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UBC Theses and Dissertations

An ion exchange loading correlation for the simulation of base metal resin-in-pulp circuits McKevitt, Bethan Ruth


This thesis investigates the loading rate of nickel onto an iminodiacetic ion exchange resin, with the goal of gaining insight into operation of a base metals resin-in-pulp (RIP) circuit. A modified pH-stat method was used to generate loading data under infinite solution volume conditions. A comparison of several commercially available iminodiacetic resins was performed, using this method. The standard linear approach to equilibrium was found to fit well to the portion of loading under film diffusion control, but none of the standard engineering approximations could adequately describe the data from the intraparticle diffusion / exchange rate limited regime. A hybrid correlation was developed and was found to adequately describe single element loading of nickel, copper, and cobalt from synthetic solution. In order to know which of the two models to use at a given point in time, a modified Helfferich number was derived. This dimensionless number can be used to track when the resin bead switches from film diffusion control to intraparticle diffusion control. The experimental fit parameters of the film diffusion model and the hybrid correlation were used to successfully predict the results of batch experiments with varying solution concentration. The effectiveness of these equations were also assessed and verified through the operation of a five stage RIP miniplant, using synthetic solutions. Using these circuit models, various RIP circuit operating configurations were simulated. Results from these simulations suggest that all operating configurations and strategies have both advantages and disadvantages. A table summarizing the process sensitivity of a cascade circuit to various operating conditions has been generated.

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Attribution-NonCommercial-NoDerivatives 4.0 International