Metallurgy

volatile matter

I) Calcination: Calcination involves heating of the ore in the absence of air and the ________ escapes leaving behind the metal oxide.

Distillation

________: This is useful for low boiling metals like zinc and mercury containing high boiling point metals as impurities.

Ores

Naturally occurring sources from which a metal or valuable mineral can be extracted profitably.

Liquation

________: In this process low melting metal like tin can be made to flow on a sloppy surface.

suitable solvent

D. Leaching: Leaching is often used if the ore alone but not the gangue is soluble in some ________.

Removal

________ of the gangue from the ore is known as Concentration /dressing /benefaction.

Hydraulic washing

Hydraulic washing is a type of gravity separation, which is based on gravity differences between the ore and the gangue particles

lighter gangue particles

The ________ are washed away and the heavier ore particles are left behind.

Hydraulic washing or Levigation

In this process an upward stream of running water is used to wash the powdered ore

Magnetic Separation

Magnetic separation is a method of waste management where magnets are used to separate metal from refuse.

Example

Iron ores

Froth Floatation Method

Froth flotation is a process for selectively separating hydrophobic materials from hydrophilic. Froth is used in this process.

Example

Sulphide Ores

Leaching

Leaching is often used if the ore alone but not the gangue is soluble in some suitable solvent.

Example

Leaching of Alumina (Al2O3) from Bauxite

Calcination

Calcination involves heating of the ore in the absence of air and the volatile matter escapes leaving behind the metal oxide.

Example

ZnCO3→ ZnO+ CO2(g)

Roasting

Roasting involves heating of the ore in a regular supply of air.

Example

2ZnS+3O2→ 2ZnO+ 2SO2

Example

MxOy+ yC→ xM+ yCO

Distillation

extracted metal is distilled to obtain the pure metal as distillate.

Liquation

In this process low melting metal like tin can be made to flow on a sloping surface and is separated from high melting impurities.

Poling

The molten metal is stirred with logs of green wood.

Electrolytic Refining

Impure metal as anode and pure metal as cathode with the salt of the same metal as an electrolyte.