Metallurgy

Question 1

Seven metals of antiquity

Answer 1

Gold
Cu
Ag
tin 
Pb 
Fe 
Hg

Question 2

Elements which occurs in free state

Answer 2

C
S
Gold
Noble gas

Question 3

Most abundant metal

Answer 3

Aluminium

Question 4

Third most abundant element in earth crust

Answer 4

Al

Question 5

mjor component of many igneos minerals like mica and clay

Answer 5

Al

Question 6

Many gemstones are impure form of

Answer 6

Al2O3

Question 7

Impurities in gems
Ruby
Sapphire

Answer 7

Cr Ruby

Co Sapphire

Question 8

Second most abundant metal

Answer 8

Fe

Question 9

Naturally occurring chem substance in earth crust called

Answer 9

Minerals

Question 10

Source of that metal

Answer 10

Ore

Question 11

Ores of Al

Answer 11

REMEMBER KABALI
Bauxite AlOx(OH)3-2x 0

Question 12

Ores of Fe

Answer 12

REMEMBER HMS Beagle is ship made of iron
Haematite fe2o3
Magnetite fe3o4
Siderite feco3
Iron pyrites fes2

Question 13

Ores of cu

Answer 13

Copper pyrites cufes2
Malachite cuco3 cu(oh)2
Cuprite cu2o
Copper glance cu2s

Question 14

Ores of zinc

Answer 14

Zinc blende/sphalerite zns
Calamine znco3
Zincite zno

Question 15

For the the purpose of extraction which ores are used for
Aluminium
Iron
Copper and zinc

Answer 15

Bauxite
Oxide ores
Any of the ores

Question 16

What is gangue

Answer 16

An ore which is usually contaminated with earthly or undesired materials

Question 17

What are the steps involved in the extraction and isolation of metals from ores

Answer 17

Concentration of the ore
Isolation of the metal from its concentrated ore
Purification of the metal

Question 18

Define concentration of ore

Answer 18

Removal of the unwanted materials ( sand and clay )from the ore is known as concentration dressing or benefaction

Question 19

Name some of the important procedures for concentration of ore(4)

Answer 19

Hydraulic washing
Magnetic separation
Froth flotation method
Leaching

Question 20

What is the principle behind hydraulic washing

Answer 20

It is based on the difference between specific gravity of the ore and the gangue particles

Question 21

Which method is also called gravity separation

Answer 21

Hydraulic washing

Question 22

What is the principle behind magnetic separation method

Answer 22

This is based on differences in magnetic properties of the ore components

Question 23

Example for magnetic separation method

Answer 23

Iron ore

Question 24

Which method is used for removing gangue from sulphur ores

Answer 24

Froth floatation method

Question 25

Example for collectors

Answer 25

Pine oil fatty acid xanthates

Question 26

Examples for froth stabilizers

Answer 26

Cresols | Aniline

Question 27

enhances non wettability of the mineral particles

Answer 27

Collectors

Question 28

The mineral particles become wet by | Gangue particle become wet by

Answer 28

Oil | Water

Question 29

Sometimes it is possible to separate two sulphide ores by adjusting proportion of

Answer 29

Oil to water or by using depressants

Question 30

In the case of an ore containing zns and PbS the depressant used is

Answer 30

NaCN which selectively prevents zns from coming to the froth but allows pbs to come with the froth

Question 31

When leaching is used

Answer 31

If the ore is soluble in some suitable solvent

Question 32

What are the impurities in bauxite(3)

Answer 32

Sio2 iron oxides titanium oxide

Question 33

Describe the leaching of alumina from bauxite

Answer 33

#concentration is carried out by heating the powdered ore with a concentrated solution of naoh . #this process is called digestion. #this way Al2o3 is extracted out as sodium aluminate. #the sodium aluminate present in solution is neutralized by passing CO2 gas and hydrated al203 is precipitated #At this stage small amount of freshly prepared sample of hydrated Al2O3 is added to the solution #This is called seeding it induces the precipitation #Hydrated alumina is filtered dried and heated to give back pure Al2O3

Question 34

Short note on metallurgy of silver and gold

Answer 34

#The respective metal is leeched with a dilute solution of NaCN or KCN in the presence of air which supplies O2. #The metal is obtained later by replacement reaction