Processing ponds, whether they’re designed to hold pregnant or barren solutions, require durable liners you can count on. Liner failures in processing ponds can lead to serious environmental damage and corresponding fees from the Environmental Protection Agency (EPA). Few water storage environments are as challenging as a processing pond due to use of highly reactive and corrosive leaching solutions. Unlined ponds were once widely used for holding and processing ponds in the precious metals industry, but modern regulations won’t allow for this today. The right type of material from BTL Liners will protect your processing ponds and ensure you deal with as few environmental issues as possible.
Controlled Leaching
An entire metal or mineral processing system relies on careful control of leaching speed. Without a liner, soil conditions could speed up leaching or interfere with it. Speedy or slow leaching results in solutions that are low in the target ore or mineral. When the solution moves too quickly through the heap, the solution doesn’t get a chance to break down enough of the preferred compound. Slow leaching allows heavy precious metals and minerals to settle at the bottom of the heap pad pond rather than running out into the drainage ditches. Liners give you better control over leaching speed by preventing seepage through the soil and other sources of water loss.
Loss of Valuable Material
When you store and process valuable ore solutions in unlined natural ponds, you end up losing some percentage of the most valuable material to seepage. Once part of the solution has soaked into the ground below the pond, it’s impossible to reclaim that lost material in most cases. When you’re dealing with a precious metal like gold or uranium, even a few ounces of valuable material reclaimed from each pond on a regular basis can add up to a substantial increase in profit. If secondary processing is needed, to remove unwanted compounds, liners are definitely necessary to prevent material loss at this stage as well.
High Rate of Contamination
Even after extensive processing, the barren leachate left at the end of this technique is contaminated with a mix of acidic or alkaline chemicals, residual particulates, and secondary dissolved minerals and compounds. Improper storage and handling of the leachate liquids, whether pregnant or barren, runs a high risk of environmental damage. The residues left by leaks and seepage last for years, leading to fines far down the road when shutting down the site. Reliable and flexible geomembrane liners, particularly those made from multi-layered reinforced polyethylene (RPE), offer the best protection against processing pond contamination.
Liner Damage from Reactivity
It’s not enough to simply choose the right general type of pond liner either. Some flexible liners are reactive to the acidic or alkaline solutions used for encouraging leaching from the mined materials. If your selected liner material weakens or breaks down due to constant exposure to reactive solutions, leaks can develop and release thousands of gallons of valuable leachate liquid per year. Multi-layered RPE liners are particularly chemical resistant, even when the liquid stored in the liner is highly acidic or alkaline. The right kind of flexible material won’t peel or separate due to exposure to harsh chemicals.
Abrasion and Tear Resistance
Even with extensive grading and clearing work, it’s all too easy to leave a few sharp-edged rocks or roots behind on the surface of the soil. As the liner is stretched over the surface, some materials are particularly prone to tearing or cracking during installation. Multi-layered liners are the best choice because the engineered coating increases durability and tear resistance, especially when you choose a reinforced product. The rock sands and dusts used for leaching are also highly abrasive. Make sure to pick a liner that can resist constant abrasion without developing regular new leaks.
UV Resistance
Finally, some processing ponds also require the installation of a pond liner with no ballast or cover material over it. These liners must be UV resistant and graded for exposed installation since the sun’s rays are surprisingly destructive to flexible materials. Using a liner designed for covered installation in an open pond with no gravel or soil over the surface will result in extensive leaks and a very short lifespan. Since our ArmorPro liners combine multiple layers of engineered coating and woven polyester reinforcement, they offer advanced UV and chemical resistance that makes them the ideal materials for processing ponds of all kinds.
Still not sure what you’re looking for when selecting a liner for a barren pond or processing trench? Don’t worry, BTL Liners is ready to help. Contact us for custom recommendations on liner selection and installation based on your project requirements. Our ArmorPro material in particular is a great choice for any mining pond, including barren and pregnant processing ponds. The material is flexible enough to conform to any shape, allowing you to use the same material for all of the ponds and the ditches or trenches connecting them.
