At September 2001 the beneficiation plant at BHP Billiton Iron Ore's Mt Whaleback mine is set to treat 9.5 million tonnes per annum (Mtpa) of iron ore, 40 per cent better than original design. This paper describes the steps, decision-making processes and innovations used to increase capacity at minimum cost._x000D_
The plant was designed in 1979 to operate at 1133 t/h for 6000 hours per annum, treating 6.8 Mtpa. Sufficient suitable contact ore was unavailable and feed was finer than planned. The plant was designed with minimum surge capacity between multiple process units. It had never reached design capacity._x000D_
In 1993 a study by Fluor Daniel to treat increased tonnage resulted in modifications to improve plant operations. Efforts to expand production by increasing reliability did not achieve the desired capacity._x000D_
NJ Morrow (Pty) Ltd (NJM) conducted a technical audit in 1996 with process evaluation by Mineral Processors._x000D_
Replacement of operator interface and PLC logic in 1997 made plant operation and diagnosis easier. Involving operators in logic development enhanced their plant knowledge. Fluor Daniel Simulation developed a simulation model of the process._x000D_
Mineral Processors and NJM reviewed the model findings, recommended metallurgical improvements and developed preliminary designs and costs._x000D_
BHP Engineering produced a detailed design with a cost estimate of $A34 million. After analysis and revision of the design, a $A10.4 million upgrade to 8.5 Mtpa was carried out. Detailed modifications to the process units, particularly the HM drum plant, allowed significantly higher capacities and improved metallurgical performance. The target capacity was achieved in June 2001. Further modifications are progressing to treat lower-grade ores.