Surface renewal driven copper recovery by cementation in a stirred reactor with a rotating wiper mechanism

The rate of Cu²⁺ cementation on a Zn cylindrical sheet lining the inner wall of a cylindrical batch-stirred reactor was studied, where a U-shaped wiper consisting of two plastic-coated steel rods was used to agitate the solution. The novelty of the reactor lies in the integration of a rotating U-shaped wiper that provides simultaneous mechanical surface renewal and bulk agitation, enhancing copper removal efficiency without the need for additional stirring mechanisms. Variables studied were wiper rotational speed, wiper diameter, pH of the solution, and the initial concentration of CuSO₄ solution. The results revealed that the rate of cementation was unaffected by pH, however, it was increased by increasing other variables. Under optimized operational conditions, the wiper-assisted cementation process achieves nearly complete removal of Cu²⁺ ions from solution within 10 min. Mechanical power consumption measurements indicated that the reactor is energy efficient when the cell is agitated using a large-diameter wiper that rotates at relatively low speeds.