Three-dimensional orebody modelling and intellectualized longwall mining for stratiform bauxite deposits

Acoupled biharmonic spline and linear interpolation algorithm was proposed to create a three-dimensional smooth deposit model with minimal curvature containing grade and position data. To obtain the optimal technical parameters, such as cuttingheight and drum diameter, a virtual longwall mining procedure was modelled by simulating the actual fully mechanized longwall mining process. Based on the above work, a bauxite deposit in a longwall mining panel was modelled by scattered grade data from ores sampled on the entry wall. The deposit was then demarcated by industrial indexes and sliced according to the virtual longwallmining procedure. The results show that the proposed interpolation algorithm can depict the stratiform structure of bauxite depositsand that the uncovered bauxite deposit has high proportions of high-grade and rich ore. The ranges of optimal cutting height and drum diameters are 1.72-2.84 m and 1.42-1.72 m, respectively. Finally, an intellectualized longwall mining procedure was designed to guide the mining process with the lowest dilution and loss rates.

A Study on Palaeogeography and Metallogenic Conditions of Early Carboniferous Bauxite Deposits of Old Weathered Crust in Guizhou, Sichuan, Hunan and Hubei Provinces

There are four subtypes. namely, Ia, Ib, Ic and Id of the Early Carboniferous bauxite deposits of the old weathered crust type in Guizhou, Sichuan, Hunan and Hubei provinces. They are all distributed in the Upper Yangtze old land. As a result of the Hunan-Guizhou palaeo-faulting, the crust on the northern side of the fault was uplifted and became land, thus suffering denudation. The bauxitic substances left in the weathered crust evolved and were reworked into bauxite. On the other hand, the crust on the southern side of the fault sank and remained to be part of an ocean. The bauxite deposits of Ia and Ib subtypes were formed by in-situ enrichment of residual bauxitic substances in the weathered crust of the old land, but bauxite deposits of Ic and Id subtypes resulted from transportation, accumulation and sedimentation of allothogenous bauxitic substances on the weathered crust of the old land. The processes of transportation may be distinguished as dry transportation and wet transportation, both of which proceeded under atmospheric conditions.

PROSPECTING FOR LARGE TRIHYDROXY BAUXITE DEPOSITS IN CHINA: THINKING AND PERSPECTIVE

Large trihydroxy bauxite deposit was once considered unavailable in China.With the prospecting think-ing of diwa theory,the author has drawn a contrary conclusion.From the view of the law of progression with transformation between mobile and stable regions and the metallogenic specialization of tectonic elements,he reveals the principal reason why the known bauxite deposits in China are mostly of monohydroxide type,and acquires the way of searching for trihydroxide bauxite deposits.He considers that the residual-mobility period of the diwa stage in the crustal development in South China pocesses-tectonic conditions favourable to the formation of bauxite deposits of this type.He believes that the Cenozoic structural sublayer of the residual-mobility period of the diwa stage developed on the carbonate rock of the Paleozoic platformal structural layer is the preferrential target of prospecting.With this thinking and many years of efforts,we have gained prelimi-nary achievements and have discovered Guigang-type latee-ritic trihydroxied bauxite deposits in Guangxi.In future,by extension and analogy of the thinking,we are likely to find large,high-grade bauxite deposits in its vicinity and to discover weathering-type bauxite deposits with other parent rocks.

Viséan Fossil Plants from the Jiujialu Formation in Central Guizhou Province: Implications for Age of Bauxite and Palaeoenvironment

Fossil plants from the carbonaceous shale of upper part of the Lower Carboniferous Jiujialu Formation in Lindai bauxite deposit fill a gap regarding the distribution of Early Carboniferous flora in Central Guizhou Province.Here the Lindai plant assemblage is systematically described,and its composition and geological age are discussed.Research demonstrates that 9 species in 6 genera of the fossil plants are discovered in this study,and they belong to lycopsids,sphenopsids and ferns,respectively.Based on the analysis of the floral composition,the geological age of the Lindai plant assemblage belongs to the Early Carboniferous Viséan.The discovery of Lindai plant assemblage not only provides a new fossil evidence to restrict the age of bauxite deposits in Lower Carboniferous Jiujialu Formation of Central Guizhou Province,but also has great significance to further research the palaeoecological setting and floral evolution during the Early Carboniferous.

Super Large-scaled Bauxite Deposit Detected in Guizhou Province

Recently, the Bureau of Geology and Mineral Exploration and Development of Guizhou Province detected an about 140 million tons resource in Zheng＇an County, 100 million tons of which was bauxite. This is the second detected super large-scaled bauxite deposit after the Dazhuyuan bauxite deposit in Wuchuan County.