Mining, Overburden Removal, Quarrying, Drilling and Blasting and allied services:
- Miningis the process of digging things out of the ground. Any material that cannot be grown must be mined. Mining things from the ground is called extraction. Mining is done by scraping away the soil (dirt) from the top of the ground. This is called surface mining. Mining can include extraction of metals and minerals, like coal, diamond, gold, silver, platinum, copper, tin and iron. In our company, we used to mine mostly Coal/ Lignite, Iron Minerals.
- Quarrying is the process of removing rock, sand, gravel or other minerals from the ground in order to use them to produce materials for construction or other uses. So, a quarry is any such working on the surface of the earth where minerals are extracted. Quarries are also known by other names around the world: ‘surface mine’, ‘pit’, ‘and open pit ‘or ’opencast mine’.
- Drilling and blasting is the controlled use of explosives and other methods. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut. For mining to extract the coal blasting mostly done by departmental by supplying blasting materials.
I. Method of Lignite Mining:
The mining operations by opencast mining method, are carried out using conventional mining machinery like hydraulic excavators/hydraulic shovels and dumpers for OB/IB removal including hard strata, and excavation & loading of lignite in to consumer’s trucks or dumpers/trucks of other agency from mines working face. Entire mining operations inclusive of all ancillary activities are to be carried out by the contractor selected through tendering process. The entire topsoil excavated from the mining area will be stacked separately or spread over the reclaimed area.
II. Definition of Work:
Turnkey Mining Contract involving Overburden/ Inter burden removal, Excavation and/or Loading of Lignite from mines face:
Overburden (OB)
Lignite being sedimentary in nature occurs either in a single layer or in multiple layers at various depths. Opencast mining method to win this lignite involves excavation of the entire overlying materials up-to the depth of lignite formation in the proposed area. The materials lying above first layer of lignite in the proposed area is termed as Overburden (OB). For the purpose of this tender, the OB materials chiefly constitute top soil, silica sand, sandstone, clay, hard compact clay, hard strata, shale and material already dumped on surface/ground surface etc.
Inter-burden (IB)
By virtue of the sedimentary origin of lignite, it occurs either in a single layer or in multiple layers. In case of multiple layered lignite deposits the materials, lying in between two subsequent layers of lignite in the proposed area is termed as Inter-burden (IB). For the purpose of the tender, the IB materials chiefly constitute various types of clays, hard strata, shale etc. This does not include water spread over lignite due to any reason including inundation while carrying out excavation/mining or any other operation.
Exposed Lignite
Exposed Lignite means, the area in which the entire OB/IB has been removed up to the lignite layer excluding a thickness of 0.30 Mtr. of OB/IB material, which are being purpose fully left to maintain the quality of lignite over a period of time.
Dump
Dump means the stack of materials which was removed from the mines for Lignite mining. The dumps may be located within and outside of the mine pit and OB/IB materials removed from the proposed working area is to be stacked.
Lignite Dump Area
Lignite Dump Area means where lignite is to be dumped. Lignite Dump Area may be located on ground surface or at intermittent level/place within mine lease boundary. Lignite from mine faces to be transported and unloaded at Lignite dump area and Re-loaded in to the consumer’s trucks/dumper.