Open Cut and Underground Mining | iMINCO

Open Cut and Underground Mining

What are the differences between open-cut and underground mining?

Open Cut Mining

There are many differences between open cut and underground mining.

When minerals and deposits are found close to the surface and spread across a large distance, the best way to mine is to use the open cut mining method.

In this process, the area is cleared of all topsoil and vegetation, this material is stockpiled and used later when rehabilitating the area once mining is finished.

Next the waste rock layer is removed and a pit is dug into the ground to reach the mineral seam. A sloping road is created for transporting the unprocessed mineral out of the pit.

Explosives are used to break up the ore which is then scooped into large haul trucks by front end loaders or large electric shovels and transported to a processing plant.

The mineral is extracted from the ore and the material remaining (known as tailings) is deposited in a tailings dam and covered with clay, topsoil and vegetation.

Once the mine has been depleted and all work has been completed, the leftover rock and soil will either be covered with topsoil and revegetated to create new landforms, or it can be used to fill and re-vegetate the pit.


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Sometimes the pit is used as a storage area for water or for other uses after consultation with the local community.

Underground mining longwall

Underground Mining

Underground Mining is generally used for areas where the mineral seam is too far underground for open cut mining to be of use.

A tunnel, called a decline, is created to allow workers and machinery to reach the location of the minerals. Stope mining is used for most hard rock mining of minerals such as copper, silver, lead and zinc.

Stopes are large openings or rooms connected by tunnels in which miners drill and blast the ore. A pillar or wall is left between each room (stope) to prevent the mine from collapsing. After drilling and blasting, the ore is removed using remote controlled vehicles or boggers.

One of the main pieces of equipment used in this room and pillar type of stope mining, is a machine called a Continuous Miner which breaks the coal seam mechanically by using a long rotating drum which has picks around the outside, it is then transported to the surface using a combination of shuttle cars and conveyor belts.

Long Wall Miners are another piece of machinery, sometimes remotely controlled, which can be used after the Continuous Miner has cleared the tunnel and roadways. This technique uses tunnels which are about 1500m long and 250m apart. The unit moves along the coal face allowing the roof over the area behind the face to collapse, after it has finished its 1500m journey, it is moved to a new location.

When the Long wall Miner is used, the roof of the tunnel is reinforced using large hydraulic jacks connected to the machine, as a measure to maintain the safety of workers and machinery in the underground environment. Remote controlled Longwall Miners are now used in many Australian mines.

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Open Cut and Underground Mining

Learn more about the Bowen Basin mining location.

The Bowen Basin contains the largest coal reserves in Australia. This major coal producing region contains one of the world’s largest deposits of bituminous coal.

The Basin contains much of the known Permian coal resources in Queensland including virtually all of the known mineable prime coking coal. It was named for the Bowen River, itself named after Queensland’s first Governor, Sir George Bowen.

The Bowen Basin covers an area of over 60,000 square kilometres in Central Queensland running from Collinsville to Theodore and is dotted with many coal mines operated by multiple mining companies.

Caterpillar Haul truck 793

Caterpillar Haul truck 793

The 793F has a load cpacityof 226.8 ton (US) and a top speed of 60 kilometres an hour. It's a turbocharged air-to-air aftercooled diesel engine that has enhanced power management capability for maximum hauling performance. The C175-16 is a 16-cylinder, four-stroke design that uses long, effective power strokes for optimum efficiency.

The 793F, is an autonomous-driven truck. Over 100 793F trucks are now operating via Command for hauling, the Cat autonomous truck operations system, which is a part of Cat MineStar™

Read more about the CAT 793 automomous mining dump truck on our website.

Resources and Infrastructure Industry (RII)

Commonly refered to as Black Coal Competency (BCC), the RII competency is one that can be attained by an operator who has previously worked in the industry and has completed a number of operating hours on various types of machinery.

RII competency is granted to prove correct and safe operation of mine site machinery. It is a very useful qualification to have, as it confirms the operator has the required experience and expertise.

Find out more about RII Competencies here

You can transfer your nationally recognised civil Excavator, Front End Loader or Dozer tickets only to RII Black Coal Competencies.

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