Course:SPPH381B/TermProject/Alkaline battery- Samin/Open pit and underground mining

Introduction

Graphite is a natural form of carbon characterized by its hexagonal crystalline structure. It is extracted using both open pit and underground mining methods. Although the naturally occurring ore is abundantly found and mined in many countries, including the U.S., the largest producer of graphite is China, followed by India. Graphite is the only non-metal element that is a good conductor of electricity.

Open pit mining is a method of extracting rock or minerals from open pits, like quarries and burrows

Open pit mining Open pit mining involves extracting rock or minerals from an open pit or burrow. Open pit methods are used when the ore is close to the earth and the surface material covering the deposit is thin. Quarrying is a form of surface mining employed to obtain graphite by breaking the rocks either by drilling or by using dynamite explosives to cut open the rocks and compressed air or water to split it. Bore hole mining that is common to both open pit and underground methods involves drilling a hole to reach the ore, making a slurry using water through a tube and pumping back the water and mineral to the storage tank for further processing. Drilling and blasting methods are used on hard rock ore to liberate large-sized graphite flakes that are then crushed and ground before being subjected to flotation. The extracted graphite is brought to the surface by locomotives or, in developing countries, handpicked, shoveled and pulled in a cart and moved to the plant for further processing.

Underground hard rock mining refers to various underground mining techniques used to excavate hard minerals, mainly those containing metals such as ore containing gold, silver, iron, copper, zinc, nickel, tin and lead, but also involves using the same techniques for excavating ores of gems such as diamonds.

Underground mining Underground mining is done when the ore is present at a greater depth. Drift mining, hard rock mining, shaft mining and slope mining are exclusive to underground mining and are employed in graphite extraction.Shaft mining is employed to reach the deepest ores. There are shafts or tunnels for miners and heavy equipment to move in and out. A different shaft is used for transportation of extracted ore and an air shaft for ventilation. Slope mining is done with slanted shafts that are not too deep and helps to extract ore that occurs parallel to the ground. Conveyors are used for transporting men and load using separate shafts. Drift mining, mostly done in mountainous regions, is common in the eastern U.S.; it has horizontal tunnels made lower than the mineral vein for gravity-aided extraction.

List of hazards

Physical hazards

1. Rock falls

2. Fire

3. Explosions

4. Mobile equipment accidents

5. Entrapment

6. Noise-induced hearing loss

7. Tunnel collapse and land subsidence

Chemical hazards

1. Asbestos-like minerals exposure

2. Dust inhalation-graphite pneumoconiosis

3. Toxic and radioactive elements exposure (from residual rock slurries)

Biological hazards

1. Malaria

2. Dengue fever

3. Leptospirosis and ankylostomiasis

Ergonomic hazards

1. Ankle and knee injuries (due to broken ground)

Psychological hazards

1. Fatal and severe traumatic injuries