Abstract:
The objects studied in this paper were the kaolin samples collected from Huashiban mining area of the Lower Permian Liangshan Formation in Enshi, Hubei province. The phase compositions, principal components, trace lithium contents, impurity states, whitenesses, particle sizes, values of oil adsorption and pyrolysis characteristics of these samples were studied by the methods like XRD, XRF, SEM/EDS, ICP-MS, TG/DSC, optical microscope, whiteness and particle-size analyzer. The experiments of the preliminary processing and the calcination were operated to research their processabilities. The results show that the ore in the industry type is hard kaolin. The content of kaolinite is 86.79%~99.45% in some layers. The crystallizations of kaolinite in these samples are not high and they have disorder structures. The trace Li in kaolin needs subsequent researches. The pyrite is in oolitic-shape and distributes between the kaolinite particles. After the preliminary processing of kaolinite, the proportion of less than 1 μm particles is 32.35%. The contents of Fe and chemical oxygen demand (COD) in the undersize material both decreased. The samples were considered to be used as the raw materials for glass fibers and other additives in cements and fertilizers. After the calcination, the whiteness of a sample can reach 79.1% at 950 ℃, and the oil absorption value is 48.23 g/100g after calcination at 750 ℃. Their applications can be extended to be metakaolinite, the raw materials for the mullite and ceramic glazes. Therefore, the researches in this paper propose possible processing methods and potential applications for Enshi kaolinite resources, which can provide references for other similar resources.