Mining iron ore begins at ground level. To uncover taconite reserves, the mine area is first "stripped" of the overburden or glacial drift, comprised primarily of rock, clay and gravel. The overburden is loaded by large hydraulic shovels into production trucks, which haul it to contour dumps. Once prepared, the mine site is cleared of workers and iron ore mining equipment, and the blast is detonated.
After blasting, hydraulic face shovels and larger loaders load the taconite into 205-ton or 240-ton production trucks, which haul it to crushers. The taconite is ground to a fine powder and mixed with water. A series of magnets is run over the mixture. The magnets grab the iron particles and the rest is discarded. For every ton of iron retained, two tons of waste, or tailings, are discarded.
After mining, the iron ore processing of crushing, separating is needed. The mining equipment is vary significantly, and the energy requirements and the opportunities for reduced energy consumption are also different. Iron ore mining equipment has a special place in the global mining industry.
- The application of more efficient vertical roller mill technology has provided opportunities to further reduce the operating costs associated with grinding;
- The application of ball mill technology is indicated to reduce energy consumption by up to 25 percent compared with conventional flowsheets with wet tumbling mills.
- Raymond mill technology is recorded in the last decade, driven by the benefits of increased energy efficiency and supported by improvements in iron ore mining equipment reliability;