Applies to establishments engaged in the reduction of coarse ores by a wet or dry process at a mine site. Work contemplated by this classification involves a variety of ore milling activities. The process begins by crushing, screening and washing the ores. Next, ores are placed in a rotating cylindrical mill which contains steel balls, flint pebbles, rods or rock for further grinding. Then with the use of amalgamation (introduction of a chemical such as mercury to break down the ores) or flotation (uses water to separate by buoyancy and densities), the ore material is broken down and dried to obtain concentrated ores of metals. The milling of ores to recover some nonmetallic minerals which do not require amalgamation or flotation are also included within this classification.

This classification excludes underground mining operations which are to be reported separately in classification 1702, and open cut mining operations which are to be reported separately in classification 1703.