Mineralogical characteristics study of natural cryptomelane in the Xialei manganese deposit, Guangxi

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	Mineralogical characteristics study of natural cryptomelane in the Xialei manganese deposit, Guangxi
	Zhao, Dongjun ; Lu, Anhuai ; Wang, Lijuan ; Zheng, Xikun ; Liu, Rui ; Guo, Yanjun
刊名	北京大学学报自然科学版
	2005
英文摘要	In the supergene zones of Xialei manganese deposit in Guangxi, south China, there is abundant resource of natural cryptomelane, which is well known as a manganese oxide octahedral molecular sieve having a well-defined 2 ?? 2 tunnel structure (OMS-2) with K+ situated in tunnel positions. This study was focused on the occurrence characteristics of the cryptomelane-bearing ores and the mineralogical characteristics of natural cryptomelane. The morphology, chemical and structure features of natural cryptomelane were characterized by means of powder X-ray diffraction (XRD), scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), energy dispersive spectrometer (EDS) and X-ray fluorescence(XRF). The morphology of the natural cryptomelane crystals via SEM showed short prismatic, needle-like and fibrous shapes with the diameters varying from few nanometers to hundreds nanometres. The MnO2 content was by and large over 90% and K2O ranged from 2.52 to 4.37wt%. However, the composition resulted from EDS revealed a higher content of K, 3.37 ~ 4.17wt%. The XRD of the samples agreed with a monoclinic cryptomelane and the cell parameters were given as a = 9.956 nm, b = 2.870 nm, c = 9.706 nm and ?? = 90.95??. The phase transformation temperature of the natural cryptomelane was about 635.5??C examined by TGA and DTA and the cryptomelane was changed to bixbyite at a higher temperature. These studies reveal the significant features of cryptomelane for the potential application in the environmental materials science.; EI; 0; 6; 859-868; 41
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/411044]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhao, Dongjun,Lu, Anhuai,Wang, Lijuan,et al. Mineralogical characteristics study of natural cryptomelane in the Xialei manganese deposit, Guangxi[J]. 北京大学学报自然科学版,2005.
APA	Zhao, Dongjun,Lu, Anhuai,Wang, Lijuan,Zheng, Xikun,Liu, Rui,&Guo, Yanjun.(2005).Mineralogical characteristics study of natural cryptomelane in the Xialei manganese deposit, Guangxi.北京大学学报自然科学版.
MLA	Zhao, Dongjun,et al."Mineralogical characteristics study of natural cryptomelane in the Xialei manganese deposit, Guangxi".北京大学学报自然科学版 (2005).