The growth of Broken Hill, for decades Australia’s most profitable mining centre, was based on zinc, lead and silver.

Two of the original mining companies at Broken Hill (BHP and Zinc Corporation) each became part of BHP Billiton and Rio Tinto, respectively.

The flotation process for concentrating minerals was developed between 1900 and 1910 at Broken Hill, triggered by the difficulties originally experienced in separating zinc from lead.

In the view of historian Geoffrey Blainey, flotation “stands with the cyanide process (gold) and the Bessemer process (steel) as one of the three greatest advances … in the last thousand years in metallurgy”. (The Rush that Never Ended)

Australia is the world’s third-largest producer of zinc (after China and Peru).

Mining continues at Broken Hill. However, the country’s largest zinc miners – Xstrata and the Chinese-controlled Mining and Metals Group (MMG) – operate elsewhere. Xstrata is increasing production around Mount Isa in Queensland and plans a major increase at McArthur River in the Northern Territory, while MMG plans to commence construction by early 2013 at Dugald River in Queensland.

For years, analysts have forecast a turnaround in the zinc market from surplus to deficit by 2015, with prices increasing accordingly. However, the outlook for zinc is closely tied to the outlook for China, the world’s largest zinc consumer. And optimism about China has declined in the last six months.