FLSmidth Dry Tails Stacking Solutions

tailings operation should be about asset management not liability management FL Smith's try stacked tailings technology gives our clients greater control to manage water assets significant financial savings are realized by recouping operational costs through effective wastewater recycling back into the mining operation perpetual maintenance costs of wet tailings dams are eliminated removing the financial burden from future generations a typical mining operation using a concentrator with a 100 thousand ton per day capacity requires greater than 200 thousand tons of water per day for existing thickener technology and pond evaporation approximately 50 percent of that water is lost compare that with FL Smith's new large capacity filter press technologies approximately 50 thousand tons per day of water can be saved at a cost of 2 dollars and 50 cents per ton this amounts to his savings of 45 million dollars per annum in this example Ethel Smith's dry tails process starts when the waste material would usually be pumped out to a tailings pond the wet slurry enters a filter press where the moisture content of the material is reduced the feed slurry pump delivers the material to the filter press chambers via a lower center feed I the force generated by the feed pump results in solids formation on the surface of the filter media with the liquid filtrate passing through the cake and the filter media water exits the filter chamber it's reported in the filter plates the lower feed eye promotes turbulence and mixing in the chamber allowing for a homogeneous filter cake production once the filter cake is formed bay doors under the filter plates open up as the filter plates move apart the filter cake falls on to FL Smith's hybrid apron bail feeder where it is fed to the conveyor system this dewatering process may take five to thirty minutes depending on material characteristics such as density porosity and other factors the arrangement and number of filter presses will determine tonnage of material that is processed per hour the water that is collected in this process can be treated and returned to use in mining operations minimizing the amount of makeup water required the filter cake produced by the filter press is capable of being conveyed stacked and compacted waste material with this versatile characteristic it's the major benefit of dry taeil's stacking when planning for a wet tailing storage facility a mime plan contains an ongoing maintenance strategy this also comes with a perpetual cost that can only be guessed at as the decades pass a dry tailings handling plan has the goal of ending stacking operations and rehabilitating the stacking area to match the surrounding environment after dewatering is complete and the filter cake is deposited on the hybrid apron belt feeder the material is transported via conveyor to the stacking area filter cake can be conveyed using trough or pipe conveyors depending on the application defined in the mine plan conventionally Chhath conveyors are the most commonly used form of conveyor increasingly desirable technology is the use of pipe conveyors pipe conveyors provide additional functionality in that the material is completely enclosed in a pipe conveyor pipe conveyors easily transverse difficult anja lading surfaces in multiple directions eliminating transfer points and are the most environmentally sensitive method of material transfer over long distances the stacking area is smaller than required for wet tailings ponds the inherent stability of the dry stack material allows it to be stuck to much greater heights thereby creating a smaller footprint perimeter lips are not required around stock materials as they are with wet impoundment facilities at the stacking area the most commonly implemented stacking devices are either a mobile sacking conveyor or a boom spreader while they both perform a similar function in that they discharge dry material to the final resting place the differences in their applications depend on the mine plans specific requirements FL Smith's Rocko mobile stacking conveyors are designed to stack tailings while maintaining a low ground pressure this system is a long track mounted stacking conveyor that can vary in length from 200 meters to 1,000 meters the mobile stacking conveyors method of laying down material is based on a sweeping process and then adding additional sections to the extendable feed conveyor as the stacking of the pile progresses the mobile stacking conveyor can stack both in advance mode on top of the stockpile depositing material have varying stacking depths typically 10 to 100 metres deep it can also stack in retreat mode allowing it to stack behind itself however in this mode it is usually limited to a maximum discharge height of approximately 10 meters these machines range in capacity from 500 to 15000 tons per hour as material is stacked the pile can be contoured to match the surrounding topography once a dry stack tails pile is complete the pile is rehabilitated with native vegetation to be restored as part of the natural environment this reduces the environmental impact of the mining operations and improves the social responsibility with local residents governments and investors contact Ethel Smith to find out more how FL Smith's dry tails stacking technology can improve tailings management