Mining Classroom

INTRODUCTION Longwall Mining Method is a very popular method of Coal Mining. It is widely in all over the word. In this method, mining is done below the ground by forming a long face(60 to 200m). The production of Longwall Mining Method is by Shearer Machine. It is maintain a continuous line of advancement leaving behind a goaf or void. The roof is supported by packing the packing of stand or other crushed stone(partially or completely) to prevent collapse. Only a few meter is left from face (up-to 3 to 6m) and it is supported by timber, steel props, bars or chocks.  ADVANCING I n Longwall Advancing, the extraction of coal is from the vicinity of shaft and advance towards the boundary of mine. Face is approached by parallel roads. The over may support by sand or pack wall or allow to cave in. RETREATING  In Longwall Retreating pair of headings are in solid coal at certain interval to the pre-determined boundary. The extraction of coal is from the bo...

Bord and Pillar Method of mining involves in the formation of roadways and the development of Mines. The first stage of working of Bord and Pillar Method is Called Development. In the development stage parallel roads are driven nearly at right angle to the first set. These roads are also use to join the separated coal blocks. The network of roads regularly increases as development of the mine. The second stage of working of Board and Pillar Method  of mining is called Depillaring. The Depillaring can be understood by It's name(De-Pillaring). In Depillaring the working involves in the extraction of coal from the Pillars. These are two stages of this mining method. The another name of Bord and Pillar method is "Pillar and Stall". For the application of Bord and Pillar Method there are some conditions to be full filled. Conditions are.... •The thickness of seam seam should be more than 1.5m. •There is less amount of dirt bands present in seams. •Se...

Before firing a shot, it is important to drill holes and drill holes are followed by different Drilling Patterns. The selection of Drilling Patterns are different to satisfy the different conditions. So now we will know the different Drilling Patterns which are used(one by one). • Drilling Patterns are also known as shot-hole patterns. 1. Pyramid or Cone cut :-  In this type of drilling the pattern of holes something alike pyramid or cone. Pyramid cut involves the drilling of holes in centre and also at the side which meet at a point at the back. Now in modern design of cone cut involves in forming of polygon, in this also holes meet at a point with central hole. It's depth is restricted up to 60% to the width of drift. 2. Drag Cut :- It is used for smaller drift of 1.8m to 2.4m width. By making the angle so that the strata breaks along to cleavage plane. 3. Wedge Cut :- In this cut holes are drilled, whose angles are less than 45° and the centre meet along a line at...

As we know the Flame Safety Lamp having different components and the function of each component is different and also their important. So, it it important to know about every component and their function... So let's know....... 2-D of Flame Safety Lamp The above figure may not be appropriate but you can understand almost every part of lamp.. 1. Oil vessel :- It reserves oil. 2. Wick adjuster :- It is used to adjust height of wick. A pointer is passes from oil vessel and welded at the bottom of vessel. By this we can adjust height of flame without opening the lamp. 3. Wick Holder :- It is a small narrow tube. 4. Glass Holder :- It is threaded with bonnet on which the glass rests. 5. Asbestos Ring :- Two rings are use for the safety purposes which makes the glass joint leak proof. One ring is at the top of glass and other the bottom. 6. Combustion Chimney :- In combustion chimney the gases passes after the combustion. 7. Outer and Inner wire gauze :- The wire gauze i...