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Interactive PHREEQ-N-AMDTreat+REYs water-quality modeling tools to evaluate potential attenuation of rare-earth elements and associated dissolved constituents by aqueous-solid equilibrium processes (software download)

July 11, 2022

Software utilizing PHREEQC with user interface. The PHREEQ-N-AMDTreat+REYs geochemical modeling tools have the fundamental capability to simulate and predict key reactions related to the treatment of acid mine drainage and the formation of treatment solids, including the adsorption of rare-earth elements plus yttrium (REYs) onto hydrous iron, aluminum, and manganese oxides. These new tools were expanded from the PHREEQ-N-AMDTreat tools ( to include trace-element attenuation. Additions include a caustic titration model that indicates equilibrium surface and aqueous speciation of REYs as functions of pH and caustic agents, and a sequential kinetics+adsorption model that simulates progressive changes in pH, major ions, and REYs in water and solids during passive and/or active treatment.