Give reasons for the following observations:
Lyophilic sol is more stable than a lyophobic sol.
What is the role of silica in the extraction of copper?
Ores of copper contain iron oxide as an impurity. Silica reacts with iron oxide and forms iron silicate, which is removed as slag. In the smelting process such chemical reactions are taking place:
1) Oxidizing of the copper pyrite: 2 CuFeS2 (s) + 3 O2 (g) → 2 FeO (s) + 2 CuS (l) + 2 SO2 (g)
2) Conversion of iron oxides and sulfides into molten slag:
FeO (s) + SiO2 (s) → FeSiO3 (l)
2 FeS (s) + 3O2 (g) + 2 SiO2 (s) → 2 FeSiO3 (l) + 2SO2 (g)
Which reducing agent is employed to get copper from the leached low-grade copper ore?
Outline the principles behind the refining of metals by the following methods:
Zone refining method
Outline the principles behind the refining of metals by the following methods:
Chromatographic method
Which solution is used for the leaching of silver metal in the presence of air in the metallurgy of silver?