McLanahan Filter Presses a Sustainable Solution to Fine Material Waste
Aggregate and minerals processing producers typically send the fine material waste from their wet processing plant to settling ponds or tailings dams, which provide a space for the solid material to settle and allow the recovery of reusable water.
Usually, these ponds are difficult and costly to manage in terms of maintenance, since full ponds require the periodic removal of material. Permitting new ponds to hold the additional fine material waste can be a challenge as well. Ponds can also take up quite a bit of valuable land space, potentially covering up mineable reserves.
A sustainable solution
McLanahan Filter Presses provide many benefits to aggregate producers who want to manage their waste material more efficiently and effectively. They separate solids and liquids in slurries to create dry, stackable material and recover process water that can be reused in the wet plant.
“The McLanahan Filter Press gives the customer the opportunity to completely eliminate a settling pond and the associated higher cost of managing that pond and the waste material in it,” explained Dennis Zink, Global Product Manager - Filter Presses. “It gives them the potential of recovering the maximum amount of reusable water. It generates a much more easily managed solid waste material, and there’s some possibility it could create a new salable product.”
Eliminate settling ponds
By separating the fine material waste slurry into a dewatered solids portion and a reusable liquid portion with a McLanahan Filter Press, producers can eliminate the need for settling ponds, as well as the cost associated with maintaining those ponds.
“You wouldn’t be faced with permitting for the pond or getting permitting for a new pond, and you don’t have to deal with cleaning out the pond periodically,” Zink said. “You also free up a lot more available space.”
Recover reusable process water
Filter Presses recover between 80-90% of the water volume from a slurry feed that’s 30-35% solids. The recovered water can be reused immediately in the upstream wet processing plant, reducing the need to rely on municipal supplied water or a nearby groundwater source and the cost associated with purchasing/pumping that water.
“From a water usage standpoint, the Filter Press is a lot more effective way to recover water,” Zink said. “Especially in areas where water is scarce or expensive, being able to recover as much water as possible to reuse is really important.”
By recycling water with a McLanahan Filter Press, the need for fresh water for processing is minimized. It creates a nearly closed-loop system where the plant keeps reusing its own process water to operate.
Create a new salable product
Another benefit of the dewatered solids besides being easier to manage is the potential to create a salable product from the waste material. Rather than sitting in a settling pond taking up space, the dewatered solids could be a potential source of additional revenue.
“It’s possible that the McLanahan Filter Press could be used to create a new product from the waste that had been historically just stored in ponds or dams,” Zink said. “Depending on the type of material, some customers have found that they can sell the material as a product. It’s been used as trench lining and levy fill.”
Use land more effectively
The lifecycle of a mining or aggregate location takes usable material out of the ground and separates it from the waste material, which then has to be placed back into the ground. McLanahan Filter Presses allow the solid waste material to be placed permanently on the mine site much quicker.
“Using the McLanahan Filter Press allows you to more quickly place the material where it’s going to stay forever — you won’t have to dig it up again, won’t have to process it again. The land could be reused once the site is no longer in operation a lot more effectively.”
Benefits of McLanahan Filter Presses
McLanahan Filter Presses offer a way to eliminate settling ponds to free up land space and/or mineable reserves, which helps with permitting costs/restrictions. They create a more manageable dewatered solid material with reduced handling costs and the potential for sale. They recover immediately reusable process water for those facing limited water availability or high fresh water usage and cost.
“A lot of times, producers don’t think about what it’s costing them in terms of permitting costs, the costs of cleaning out the pond, the wear and tear on the equipment used, the cost of moving the material around,” said Zink. “The McLanahan Filter Press immediately puts the waste material in a solid form that’s much more easily managed, and it immediately recovers the water that can be reused in the plant."