Welcome Guys to another blog. Today as promised in my previous blog about Coal Mining I am writing this one on Surface Mining.
Lets get started..
Surface Mining is a form of mining for ore material on the surface layer of the Earth’s crust. This method is famous with coal mining. I will be sharing the general steps that are present in this method.
1.Removing the trees and vegetation present in the area.
2.Removing the top layer of the Earth and storing it .
3.The mine is drilled with explosives for breaking the hard strata.
4.Using Explosives for the hard strata .
5.Transporting the exploded strata to store them.
6.Fragmenting the seam as required, by drilling and blasting.
7.Loading the loose coal into conveners to transport to the plant.
8.Milling the loose material to improve its workability for extraction.
9.Reclaiming the mining land.
Mining Methods
Surface mining can be broadly classified as
1.Contour Strip Mining
2.Area Strip Mining
3.Open Pit Mining
4.Auger Mining
Contour Strip Mining
This type of mining method is primarily used for extracting coal seam from rolling or hilly terrain. This method consists of removing the overburden over the ore material material, then starting to outcrop along the hillside. This creates a bench around the hill. Historically, creating bench on a hill was by carrying the spoil down using a shovel. The stripping ratio if remains favorable the method will be continued. On the contrary, if there are sufficient reserves of ore under the knob the hill, the mining then will be underground mining.
Area Strip Mining
This mining method, applied on flat area of land, starts with removing overburden in a pattern of trenches also known as box cut. These trenches run the whole length of the claim. A second cut would be prepared by removing the overburden and stored in the void of the first cut. This methods are successively used till the stripping ratio is acceptable and is economical.
Open Pit Mining
In this method of surface mining, they make several layers of cuts and form benches of strata and coal seam. This method is particularly advantages where the mineral is present in thick layers overlain by overburden. This overburden is generally thin but can be thick in specific areas. In the initial stages of mineral extraction, a lot of material has to be removed.
Auger Mining
In this mining method used in conjunction with the above methods primarily contour strip mining. In this method, auger holes are drilled to extract the coal seam from the last contour cut. To put it in prospective it is similar to the shavings of a carpenter’s bit. This method have shown recovery rates of around 60 percentage. The holes made in this method use a special type of cutting head which are as high as 2.5m.
I will be be ending my blog today here. For more information and topics you want to learn about. Please comment in the article and I will make sure they are covered in future topics.
