Question #68ce1

2 Answers
May 5, 2017

Aluminium by Hall Heroult process

Explanation:

For extraction of Aluminum generally Hall Heroult process is generally used in industries

Process is :
Bayer's process
1) the Alumina ore is treated with NaOH at high pressure and temperature to form #NaAlO_2#
#Al_2O_3+NaOH=2NaAlO_2#
2)This #NaAlO_2# solution is then recrystallized with #Al(OH)_3# to form #Al(OH)_3# crystals
3)This #Al(OH)_3# crystals are heated to form pure Alumina
#2Al(OH)_3=Al_2O_3+3H_2O#
Hall Heroult process
1) initially the Alumina #Al_2O_3# obtained by Bayer's process is taken in a steel container acting as cathode
2) The Alumina is added to Cryolite solution(#Na_3AlF_6#) which decrease melting point of Alumina to nearly #960°C#
3)Then the graphite electodes(Anode) are inserted and operating at high voltage we get Aluminium at Anode of 99.95%purity.
#2Al_2O_3+3C=4Al+3CO_2# in electrolysis

May 5, 2017

Titanium by Krolls process

Explanation:

Titanium is generally produced by Krolls process

Ilmentite ore is reduced in presence of coke in a fluidised bed reactor
This reaction produces #TiCl_4#
#TiCl_4# is reacted with Mg to form #Ti#
#TiCl_4+2Mg=2MgCl_2+Ti#
This Titanium​ is then vacuum refined to produce Pure Titanium ,as the unrefined Titanium has no use commercially due to presence of #MgCl_2#in Titanium Sponge