What is flux ? What is itz role in metallurgy of Iron n Copper ?
in metallurgy, is any substance introduced in the of ores to promote fluidity and to remove objectionable impurities . When it is heated with ore, it combines with the earthly impurities present in ore to form easily fusible mass known as slag. The slag is lighter and insoluble in the molten metal. So it can be easily removed from the surface of the molten metal.
process by which a is obtained, either as the element or as a simple compound, from its by heating beyond the , ordinarily in the presence of , such as air, or , such as coke. ]
There are two types of fluxes.
Basic fluxes like lime (CaO), magnesium oxide (MgO) are used to remove acidic gangue such as SiO.
Limestone(CaCO3) is commonly used as basic flux for this purpose in smelting iron ores. Limestone is decomposed to CaO which removes silicate impurity of the iron ore as slag.
CaCO3 ------------> CaO + CO2
CaO + SiO2 ------> CaSiO3
Silica (SiO2) is commonly used as acidic flux for this purpose in smelting copper ores. It reacts with impurity (FeO) of copper ore and removes it as slag (FeSiO3).
FeO + SiO2 ------> FeSiO3