Annual Report 2000 in PDF - Antofagasta plc

Harvesting cathodes from electrowinning tankThe existing mine plan for the period to 2006indicates a decreasing copper grade which willresult in lower copper production from the endof 2003. Michilla has adopted an aggressiveexploration strategy in order to counter andreverse this trend.of a metallurgical process which allows sulphideores to be leached for a period of 100 days givinga satisfactory copper recovery of over 80%.This metallurgical process has been patented andwill now be available to other mines with highchalcocite minerals contained in the ore bodies.A two year exploration programme began inJanuary 2001, which will entail 60,000 metresof systematic drilling of short drill holes ona grid of 200 x 100 metres over an area of10 x 12 kilometres centred around the existingmine. The short drill hole programme will costUS$2.3 million and will be followed up, ifsuccessful, by a further 42,000 metres ofReverse Circulation drilling to delineateeconomic oxide ore deposits in the area.As mentioned in last year’s review, Michilla hadbegun extensive industrial scale tests to improverecoveries from its leaching of sulphide ores.Research has culminated in the developmentSafety, Environment and Human ResourcesOne of Michilla’s notable achievements during2000 was its improved safety record throughoutits mining operations. The accident frequencyrate was reduced by 48% to 2.8 accidents perone million man hours, one of the lowest in theindustry. Michilla underlined its commitmentto the environment by implementing controls inits mine processing which complied or exceededall government standards and recommendations.In addition, supervisors and managers havebeen encouraged by the introduction of a newbonus scheme related to productivity and unitcost reductions.ANTOFAGASTA PLC Annual Report 200011