Surface and Underground Mining Methods

In different parts of the world, people have their own style of eating such as Chinese eat with chopsticks, Indians eat with their hands, western people eat with spoon, fork and knife. While God knows how these people manage with three; rather than eating focusing on spoons for eating. While this goes true for mining too. Different parts of the world has different types of conditions in which a mineral is found and which led to adopting of different types of mining methods.

These mining methods can be broadly divided into two: 

1. Surface mining methods
2. Underground mining methods 

Child digs a pit to hide his belongings, so does the mining engineer digs a pit to extract the coal out of the mother earth. Extracting the coal from surface by removal of overburden are known as surface mining methods. Mining methods are specifically dependent on the type of the mineral to be extracted which can be classified into soft rocks and hard rocks. The soft rocks include coal, limestone, oilshale and other sedimentary rocks while the hard rocks include gold, silver, iron, copper, zinc, lead, tin and other igneous rocks. Following are the surface mining methods which are commonly used in extraction of a mineral are:

1. Strip mining
2. Open pit mining
3. Open cast mining
4. Mountain removal technique
5. Quarries
6. Highwall mining (Auger mining)
7. Placer mining
8. Solution mining

The minerals which are deep inside the mother earth are not feasible to be extracted by surface mining methods. There are numrerous underground mining methods which can be broadly divide into underground mining in soft rock and Underground mining in hard rock.

Following are the commonly used mining methods in soft rock mines:

1. Room/Bord and Pillar Mining
2. Longwall Mining
3. Shortwall Mining

There exist special type of mining methods depending on the specifications of the site which are:

1. Plowing mining in thin seams.
2. High pressure water jet mining.
3. Blasting gallery method for thick seams.
4. Longwall top coal caving method in thick seams.
5. Multislicing mining method in thick seams.
6. Cut and fill mining method in steep seams.
7. Sublevel caving method in steep seams.
8. Scraper assisted chamber method for moderately dipping seams. 
9. Short longwall method for extraction of standing pillars. 

The underground mining methods in the hard rock mines include:

1. Room and Pillar Mining
2. Post Room and Pillar Mining
3. Step Room and Pillar Mining
4. Shrinkage stoping
5. Sublevel Open stopping
6. Bighole Open stopping
7. Vertical Crater Retreat mining
8. Cut and fill mining (overhand/underhand)
9. Longwall mining
10. Sublevel caving 
11. Block caving
12. Vein Mining (Resuing)

These are the mining methods which are widely used throughout the world. Hope to describe these methods one by one in the upcoming posts. Good luck.