All over the world, more than 75% of electricity is being generated from thermal power plant and coal contains sulphur in the range of 0.3%-1% depending upon origin location. Whereas, in some regions suphur content is up to 1.5%. In thermal power plants, sulphur (present in coal) reacts and form sulphur dioxide (SO2), which is very harmful to the environment. So to save our environment, many countries like US and European countries have stringent regulations that discharge of sulphur dioxide (SO2) should be less than 0.05%. For this, power plants are installing Flue Gas Desulphurisation Plant (FGD) or unit.
Limestone slurry is sprayed on the incoming flue gas. The sulphur dioxide gets absorbed. The limestone and sulfur dioxide react as follows :
CaCO3 + H2O + 2SO2 ----> Ca+2 + 2HSO3- + CO2
CaCO3 + 2HSO3- + Ca+2 ----> 2CaSO3 + CO2 + H2O
A process improvement called forced oxidation which further oxidizes the calcium sulphite to Calcium sulphate in the following reactions
CaSO3 + H2O + ½ O2 ----> CaSO4 + H2O
Our Limestone Grinding Circuit We provide both wet and dry grinding circuits. And we are leading supplier of ball mills, rod mills and classifiers. We have supplied more than 200 mills around the globe.
For limestone grinding, among our supplies few were open circuit rod mills, close circuit dry grinding ball mill with double deck screen and dry grinding ball mill with air swept circuit.