Located in Queensland, Australia, Ernest Henry Mining is a Glencore company that first began operating in 1998 as an open pit mine. As the open pit’s economic life span was due to end in 2011, plans in 2009 were confirmed to invest $589 million and transform the mine to underground shaft mining. By early 2012, a 5 km decline had been established to enable the trucking of ore from underground to the surface. Rates of production with this method were approximately three million tonnes annually resulting in about 25,000 tonnes of copper concentrate and 35,000 ounces of gold concentrate per year. By moving to shaft hoisting, 2015 production was forecast to double to six million tonnes of ore. That rate is projected to be achieved on an annual basis over the extended lifespan of the mine to 2026.
Construction of the Shaft and Hoisting System
The sinking of Ernest Henry’s 1 km deep shaft began in May 2012. Associated infrastructure that was subsequently constructed included a 75 metre high permanent head frame for the hoisting system that has a 1,000 tonne per hour lifting capacity. The state-of-the-art shaft haulage system features a 5,000 kW hoist and utilizes bottom-dump ore skips. Control of the fully integrated hoisting system from loading conveyors to the surface dump station is automated.
Considerations for Mine Skip Manufacture
The incorporation of high-quality mining skips, as Ernest Henry shows, can have a major effect on overall production. While Ernest Henry utilizes bottom dump ore skips, a range of other configurations are available in order to suit the configuration, expected output and shaft size of an individual mine. These include Kimberly, front-dump (types 1 and 2), and arc gate skips. The type of material selected to manufacture mine skips is also an important factor. Aluminum skips, for example, provide superior resistance to corrosion compared to steel and are about one-third lighter in weight. The result, according to experts, is that aluminum skips can haul about 15 percent more payload weight compared to those constructed of steel.
To meet the specific needs of any particular mining operation, there are many proven mine equipment manufacturers, such as Wabi Iron & Steel Corp., that can design and build superior quality skips that will provide many years of efficient operation.
(Glencore Commissions its Ernest Henry Mine Shaft Hoist, http://www.australianmining.com.au/news/glencore-commission-its-ernest-henry-mine-shaft-ho)
(Re-inventing Ernest Henry Mining, http://www.infomine.com/library/publications/docs/InternationalMining/Chadwick2012ii.pdf)