Research On Processing And Comprehensive Utilization Of The Sandy Kaolin In Jiangxi

With the increasing shortage of high-quality kaolin in our country,most of kaolin in south China is low grade ore,and all need the beneficiation to improve its quality.So the technical research on low grade kaolin's purification and mineral processing will be the key to improve the utilization of kaolin resources and the quality of kaolin products.The kaolin mining in Jiangxi province has high content of iron and mica.The purpose of this paper is to confirm the comprehensive recovery project of the related resources in kaolin,and also to find applications which is suitable for the ore based on the nature of the ore.On the basis of technological mineralogy,the system research of processing including blunging,classification,gravity separation,magnetic separation,flotation and bleaching are studied.By the means of the infrared spectrum analysis and Zeta Potential measurements,the studies of the interaction mechanisms between dodecylamine and minerals were carried on.The conclusions are as follows:The ore contains 45%quartz,12%feldspar,12%kaolinite,30%muscovite,and1%hematite-limonite hornblende.The main impurity element in kaolin is iron,which occurred mainly in three ways:one is present in the lattice of the kaolinite and mica;the other is present in the surface of the kaolinite and mica;the third one is contained in iron oxide minerals.The blunging,spiral classifier classification,the?75 and?50 hydroeyclone are used for continuously purification,the yield of the overflow of the?50hydroeyclone is 22.33%,in which the content of Al₂O₃ is 31.03%,the content of SiO₂ is 51.18%,the content of Fe₂O₃ is 1.75%,and the content of TiO₂ is 0.097%.the natural whiteness is 59.70%and the calcination whiteness is 68.84%,coming up to the third grade of ceramic industry.The high-gradient magnetic separation-reduction bleaching joint process is used to iron removal of the kaolin.After the high-gradient magnetic separation-reduction bleaching joint process,the yield of the kaolin concentrate is 18.79%,in which the content of Al₂O₃ is 30.49%,the content of SiO₂ is 49.96%,the content of Fe₂O₃ is reduce from 1.75%to 1.36%,and the iron removal rate is 22.29%.the natural whiteness is 73.90%and the calcination whiteness is 80.10%,coming up to the third grade of ceramic industry.A part of the kaolin tailings is used as building sand,the rest is used to recycle mica by flotation.By adopting the opened flotation flowsheet of single-stage roughing,two-stage cleaning and one-stage scavenging,the yield of the mica concentrate is 42.05%,in which the content of K₂O is 6.13%,the content of Al₂O₃ is32.89%,the content of SiO₂ is 49.09%,the content of Fe₂O₃ is 2.63%.The mica concentrate can be used as ceramics raw material,and the middlings and tailings can be used as filling material.The tailings after desliming still contain much fine-grained kaolinite,which affect the flotation of mica.The infrared spectroscopy analysis showed that,in acidic conditions,the adsorption which is on the kaolinite and mica surface of the laurylamine is typical physical adsorption and electrostatic adsorption,and there is no chemical reaction.The zeta potential analysis showed that after adding laurylamine,the surface potential of the two minerals all increased,indicating that there are strong adsorption between laurylamine and the kaolinite and mica surface,which made it have strong collectivity capacity for the kaolinite and mica.