↪ Metallurgy is a process that involves different scientific techniques for the extraction of metal in pure state from it ore.
↪ In other words, entire principles and technological procedures used to obtain metal in pure state is known as metallurgy.
Types of metallurgy
↪ Depending up on the methods involve in extraction metals, metallurgy is broadly classified in to three types:
↪ The process of extraction of metal from ore by chemical reduction (smelting) applying high temperature is known as Pyrometallurgy (Pyro=heat).
↪ In this method, ore is strongly heated to convert ore into metallic oxide and then reduction is carried by burning with coke to get free metal.
↪ Most of heavy metals like Fe, Cu, Zn, Hg, Sn etc. are extracted by pyrometallurgy.
↪ The technique/ process of extraction of metals by electrolytic reduction of fusible ore in molten state is called electrometallurgy.
↪ Alkali metals and alkaline earth metals are extremely reactive.
↪ They can’t be extracted by pyrometallurgy. Therefore, alkali metals (Na, K) and alkaline earth metals (Mg, Ca) extracted by electrometallurgy.
↪ It is the method of extraction of metals from aqueous solution ore by precipitation of metal with other more active metals (e.g. Zn).
↪ In this process, the ore is dissolved in suitable chemical reagent to make water soluble and then suitable reducing agent is added in order to precipitate the metal of ore.
↪ Hydrometallurgy is suitable if the percentage of metal in the ore is very low.
↪ This is commonly applied for the extraction of gold and silver.