Question

Explain the terms.
a. Metallurgy b. Ores
c. Minerals d. Gangue

Answer 1

a. Metallurgy: The various processes involved in the extraction of metals from its ores and refining is called metallurgy.
The major steps involved for the extraction of a metal from its ore are:
(i) Concentration of ores (or enrichment of ore)
(ii) Conversion of concentrated ore into metal
(iii) Refining (purification) of impure metal

b. Ores: Those minerals from which a metals can be extracted convenietly and profitably.

c. Minerals:

• "A mineral is an element or chemical compound that is normally crystalline and that has been formed as a result of geological processes" (Nickel, E. H., 1995).
  
• "Minerals are naturally-occurring inorganic substances with a definite and predictable chemical composition and physical properties." (O' Donoghue,1990).
  
• "A mineral is a naturally occurring homogeneous solid, inorganically formed, with a definite chemical composition and an ordered atomic arrangement" (Mason, et al,1968).
  
• "These... minerals ...can be distinguished from one another by individual characteristics that arise directly from the kinds of atoms they contain and the arrangements these atoms make inside them" (Sinkankas, 1966).
  
• "A mineral is a body produced by the processes of inorganic nature, having usually a definite chemical composition and, if formed under favorable conditions, a certain characteristic atomic structure which is expressed in its crystalline form and other physical properties" (Dana & Ford,1932).
  
• "Every distinct chemical compound occurring in inorganic nature, having a definite molecular structure or system of crystallization and well-defined physical properties, constitutes a mineral species" (Brush & Penfield

d. Gangue is the unwanted impurities like rock material, dust, soil, sand, earthy particles, limestone, mica etc. present in an ore.