61. The Al2O3 content of cryolite in Hall-Heroult's cell is maintained between
62. Hydrometallurgy is a process of extraction in which extraction of metal is done
63. Percentage of nickel present in concentrated Ni ore is
64. Which metal is extracted by leaching?
65. Mattee smelting is used in the extraction of
66. If supposed speed of rotation of ball mill is too much high, then what force generally take place inside the container.
67. Process of extraction of Zn is
68. In a roasting process, the set of conditions that favour sulphate formation from metal sulphide concentrates are.
P. high temperature
Q. high partial pressure of oxygen
R. use of excess air
S. high partial pressure of SO3
P. high temperature
Q. high partial pressure of oxygen
R. use of excess air
S. high partial pressure of SO3
69. What are the uses of Manganese
70. Match the extraction methods in Group 1 with the metals in Group 2.
Group 1
Group 2
P. Roasting followed by carbothermic reduction
1. Ti
Q. Electrolysis of fused salt
2. Pb
R. Roasting followed by controlled oxidation
3. Al
S. Halide process
4. Cu
5. Au
| Group 1 | Group 2 |
| P. Roasting followed by carbothermic reduction | 1. Ti |
| Q. Electrolysis of fused salt | 2. Pb |
| R. Roasting followed by controlled oxidation | 3. Al |
| S. Halide process | 4. Cu |
| 5. Au |