• Businesses engaged in underground mining, not covered by another classification (N.O.C.), involving the extraction of coal, ores, stone, clay, or other minerals;

• Businesses engaged in the manufacture of coke which is a solid carbonaceous residue obtained from bituminous coal after the removal of volatile materials by a distillation process.

• Underground mining and the incidental activities occurring above ground - Underground mining may involve shaft sinking, slope sinking, rock tunneling, and the building of drifts and shafts with heavy timbers or steel beams. Material is broken loose within the tunnel or shaft with explosives, drilling machines, rock drills, chippers, power hand drills, and picks. The material is then removed from underground by hoist, conveyor, or some type of haulage car on steel track. On the surface, some extracted material is further refined. For example, coal is crushed, screened, washed, and graded before being hauled away.

• Manufacture of coke - Coke is a solid carbonaceous residue obtained from bituminous coal after the removal of volatile materials by a distillation process. Coal is fed into crushers which break down oversized pieces. The coal is baked in airless kilns or beehive coke ovens at high temperatures removing volatile materials leaving behind the coke.

• Ore reduction involving heat processes.

• Bulldozers;

• Chippers;

• Communication systems;

• Conveyors;

• Crushers;

• Drilling machines;

• Elevators;

• Explosives;

• Front end loaders;

• Haulage cars on tracks;

• Hoists;

• Lighting systems;

• Picks;

• Pipes to carry water;

• Power hand drills;

• Rock drills;

• Trucks;

• Ventilation systems.

• Ore reduction operations that do not require the use of heat are classified in 1701.

• Open cut mining is classified in 1703.