Metallurgical services in the nature of metal treating, casting, and refining, for all of the following-- precious metals, bullion, grain, catalysts, sheet, wire, alloys, strips, and foil for use in the manufacture of electrical contacts, wire, plugs and connectors, common metals and their alloys, metal alloy brazing materials in the form of rods, wire, strips and flat stock, water purification electrodes, silver based precious metal alloys, recovery systems comprising canisters, pumps, filters, reservoirs, tubing and cleaners for use in recovering metals from solution, products for jewelry, silver recovery, thin film coating, electrical contacts, silver plating, and compositions for industrial treatment and cleaning drains and pipes of mineral and scale build