Claims:1. A process for the maximum utilization of mine waste i.e overburden (iron oxide) having -1mm size was used for making bricks
2. A process claimed in 1 where in overburden -1mm size powdery materials is used for preparation of bricks.
3. A process claimed in 2 where in overburden -1mm size powdery materials is used has the following chemical constituent 24 -25% silica, 28-30 Al2O3, 24-27% Fe2O3 and loss on ignition is in the rage of 11-20%.
4. A process claimed in 3 where in overburden generated during mining of iron ore lying on mineral.
5. The process claimed in 1, wherein the 80% overburden was mixed with 20% cement and 6-7 % water and 1ton pressure applied for brick making.
6. A process claimed in1 wherein the very fine overburden is having Al2O3/ SiO2 ratio is 0.85 with 2.5 -3 specific gravity.
Dated , Description:NMDC Ltd. is a Government of India Enterprise is the pioneer organization in the field of production and supply of Iron Ore to different iron and steel making industries. During the process of mining of iron ore the material that lies above an area that lends itself to economical exploitation, such as the rock, soil, and ecosystem that lies above ore body. Overburden is distinct from tailings, the material that remains after economically valuable components have been extracted from the generally fine milled ore. Overburden is removed during surface mining, It is estimated around 2 to 3 million tone of overburden will generate every year during the mining of iron ore. Overburden is the material which sits on the ore body with varying
thickness/volume. To expose the ore body before excavation of the ore minerals, it is essential to remove the overburden. This primarily comprises soil & waste rock from which it is uneconomical to extract its constituents for subsequent use. Thus, it is considered as a waste while carrying out the mining activity. However, it adds to the input cost of mining as it is like mining activity without any financial returns. The quantity of overburden varies from place to place in an opencast mine depending on the formation of the ore body – its length, breadth/thickness, and depth. Further, the excavated overburden requires enormous space for storage without affecting the mining activity – this generally associated with challenges of erosion, air pollution, damage to adjoining vegetation, contamination of surrounding water bodies during rainy season etc. Therefore, any use of such overburden will be a boon to mining industry and negates the geotechnical challenges apart from its adverse impact on the environment. Characterization of the overburden becomes a key while exploring the possibilities of its utilization.
Keeping in view of above, R & D Centre, NMDC Ltd, has decided to utilize the over burden by making bricks.
Recently the increasing demands and use of cost effective bricks is increasing tremendously. Hence utilization of mines waste i.e. overburden available raw materials for the production of above bricks is very important, because such step will obviously strengthens the economic condition of iron ore plant of NMDC.
In the process overburden 80% was taken then mixed with Portland cement (20%), and 6 to7 % water for moist then sample will kept in bricks making machine and 1 ton pressure applied for bricks cake, bricks were dried under sun after that it was kept 20 days for natural curing, Bricks were dried. Bricks sample’s physical and chemical characterization has been done as per IS standard.