The mixed ore
circuit experienced a 14% increase in throughput when the SAG volumetric filling degree changed from 21.9% to 37.2%, with little change in grind.
This complex deposit, comprising oxide, sulphide and mixed ore
bodies, is situated some 5,000 m above sea level and straddles the border between Chile and Argentina.
Such mixed ores
were therefore abandoned (perhaps the first known case in which worker safety was a factor in technology).
The results also showed a swing in primary copper mineralogy to mixed leach-ore types: in 1988, oxide ore accounted for 29% and sulphide 14%, with oxide/sulphide mixed ores
The company noted in its third-quarter report that the acid will benefit the Kansanshi operation by allowing the treatment of high acid-consuming oxide ores and the leaching of some mixed ores
. It is already looking at doubling the smelter's capacity as soon as the first unit is commissioned.
In the lower portion of the veins, there are mixed ores
with interesting contents of sulphides, which we are not planning to mine yet.