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This reduction of slag viscosity with temperature, increasing the flow of slag in smelting, is the origin of the word flux in metallurgy. The flux most commonly used in iron and steel furnaces is limestone , which is charged in the proper proportions with the iron and fuel .
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 ]
The downward flow of the ore along with the flux in contact with an upflow of hot, carbon monoxide-rich combustion gases is a countercurrent exchange and chemical reaction process. [ 3 ] In contrast, air furnaces (such as reverberatory furnaces ) are naturally aspirated, usually by the convection of hot gases in a chimney flue .
The two types are electrodynamic separators (or high tension rollers) or electrostatic separators. In high tension rollers, particles are charged by a corona discharge. This charges the particles that subsequently travel on a drum. The conducting particles lose their charge to the drum and are removed from the drum with centripetal acceleration.
Explosive charges; Flow friction: Heat generated by high velocity oxygen flow over a non-metal Note:Flow friction is a hypothesis. Flow friction has not been experimentally verified and should be considered only in conjunction with validated ignition mechanisms. Friction between relatively moving parts; Fragments from bursting vessels
A combination of molten lead and slag sinks to the bottom of the furnace, with a layer of the lightest elements referred to as speiss, including arsenic and antimony floating to the top of the molten material. The crude bullion and lead slag layers flow out of the 'furnace front' and into the 'forehearth', where the two streams are separated.
Metallurgy derives from the Ancient Greek μεταλλουργός, metallourgós, "worker in metal", from μέταλλον, métallon, "mine, metal" + ἔργον, érgon, "work" The word was originally an alchemist's term for the extraction of metals from minerals, the ending -urgy signifying a process, especially manufacturing: it was discussed in this sense in the 1797 Encyclopædia ...
A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...