Other mining continued
The presence of manganese ores in the East Pilbara and Peak Hill areas was noted by Government geologists before 1920. However, although small parcels of manganese ore were produced from the Peak Hill area in the 1920s, systematic production began there only after 1948.
Limited production, mainly from the Horseshoe deposit, continued until 1971, peaking between 1965 and 1970. Exports were initially restricted because manganese was indispensable for steel making, and was viewed as a strategic mineral. Production from mines in the East Pilbara began in 1954. Their output peaked between 1966 and 1972 at the rate of over 100,000 tonnes a year.
Exploration for nickel began in Western Australia in 1955 with the International Nickel Company that discovered a large but uneconomic deposit on the border with South Australia. Interest in nickel waned until 1964 when a Western Mining Corporation exploration team was told nickel had been identified in rocks around Kambalda, south of Kalgoorlie. Nickel sulphides were subsequently discovered at depth in 1966 and production began the following year.
In 1970 a nickel refinery was established at Kwinana, followed by a smelter near Kalgoorlie in 1973. In 1979 it was expanded to accommodate production from
Agnew. By the 1990s production had been expanded at Leinster to sustain capacity at Kambalda, and to expand the capacity of the smelter at Kalgoorlie and the refinery
at Kwinana by 50%. The extra smelter and refinery capacity became operational in 1994. Along with the move to underground operations at Forrestania, these measures
have combined to make Western Australia one of the lowest cost producers in the world.