evaporationpond

An evaporation pond is a shallow artificial basin used to evaporate water from salty or brine solutions to recover dissolved solids such as salts or minerals. They are common in mineral processing and salt production, especially in arid regions with high solar radiation.

Design and operation: Ponds are wide, shallow basins with liners to prevent leakage into groundwater, commonly HDPE liners or compacted clay. They rely on solar energy and wind to evaporate water; water depth is kept shallow to maximize surface area. Brine flows through consecutive ponds, with increasing salinity until salts precipitate, and crystallization ponds may be used to separate and harvest solids.

Applications: In salt production, evaporation ponds concentrate seawater or brines to harvest sodium chloride. In potash and lithium operations, brine from underground reservoirs is pumped into series of ponds to concentrate potassium or lithium salts before downstream processing.

Process: Brine inflow enters the first pond and undergoes evaporation and concentration through successive ponds. Crystals form in designated crystallization ponds, where salt is separated and harvested. The remaining brine may be recycled to earlier ponds or directed to disposal or reinjection streams as part of overall water management.

Environmental considerations: Evaporation ponds can affect local groundwater and surface waters through salinity and chemical loads. Leakage or seepage, dust, and wildlife hazards (notably birds) are concerns. Proper liners, leak detection, water balance management, and closure plans are required, along with ongoing environmental monitoring.

Limitations: Climate strongly influences efficiency; large land area and water use are required; variability in weather affects production output and salt purity; facilities require post-processing or refinement depending on target products.