The Use Of Selective Ion Exchange For The Recovery Of Base Metals From Effluent Streams

Base metal refinery effluent streams may contain low metal concentrations that cannot be recovered by precipitation. Although the concentration is low, the total mass of unrecovered metal can have significant value because of the volumes of effluent generated. This metal may be recovered with high efficiency using selective ion exchange resins. Three process schemes are considered, viz., fixed bed column ion exchange, continuous countercurrent resin-in pulp, and continuous carousel resin-in-pulp. Each of these has different requirements in terms of equipment, resin inventory, capital and operating costs, and different limitations on feed conditions. Bateman and Mintek recently developed a model which allows an upfront economical evaluation of ion exchange options. The model evaluates the capital and operating costs for each process scheme for various base metals. This provides a general guideline for selecting the appropriate process arrangement for a given process stream.