Evaporation ponds

Evaporation is used in a variety of mining operations to separate valuable materials from water or brines. Diverse salts, for example, can be extracted by evaporation. Lithium-rich brines may be concentrated through evaporation. These materials, when harvested from solar ponds, are then able to be refi ned into items used across a wide variety of industries, in agriculture, in food products, etc.

For sites where remediation or isolation of a contaminant is a goal, the act of evaporation in an engineered pond can also be an effective solution, especially in the case of contaminated sediments.

The evaporation process generally requires a signifi cant scale to be more effi cient and economical.

Geosynthetic lining solutions are used to prevent the loss of valuable materials in seepage. They also provide strong environmental protection. The potentially aggressive nature of the material being mined by evaporation demands environmental care, especially with the concentrated masses that the evaporation process yields.

In many situations, pregnant solutions are pumped into the engineered pond for multiple cycles until the pond has been fi lled with a sizable enough harvest to economically justify collecting it. The system will likely be exposed to both the material of interest and diffi cult environmental conditions for a considerable period of time (e.g., years) before harvesting occurs.

As such, long-term performance and durability are essential for an evaporation pond lining system.

NAUE Solutions for evaporation ponds

Carbofol® high-density polyethylene (HDPE) geomembranes feature exceptional chemical, stress crack, and UV resistance.

Their durability in tough installation conditions makes them an ideal lining material for many mining installations, including evaporation ponds. Carbofol® is suitable for exposed and buried containment designs and robust against a wide variety of fluids used in mining operations.

Bentofix® geosynthetic clay liners (GCLs) can also be used in evaporation pond applications, depending on what is being contained. Just as one must ensure that a geomembrane polymer is chemically compatible with the solution to be contained, with GCLs one must check for chemical compatibility with the bentonite core. In more aggressive environments, Bentofix® coated GCLs, with their additional extrusion polymer barrier, might be the better solution.

Both Carbofol® and Bentofix® are engineered for strong, long-term containment in difficult environments. Their efficient rolls, including the 9.3m-wide Carbofol® option, enables considerable coverage, reducing installation time and on-site material waste.