Dissolution kinetics of a lateritic nickel ore in sulphuric acid medium

Abstract

The dissolution kinetics of a lateritic nickel ore in the sulphuric acid solution were investigated. The shrinking core model wasapplied to the results of experiments. The effects of stirring speed (100–600 rpm), H2SO4 concentration (0.1–2 mol l-1), leachingtemperature (40-96 °C) and the particle size of the ore were studied on the nickel dissolution rate. The correlation coefficients for eachdifferent parameters were calculated. The results indicated that the dissolution rate of Ni is controlled by diffusion. The activationenergy (Ea) for the dissolution reaction was determined to be 68.66 kJ mol-1. The Arrhenius constant was calculated to be 8.2578 s−1.The order of reaction for the H2SO4 concentration and the particle size were also obtained. It was found that the stirring speed hadno effect on the rate of nickel dissolution.

Keywords

• Nickel
• leaching
• dissolution kinetics
• sulphuric acid
• diffusion