Abstract

This is a study of the leaching and dissolution kinetics of zinc and copper from polymetallic sulphide ore obtained from Zarara Hill, Kaduna state, Nigeria. The elemental analysis ICP-OES showed that the ore contains iron (68440 mg/kg), Zinc (27477mg/kg), Copper (26387mg/kg), lead (25130mg/kg) and Sulphur (33017mg/kg) as major elements. After leaching in different concentrations of HCl, the amount of zinc and copper dissolved increased meaningfully by an increase in HCl concentration from 0.5 to 9 M. The findings of this study demonstrate that increase in temperature is accompanied by an increase in the amount of zinc and copper that is leached from the roasted sulphide ore. From the plot of 1 – 2/3X – (1 – X)^2/3 versus leaching time for data displayed on the effect of HCl Concentration on zinc and copper dissolution, The slope of the straight-line graph (K₁) was calculated, this means that the order of reaction concerning H⁺ ion concentration for zinc and copper dissolution is 0.53 and 0.67 respectively. Also, from the plot of 1 – 2/3X – (1 – X)^2/3 versus leaching time at different temperatures for the data presented on effect of temperature on zinc and copper dissolution by 9M HCl. The rate constants K₂ were determined from the gradient of the straight lines in the various plots and were used to plot the Arrhenius plot where the activation energy was calculated to be 24.3 and 19.7kJmol^-1 for zinc and copper dissolution respectively.

Key Words: Sulphide ore, Dissolution, Zinc, Copper, Leaching, HCl