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Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon , such as carbon monoxide from incomplete combustion of coke —or, in earlier times, of charcoal . [ 1 ]
In operation, after the bloomery is heated typically with a wood fire, shifting to burning sized charcoal, iron ore and additional charcoal are introduced through the top. Again, traditional methods vary, but normally smaller charges of ore are added at the start of the main smelting sequence, increasing to larger amounts as the smelt progresses.
Casting pig iron at the Iroquois smelter in Chicago between 1890 and 1901 The Chinese were already making pig iron during the later Zhou dynasty (which ended in 256 BC). [ 5 ] Furnaces such as Lapphyttan in Sweden may date back as far back as the 12th century; and some in the County of Mark dating back to the 13th century, which is now part of ...
Blast furnaces are currently rarely used in copper smelting, but modern lead smelting blast furnaces are much shorter than iron blast furnaces and are rectangular in shape. [76] Modern lead blast furnaces are constructed using water-cooled steel or copper jackets for the walls, and have no refractory linings in the side walls. [ 77 ]
Steelmaking is the process of producing steel from iron ore and/or scrap. ... It reduced plant capital costs and smelting time, and increased labor productivity ...
Elemental iron is virtually absent 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 Earth's crust, composing about 5% by weight, [4] the vast majority is bound in silicate or, more rarely, carbonate minerals, and smelting pure iron from these minerals would require a prohibitive ...
Copper was initially recovered from sulfide ores by directly smelting the ore in a furnace. [10] The smelters were initially located near the mines to minimize the cost of transport. This avoided the prohibitive costs of transporting the waste minerals and the sulfur and iron present in the copper-containing minerals.
Iron smelting—the extraction of usable metal from oxidized iron ores—is more difficult than tin and copper smelting. While these metals and their alloys can be cold-worked or melted in relatively simple furnaces (such as the kilns used for pottery ) and cast into molds, smelted iron requires hot-working and can be melted only in specially ...