The correct statement(s) related to processes involved in the extraction of metals is(are):

The correct statements are:
- Calcination of Calamine produces Zincite.
- Copper pyrites is heated with silica in a reverberatory furnace to remove iron.
- Impure silver is treated with aqueous KCN in the presence of oxygen followed by reduction with zinc metal.

Let us analyze each statement step-by-step to understand the metallurgical processes involved:

1. Roasting of Malachite produces Cuprite (Incorrect):
Malachite is a carbonate ore of copper with the formula ${\text{CuCO}}_3·{\text{Cu(OH)}}_2$. The process of heating carbonate ores in the absence or limited supply of air to decompose them into oxides is called calcination, not roasting. Roasting involves heating the ore in excess air, which is typically done for sulfide ores. Upon heating, malachite decomposes to form copper(II) oxide ($\text{CuO}$), carbon dioxide, and water vapor, rather than cuprite (${\text{Cu}}_2\text{O}$):

${\text{CuCO}}_3·{\text{Cu(OH)}}_2\to 2\text{CuO}+{\text{CO}}_2+{\text{H}}_2\text{O}$

2. Calcination of Calamine produces Zincite (Correct):
Calamine is zinc carbonate (${\text{ZnCO}}_3$). Calcination involves heating the carbonate ore strongly in the absence of air, causing it to decompose into zinc oxide ($\text{ZnO}$, also known as Zincite) and carbon dioxide gas:

${\text{ZnCO}}_3\stackrel{\Delta }{\to }\text{ZnO}+{\text{CO}}_2$

Hence, this statement is correct.

3. Copper pyrites is heated with silica in a reverberatory furnace to remove iron (Correct):
Copper pyrites (${\text{CuFeS}}_2$) contains iron impurity. During smelting in a reverberatory furnace, silica (${\text{SiO}}_2$) is added as a flux. Iron sulfide oxidizes to iron oxide ($\text{FeO}$), which reacts with silica to form iron silicate (${\text{FeSiO}}_3$), a fusible slag that can be easily removed:

$\text{FeO}+{\text{SiO}}_2\to {\text{FeSiO}}_3\text{(slag)}$

Hence, this statement is correct.

4. Impure silver is treated with aqueous KCN in the presence of oxygen followed by reduction with zinc metal (Correct):
This is the MacArthur-Forrest cyanide process used for the extraction of silver (hydrometallurgy). Impure silver reacts with potassium cyanide solution in the presence of atmospheric oxygen to form a soluble complex, potassium dicyanoargentate(I):

$4\text{Ag}+8\text{KCN}+2{\text{H}}_2\text{O}+{\text{O}}_2\to 4\text{K}\left[\text{Ag}{\left(\text{CN}\right)}_2\right]+4\text{KOH}$

Silver is then precipitated/reduced from this soluble complex by displacement using zinc metal:

$2\text{K}\left[\text{Ag}{\left(\text{CN}\right)}_2\right]+\text{Zn}\to {\text{K}}_2\left[\text{Zn}{\left(\text{CN}\right)}_4\right]+2\text{Ag}$

Hence, this statement is also correct.