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EXTRACTIVE METALLURGY
* it is the study of the processes used in the separation
and concentration (benefication) of raw materials.
* The field is an applied science, covering all aspects
of the physical and chemical processes used to
produce mineral-containing and metallic materials,
sometimes for direct use as a finished product, but
more often in a form that requires further physical
processing
* Extractive metallurgy is the practice of removing
valuable metals from an ore and refining the
extracted raw metals into a purer form.
*
In order to convert a metal oxide or sulfide to a
purer metal, the ore must be reduced physically,
chemically, or electrolytically.
* Extractive metallurgists are interested in three
primary streams: feed, concentrate (valuable metal
oxide/sulfide), and tailings (waste).
* After mining, large pieces of the ore feed are
broken through crushing and/or grinding in order to
obtain particles small enough where each particle is
either mostly valuable or mostly waste.
* Concentrating the particles of value in a form
supporting separation enables the desired metal to be
removed from waste products.
* The sub disciplines are mineral processing,
pyrometallurgy, and hydrometallurgy. ,
electrometallurgy
PYROMETALLURGY : involves high temperature
processes where chemical reactions take place
among gases, solids, and molten materials.
HYDROMETALLURGY : is concerned with
processes involving aqueous solutions to extract
metals from ores.
* The most common hydrometallurgical process is
leaching, which involves dissolution of the valuable
metals into the aqueous solution.
* After the solution is separated from the ore solids,
the solution is often subjected to various processes of
purification and concentration before the valuable
metal is recovered either in its metallic state or as a
chemical compound.
ELECTROMETALLURGY : involves metallurgical
processes that take place in some form of
electrolytic cell.The most common types of
electrometallurgical processes are electrowinning
and electro-refining.
CARBONYL METALLURGY : is used to manufacture
products of iron, nickel, steel, and other metals.
* Coatings are produced by vapor plating using
metal carbonyl vapors.
* Carbonyl metallurgy is useful as a low temperature
metal coating technique that may well find many
applications in the future.