Natural Phenomenon: Renison Bell Deposit
Summary
The Renison Bell Deposit is a world-class orebody, estimated to contain 26.0 million tonnes of 1.46 percent tin. The mineralisation is associated with Devonian aged granite plutons. The Renison tin mine began operation in 1890 after George Renison Bell discovered alluvial cassiterite (tin oxide). Hard rock mining began in 1936, from an iron-sulphide cassiterite strata-bound replacement body in dolomite. The Renison Bell mine became the largest tin mine in the world.
Details
The Mount Lyell Mining and Railway Company Limited acquired the mine in 1958 and new ore reserves were found at depth. In 1965, a sharp increase in the price of tin stimulated intense exploration. The mine owners, Renison Limited, embarked on a $10 million development which brought the Renison Mine international renown. A trackless cut and fill operation used diesel loaders and trucks via a decline into the ore zones. A combined gravity and flotation processing plant treated the ore. As mining progressed, an underground crusher and shaft were installed in 1996 to reduce transport costs.
From the 1980s, production quotas, low tin prices, increased costs and industrial strife led to financial difficulties. Efficiencies were made through mining higher grades of ore and control of the dilution of the ore. In 1996, the $34 million Rendeep Project was implemented to develop deeper ore reserves, but the mine closed in 2004. That year, however, the lease was taken over by Bluestone Nominees, who re-opened the mine in 2004.
Carol Bacon, Greg Dickens and Wojciech Grun