Environmental DesulphurisationWater Treatment and Acid Rain Remediation

Calcium carbonate is crucial in the reaching of several significant environmental targets – a number of these aims are concerned with the purification of our natural resources. They remove hydrogen chloride and sulphur dioxide from the waste produced by power plants, and at council waste-to-energy plants, as well as at coal-burning power facilities in the desulphurisation of flue gas.

Desulphurisation

When coal is burned in power plants to generate electricity, the sulphur that is embedded in the coal is released into the air. The amount of sulphur emitted is determined by the origin and quality of the coal. Sulphur dioxide is the gas (SO2) released. However, our calcium carbonate fillers can be included and this removes the sulphuric gas before it reaches the air, by forming calcium sulphate, also called gypsum. In a dry procedure, the reaction takes place in the furnace and the gypsum is combusted. If the process is wet, the reaction takes place in the scrubber and the by-product can be used as an ingredient in cement, fertilisers, or in the production of plasterboard.

Up to 95% of the sulphur can be taken out, depending on the procedure and the quality of the filler used. The purer the filler, and the more precise the particle size distribution, the higher the concentration of sulphur removed. Sulphur released into the air directly effects the pH level of soil and water, and is drawn back into the natural cycle in the form of acid rain.