PASTE & FILTERED TAILINGS
FLSmidth Thickener Spiral Rake Blade installation
Improved raking power at lower torque
Thickener efficiency is coming to the fore with increased focus on better tailings management . IM spoke to Steve Ware , Vice President , Product Group Manager – Thickening and Filtration , and Craig Gilbert , Global Product Line Manager - Thickening at FLSmidth about its latest innovation
Above left : Steve Ware , Vice President , Product Group Manager – Thickening and Filtration , FLSmidth , Above right : Craig Gilbert , Global Product Line Manager - Thickening , FLSmidth we have developed our spiral rake blade for thickeners .”
For specific applications , Ware says that one common issue with traditional high-tonnage thickener rakes is the inability to move mud evenly to the discharge , whereas the spiral design steadily pulls more material along the floor allowing for a much more even mud bed
distribution limiting the potential for ratholing , which is often caused by the less dense slurry bed being drawn down from above the discharge . This reduces short circuiting and eliminates dead zones .
This innovation FLSmidth ' s Gilbert says has a side benefit of reducing the torque requirements dramatically . " The spiral rake blade combined with a low-drag rake arm , which has proven critical to discharging high underflow densities , allows for easy operation and control . And because the spiral rake assembly produces a denser material in the thickener discharge , less water is lost in the tailings , allowing more water to be recycled back into the plant ."
The spiral design of the inner rake blades Ware says offers a number of unique benefits that the blades on traditional rake arms cannot provide . By having a more consistent bed with a more even mud bed residence time , the arms with spiral rake blades reduce power peaks and valleys , and as stated reduces the ratholing that conventional rake blades can create .
The combined advantages of reduced torque and the spiral rake blades ’ steady and consistent action in the mud bed ( improving underflow density and clarified overflow ) result in overall lower energy consumption and increased water reclamation . By lowering overall torque while more effectively moving solids , the spiral rake blade assembly improves the life of the rake
As the need for better tailings management increases , so does the demand for efficient high-capacity dewatering . With its improved raking power at lower torque , FLSmidth ' s Ware says its new Thickener Spiral Rake Blade plays a critical role in managing underflow densities and mud bed residence time , increasing the thickener efficiency .
Thickeners not only help create a more sustainable site by producing reusable process water , they also minimise the environmental impact and safety risks associated with multiple or large settling ponds . " The spiral design of our thickener rake blade addresses the challenges operators often face with raking capacities of traditional high-tonnage machines - including ratholing , high energy consumption and water loss ," says Gilbert .
Mine operators must meet increasing demands for environmentally conscious practices . Ware : " We know that properly optimised thickeners will help to increase mine performance , reduce operating costs and improve a mine ’ s sustainability – which is why
P8 International Mining SUPPLEMENT | APRIL 2023