What are the main methods of mining? (2024)

FAQs

What are the 4 main mining methods? ›

There are four main mining methods: underground, open surface (pit), placer, and in-situ mining. Underground mines are more expensive and are often used to reach deeper deposits. Surface mines are typically used for more shallow and less valuable deposits.

Open-pit mining

Open-pit is one of the most common mining methods used and starts from the earth's surface, maintaining exposure to the surface throughout the extraction period.

The mining industry operates through a sequence of stages: exploration, discovery, development, production and reclamation. All stages of this Mining Cycle provide direct economic stimulus.

While there are numerous types of mining processes, the most common is surface mining. Other types of mining include underground mining, placer mining, and in-situ mining. There are advantages to each as each uses specialized equipment suited for a variety of purposes.

The three most common types of surface mining are open-pit mining, strip mining, and quarrying. See also mining and coal mining.

The two major categories of modern mining include surface mining and underground mining. In surface mining, the ground is blasted so that ores near Earth's surface can be removed and carried to refineries to extract the minerals.

There are three main classes of process mining techniques: process discovery, conformance checking, and process enhancement. In the past, terms like workflow mining and automated business process discovery (ABPD) were used.

Coal mining is a lot more dangerous than salt mining, mainly because of the combustible gases such as methane as well as toxic gases such as carbon monoxide. Potentially explosive coal dust is regularly created during the mining process, and explosions can be caused by even a minor spark in the mining equipment itself.

Open-pit mining, one of the most common forms, is one of the most damaging. Miners hollow out a section of land, digging down to create a workable area and extract valuable raw materials. This method leaves behind large pits in the earth and can contaminate the groundwater with chemicals used in the mining process.

Hard rock mining extracts gold encased in rock, rather than fragments in loose sediment, and produces most of the world's gold. Sometimes open-pit mining is used, such as at the Fort Knox Mine in central Alaska.

How long does it take to mine 1 oz of gold? ›

Let's say that yields a quarter of a gram, which amounts to about 0.75 grams of gold per hour, and that gives just about 42 hours to get an ounce of gold by panning in a typical but decent spot.

Miners use heavy mining machinery to drill wide steps known as benches, which separate the rock containing gold (ore) from the rock with no economic quantities of gold (waste). Next, blasting occurs to break down the rock making it easier to move.

Advantages of surface mining include lower cost and greater safety compared to underground mining.

Subsurface mines are some of the safest, according to records kept by the Mine Safety and Health Administration. They have less risk of surface hazards like flooding, subsidence, and landslides that can occur with open-pit mining.

The oldest-known mine on archaeological record is the Ngwenya Mine in Eswatini (Swaziland), which radiocarbon dating shows to be about 43,000 years old. At this site Paleolithic humans mined hematite to make the red pigment ochre.

The oldest form of room and pillar mining--conventional mining--uses a 4-step process where the coal seam is cut, drilled, blasted and then loaded into cars. The more prevalent form of underground mining today is continuous mining.

More than 90 percent of the world's gold has been produced following the rushes of the mid- to late 1800s [source: World Gold Council]. The entire process of gold mining can be broken down roughly into four steps: prospecting, mining, extracting and refining.

In particular, surface mining is used to retrieve sand, gravel, stones, coal, iron and other metals. There are five recognized types of surface mining, each with specific variations depending on the minerals being extracted. These include strip mining, open-pit mining, mountaintop removal, dredging and highwall mining.