First steel produced from local ironsand

15 September 1969

New Zealand Steel mill, Glenbrook, 1968
New Zealand Steel mill, Glenbrook, 1968 (Alexander Turnbull Library, WA-68102-G)

New Zealand Steel’s Glenbrook mill, near Waiuku, south of Auckland, produced iron and steel from local ironsand (titanomagnetite) for the first time. In 2020 ironsand and coal were being used to produce about 650,000 tonnes of steel a year.

Black iron-rich sands are found along much of the western coast of the North Island. The ironsand is the product of rocks formed by volcanic activity in the Taranaki area 2.5 million years ago. In some places the ironsand deposits have formed dunes up to 90 m high.

European settlers were fascinated by the sands’ magnetic qualities. Early attempts to smelt iron from the ironsand met with little success. In the 1950s the government made renewed efforts to utilise this valuable resource. A New Zealand Steel Investigating Company was set up in 1959 to determine the feasibility of manufacturing steel from local raw materials. New Zealand Steel Ltd was incorporated in 1965 and Glenbrook mill opened in 1968.

Glenbrook remains the only steel manufacturer in the world to use titanomagnetite sand as its source of iron.