Mining Glossary for Beginners: Terms You Need to Know

Mining is the process of extracting valuable minerals, metals, and other geological materials from the earth’s crust.

These mineral deposits, which include coal, iron ore, precious metals, and other valuable minerals, are found in various types of rock formations such as sedimentary, igneous, and metamorphic rocks. Mining plays a crucial role in providing raw materials that fuel industries, infrastructure, and everyday products.

Understanding the terminology used in mining is essential for investors, professionals, and enthusiasts alike. The mining industry involves complex processes and specialized equipment, and having a clear grasp of mining terms helps demystify these operations.

This blog aims to provide a comprehensive mining glossary for beginners, simplifying key concepts and terms related to mineral extraction, mining methods, and safety.

By familiarizing yourself with this glossary, you will gain insights into the mining value chain, from exploration and extraction to processing and reclamation.

This knowledge not only enhances your understanding of how minerals are sourced but also highlights the environmental and safety considerations integral to modern mining operations.

Types of Mining Operations

Mining operations can be broadly categorized based on how minerals and valuable metals are extracted from the earth’s crust. The two main types are surface mining and underground mining, each suited to different kinds of mineral deposits and rock formations.

Surface mining is used when mineral deposits are located close to the earth’s surface. This includes methods like open-pit mining, where large quantities of overlying rock or country rock are removed to access valuable minerals such as iron ore or coal seams. Strip mining is another surface technique, often used for extracting coal from sedimentary rock consisting of horizontal layers. Surface mining is efficient for large, shallow ore deposits and is commonly used in coal mining and for bulk commodities.

Underground mining is necessary when valuable mineral deposits are buried deep beneath solid rock or country rocks adjacent to the ore body. Techniques like room and pillar, longwall mining, and drift mining are used in underground coal mines to extract coal seams or precious metals from beneath the surface. Underground mining cavities, such as mine shafts and tunnels, are created to reach and remove ore deposits. This method is essential for accessing mineral deposits in igneous rocks, metamorphic rocks, or deep sedimentary rock layers.

Placer mining targets valuable mineral particles found in riverbeds or alluvial deposits, often using water to separate heavier, valuable metals like gold from lighter waste material.

Each mining operation is chosen based on the type of mineral deposit, the surrounding rock formation, and the depth at which valuable minerals or precious metals are found. Whether extracting pure carbon from coal seams or valuable metals from a vein or mineral deposit, the choice of mining method impacts both the efficiency of actual coal extraction and the environmental footprint of the operation.

360 degree collision avoidance system

A 360 degree collision avoidance system is a critical safety feature in modern mining operations, especially in environments like underground coal mines and coal preparation facilities where large mining equipment operates in confined spaces. These advanced systems use a network of sensors, cameras, and real-time data processing to monitor the position of vehicles, machinery, and personnel within and around the underground mining cavity.

Source: Wabtec Corporation

By constantly scanning the environment, the system can detect potential hazards, such as other vehicles, solid rock walls, or workers in the vicinity. When a risk is identified, the system issues immediate advisories or warnings to operators, and in some cases, can automatically take preemptive actions to avoid collisions. This technology is particularly important in coal mines, where visibility can be limited by coal dust or poor lighting, and where the movement of heavy equipment in close quarters poses significant safety challenges.

The integration of 360 degree collision avoidance systems with mining equipment not only helps prevent accidents but also improves operational efficiency by reducing downtime caused by incidents. As mining operations become more automated and complex, these systems play a vital role in protecting workers and ensuring the safe extraction of valuable minerals, iron ore, and other resources from both surface and underground mining sites.

A

Adit is an underground tunnel on a mine that follows a seam or vein of ore, which can be used for access or drainage purposes.

Alloy stream is a patented process which is used to convert ore directly into a metal. The process, which was developed by a company called Exxaro, is cheaper and more environmentally friendly than other similar approaches.

Assay is the testing of an ore to determine the content of valuable minerals.

Automation is a technique of making an apparatus, process, or system operate automatically. It is the creation and application of technology to monitor and control the production and delivery of products and services.

B

Back the roof or upper part in any underground mining cavity.

Base metals natural metals, such as copper and nickel, that are more readily available and less expensive than their precious metal cousins such as gold.

Bed: a layer or stratum of minerals.

Bench, a coal mining term used to describe the horizontal low ledge or floor on which material is quarried or worked on, or a geological subdivision of a coal seam separated by slate or created during the cutting process.

Beneficiation is any process that improves the value of ore by removing waste.

Bioleaching is an environmentally friendly method of extracting precious metals, such as gold, from the ore in which it is embedded by using bacterial microorganisms.

Blast hole: This is a hole drilled into a material due to be blasted to contain the explosive charge.

Blind sink the establishment of a ‘hole’ in the ground from surface to a required depth, by creating a shaft collar and then drilling, blasting, loading the blasted rock to the surface, and shaft lining.

Bord and pillar mining is a system of coal mining in which tunnels are driven in a checkerboard pattern with massive square pillars between them. These are gradually cut away as the work proceeds.

Broken ore: ore that has been physically broken down or fractured, often during extraction or crushing processes. Broken ore is easier to process and may indicate ore that is no longer intact.

Brownfield exploration: exploration work that’s done close to or at existing mines.

Bulk commodity: the raw form of products such as iron ore and coal that is shipped and sold in large quantities.

C

Coal combustion: The process of burning coal to produce energy, typically in power plants or industrial facilities. Coal combustion releases emissions such as sulfur oxides, nitrogen oxides, carbon dioxide, and particulate matter, which contribute to air pollution, acid rain, and climate change.

Coal crushing: the process of reducing large chunks of coal into smaller, manageable sizes using crushers or breaker machines. Coal crushing is essential for preparing coal for transport, sale, or further processing.

Combines coal crushing: refers to the mechanical process of reducing large pieces of coal into smaller, more manageable sizes using industrial machinery called coal crushers or grinders.

Coal gas: a combustible gas formed primarily of methane, produced during the decomposition of coal or organic matter in coal mines. Coal gas can pose explosion risks if accumulated and must be carefully ventilated, detected, and managed for mine safety.

Coal gasification: a process that converts coal into gaseous fuels or chemicals through chemical reactions. Coal gasification is an advanced clean coal technology that can reduce emissions and improve the efficiency of coal resource utilization.

Coal mining term: a phrase or word used to describe specific processes, equipment, or features in coal mining, such as ‘Bench’ for a subdivision of a coal seam.

Combustible gas formed: refers to gases like methane generated from the decomposition of coal or organic matter in mines. These gases are hazardous due to their explosion risk and require proper ventilation and detection systems.

Collar: the term applied to the timber or concrete around or on top of a shaft; the starting point of shaft or drill hole at the surface.

Concept study: a business case to determine whether it’s worth proceeding to extract ore from a specific area or mine.

Comminution: the process of reducing the size of a particle by crushing and grinding it, using crusher machines.

Concentrate: what is left after the raw ore has been ground down and the waste has been removed.

Core or core sample: a sample of rock that has been drilled out of the potential mine area.

Crushed ore: ore that has been mechanically broken down into smaller pieces in preparation for further processing steps such as amalgamation, smelting, or other metallurgical methods.

Crushing rock: the process of breaking down large rock and mineral material into smaller, manageable pieces using crushers or similar equipment, often as part of coal or ore preparation.

Cut off: low grade ore that can just about be mined profitably.

Collision avoidance system: these are systems installed to help vehicles and heavy machinery at mines avoid each other and people in adverse condition such as dust, fog or heavy rain.

D

• Decline tunnel: this is a tunnel driven from the surface towards the base of the mine to allow vehicles and equipment to go in and out of the mine.
• Deposit: this term is used to describe an amount of ore or mineral that makes exploitation worthwhile.
• Diamond drill: a drill used to collect core samples from rock.
• Deposit: an amount of ore or mineral that makes exploitation worthwhile.
• Drift: a horizontal passageway underground, which follows the vein or seam of the mineral ore.
• Drift mine: an underground coal mine that is accessed above water level. These are usually situated on the slope of a hill.
• Drill holes: holes created in rock or coal faces using drilling equipment such as percussion drills and carbide bits. Drill holes are essential for exploration, blasting, sampling, or installing supports in mining operations.

E

• Electro-refining – the use of electrolysis to improve the purity of the metal extracted from ore.
• Electro-winning – a process that uses electric currents to remove metal ions from liquid solutions, usually to recover precious metals.
• Endowment – the full economic potential of an area due to be mined.
• Enhanced flue gas desulfurization: advanced scrubbing systems that chemically or physically remove sulfur compounds from emissions during coal combustion, providing improved air pollution and acid rain control compared to standard flue gas desulfurization.

F

Face drilling – a method used in conventional mining to drill a hole in the coalbed for inserting explosive charges. The holes are drilled into the rock and packed with explosives.

Fine-grained – a material consisting of very small particles, each with an average size smaller than 1 mm in diameter.

First class ore – ore of sufficient quality to be sent to market without any treatment or processing.

Fleet monitoring collision avoidance system – the basic hardware and software infrastructure required to provide fleet monitoring capabilities. This system provides information about haul truck utilization without any additional communication infrastructure.

Float – pieces of rock that become separated from the main body over time.

Flue gas desulfurization: a chemical or physical process, often called ‘scrubbing,’ that removes sulfur compounds from emissions produced during coal combustion. Flue gas desulfurization helps reduce air pollution and acid rain.

Fluidized bed combustion: An advanced coal combustion technology where crushed coal and limestone are suspended in a bubbling, liquid-like bed of hot air. This process allows for cleaner and more efficient burning of coal, removing sulfur and other pollutants during combustion.

Footwall – the area below where ore is present in a mine.

Froth flotation – a process used to separate water-loving materials from material that repel water. In mining it’s used to separate valuable mineral or metal from waste material making making it gather on the surface of a ‘froth’ layer.

G

Gangue – the worthless material surrounds or is mixed with the mineral in ore.

Geologic and chemical analysis: the evaluation and characterization of mineral deposits and coal seams by analyzing rock formations, mineral content, and chemical properties. Geologic and chemical analysis supports resource quality assessment, deposit location, and mining decisions.

Grade – the amount of mineral contained in a piece of ore.

Grind – to crush ore into grains or powder.

Ground-penetrating radar – radar used to scan images of what lies beneath the surface.

H

• Hanging wall – the area above where the ore is present in a mine.
• Hazardous air pollutants –

toxic emissions such as gases and dust produced during mining and coal combustion. Hazardous air pollutants must be monitored and controlled to ensure safety and compliance with environmental regulations.

• Heating coal –

coal used for home heating, cooking, and industrial processes. Heating coal is valued for its high heat value and purity compared to other coal varieties.

• High volatile bituminous coals –

a rank of bituminous coal characterized by high volatile matter content, high Btu value, and suitability for metallurgical processes such as steel manufacturing. High volatile bituminous coals are used for energy production and industrial applications.

• Hydrometallurgy – a method of extracting minerals/metals from ore using water-based liquids.

I

• Integrated gasification combined cycle –

an advanced power generation technology that converts coal into gas using coal gasification, then uses both gas and steam turbines to generate electricity. IGCC offers cleaner and more efficient coal-based power with reduced emissions.

• Iron ore – rocks and minerals from which metallic iron can be profitably extracted.
• Inbye – the direction in a coal mine away from the pit shaft towards the coal face.

J

• Jig – a machine used to collect concentrates of ore.

K

• Koepe winding – a system of winding, using the friction between the winding ropes and the drive pulley, used in coal mines. It was developed in Germany and introduced to England by the National Coal Board.

L

• Leaching – a method of extracting minerals from ore using a technique that converts them into soluble salts in a liquid.
• Life of mine – the plan for the way in which a company will mine in a particular area and for how long.
• Liberation – the crushing, grinding and sieving of ore.
• Load haul dumper – these vehicles are used in underground mines to load and transport ore and minerals. They can be operated manually or automatically.
• Lode – a mineral deposit contained in solid rock.
• Longwall mining – a form of underground coal mining where a long wall of coal is mined in a single slice.

M

• Medium volatile bituminous coals –

a classification of bituminous coal with medium levels of volatile matter, positioned between high volatile and low volatile bituminous coals. Medium volatile bituminous coals are valued for their heating value and carbon content, and are used in industrial and energy applications.

• Metallurgy – the art of working metals, especially extracting them from their ores.
• Middle rank coal –

coal that is intermediate in the coal rank hierarchy, such as bituminous coal. Middle rank coal forms between subbituminous and anthracite, and is important for industrial and energy uses.

• Mine value chain – the entire mining process, from the moment the potential of an area is identified to the day product is delivered to customers.
• Mine recovery – the percentage of mined ore that makes it to the processing plant.
• Mineral – a chemical compound, such as copper or iron, formed into crystals by geological processes.
• Muck – in open pit mining, muck is the ore that has been broken into pieces by explosives. In underground mining, muck is the clearing up that’s done after blasting to sort the rich ore from the poor rock.

N

• Non-destructive testing – a way to measure the integrity of materials or structures, without causing any harm.

O

• Opencast mining – a method of mining rock or minerals by removing them from an open-pit mine situated close to the surface above ground.
• Ore deposit –

a natural occurrence of minerals or metals in sufficient quantity and concentration to make extraction economically viable. Understanding and classifying ore deposits is essential for exploration, mining, and resource estimation.

• Outbye – going towards the pit shaft from the coal face.
• Outcrop – a place where a coal seam is exposed at the surface.
• Ore – rock from which we can extract valuable minerals and metals.

P

• Pit de-watering – the removal of water by pumping or evaporation to remove or drain groundwater or surface water from a site or mine shaft.
• Precious metal – rare and sought-after, naturally occurring metallic chemical elements regarded as investments or used in industry. Examples include gold, silver and the platinum group metals or PGMS: ruthenium, rhodium, palladium, osmium, iridium, and platinum.
• Pre-feasibility – a detailed examination of the business case for mining in a particular location.
• Processing – extracting metals and minerals from ore and then purifying them.
• Process recovery – the percentage of product we can extract by processing.
• Production – the amount of ore mined in a specific timescale, which is often measured on a quarterly basis.

Q

• Quartz – one of the most abundant minerals in the Earth’s crust
• Quartoze – sedimentary rock made up primarily of quartz.

R

• Refine – to produce the pure state of a commodity from its ore.
• Rehabilitation – leaving the mine area in the condition in which you find it or the condition agreed with the local community.
• Reject – the coarse (pebbles) and fine (tailings) waste produced at processing plants.
• Reserve – resources of coal, ore or minerals which can be mined profitably under existing conditions.
• Resource – a naturally occurring liquid, solid or gas in the earth’s crust that can be extracted for profit.
• Rock or vein material: material that fills voids or occurs as distinct formations within a mine, such as veins of minerals or the rock surrounding them. Understanding rock or vein material is important for mining support, stability, and mineral extraction.
• Rock surrounding: the rock that encases or is adjacent to mine workings. The stability and characteristics of the rock surrounding tunnels and shafts are critical for mine safety and structural integrity.
• Roof bolting –

a common application in underground coal mines for securing the mine roof to be self-supportive.

• Run of Mine (ROM) – Run of Mine (ROM) – ore that’s mined and ready to go to the processing plant.

S

Seam – an underground layer of a mineral such as coal.

Shaft – a column that runs down to the bottom of the mine. It is used to transport people, ore and equipment up and down the mine.

Shaft sinking – the activity of establishing a vertical or declined tunnel to obtain the precious metal and/or mineral.

Slope stability – the walls of a pit have a certain slope (stepped, benched or side) determined by the strength of the rock mass and other factors. The stability of these walls and even of individual benches and groups of benches, is very important particularly as the pit gets deeper. Increasing the pit slope angle by only a few degrees can decrease stripping costs tremendously or increase revenues through increased ore recovery.

Solid coal ahead: refers to the intact, unmined coal seam in front of the mining face. Solid coal ahead is significant for geological stability and planning extraction activities.

Stripping ratio – the amount of waste rock mined relative to the of ore rock mined.

Stope – a step-like excavation that’s formed as ore is removed from around the mine shaft.

T

Tailings dam – a dam used to store the waste byproducts or tailings produced during the process of extracting the valuable commodity/product from ore.

Term used to describe: a placeholder phrase for technical definitions or descriptions of equipment, processes, or features within mining operations, emphasizing the need for clear terminology.

Tunnel boring machine – a machine that is used as an alternative to drilling and blasting. These machines can excavate tunnels with a circular cross-section and can bore through anything from hard rock to sand.

Transformation – the refining and smelting of metal.

V

Vein: a fracture or crack in a rock that contains mineralised material.

Vug: a small to medium-sized rock crevice or cavity.

W

Waste: rock that is mined but not processed.

Working face: the location where ore and waste are removed from solid rock.

Other Terms

Bituminous coal

A middle rank coal with significant industrial and energy uses. Bituminous coal is positioned between subbituminous and anthracite in the coal rank spectrum, has a high carbon content, and is commonly used for electricity generation and metallurgical processes.

Constantly extracts coal

Refers to continuous mining systems or machinery that operate without interruption to perpetually remove coal from the seam, increasing efficiency in mining operations.