Bayer process red muds are highly alkaline, and their disposal and potential for reuse are complicated by high concentrations of sodium, high pH, and high alkalinity. Several methods of neutralization of red muds have been reported including: infiltration of rainwater and atmospheric CO2, treatment with strong acids, gypsum addition, and seawater neutralization. Using seawater to neutralize red mud at the Queensland Alumina Ltd. (QAL) refinery at Gladstone, QLD, began as a fresh water conservation measure but led to many benefits, including reduced freshwater use at the refinery, increased settling rates at the pond and reduced alkalinity and sodicity in the solid wastes and entrained liquor. The study reported here describes and quantifies the geochemical consequences of seawater neutralization of bauxite refinery residues. Methods and results presented allow description of the chemical, mineralogical, and physical characteristics of seawater-neutralized red mud. Experiments then identify and quantify th...