Digging deeper to extract products from the ground is a kind of art. There are different methods that can be apply for digging. The three main methods are- underwater, open-pit, and underground mining. Underwater mining is required when the products are situated in an aquatic environment. Open-pit mining is necessary to extract the products that are located closer to the earth’s surface. And to extract the ore or products from below the surface, underground mining is used. The process used to extract ore is done economically and safely so that as little as possible goes to waste.
If you have an interest in underground mining, read on to know more about it.
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Table of Content
- Underground Mining
- Hard-Rock Underground Mining
- Soft-Rock Underground Mining
- Dangers of Underground Mining
Underground mining is necessary when the ore is too deep to dig out using an open-pit. When the quality and grades of the ore are economically high to cover costs, this method is used. It is practical if it has a footprint of lower ground than open-pit mining. The main equipment used for underground mining are a Caterpillar wheel dozer, Komastu excavator, Sandvik roof bolter, Hitachi dump truck, Caterpillar continuous miner, Hitachi feeder breaker. Some top jumbo drills used in underground mining are Sandvik drill rig, Hitachi drill, etc.
Hard-Rock Underground Mining
Hard-rock underground mining is required to excavate hard minerals containing metals. It refers to different techniques used for excavating minerals like lead, tin, nickel, zinc, copper, iron, silver, and gold. It is also used to excavate ores of gems like rubies or diamonds. Some methods of hard-rock underground mining are:
Cut and Fill
It is a short-hole mining method, used in ore zones that are irregular or steeply dipping. The ore is dug out in slightly inclined slices or horizontally. And sand will fill it, waste rock, or tailing. This method is a selective and expensive one. It has the advantages of low ore dilution and loss.
Drift and Fill
To mine the ore zone with enough width for drifting method they will use drill and fill. In this method, the first drift will advance in the ore, and then consolidate the fill to backfill it. Next, induce the second fill, than continue until it excavate the full-width ore zone.
It is suitable for the orebodies that are dipped steeply. It is similar to cut and fill mining. The broken ore left behind from blasting can be use as a platform to work from, by supporting the surrounding rock. We will drill and blast the next slice after removing enough ore from the stope. We will excavate the ore slowly, therefore a delay in the return of investment in this method will happen.
Vertical retreat mining (VRM) is a selective mining method that is used to divide mines into vertical zones. It is also known as Vertical crater retreat (VCR). It divides the mines with a depth of about 50 meters. This method use open stopping, a bottom-up mining technique.
It is one of the bulk mining methods. It is necessary to excavate steeply dipping orebodies that has a low grading and have high friability. In this case, drilling a part of ore is very necessary at the bottom of the deposit that we select, after blasting the roof collapses under its weight With the help of gravity, we will haul out and excavate the ore adjacent to the fracture structure for processing.
Room and Pillar Mining
Generally we do this in gently dipping or flat bedding or bodies. To mine out the rooms, using a regular pattern, placing a pillar is important. The roof of the rooms must collapses to get the ore from the pillars. For this, take the pillars out to fill the stope. This is done from the farthest point of the stope-entrance.
Soft-Rock Underground Mining
Soft-rock underground mining is necessary to excavate potash, oil shale, coal, and other geological materials or minerals from sedimentary rocks. This method is for mining relatively less hard materials. Methods in soft-rock underground mining are:
In this method, a longwall machine cuts through the ore deposits and shaves off slices that are more than 600 feet long. The slices go into a conveyor that moves continuously and carries them to a haulage shaft. The haulage shaft lifts the products out of the mine. It can recover about 90 percent of the ore.
It is an older method that use explosives like dynamite to mine. It was helpful to break up the seam of the coal. Then gather the coals that will be load onto the conveyors or shuttle cars for removal.
Hard rock use the same technique. By using this method, oil shale, salt, phosphate, potash, coal, and bedded uranium ores are excavated. It can recover about 50% of the ore.
Short-wall mining is a general method for coal mining. It is requirement when the ore deposits are comparatively narrow. It involves the usage of continuous mining that has moveable roof supports.
Dangers of Underground Mining
Underground mining can be dangerous with the wrong management. The most common hazards due to mining are listed below:
- Explosions: It is a potential threat that is seen in underground mining. Flammable gases and chemicals are always running through the pipes. It is important to check the ventilation system while working and use warning signs to make the workers careful.
- Cave-ins, rock falls, or collapses: Be aware of collapses while mining. We can systematically do planning or scheduling. it needs an appropriate safety plan and train the workers until they can properly do the work without any risk.
- Fire and noise: The workers must have a proper training so that they can be ready in case of fire. It is important to have correct hearing protection because of the loud equipment and work process to avoid any kind of threat.
- Other risks: Electrical hazards, dust exposure, vehicle hazards are some typical risks that exist in mining works. Checking out all equipment is necessary before starting the work to avoid any threats.
Underground mining is an efficient way to excavate ores from the ground. It needs less human labor. It is a useful way to get the materials out of the surface. Just ensure to take the proper precautions to avoid any kind of dangers and risks. Automation your business with cloud ERP software suitable for multiple types of companies. Take more accurate decisions with the support of the most advanced business management software.