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Iron ore (banded iron formation) Manganese ore – psilomelane (size: 6.7 × 5.8 × 5.1 cm) Lead ore – galena and anglesite (size: 4.8 × 4.0 × 3.0 cm). Ore is natural rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process.
The huge quantities of nickel ore processed makes up for the fact that platinum makes up only two parts per million of the ore. South Africa , with vast platinum ore deposits in the Merensky Reef of the Bushveld complex , is the world's largest producer of platinum, followed by Russia .
The oxygen in the ore binds to carbon at high temperatures, as the chemical potential energy of the bonds in carbon dioxide (CO 2) is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasted before smelting in order to convert the sulfides to oxides, which are more readily ...
Iron ore was also used as a flux in the smelting of copper. These agents served various functions, the simplest being a reducing agent, which prevented oxides from forming on the surface of the molten metal, while others absorbed impurities into slag , which could be scraped off molten metal.
Metallic iron is virtually unknown on the Earth's surface except as iron-nickel alloys from meteorites and very rare forms of deep mantle xenoliths.Although iron is the fourth-most abundant element in the Earth's crust, composing about 5%, the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive amount of ...
Depending on the processes used in each instance, it is often referred to as ore dressing or ore milling. Beneficiation is any process that improves (benefits) the economic value of the ore by removing the gangue minerals , which results in a higher grade product ( ore concentrate ) and a waste stream ( tailings ).
A native platinum nugget, Kondyor mine, Khabarovsk Krai Platinum-palladium ore, Stillwater mine, Beartooth Mountains, Montana, US Sulfidic serpentintite (platinum-palladium ore) from Stillwater Mine, Beartooth Mountains, Montana, USA. Platinum is an extremely rare metal, [26] occurring at a concentration of only 0.005 ppm in Earth's crust.
The most prominent example is that of iron ore smelting. Many reactions are involved, but the simplified equation is usually shown as: [2] + + Some metal oxides dissolve in the presence of reducing agents, which can include organic compounds.