Independent R&D for the heavy lubrication basket that opencast and underground mining actually consumes — fire-resistant hydraulic fluid HFC water-glycol and HFD synthetic ester for longwall shearers and roof bolters, asphaltic open-gear lubricant for SAG mills and dragline pinion drives, EP lithium-complex crusher bearing grease with MoS2, high-viscosity conveyor chain oil, biodegradable fluid for underground coal under DGMS guidance, and the wire-rope dressing for dragline boom suspension. Built for the working conditions at Coal India open-cast, NMDC iron ore, Vedanta-Hindustan Zinc, NLC lignite and SCCL coal blocks.
Fire resistance is a statutory requirement underground. The Directorate General of Mines Safety (DGMS), under the Ministry of Labour, requires fire-resistant hydraulic fluid in any mobile or stationary hydraulic system in underground coal — longwall shearers, powered roof supports, roof bolters, continuous miners. Mineral hydraulic oil is not allowed. The two practical chemistries are HFC water-glycol (cheap, water-cooled effect, but limited high-temperature performance) and HFD synthetic ester (more expensive, better lubricity, higher operating temperature). The choice is per-application: HFC dominates longwall and powered supports; HFD-U is preferred for hot-running roof bolters and surface drilling at minehead.
Open gears need tackifier, not just EP. SAG mill girth gears, ball-mill drive pinions, kiln drives and dragline rack pinions are open — lubricant is sprayed or painted onto the mesh and must adhere through vibration, pitch-line velocity above 6 m/s, and atmospheric dust ingress. The defining additive is the tackifier (typically a styrene-butadiene or olefin-copolymer polymer at 1 to 3% in an asphaltic carrier) which gives the lubricant its characteristic "stringy" behaviour. EP additive at 5 to 7% active sulphur protects under shock load. Graphite or MoS2 solid at 5 to 10% gives boundary-film protection.
Crusher bearings see shock load every revolution. A jaw or gyratory crusher main bearing absorbs an impact load every time the mantle closes on a feed lump. A standard EP lithium grease loses its film instantly. The standard answer is lithium-complex NLGI 2 base grease with 8 to 10% MoS2 added — the MoS2 provides a boundary-layer solid film that survives the moment of metal-to-metal contact even when the hydrodynamic oil film is broken. We dose MoS2 to a controlled particle size to avoid blocking the centralised lubrication injectors.
Dust contamination is constant. Coal dust, iron-ore fines and limestone dust enter every oil and grease in a mining environment. The formulation must remain functional with 1 to 3% solid contaminant suspended. Detergent-dispersant chemistry holds the dust in suspension and prevents lacquer buildup on bearing surfaces. We use ash-free dispersant heavily on mining oils for this reason. See our oil formulation service.
| Product | Standard / Specification | Issuing Body | Where It Applies |
|---|---|---|---|
| Fire-Resistant Hydraulic | ISO 12922 HFA / HFB / HFC / HFD | ISO | Underground coal and surface mining hot hydraulic service |
| FR Fluid · India | DGMS Approval · Luxembourg LRMH | DGMS / Lux | Underground coal mine fluid approval |
| Open Gear Lubricant | AGMA 9005 · ISO 12925-1 CKM | AGMA / ISO | SAG mill, ball mill, kiln drive, dragline pinion |
| Enclosed Industrial Gear | AGMA 9005-F16 · ISO 12925-1 CKD · CLP | AGMA / ISO / DIN | HEMM gearbox, conveyor drive gearbox, dragline house |
| HEMM Engine Oil | API CK-4 / CJ-4 · CAT ECF-3 | API / Caterpillar | HEMM diesel engines — CAT, Komatsu, BEML |
| HEMM Gear Oil | API GL-5 · MIL-PRF-2105E | API / US DoD | HEMM differential and final-drive planetary |
| Mining Grease | BIS IS 7623 · DIN 51825 KP2K | BIS / DIN | Crusher, conveyor and mill main-bearing grease |
| Conveyor Chain Oil | IS 1448 · ISO 6743-1 CKE | BIS / ISO | Apron feeder, drag chain conveyor |
| Biodegradability | OECD 301B · ISO 9439 | OECD / ISO | Underground HEES, surface biodegradable applications |
HFC is a water-glycol fluid with 35-50% water content. The water provides inherent fire resistance — the fluid cannot burn until the water boils off. HFC is cheap and DGMS-friendly but is viscosity-limited (ISO VG 46 maximum effectively), operates only up to about 60C continuous, and is hard on pumps because it does not have the same lubricity as mineral oil.
HFD is a synthetic non-water fluid — HFD-R is phosphate ester (excellent fire resistance, narrow seal compatibility), HFD-U is polyol ester (good fire resistance, broad seal compatibility, biodegradable). HFD-U is the modern preferred chemistry: it lubricates like a real hydraulic oil, runs to 130C, and is biodegradable.
Open gears on SAG mills, ball mills, kilns and dragline pinions are sprayed or painted with lubricant that must adhere through severe vibration, pitch-line velocity up to 10 m/s, and atmospheric dust loading. A conventional gear oil simply throws off the gear teeth. The lubricant needs body, stringiness and adhesion — properties that an asphaltic bitumen carrier provides naturally and that a polymeric tackifier reinforces.
Modern lighter-grade open-gear lubricants use a non-asphaltic synthetic carrier with a high-molecular-weight polymeric tackifier for the same effect — they spray cleaner and leave less black residue, but cost roughly twice as much per kg.
DGMS requires fire-resistant hydraulic fluid in any mobile and stationary hydraulic equipment in underground coal mines. The default qualifying fluid is HFC water-glycol. Biodegradability is not yet mandatory but is increasingly specified for environmental compliance — particularly where mines are near surface water or where rehabilitation timelines are short.
For open-cast operations, biodegradable hydraulic is increasingly specified by client tenders even when not statutorily required — environmental clearance conditions often reference biodegradable lubricants. HEES synthetic ester is the dominant compliant chemistry.
Tell us which mining lubricants you need (FR hydraulic, open gear, crusher grease) and which sites you are supplying. We respond within one business day.