Occurrence and Extraction Aluminium occurs widely as a constituent of rocks and soils. The main ores of aluminium are : Bauxite : Al2O3.2H2O Cryolite : Na3AlF6 Feldspar: KAlSi3O8 Mica : KAlSi2O10(OH)2 In India, aluminium occurs mostly in the form of mica. The ores of mica are located in the states of Bihar, Tamil Nadu, Madhya Pradesh, Jammu and … [Read more...] about Extraction of Aluminium
Class 12
Thermodynamic and Electrochemical Principle of Metallurgy
Thermodynamic Principles of Metallurgy Thermodynamic considerations are very important in metallurgical processes. These help in deciding the temperature and the choice of reducing agents in the reduction processes. The feasibility of a process can be predicted in terms of Gibbs energy change (ΔG) at any specified temperature. This is related to enthalpy change (ΔH) … [Read more...] about Thermodynamic and Electrochemical Principle of Metallurgy
Purification or refining of the Metal
Purification or refining of Metals The metal obtained by any of the above methods is usually impure and is known as crude metal. Therefore, the crude metal is to be purified. The impurities may be in the form of 1) unreduced oxides of the metals 2) non-metals like C, Si, P, As, S etc. 3) foreign metals 4) slag or flux. The process of purifying the crude … [Read more...] about Purification or refining of the Metal
Extraction of Crude Metal from Concentrated Ore
Extraction of Crude Metal from Concentrated Ore The process of working of the concentrated ore to extract metal depends upon the nature of the ore as well as the nature of the impurities present in the ore. The concentrated ore must be converted into a form which is suitable for reduction. Generally, the sulphide ores are converted to oxides before reduction because oxides … [Read more...] about Extraction of Crude Metal from Concentrated Ore
Crushing, Grinding and Concentration of the Ore
Extraction of Elements Most of the elements do not occur in the free state in nature but these occur in the combined states. In the combined states, metals are usually found in the oxidised form (e.g., Fe2O3, MnO2, SnO2 etc.), while non-metals occur in the reduced form such as halide ions (Cl¯, Br¯, I¯). The metals can be obtained from their oxidised forms by reduction … [Read more...] about Crushing, Grinding and Concentration of the Ore