A Solution to Settling Pond Maintenance Headaches
Aggregate operations utilizing wash plants to create clean, in-spec sand and rock inevitably produce a waste stream. This waste stream consists of the water used to clean the material as well as any silts, fines and clays that are removed in the process. Traditionally, this waste stream has been disposed of in the cheapest and easiest way possible– a settling pond.
The Hidden Costs of Settling Ponds 
Over time, however, settling ponds may prove not to be the cheapest, easiest option. When they fill up, the settled solids have to be removed or the surface water has to be pumped off to make room for the incoming waste. Undertaking this task can be both time consuming and expensive. Depending on the size of the operation, ponds may require cleanout several times a week. These costs can add up in the long run, making ponds more of a chore than a solution for waste.
Fines Recovery: A Better Solution
Enter fines recovery systems, such as EIW’s Hawk Fines Recovery Plant. These systems help to alleviate the burden of settling pond maintenance by reducing the volume of material going into the pond.
A fines recovery system features a sump, pump, hydrocyclones and dewatering screen. The waste stream from the wet processing plant enters the sump of the fines recovery system, where it is pumped up to the hydrocyclones. Hydrocyclones used for fines recovery are specifically designed to capture fine particles down to 400 mesh. These particles are then discharged onto a dewatering screen to remove additional moisture for conveying and stacking the material.
Particles smaller than 400 mesh and water are then sent to the settling pond or downstream processing equipment, such as a thickener or filter press.
The Benefits of Fines Recovery
The benefits of fines recovery systems are many but largely include:
• Reduction in pond cleanout/maintenance costs: By reducing the volume of material that goes to the settling pond by first processing it through a fines recovery system like EIW’s Hawk Plant, aggregate producers can reduce their pond cleanout frequency. Reducing pond cleanout frequency saves money on fuel and equipment rental fees.
• Reduction in load on downstream equipment: If an aggregate site has installed tailings management and water recycling equipment, such as a thickener and/or filter press, to recycle water or to reduce pond size, or if a site is considering adding one or both of these pieces of equipment to a new build, a fines recovery system can be a big benefit. Adding a fines recovery system reduces the solid material that is sent to the thickener or filter press, reducing the size or number of units required. Ultimately, this can save on capital equipment costs as well as maintenance costs from component wear and tear.
• Creation of a salable product: Fines recovery systems remove particles greater than 400 mesh from the waste stream and discharge it as a drip-free solids material. This material can potentially be sold as back fill or pond lining, adding an additional revenue stream from what would have once been disposed of as waste. In some cases, the material discharged from the Hawk can be mixed into a product stream without knocking the product out of spec.
Who Can Benefit from Fines Recovery?
Fines recovery equipment is beneficial for any aggregate application with a waste stream and a settling pond. It is a good consideration when planning for a new build, but it can also be added to any existing site, even those already operating thickeners and/or filter presses.
By installing a fines recovery system, aggregate producers can spend less time and money on settling pond maintenance, reduce the load on downstream processing equipment and potentially create a usable, if not salable, product.
Find the Perfect Solution
Allow one of our experts at NorX to help you decide on the best fines recovery equipment to suit your individual operation. Contact us at (770)338-0111.