CoMMERCIAL Production

Mining - the accessing/removal of minerals from the earth - is a complicated operation requiring methods tailored to each ore deposit. Open pit mining is used to mine ore deposits close to the surface. Huge shovels and trucks deliver a steady supply of ore to the mill. Underground mining requires more intricate methods to access/remove ore. The underground mine is a complex operation transporting workers, equipment, supplies and ore; pumping groundwater; and supplying power, water and fresh air.

Ore from the mine is transported to a mill for crushing and grinding. Once the ore is reduced to a sand-like fineness, minerals are separated with the use of chemicals (flotation), gravity, magnetism and electrical conductivity. Flotation, the most common method, involves adding water and "air-seeking" chemicals to the ore. The chemicals adhere to the minerals and rise like bubbles to the surface. The froth is skimmed, dried, filtered and shipped as mineral concentrate.

After separation, metals are recovered from minerals by smelting, acid leaching and even bacterial activity. The refining process then produces purified metal products tailored to client needs.

Separation and recovery extract many different minerals and metals from the same rock. The remaining ground rock (tailings) is pumped to tailings ponds. Gases and water used in production are treated and then released or reused. Milling, separation, smelting and refining are controlled by specific conditions set out in a mine's permits and Environmental Compliance Approvals. Mines must monitor their impact on air and water quality and prepare public reports summarizing effluent and emissions data.

Any changes to a mine's operations or surrounding environment must comply with provincial standards and be added to the mine's closure plan.

Learn more at the Ontario Ministry of Northern Development and Mines. Read the Exploration and Mining Guide for Aboriginal Communities.  

Vale miners in front of computer screens