To select one example to illustrate this maturing of Australian technology the case of Bougainville Copper Ltd deserves special attention. The discovery of the large low grade porphyry copper deposit at Panguna in 1964 was the culmination of a deliberate search that employed the right geological thought, the right exploratory techniques and people, together with the right corporate funding and support. The exploration group of Consolidated Zinc Pty Ltd was the first to use geochemical drainage reconnaissance with special attention to copper. After studying and rejecting a number of prospects within Australia the group (now Conzinc Riotinto of Australia Ltd) turned its attention to Papua New Guinea and ultimately to the Panguna area where drilling based on the geochemical drainage anomaly established large scale porphyry type mineralization of copper with associated gold.

The evaluation of the deposit was a complex exercise in engineering and economics, in which computer evaluation, at the time a new science in the mineral industry, was used to study many projection scenarios of increasing volume and mining rate. It became evident that if the operation could be made large enough it could be profitable through economies of scale to cover the huge infrastructures of port, towns, power and water supplies in a mountainous terrain with rainfall of 5 m/yr and in the political climate of a country moving rapidly towards independence from Australian trusteeship. To achieve maximum economies of scale the capacity of the concentrator would have to be the largest (80,000 t/d) single concentrator in the world, and the mining and transportation equipment would have to be the biggest available, with appropriate maintenance facilities.

The design phase which followed incorporated all current state of the art sciences such as on-stream analysis, hydraulic transportation of solids and computerised orebody modelling. Hydraulic transportation was adopted for pumping the 500,000 t/yr of concentrates to the coast, involving a distance of 30 km and a lift of 400 m, a revolutionary scale of application of slurry pumping; hydraulic sluicing of overburden was adopted in the preparatory and early mining phases to dispose of the volcanic ash which covered much of the orebody.

Mine planning and mine design were assisted by the new generation of computers of the 1960s which made it possible to construct a mathematical model of the orebody and to study hundreds of mining alternatives which would ensure maximum extraction of copper and gold over the longest economic life commensurate with optimum profitability.

Australian Academy of Technological Sciences and Engineering