Copper under the stars: The history of discovery and mining at Girilambone, northwest New South Wales

Copper was discovered at Girilambone in 1875, shortly after the initial discovery of copper in the region at Cobar and by one of the same discoverers. Early mining from 1881 to 1885, with hand sorting of oxidised ore and direct smelting or shipment for custom smelting, was a technical failure and financial fiasco. Failure was largely due to metallurgical difficulties with the smelting and lack of ore concentrating machinery. Redevelopment by another company from 1896 introduced gravity concentration of the ores, with both on-site smelting and shipment of concentrates. This group was more successful, but unable to repay its capital investment, again due to the difficult metallurgy of the ores. By the early 1900s the company had resorted to small-scale chemical leaching of low-grade ores and tailings, with copper recovery by the cementation process. This phase of mining ceased in 1907.