Smelting
Smelting extracts metal from ore by heating it with a reducing agent, separating the molten metal from waste material such as slag.
Oxidation–reduction reaction: A chemical reaction in which electrons transfer between substances, changing their oxidation states. Smelting reduces metal compounds by transferring oxygen or electrons to a reducing agent.
Ore: Naturally occurring rock or mineral from which a valuable substance can be extracted economically. Smelting begins with ore containing a recoverable metal compound.
Copper smelting: The extraction of copper from copper ores by heating them with fuel and, commonly, a reducing agent. Copper smelting was among the earliest ways people produced metal from ore.
Copper extraction: The processes used to recover copper from ores, concentrates, and recycled materials. Copper production combines smelting with other extraction and refining steps.
Sulfur dioxide: A pungent, colorless gas produced by burning sulfur-containing fuels and processing sulfide ores. Roasting and smelting sulfide ores can release it unless captured.
Carbon monoxide: A colorless gas that forms when carbon burns with limited oxygen and can reduce many metal oxides. In a blast furnace, it removes oxygen from iron oxides.
Metallurgy: The science and technology of extracting, processing, and studying metals and their alloys. Smelting is one stage within the broader practice of metallurgy.
Bronze Age: A period in many regions when bronze became a major material for tools, weapons, and trade. Smelted copper made bronze production possible at scale.
Aluminum smelting: The industrial production of aluminum by electrolyzing alumina dissolved in molten cryolite. It is called smelting, though electricity rather than a chemical reductant drives the reduction.
Acid rain: Precipitation made unusually acidic by atmospheric sulfur and nitrogen compounds. Sulfur dioxide from smelters can form acids that damage ecosystems and structures.