Welcome Guys! for a new blog .
Today I will be discussing Underground mining techniques used in Coal Mining.
In Underground mining, workers go inside the Earth’s crust through a series of opening present in the Earths crust naturally or man made. These cracks are used to access and transport material. Secondary services are provided for human and material transportation, ventilation, water and drainage handling and power for machines. This phase famously known as “mine development”. The material removed by in this phase is known as “First Mining”. All mined coal after this phase is “Second Mining”.
Mining Methods
Underground Coal Mining has had a long history but it has also transformed a lot and I will be discussing four of them. They are:
- Room and Pillar
- Longwall
- Short Wall
- Thick Seam
Room and Pillar
![](https://materials101.science/wp-content/uploads/2021/04/Room-and-pillar-1024x768.jpg)
This is a variation of breast stoping method and is a profitable method of underground mining. In this method a good number of entries. These entries are parallel to each other. In addition to this bigger and wider entries are present at regular intervals to form rooms like structure. The resulting grid formation looks like a structure with thick pillars of coal that supports the overhead Earth.
Long wall
![](https://materials101.science/wp-content/uploads/2021/04/Longwall-1024x768.jpg)
In this method, large batch of area of coal seam approximately 100 to 300m wide and 1000 to 3000m long gets available. This area of mineral deposit is then taken using manual or semi mechanized machines in batches. The area is drilled, blasted and broken coal is transported via a conveyor.
Short Wall
![](https://materials101.science/wp-content/uploads/2021/06/Short-Wall.jpg)
This mining method is similar to long wall mining but on a smaller scale. To be specific they would be 100 m wide and tens of meters thick. The profitable way of removing material in this method is in the continuous mode. In continuous mode material is transported using large face conveyors and other equipment’s. The roof of the mine site is supported using specialized machines.
Thick Seam
![](https://materials101.science/wp-content/uploads/2021/06/Crowsnest-Exploration-reveals-thick-coal-seams.jpg)
This is a type of coal mining method, where the seam thickness is more than 3.5m. These type of mining sites are present in countries like India, Australia, United States, Poland, China. The reserves and production of Thick seam mining accounts for nearly, half of the underground coal resources. The most common ways of this method in use are large cutting height mining and top coal caving method.
So guys we will finish this blog at this point. I will be coming up with blog covering each of the methods.