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Equilibrium data for the adsorption of gold tetrachloride from aqueous solutions of four different concentrations of hydrochloric acid (0.250,0.500,0.750, and 1.00 mol.dm-HC1) by macroporous crosslinked polyacrylate (MET) resins which have the same functional groups and different structural characteristics have been obtained at a temperature of 25 2 0.5"C. It was found that the mechanism of adsorption can be regarded as simple ion exchange, and that the adsorption of gold in the resin phase is a "homogeneous" adsorption. The equilibrium constants and the capacities for the adsorption of gold by MET resins were estimated, and the influence of the acidity of the solutions on the equilibrium parameters were discussed.

The kinetic behaviors of the adsorption of gold(II1) with macroporous crosslinked polyacrylate (MET) resins from hydrochloric acid solutions were studied by employing the "shallow-bed'' technique. The MET resins (corresponding to XAD-7) used in the study vary in structural characteristics. The particle interdiffusion coefficients for every kind of MET resins at four temperatures (25. 35, 45, and 55°C) were calculated from the experimental data, and the kinetic properties were carefully researched. It was found that the experimental results can be interpreted in the light of the concept of the adsorption double layer on the resin/ solution interface.

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