Removal of nickel ions by cementation on zinc from NiSO4 solution in presence of accelerator non-toxic organic compounds

This work deals with the removal of nickel ions by cementation on zinc from dilute nickel sulphate solution. The effect of different parameters such as, initial nickel ion concentration, temperature, rotation speed of a magnetic stirrer and concentrations of 1-aryl-3-(1-phenylpyrazolo [3,4-b]quinoxalin-3-yl)-2-propenone derivatives on the rate of nickel ion removal were investigated. The cementation reaction followed first‐order kinetics and diffusion controlling steps. The rate of cementation was found to increase in the presence of pyrazolo-quinoxaline derivatives. The value of activation energy and the increase in the rate of cementation with stirring support the fact that cementation of Ni2 + on Zn is diffusion controlled. The deposit morphology of nickel in the presence of chalcones was found to be dendritic. The dendrites create a local surface roughness which induces the formation of eddies. These eddies enhance the rate of nickel cementation. The experimental results were analysed by quantum chemical calculations.

► Kinetics removal of Ni using non-toxic pyrazolo-quinoxaline derivatives.
► Increasing temperature and rotation speed increase rate of reaction.
► A good correlation was found between theoretical and experimental data.