Mass transfer correlation of removal of nickel by cementation onto rotating zinc disc in industrial zinc sulfate solutions

A rotating zinc disc was used to study the cementation of nickel from an industrial acidic solution of zinc sulfate. The reduction of nickel was evaluated for a wide concentration range of initial nickel concentration, electrode rotation speed and temperature. The rate of cementation giving the product kae of the local mass transfer coefficient k and the effective surface area ae was analyzed and expressed in terms of the rate of mass transfer versus the apparent mass transfer coefficient and correlated by a controlling numbers relationship.An estimation, by two methods, of the surface roughness variation caused by the nickel deposit was presented.