Lime is a key ingredient in the production of non -ferrous metals.

Both anhydrous lime and hydrated lime are widely used in flotation or recovery of many non – ferrous metals – particularly copper ore flotation in which lime acts as a sedative ( precipitation strengthening ) and maintains proper alkalinity flotation circuit.

With the recovery of mercury from cinnabar, lime is used to remove sulfur. Lime is also used in the flotation of zinc , nickel, such as also commonly used for the recovery of gold and silver.

Additional lime is used in varying quantities to remove silica from bauxite ore and the production of ‘alumina’. Lastly, lime is used to produce magnesium metal . In thermal reduction techniques , magnesium oxide of dolomitic lime is reduced with ferrosilicon at high temperatures.

This process produces a magnesium gas which is finally concentrated.