Refining

Q. Which of the following reduction reactions are actually employed in the commercial extraction of metals?

1. $F{e}_2{O}_3+2Al\to A{l}_2{O}_3+2Fe$
2. $C{r}_2{O}_3+2Al\to A{l}_2{O}_3+2Cr$
3. $2Na\left[Au\right(CN{)}_2]+Zn\to N{a}_2[Zn\left(CN{)}_4\right]+2Au$
4. $C{u}_{2}O+H_2\to 2Cu+H_{2}O$

Q.

After extracting the crude metal from its ore, what should be the next logical step?

1. Refining

2. Alloying

3. Pickling

4. Pulverizing

Q.

Which of the following can be termed as refining?

1. Baeyer’s process

2. Var Arkel – de Boer Process

3. Levigation

4. Smelting