Extraction of Al

Question 1

concentration methods (Al)

Answer 1

leaching

Question 2

if FeO is main impurity, ______ type of leaching is used (Al)

Answer 2

Bayer’s Process

Hall’s Process

Question 3

if SiO2 is main impurity, then ___ leaching process is used (Al)

Answer 3

serpex process

Question 4

in Bayer’s and Hall’s process, FeO is converted into (Al)

Answer 4

Fe2O3 by roasting

Question 5

reagant used in hall’s process (Al)

Answer 5

Na2CO3

Question 6

reagent used in bayer’s process (Al)

Answer 6

NaOH

Question 7

reagant used in serpex (Al)

Answer 7

C in presence of air

Question 8

Al2O3 + C + N2 at 2075K (Al)

Answer 8

CO + AlN

Question 9

impurities in serpex process forms (Al)

Answer 9

Si + CO

volatizes

Question 10

AlN + H2O = (Al)

Answer 10

Al(OH)3 + NH3

Question 11

oxidation method (Al)

Answer 11

calcination

to remove hydrate

Question 12

reduction method used (Al)

Answer 12

electrometallurgy

Question 13

anode in electrometallurgy is made up of (Al)

Answer 13

graphite rod

Question 14

cathode in electrometallurgy is made up of (Al)

Answer 14

carbon lining

Question 15

why graphite at anode reduces in electrometallurgy (Al)

Answer 15

it reacts with O2 formed during electrometallurgy

Question 16

electrolyte in electrometallurgy (Al)

Answer 16

molten Al2O3, cryolite, florspar

Question 17

cryolite (Al)

Answer 17

Na3AlF6

Question 18

electrometallurgical process used in reduction (Al)

Answer 18

Hall Heroult’s method

Question 19

cryolite and florspar is added for in electrometallurgy (Al)

Answer 19

lower the MP of Al2O3 and improve electrical conductivity

Question 20

refining method used (Al)

Answer 20

electrolytic refining / hoop’s process