Coal Mining Process Steps: Surface vs Underground

Coal mining process in six stages

The process of coal mining has six basic stages: find and permit the seam, open access to it, cut or expose the coal, haul it out, clean it at a preparation plant, and restore the land. Whether a mine works from the surface or underground depends mostly on how deep the coal lies.

This guide follows each stage with US government data, because the US publishes mine-by-mine statistics. The physical steps are similar elsewhere, though the rules differ by country. It is written for mine owners, consultants and investors who want the method, the output per worker hour and the legal duties in one place.

Those stages sit inside the wider stages of a mine, from exploration to closure. Scale matters too: the IEA expected world coal demand to reach a record 8.85 billion tonnes in 2025. In the US, output fell to 512.5 million short tons in 2024 from 578.0 million in 2023, from 524 mines, with 44,060 employees across US coal operations (EIA).

Infographic

Coal mining process in 6 stages

1. 1Find and permitMap the seam and secure the permits.
2. 2Open accessStrip the overburden, or drive shafts and entries.
3. 3Cut the coalUse shovels, longwalls or continuous miners.
4. 4HaulMove it by truck, belt or hoist.
5. 5PrepareCrush, screen and clean it.
6. 6RestoreBackfill, regrade, replant.

Surface or underground: how a mine chooses

The coal mining process divides into two main types: surface mining and underground mining. The choice depends on seam depth, seam thickness, terrain and how much rock (the overburden) must be moved to reach the coal.

• Surface mining: often used when coal lies less than about 200 feet down, according to the US Energy Information Administration (EIA). It produced 59.7% of US coal in 2024.
• Underground mining: used for deeper seams, reached by shafts or sloped tunnels. It produced 40.2% of US coal in 2024; refuse recovery made up the small remainder.

Three things decide how well either method works:

• Recovery: the share of the coal in the ground that actually gets mined
• Environmental control: water discharges, dust and how the land is restored
• Worker safety: roof and highwall stability, methane, dust and moving machinery

Geography shapes the answer. The Powder River Basin of Wyoming and Montana produced 204.9 million short tons in 2024, 40% of the US total, entirely from surface mines (EIA). Appalachia shows the opposite pattern: underground mines produced 125.7 million short tons there in 2024 and surface mines 32.0 million. Modern coal mining and mining insurance have their own guides on this site.

Output per worker hour by method

Labor productivity is the clearest gap. EIA reports 8.94 short tons per employee hour at US surface mines in 2024, against 3.24 underground, and 23.20 in the Powder River Basin. Productivity also fell overall, from 5.66 in 2023 to 5.22 in 2024.

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US coal output per employee hour by mining method

Short tons per employee hour, 2024, selected methods, US

Surface coal mining process steps

A US Department of Energy (DOE) profile of the mining industry, using data from around 2000, says most surface mines follow the same basic steps. Here they are in order, with the legal duties that apply in the US.

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The general method is covered in our guide to surface mining. For coal, DOE groups surface mines into area, contour, mountaintop and auger types. EIA data show the mix in 2024: open pit 134.7 million short tons, contour strip 132.3 million, area 20.8 million, mountaintop 2.1 million and other methods 15.9 million.

• 1. Survey and Exploration
• Drill holes and geophysical surveys map the depth, thickness and quality of the seam.
• Satellite images help with access, terrain and land-cover planning, but drilling is what confirms the coal.
• 2. Land Clearing
• Bulldozers clear and level the mining area.
• Topsoil is removed and stored for reclamation. US law requires it to be kept separate from other spoil and protected if it is not reused quickly.
• 3. Drilling and Blasting
• Holes are drilled through the overburden and loaded with explosives, which shatter the rock.
• Permits and state rules set blasting conditions, so check them with the regulator for your site.
• 4. Overburden Removal
• Power shovels or draglines clear the broken rock until the coal is exposed. A dragline swings a large bucket from a long boom.
• 5. Coal Extraction
• Smaller shovels load the coal onto trucks, which carry it to the preparation plant or a loadout.
• In area mining, the rock from each new cut fills the cut mined before it.
• 6. Reclamation and Restoration
• Spoil is backfilled and graded. US law generally requires the land to return to its approximate original contour, with some exceptions.
• Topsoil goes back on and vegetation is established.
• Satellite images taken over several years can show whether the regrowth is holding, which supports field checks but does not replace them.

Surface mining recovers a high share of the deposit: DOE puts it at as much as 95%. EIA says it is less expensive than underground mining, and 79% of US surface coal in 2024 came from beds thicker than 120 inches (10 feet).

Estimate the stripping ratio

The stripping ratio is the rock moved per ton of coal. Thick, shallow seams give low ratios, which is why they suit surface mining. Use the calculator to test your own seam. It gives a first rough check, not a mine design.

Underground coal mining methods

EIA describes underground, or deep, mining as the choice when coal is more than about 200 feet below the surface. Some mines run thousands of feet deep. These are the usual stages.

1. Shaft Sinking or Incline Development
   • Vertical shafts, or sloped tunnels called drifts and slopes, give access for people, air and coal.
2. Development
   • Roadways called entries are driven into the seam and supported with roof bolts and mesh.
   • These entries also lay out the panels, the blocks of coal to be mined.
3. Cutting the coal: longwall and room-and-pillar
   • Longwall: a shearer moves back and forth across a long coal face under moving roof supports. The roof behind them is allowed to cave. DOE says recovery can reach about 80%.
   • Room-and-pillar: machines cut rooms 20 to 30 feet wide and leave pillars 20 to 90 feet wide to hold the roof. DOE puts recovery at generally 50% to 60%.
   • Continuous miners, the cutting machines used in room-and-pillar work, also prepare longwall panels.
4. Moving the coal
   • Belts, shuttle cars and hoists move the coal from the face to the surface.
5. Ventilation and safety
   • Fresh air is forced through the mine to dilute explosive methane and carry away dust.
   • US rules treat 1.0% methane in a working place or intake air course as an action level: electric equipment is powered down, ventilation must be changed at once, and other work in the area stops until the level falls (30 CFR 75.323).
   • Dust control protects miners from black lung and silica-related disease.

Longwall is the larger method by tonnage: it produced 112.8 million of the 206.2 million short tons mined underground in the US in 2024, or 55%. Continuous mining produced 92.8 million.

What a longwall accident record shows

MSHA, the US mine safety regulator, reports 545 longwall accidents from January 2013 to March 2023, with seven deaths and 333 serious injuries, many during routine work. US underground mines also fall under separate federal performance standards covering their surface effects, such as subsidence and water.

How coal is prepared after mining

Raw coal from the mine is called run-of-mine coal. Preparation, also called washing or beneficiation, turns it into a graded product. DOE lists six levels, from no preparation or crushing only up to the most rigorous cleaning of all sizes.

1. Crushing breaks the coal down to a usable size.
2. Screening sorts it by size.
3. Cleaning removes ash-forming minerals and some sulfur.
4. De-watering and drying remove the process water.

The plant also creates waste and wastewater. In the US, the EPA coal mining effluent guidelines cover discharges from mine drainage, coal storage and preparation plants. Waste storage planning has much in common with tailings management at metal mines.

Safety and production record in numbers

US coal deaths have stayed in single or low double digits in recent years, as MSHA data show. Production has dropped sharply over the last decade, with surface tonnage falling faster than underground.

Chart

US coal production by mine type

Million short tons, 2015 to 2024

Automation and sensors are used in parts of the industry, so ask any vendor for the site, period and baseline behind a percentage claim. Our coal equipment guide covers the machines themselves.

Chart

US coal mining deaths by year

Deaths per year at US coal mines, 2018 to 2025 (MSHA)

Environmental rules for coal mines

The main issues are land disturbance, water and dust. The EPA says Appalachian mountaintop mining puts excess rock into engineered valley fills, which affects streams below them. Mine water can also turn acidic, so the US effluent rules include a separate acid or ferruginous drainage category.

• Land: US law requires backfilling, grading, topsoil replacement and revegetation.
• Water: discharges are regulated under federal effluent standards.
• Practice: see our guide to sustainable mining for wider methods.

Rules differ outside the US. Mining companies in other countries answer to their own regulators, so check locally before relying on any figure here.

Farmonaut, a satellite data company, has separate pages on carbon footprinting, fleet management, product traceability, satellite verification and its API.

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Frequently asked questions

What are the steps of the coal mining process?

Find and permit the seam, open access, cut or expose the coal, haul it, clean it at a preparation plant, then restore the land. Surface mines add topsoil removal, blasting and overburden removal before the coal is reached.

How does a coal mine work?

A surface mine strips away rock and digs the exposed seam. An underground mine reaches the seam through shafts or sloped tunnels, then cuts it with longwall or continuous mining machines while fans supply fresh air.

What is the difference between surface and underground coal mining?

Depth is the main difference. EIA says surface mining is often used when coal is less than about 200 feet down, and underground mining when it is deeper. In 2024 the US had 339 surface mines and 177 underground mines (EIA Annual Coal Report).

How deep is coal mined?

Surface mining is often used when coal is less than about 200 feet down. EIA notes some underground mines are thousands of feet deep.

What are the main underground coal mining methods?

Longwall and room-and-pillar. Room-and-pillar work in the US mostly uses continuous mining machines. Longwall had 55% of US underground tonnage in 2024, and continuous mining 45%.

What are the main types of surface coal mining?

Area mining on flat land, contour mining along hillsides, and mountaintop removal, plus auger or highwall mining to reach coal beyond the final cut. EIA also reports a separate open-pit category.

What happens to coal after it is mined?

Most coal needs some preparation. DOE describes basic cleaning as crushing, screening, cleaning, de-watering and drying, though some coal is only crushed or not prepared at all. Trains then carry nearly 70% of US coal deliveries for at least part of the trip, according to EIA.

What is a stripping ratio?

It is the waste moved for each unit of coal, often given as cubic yards of overburden per ton. A higher ratio means more rock to pay for per ton, so it is a first test of whether a surface mine can work. The calculator above gives a rough figure.

Is coal mining safer than it was?

US coal deaths fell from 1,489 in 1900 to 8 in 2025, while the workforce also shrank from 448,581 to 62,246 (MSHA). The hazards have not gone away: MSHA counted 545 longwall accidents from January 2013 to March 2023.

Do coal mines have to restore the land?

In the US, yes. The Surface Mining Control and Reclamation Act sets performance standards for backfilling, grading, topsoil and revegetation. Other countries set their own rules, so confirm them with the regulator.

Why is coal still mined?

Mainly for electricity and steelmaking. The IEA expected world coal demand to reach a record 8.85 billion tonnes in 2025, with China using more than the rest of the world combined (IEA, Coal 2025).