewhiteness of83.92%, and composition of metakaolin if we calcinate the kaolin by950℃with3%NaCl for2h in the weak oxidizing atmosphere. The average whitenessof7days industrial test production which has a stable quality is82.3%. The calcinedkaolin products meet the second grade kaolin requirements (XT-(D)2) of the nationalstandard, and can be used as the white or light coloured semi reinforcing filler in theareas such as rubber,cables and plastics.The decarburization test is carried out. we represented and analysised theproduction by COD, XRD and IR. The result indicates that the COD value has a Stype change with temperature, and has different low limit at different calcinitetemperetures, and the higher the temperature, the low limit is lower, the time to reachequilibrium is shorter at the same time; we can not get the qualified products whenthe temperature was below375℃. We can get the best results that the COD decreasedfrom10056μg/g to2523μg/g which meet the requirement of kaolin used by glass fiber by the425℃calcining decarbonization for0.5h,so the kaolin can be used inproducing glass fiber after treatment by this method.The chloride，which are NaCl，NH4Cl and CaCl2，can white the kaolin throughthe reaction product—Cl2to remove the Fe at950℃to whitening the kaolin.Through the research study, we have determined the best conditions ofcalcination and producted the qualified products through the industrial test, andconfirmed the kaolin can be used in producing glass fiber after treatment by calciningdecarbonization at the same time, and provided theoretical and technical reference forthe efficient, economic, rational development and utilization of a large number of coalkaolin in Xingshan and even others of our country which has high contain of Fe, Tiand high COD value.