Metallurgy Flashcards
Seven metals of antiquity
Gold Cu Ag tin Pb Fe Hg
Elements which occurs in free state
C
S
Gold
Noble gas
Most abundant metal
Aluminium
Third most abundant element in earth crust
Al
mjor component of many igneos minerals like mica and clay
Al
Many gemstones are impure form of
Al2O3
Impurities in gems
Ruby
Sapphire
Cr Ruby
Co Sapphire
Second most abundant metal
Fe
Naturally occurring chem substance in earth crust called
Minerals
Source of that metal
Ore
Ores of Al
REMEMBER KABALI Bauxite AlOx(OH)3-2x 0
Ores of Fe
REMEMBER HMS Beagle is ship made of iron Haematite fe2o3 Magnetite fe3o4 Siderite feco3 Iron pyrites fes2
Ores of cu
Copper pyrites cufes2
Malachite cuco3 cu(oh)2
Cuprite cu2o
Copper glance cu2s
Ores of zinc
Zinc blende/sphalerite zns
Calamine znco3
Zincite zno
For the the purpose of extraction which ores are used for
Aluminium
Iron
Copper and zinc
Bauxite
Oxide ores
Any of the ores
What is gangue
An ore which is usually contaminated with earthly or undesired materials
What are the steps involved in the extraction and isolation of metals from ores
Concentration of the ore
Isolation of the metal from its concentrated ore
Purification of the metal
Define concentration of ore
Removal of the unwanted materials ( sand and clay )from the ore is known as concentration dressing or benefaction
Name some of the important procedures for concentration of ore(4)
Hydraulic washing
Magnetic separation
Froth flotation method
Leaching
What is the principle behind hydraulic washing
It is based on the difference between specific gravity of the ore and the gangue particles
Which method is also called gravity separation
Hydraulic washing
What is the principle behind magnetic separation method
This is based on differences in magnetic properties of the ore components
Example for magnetic separation method
Iron ore
Which method is used for removing gangue from sulphur ores
Froth floatation method
Example for collectors
Pine oil
fatty acid
xanthates
Examples for froth stabilizers
Cresols
Aniline
enhances non wettability of the mineral particles
Collectors
The mineral particles become wet by
Gangue particle become wet by
Oil
Water
Sometimes it is possible to separate two sulphide ores by adjusting proportion of
Oil to water or by using depressants
In the case of an ore containing zns and PbS the depressant used is
NaCN which selectively prevents zns from coming to the froth but allows pbs to come with the froth
When leaching is used
If the ore is soluble in some suitable solvent
What are the impurities in bauxite(3)
Sio2
iron oxides
titanium oxide
Describe the leaching of alumina from bauxite
concentration is carried out by heating the powdered ore with a concentrated solution of naoh .
Short note on metallurgy of silver and gold
The respective metal is leeched with a dilute solution of NaCN or KCN in the presence of air which supplies O2.
