Flowsheet design and processing for a sulphide ore are driven by sulphur, iron and impurity management. As high grade feedstocks become depleted, arsenic bearing concentrates will become a more predominant feedstock. For existing copper producers, arsenic management is a key aspect of business management as arsenic impurity levels rise. Xstrata Process Support (XPS) employs an integrated arsenic management program.
The key components of the program include:
- Knowledge of process mineralogy as a means to mill optimisation in order to minimise arsenic- bearing minerals reporting to the non-ferrous metal sulphide concentrate
- Flowsheet design: Designing specific arsenic removal steps using leaching, roasting or smelting steps depending on the mineralogy of the concentrate
- Environmental Management: Techniques for stabilisation of arsenic-bearing process residues via appropriate hydrometallurgical or pyrometallurgical means
- Techno-economic evaluation
- Industrial hygiene aspects of arsenic in smelting and refining.
In a recent project Consolidated Professor Mines Ltd (CPML) contracted XPS to simultaneously define viable pyrometallurgical treatment options to remove arsenic from its cobaltite concentrate, maximise recovery of cobalt and silver and develop environmentally sound solutions to safely dispose the arsenic.
XPS reports that CPML has expressed satisfaction with the progress on this exciting and ground-breaking work program, which takes economic viability into account.
Due diligence, engineering process design/review, mineralogical modification (e.g. roasting) and other metallurgical test work involving arsenic has also been performed for copper producers inside and outside Xstrata.
