Refining
Refining
The process of purifying the crude metals is called refining. Some methods of refining are as follow:
Distillation: This is very...
Oxidation Reduction
Oxidation-Reduction
Besides reduction, some extraction is based on oxidation particularly for non-metal. For extraction of chlorine from brine.
Extraction of Aluminum
Extraction of Aluminum:
Alumina Al2O3 is mixed with Na3AlF6 or CaF2 which lowers the melting point of the mixture and brings conductivity. Fused mixture is...
Extraction of copper from cuprous oxide
Extraction of copper from cuprous oxide
Copper is extracted mainly from copper pyrites (CuFeS2). The extraction involve the following steps given in flow sheet.
Extraction of zinc from zinc oxide
Extraction of zinc from zinc oxide
The reduction of zinc oxide is done using coke. The temperature, in this case, is higher than that in...
Extraction of iron from its oxides
Extraction of iron from its oxides
Oxide ores of iron, after concentration through calcination/roasting (to remove water, to decompose carbonates and to oxidise sulphides) are...
Thermodynamic principles of metallurgy
Thermodynamic principles of metallurgy:
For any process, Gibbs free energy change (∆G) is given by
When ∆H is the enthalpy change and ∆S is the entropy...
Extraction of Crude Metal from Concentrated Ore
Extraction of Crude Metal from Concentrated Ore:
The concentrated ore must be converted into a form which is suitable for reduction. Usually the sulphide ore...
Concentration of Ores
Concentration of Ores
Removal of the unwanted materials (e.g., sand, clays, etc.) from the ore is known as concentration, dressing or benefaction. It involves several...
Isolation of Elements – General Terms
Minerals:
These are naturally occurring chemical substances in the in the earth crust obtainable by mining.
Ores:
Only a few minerals are used as sources of that...