The difficulty in screening of ores when the moisture contents reach certain critical levels has resulted in mining circuits using wet processes for screening. While this has been acceptable in past years it is no longer acceptable in certain countries and where the mining company is looking to reduce its impact on the surrounding environment._x000D_
Various mining companies have been looking at ways to remove the need of using water, with all its inherent drawbacks and to be able to produce its desired products in a dry process._x000D_
This would have the benefits of less environmental impact and cost, (due to not requiring wet processing equipment), less power consumption (reduced equipment needed), no corrosion issues, no contaminated waste waters and reduced maintenance activities._x000D_
Until recently this has proven elusive or with technical restrictions with current available acceptable technologies for high capacity plants._x000D_
One major mining company began seriously exploring ways to overcome this dilemma so that they did not replicate their current ways of operating for their new expansion plans._x000D_
They partnered with Metso Minerals to undertake extensive groundbreaking laboratory test work and provide potential solutions as to how to solve this. The laboratory test work proved interesting enough to design, manufacture and test on the actual mining site a prototype screening machine in the circuit._x000D_
This break through in screening technology reduces the environmental impact on the area in which the mine is located by: eliminating the storage and use of water, reduction in energy consumption due to having no pumps in the plant, reduction in plant costs and the upstream affects on the environment process used to manufacture and ship the materials the plant structure is built from, and no large tailings dams to take up land space and affect the environment through groundwater/ water table contamination and the negative effects on animals and ecosystems Laboratory test were conducted and a full size machine was installed at the plant site along side conventional machines. The screen size (2.4 m wide x 6.1 long double deck) was determined by the size of screens currently in operation at the mine._x000D_
The parameters that were explored were: types of screen surface (polyurethane, woven wire etc), types of screen motion (linear, circular or elliptical), angle of motion ( 40,45,55,60 degrees etc), and throw (amplitude), speed and g' force._x000D_
FORMAL CITATION:Ogawa, R, 2010. Reducing mining environmental impact - through innovative vibrating screen technology, in Proceedings Sustainable Mining 2010, pp 86-99 (The Australasian Institute of Mining and Metallurgy: Melbourne).