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Pandalai, H. S.
- Textural Studies on the Ores of Amjhore Pyrite Deposit, Rohtas District, Bihar, India
Authors
1 Department of Applied Geology, Indian School of Mines, Dhanbad, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 27, No 6 (1986), Pagination: 527-530Abstract
The pyrite ore body at Amjhore occurs as a horizontal to sub-horizontal 'bed' composed, in part, of a hard massive variety and, in part, of a more friable disseminated variety of ore. Microscopic studies reveal that the disseminated ore is made up chiefly of large spherules of pyrite (100,.μm to 1200,.μm in dia.) in a matrix of shale containing also dispersed subhedral toeuhedral pyrite (4,.μm to 30 μm in size). Occasionally, large isolated hexahedral grains of pyrite are also present in the disseminated ores. The microscopic studies indicate development of pyrite spherules from initially close-spaced growth nuclei (perhaps of the precursor-mineral pyrite). The spherules and hexahedra of pyrite fuse together to give fise to the massive variety of ore which show such textures on etching. The textural studies alone cannot, however. be used to infer the exact genesis of the deposit.
- A Geostatistical Study of Alumina Content in Ores of an Indian Iron Ore Deposit
Authors
1 Department of Earth Sciences, Indian Institute of Technology, Bombay, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 41, No 1 (1993), Pagination: 39-50Abstract
Mining and blending operations in the high grade iron ore deposit under study are performed to optimize recovery with minimal alumina content while maintaining required levels of other chemical component and a proper mix of ore types. In the present work the regionalisation of alumina in the ores has been studied independently and its effects on global and local recoverable tonnage as well as on alternatives of mining operations have been evaluated.
The global tonnage recovery curves for blocks (20m x 20m x 12m) obtained by simulation closely approximated the curves obtained theoretically using a change of support under the discretised gaussian model. Variations in block size up to 80m x 20m x 12m did not affect the recovery as the horizontal dimensions of the blocks are small in relation to the range of the variogram. A comparison of the local tonnage recovery curves obtained through multiple conditional simulations made with that obtained by the method of unifonn conditioning of block grades on an estimate of panel 100m x 100m x 12m panel grade reveals comparable results only in panels which have been well conditioned and possesing an ensemble simulation mean close to the ordinary kriged value for the panel. Study of simple alternative sequence of mining on the conditionally simulated deposit shows that concentration of mining operations simultaneously on a single bench enhances the fluctuation in alumina values of ore mined.
Keywords
Statistical Study, Alumina Contents, Iron Ore.- Origin of Fluorite Mineralisation and Hydrothermal Alteration at the Chandidongri Deposit, Rajnandgaon District, Central India-Evidence from Oxygen and Hydrogen Isotopes
Authors
1 School of Earth Sciences, The University of Melbourne, Parkville, Victoria 3052, AU
2 Department of Earth Sciences, lndian lnstitute of Technology, Powai, Mumbai- 400 076, IN
3 Department of Physics, The University of Alberta, Edmonton T6G 2J1, CA
4 Department of Geology, Aligarh Muslim University, Aligarh, IN
5 Department of Physics, The University of Alberta, Edmonton T6G 2J1, IN