This paper investigates the adsorption of copper on process dust from the production of olivine aggregates as a function of pH and the concentration of copper in solution. The olivine process dust, containing more than 90% forsterite, was retrieved from the dust removal system at A/S Olivin's processing plant at (A) over circle heim in western Norway. Following characterisation of the material, batch adsorption experiments were conducted at 25 degreesC at an ionic strength of 0.05 M using a fixed adsorbent dose of 10 g/l and initial copper concentrations ([Cu](i)) ranging from 20 to 600 muM (i.e. 1.27-38.1 mg/l). The final pH in solution (pH(f)) was varied from approximately 4 to 6. The obtained results show that the olivine process dust is capable of greatly reducing the concentration of copper in solution, even when exposed to relatively high initial copper concentrations. A linear multivariable regression model (LMVR model) was fitted to the logarithmically transformed experimental data. The good fit of the LMVR makes it possible to estimate retention as a function of pH(f) and the final copper concentration ([Cu](f)), or, alternatively, [Cu](f) as a function of pH(f) and [Cu](j). From an environmental engineering point of view, the latter would often be of greater interest since the success criteria usually are related to the resulting concentrations in solution. (C) 2002 Elsevier Science Ltd. All rights reserved.