Drilling and blasting
Drilling and blasting are crucial steps in open-pit coal mining. Geological surveys and planning precede these operations, determining drill hole placement and explosive patterns. Drills, like rotary or percussion types, bore holes in coal seams and surrounding rock.
Explosives are then loaded into the holes to facilitate controlled fragmentation during blasting, with careful consideration of explosive type and amount. Initiation systems, such as electrical caps, trigger the explosives to break the material into smaller fragments, forming a muck pile. Heavy machinery then removes the broken material for transport to processing facilities.
Safety protocols and environmental measures, including isolation, protective gear, dust control, water management, and habitat restoration, ensure worker safety and minimize ecological impact. Monitoring and coordination are integral to uphold efficient, safe, and regulated drilling and blasting practices.
Frequently Asked Questions
How many stages are there to drilling and blasting to extract coal?
There are 4 stages:
- Drilling: A drill rig is used to create holes in the rock where the explosives will be placed. The drill rig is typically mounted on a truck or trailer and is equipped with a long, rotating drill bit. The drill bit is used to create holes that are typically 2 to 4 inches in diameter and 3 to 6 feet deep.
- Charging: Once the holes have been drilled, they are charged with explosives. The explosives are typically placed in cartridges that are inserted into the holes. The cartridges are then filled with water to prevent them from prematurely detonating.
- Blasting: The explosives are detonated using a blasting cap. The blasting cap is a small, electrically-activated device that ignites a fuse that leads to the explosives. The detonation of the explosives breaks the rock and loosens the coal.
- Removal: The broken rock and coal are then removed from the mine using a variety of methods, such as continuous miners, shuttle cars, and conveyor belts.
What are the environmental impact of drilling and blasting?
- Noise pollution: Drilling and blasting can be a noisy operation, which can disturb wildlife and annoy people living nearby.
- Dust pollution: Drilling and blasting can create dust, which can be harmful to people’s health and can pollute the air.
- Water pollution: Explosives can contaminate water supplies with heavy metals, chemicals, and other pollutants. This can make water unsafe to drink, bathe in, or use for recreation.
- Land disturbance: Drilling and blasting can damage land and ecosystems. Surface mining can remove topsoil and vegetation, and underground mining can create tunnels and shafts that can collapse. This can lead to erosion, flooding, and loss of habitat for plants and animals.
What safety measures do you employ at Breyton Opencancast mine?
- All personnel must be clear of the blast area before the explosives are detonated.
- The blasting area must be fenced off and clearly marked.
- All personnel must wear protective gear, such as hard hats, safety glasses, and earplugs.
- The explosives must be stored in a safe place and handled with care.
- The blasting cap must be properly installed and the fuse must be the correct length.
- The explosives must be detonated using a blasting machine.