Copper concentrates from Sterlite Industries (India) Ltd. (SIIL)’s copper mine is blended with bought out concentrates from other sources and treated to get optimum results. The Smelter is based on a proven energy efficient and environment friendly technology, viz. IsaProcess™ from MIM, Australia, world leaders in Copper smelting technology.

The ISA™ furnace is a vertical shaft type furnace completely lined with refractory into which wet copper is charged along with quartz and limestone into the molten bath. As a result of the chemical reactions that take place in the bath, the Copper Concentrate gets converted into two products- Matte, a mixture of sulphide (containing copper and iron), and Slag. Matte is taken to the Rotary Holding furnace where the slag separates out due to differential density. The Copper Matte is converted into Blister Copper in the Pierce Smith Converter in two stages.

In the first stage, called Slag Blow, most of the iron and a small quantity of sulphur are oxidised and removed. In the second stage, called Copper Blow, sulphur is removed to get Blister Copper. Converter Slag is treated in a Slag cleaning furnace for recovery of copper. Blister Copper is further refined by oxidation and then by reduction to approximately 99.7% copper purity in the Anode Furnace, and cast as Copper Anodes. Gases produced at various stages are fully recovered and converted into Sulphuric Acid.

Latest Version of CS 3000 Distributed Control System of Yokogawa, Japan controls the entire Copper Smelter. Advance Process Control (APC) implementation methodology involves data collection, approximate candidate controller design, prototype controller design, simulation, testing, and final implementation. APC is implemented to control critical factors like Bath temperature and Lance height control.

Sulphuric Acid Plant

The sulphur dioxide gases generated in the smelting process is collected and ducted to the Sulphuric Acid Plant. Set up with basic engineering from Kvaerner Chemetics, Canada, the plant is based on the absorption process known as DCDA, and has a designed capacity to produce 1600 tonnes of sulphuric acid per day.

Phosphoric Acid Plant
Sulphuric acid is reacted with rock phosphate in the Phosphoric Acid Plant to produce phosphoric acid. Technology and basic engineering for this plant has been sourced from Hydro Agri International, UK, and the process used is known as Hemi-hydrate Di Hydrate Process. The plant has an installed capacity to produce 180,000 tonnes of Phosphoric Acid per annum.