Kinetic study of the removal of Cu (II) from aqueous solutions by rolling mill scale

Abstract

The removal of Cu (II) from aqueous solutions by rolling mill scale occurs through a process of oxidation-reduction or cementation of Cu ²⁺ ions in aqueous solution onto metallic iron (Fe⁰) contained in the mill scale. The kinectics of cementation of copper onto iron was evaluated over different temperatures, initial copper concentrations and solid/liquid relations. Process of copper removal by rolling mill scale obeys a first-order kinetic law. The rate constant value (k) varies with temperature and initial cation concentration in solution at low temperatures. At high temperatures the value of k remains practically constant. The solid/liquid relation value affects the rate constant value too.