Sulphuric acid
The sulphuric acid plant has a capacity of 1,400,000 tonnes per annum and is based on the double conversion double absorption process. The plant design is provided by Monsanto Envirochem (USA). The off-gases from the smelting furnace and PS converter containing sulphur dioxide are delivered to the gas cleaning section — comprising a two-stage reverse jet scrubber. Cleaned gases from final reverse jet scrubber are fed to a two-stage electrostatic precipitator, to eliminate mist and residual dust particles from the gases. The sulphur dioxide-rich gases are then further processed and converted into sulphuric acid of commercially acceptable quality. Two storage tanks of 10,000 tonnes each are provided to store the acid.

Phosphoric acid
The phosphoric acid plant is based on Prayon MarkIV Dihydrate Technology provided by SNC Lavalin (Belgium). The plant is designed to treat 285,000 tonnes of sulphuric acid and 300,000 tonnes of rock phosphates to produce 180,000 tonnes of merchant grade phosphoric acid (52 to 54 per cent) each year. The plant also has a fluorine recovery section, which produces about 5100 tonnes of hydro fluosilicic acid (18 per cent) per year.


Phospho gypsum
For information on phospho gypsum, go to:
http://www.birlacopper.com/Phosphogypsum.htm