Chemistry
| Extraction of Aluminium | |
|---|---|
| Step 1 : Dressing of the ore chemical method | |
| Baeyer's process - Step 1, Step 2, Step 3 | |
| 14. Bauxite to - sodium aluminate | Al2O3.2H2O + NaOH ⟶ …………… + …………… |
| 15. Sodium aluminate to - aluminium hydroxide | NaAlO2 + H2O ⟶ …………… + …………… ↓ |
| 16. Aluminium hydroxide to pure alumina | Al(OH)3 ⟶ …………… + …………… |
| Step 2: Conversion of conc. ore to its oxide | |
| Step not necessary since the ore is already an oxide | |
| Step 3: Reduction of metallic oxide to its metal | |
| Hall Heroult's Process - Reduction by electrolysis | |
| 17. Electrolytic reduction of pure alumina | Al2O3 ⇌ …………… + …………… |
| 18. At cathode | 2Al3+ + 6e- ⟶ …………… |
| 19. At anode | 3O2- - 6e- ⟶ 3[……………] ⟶ 3O2 |
| Step 4: Electrorefining of aluminium [reference] |
Metallurgy
18 Likes
Answer
| Extraction of Aluminium | |
|---|---|
| Step 1 : Dressing of the ore chemical method | |
| Baeyer's process - Step 1, Step 2, Step 3 | |
| 14. Bauxite to - sodium aluminate | Al2O3.2H2O + NaOH ⟶ 2NaAlO2 + 3H2O |
| 15. Sodium aluminate to - aluminium hydroxide | NaAlO2 + 2H2O ⟶ NaOH + Al(OH)3 ↓ |
| 16. Aluminium hydroxide to pure alumina | 2Al(OH)3 ⟶ Al2O3 + 3H2O |
| Step 2: Conversion of conc. ore to its oxide | |
| Step not necessary since the ore is already an oxide | |
| Step 3: Reduction of metallic oxide to its metal | |
| Hall Heroult's Process - Reduction by electrolysis | |
| 17. Electrolytic reduction of - pure alumina | Al2O3 ⇌ 2Al3+ + 3O2- |
| 18. At cathode | 2Al3+ + 6e- ⟶ 2Al |
| 19. At anode | 3O2- - 6e- ⟶ 3[O] ⟶ 3O2 |
| Step 4: Electrorefining of aluminium [reference] |
Answered By
9 Likes
Related Questions
Extraction of Metals — General details of stages involved Complete and balance the equation Step 1 : Dressing of the ore Step 2 : Conversion of conc. ore to its oxide Roasting of sulphide ore 1. Roasting of zinc blende ZnS + O2 ⟶ …………… + …………… [g] 2. Roasting of iron pyrite FeS2 + O2 ⟶ …………… + …………… [g] Calcination of carbonate ore 3. Calcination of zinc carbonate ZnCO3 ⟶ …………… + …………… [g] 4. Calcination of iron [II] carbonate FeCO3 ⟶ …………… + …………… [g] Step 3: Reduction of metallic oxide to its oxide Reduction by electrolysis 5. Electrolytic reduction of pure alumina Al2O3 ⇌ …………… + …………… 6. At cathode 2Al3+ + 6e- ⟶ …………… Reduction by reducing agents [C, CO, H2] 7. Reduction of zinc oxide - by coke ZnO + C ⟶ …………… + …………… [g] 8. Reduction of iron [III] oxide - by CO Fe2O3 + CO ⟶ …………… + …………… [g] 9. Reduction of lead [II] oxide - by coke PbO + C ⟶ …………… + …………… [g] 10. Reduction of copper [II] oxide - by coke CuO + C ⟶ …………… + …………… [g] 11. Reduction of copper [II] oxide - by hydrogen CuO + H2 ⟶ …………… + …………… Reduction by thermal decomposition 12. Thermal decomposition of mercury [II] oxide HgO ⟶ …………… + …………… [g] 13. Thermal decomposition of silver [I] oxide Ag2O ⟶ …………… + …………… [g] Step 4: Electrorefining of impure metals A to F below relate to the source and extraction of either Zinc or aluminium
A : Bauxite,
B : Coke,
C : Cryolite,
D : Froth floatation,
E : Sodium hydroxide solution,
F : Zinc blende.(i) Write down the three letters each from the above list which are relevant to – Aluminium.
(ii) Fill in the blanks using the most appropriate words from A to F :
(a) The ore from which aluminium is extracted must first be treated with …………… so that pure Aluminium oxide can be obtained.
(b) Pure Aluminium oxide is dissolved in …………… to make a conducting solution.
(iii) Write the formula of Cryolite.
Calcium, Copper, Lead, Aluminium, Zinc, Chromium, Magnesium, Iron. Choose the major metals from the list given above to make the following alloys :
(i) Stainless steel
(ii) Brass.
Name the following :
(i) A metal which is liquid at room temperature.
(ii) A compound added to lower the fusion temp. of the electrolytic bath in the extraction of Al.
(iii) The process of heating an ore to a high temperature in the presence of air.