Extraction of metals: Metallurgy

							











Extraction of metals: Metallurgy:- the process of extractin metals from their ores is called metallurgy. The ores are generally associated with non metallic impurities of earth and rocks. These are called gangue or matrix. The process of metallurgy depends upon the nature of the ore and the impurities present in it. Therefore it is not possible to have a universal method which may be applicable to all the metals. Thus, the extraction of each metal involves an individual procedure. However, some common steps involved in the metallurgical operations are:
1.   Crushing and grinding of the ore.
2.   Concentration or benefication of the ore.
3.   Working of the concentrated ore.
4.   Purification or refining of the metal
Crushing and Grinding of the Ore: - the ores occur in nature as huge lumps. They are broken to small pieces with the help of crushers or grinders. These pieces are then reduced to fine power with the help of ball mill or stamp mill. This process is called pulverization.
Concentration of Ore or Ore benefication: - The ores are usually found mixed up with large amounts of non metallic impurities such as, sand, mica, limeston, falspar, earthy and rocky impurities. These unwanted impurities are called gangue or matrix and have to be removed before extracting the metals.