Paul Voigt, Alistair Burrows, Michael Somerville, Dr. Chunlin Chen
To date, many types of primary concentrate have been smelted using the ISASMELT™ technology,
with annual smelting of copper concentrate alone exceeding 7 million tonnes. Most of this material
could best be described as chalcopyrite concentrate, owing to the predominance of copper attributable
to this single mineral. Chalcopyrite concentrates lend themselves readily to smelting with a fayalite
slag, and producing a matte containing 55 – 65 wt.-% Cu. However, the ISASMELT™ technology
also stands ready to meet future copper demand through the treatment of new types of
concentrates containing relatively low iron and high silica levels.
Various slag systems have been considered for direct-to-blister smelting. They have been evaluated
computationally, using the MPE thermodynamic modelling package, and practically, at pilot scale.
The lime-silica-iron oxide slag was found to have the lowest slag make, lower dissolved copper and
hence lowest copper losses.
Based on the outcomes of the modelling and pilot scale testwork a future smelter flowsheet has
been defined, comprising a single ISASMELT™ direct-to-blister furnace, an electric slag cleaning
furnace, and appropriately designed anode furnaces.