Mining & Quarrying

Built for environments wheregas, dust, water, and distancedefeat standard equipment

The problem with electric drives underground

"A mine explosion does not start with a catastrophic system failure. It starts with a single ignition source in the wrong place at the wrong moment and in an underground heading, that moment can arrive without warning."

Coal mines present a hazard that is unique in industrial engineering: two separate and simultaneous explosion risks, both capable of catastrophic consequences, both present in the same working environment. Methane gas / firedamp accumulates naturally in coal seams and releases during cutting and drilling operations. Coal dust, generated by every extraction and conveying operation, is itself explosive at concentrations as low as 50 g/m³. In a poorly ventilated heading, both hazards can coexist.

Against this backdrop, the choice of drive technology is not a performance question. It is a safety-critical engineering decision. Standard electric motors generate arc, heat, and electromagnetic energy in the body of the motor. ATEX-certified electric motors contain that energy within explosion-proof enclosures but they remain electrical devices in an environment where every electrical failure mode carries ignition risk. Pneumatic air motors remove the problem at source. Compressed air drives a rotor through mechanical action. No windings. No arc. No surface temperature that could ignite a methane or dust atmosphere.

Globe Airmotors are certified to ATEX Group I: the classification reserved exclusively for underground mines endangered by firedamp and combustible dusts. On surface installations, Group II certification covers the full range of mineral processing, ore handling, and quarrying applications. Every unit shipped for a hazardous area installation carries full certification documentation traceable to the zone and application.

Why pneumatic

Why mining engineers specify air motors over electric drives underground

Six characteristics that make pneumatic air motors the rational specification choice in underground and surface mining environments.

Compressed air is already the fourth utility underground	Most underground mining operations already run compressed air as a primary utility: powering drills, jackhammers, pneumatic loaders, and ventilation systems. Air distribution networks extend throughout the mine, often spanning kilometres of tunnel. Installing air motor-driven equipment in these environments requires no additional power infrastructure, it connects to the existing compressed air ring main. No new electrical cable runs. No additional switch gear in classified areas.
Operates fully submerged in water ingress conditions	Underground mines are wet environments. Groundwater ingress, mine drainage, dust suppression systems, and high-pressure water used in longwall operations mean drive equipment must tolerate continuous moisture exposure. Globe mining-grade air motors are rated to IP65 and IP67 protection against dust ingress and against sustained water immersion. Where an electric motor requires additional sealed enclosures and cable gland protection, an air motor tolerates these conditions as standard.
No ignition source, inherently safe by design	A pneumatic air motor generates no electrical arc, no electromagnetic energy, and no resistive heat in the motor body. In an underground environment where methane auto-ignition temperature is approximately 537°C and coal dust can ignite at concentrations encountered in normal operating conditions, eliminating ignition sources at the drive level is the foundational safety requirement not an add-on protection measure.
Resistant to abrasive dust and vibration	Mining environments generate silica dust, coal dust, and abrasive mineral particulate that accelerate wear in standard electric motors through bearing contamination and winding abrasion. Globe air motors feature sealed, robust vane construction with fewer wear components than comparable electric drives. The absence of windings eliminates the primary failure mode of electric motors in dusty environments. Insulation breakdown from particulate contamination over time.
Full ATEX documentation for site compliance	Mine operators are subject to regulatory inspection under national mining safety legislation and the ATEX Directive. Every Globe air motor specified for an underground or surface classified area application is supplied with full certification documentation Group classification, category, temperature class, and zone suitability for inclusion in the site's hazardous area equipment register. IECEx certification is available for international mining operations outside the EU.
Overload protection	Rock jams on conveyors, material bridging in transfer chutes, and viscosity surges in slurry pump systems are daily operational realities in mining. Stall an air motor and it stops drawing compressed air. No thermal runaway, no winding failure, no electrical protection trip to reset in a classified area. When the obstruction clears, the motor restarts. For operations hundreds of meters underground where the nearest maintenance engineer may take 20 minutes to reach a drive station, that characteristic directly reduces unplanned downtime.

specific applications

Unit operations where Globe air motors replace electric drives

In classified areas, wet environments, and high-dust locations, air motors are often the correct engineering answer.

underground applications - group i classified areas

Longwall & roadheader ancillary drives	Underground pump drives	Gate conveyor belt drives	Ventilation & air door actuators
Auxiliary motors on longwall shearer water systems, spray pump drives, and chain conveyor tensioning systems. Operates in the most demanding classified environment in the ATEX framework and continuous exposure to methane and coal dust during normal operation.	Sump pump and drainage pump drives in underground headings and pump chambers. Permanently wet environments in classified zones. Air-powered drives eliminate sealed electrical enclosures from the pump chamber and connect directly to the compressed air ring main at working pressure.	Auxiliary belt conveyor drives in development headings and gate roads. Overload-proof stall characteristic prevents belt damage when rock falls or material bridging causes sudden load increases. A common occurrence in narrow development headings with limited maintenance access.	Drive and actuation systems for underground air doors, ventilation regulators, and auxiliary fan adjustments. Pneumatic actuation in classified areas requires no electrical components at the point of operation connecting to the compressed air distribution network that already serves the working area.
Group I / M1	Group I / M1	Group I / M2	Group I / M2

surface & processing application - group ii classified areas

Coal handling & preparation plant	Ore screening & crushing plant	Slurry pump drives & applications	Reagent dosing & flotation
Drive systems on coal preparation equipment dense medium vessels, centrifuges, and screen drives. Combustible coal dust is present at concentrations that create Zone 21 classifications at transfer and screening points. Air motors eliminate ignition sources from these classified areas.	Auxiliary drives on screen decks, vibrators, and crusher feed conveyors in mineral processing facilities. Abrasive, dusty environments where electric motor bearing and winding contamination is a consistent maintenance cost driver. Globe motors reduce that maintenance frequency.	Drive systems for slurry pumps transferring ore concentrate, tailings, and process slurries. Corrosive, abrasive slurry environments where motor shaft seals and bearing contamination are primary failure modes. Air motors with corrosion-resistant construction extend drive service intervals.	Precision drive systems for reagent dosing pumps and flotation cell agitators in mineral processing. Chemical flotation reagents including xanthates and other flammable collectors create Zone 2 classified areas at dosing points. Pneumatic drives remove electrical ignition sources from these locations.
Group Ii / zone 21	Group ii / zone 22	Group ii / zone 22	Group ii / zone 2

The Results

mining enviroments

Where Globe air motors are specified across the mining sector

From underground coal headings to open-pit mineral processing, the operating conditions vary but the demand for reliable, certified, low-maintenance drive technology is constant.

Underground coal mining: The most demanding classification environment in mining. ATEX Group I M1 certification required. Dual gas and dust hazard. Globe air motors eliminate ignition risk at the drive level and connect directly to the existing compressed air distribution network.
Hard rock & metalliferous mining: Gold, copper, iron ore, and potash operations. Water ingress, abrasive silica dust, and high-vibration environments from blasting and heavy equipment. IP67-rated Globe motors withstand continuous wet and dusty conditions at depth without additional enclosure.
Ore processing & mineral handling: Surface processing plant handling crushed ore, concentrates, and tailings. Corrosive slurry environments, abrasive dust, and classified areas where fine mineral particulate creates Zone 21/22 combustible dust hazards. Group II certified motors across the processing circuit.
Quarrying & aggregate production: Limestone, granite, and aggregate quarrying. High-vibration environments from crushing and screening operations. Dust-loaded atmospheres at transfer points, crushers, and screening decks. Robust, sealed pneumatic drives on auxiliary equipment reduce maintenance frequency significantly.
Mine dewatering & pump stations: Pump drive systems in underground sump stations and drainage galleries. Permanently wet environments, often in classified areas. Air-powered pump drives require no electrical components in the sump chamber eliminating sealed enclosure requirements and simplifying the maintenance access regime.
Conveyor & material transfer: Auxiliary conveyor drives, belt tensioning systems, and transfer chute vibrators on underground and surface conveying circuits. Overload-proof operation on drives where rock jams occur regularly reduces the cost and frequency of belt damage events caused by stalled electric drives holding full tension.

Pneumatic vs electric underground

The drive specification decision in classified mining areas

ATEX-certified electric motors are used in mining, and for large fixed plant drives on the surface they are often the right answer. Underground, in classified areas where access is limited and conditions are extreme, the calculation changes. These are the factors that drive experienced mining engineers toward pneumatic.

GLOBE Airmotors - Pneumatic	Standard electric motor
No electrical components in the hazardous zone	Requires ATEX enclosure near product zone
Connects to existing compressed air distribution	Additional electrical cable runs in classified area
Inherently non-sparking; no arc under any fault mode	Terminal box arc risk on incorrect reassembly
IP65/67 operates in continuous water ingress	Sealed enclosures vulnerable to sustained water ingress
No thermal runaway in stall or blocked condition	Thermal runaway risk in stall; ignition source in firedamp
Overload stall; no damage, no reset procedure	Thermal overload trips require electrical reset underground
Simple maintenance; no winding inspection required	Winding condition and insulation testing on maintenance schedule
Group I M1 - remains functional during gas detection	May require de-energisation on gas detection (M2)