POHRA SILLIMANITE MINE
Owner: Maharashtra State Mineral Corporation
A little more than four decades ago, minerals Sillimanite were almost unknown outside the geological world, but today the importance of these minerals as a raw material for making high grade refractory bricks has increased manifold because of their unique properties. The utilisation of these minerals is due to their conversion into mullite, a highly refractory material when fired to 1411°C.
MSMC’s Pohara Sillimanite Mine in Bhandara District is the main producing center of aluminous ores, namely Sillimanite, Corundum and Pyrophyllite. Sillimanite and corundum are scares and high value minerals.
They command good demand in high alumina refractory bricks manufacturing industries. Pyrophyllite and the other hand, a low value and slow moving commodity. It is generated by-product to regular production of Sillimanite-Corundum from Pohara mine. Availability of Pyrophyllite is many times than that of Sillimanite and corundum.The details of mine are as under-
|Mineral||Sillimanite, Corundum and Pyrophyllite|
|Nearest Rly. Station||Bhandara Road (40kms.from Mine)|
|Reserve||0.155 Million Tonnes of Sillimanite 0.585 Million Tonnes of Pyrophyllite|
|Period of Lease||20 Years.|
|Date of expiry of Lease||5/11/2017|
|Total Lease hold Area||39.40 Hect.|
The area lies in toposheet No. 55 0/16 survey of India, at latitude North between 21°01’30″ to 21°02’55″ and longitude between 79°51’28″ and 79°51’45″ east and is situated about 800 Mt. Due east of Pohara village.
Sillimanite is the main mineral occurring in the area. The ore-body exists in isolated patches lensoid shape, encased withpyrophyllite. Corundum is also associated with Sillimanite and the former is present within the Sillimanite ore-body in very small sporadic patches. Regionally the rock formation encountered in the are belongs to south-western part of the Sakoli synclinorium consisting of Sakoli series rocks of Archean group. The area is exposed in large triangular outcrop, and is also known as Bhandara triangle, the types representing Sakoli series are Phyllite quartz-muscovite-schist,quartz-chloriteschist,quartzite,quartz-kyanite,sillimanite-pyrophyllite-schist,amphibolite-schist.
The geological sequence of the area is as follows-
|Recent||Soil and alluvium|
|Post Sakolit||Pegmetite & Amphibolite|
|Phyllite ,quartz mica schist|
|Sakoli||Chlorite Mica Schist and quartzite|
The ore-body trends NNE-SSW and has steep dip varying from 600 to 700 towards west. The rocks are highly jointed. Oblique- joints and bedding joints are prominently visible. Corundum is sporadically associated with Sillimanite and both the minerals are encased with Pyrophyllite in form of isolated lensoid bodies.
The operation is semi-mechanized, by open-cast method. Topography of the mining area is sloping, consisting of small mound. The max. level of difference from the surface is 18 m. Being highest latitude is at 264 MRL and the ground level is around 246 MRL, in which one bench of 3 m Of soil and loose weathered rock and 2 benches of 7.5 m in hard rock would be formed. The topography and deposition of geological strata is depicted in the geological map.