The kinetics of leaching galena concentrates with ferric methanesulfonate solution

• Ferric methane sulfonate is very suitable to treat galena concentrates.
• Temperature has a pronounced effect on the dissolution rate of galena.
• The dissolution can be very fast and completed in high temperature range.
• The proton and ferric concentrations have very weak effects on the kinetics.
• The kinetic process is controlled by product-layer diffusion.

A new hydrometallurgical leaching process, which dissolves lead concentrates with acidic ferric methanesulfonate solution, was proposed and investigated. The leaching kinetics of galena-containing concentrate from Red Dog Mine (Teck) was studied with respect to variables such as stirring speed, temperature, concentrations of free acid and ferric ions as well as particle size. It was found that stirring speed and acid concentration had no influence on the leaching rate, while increasing temperature moderately increased the rate. The leaching data best fitted the product-layer diffusion control mechanism based on the shrinking core model with an apparent activation energy value 36.15 kJ/mol. The apparent reaction constant for the mean value of particle size and the reaction order for initial ferric concentration were very close to the theoretical values of 2 and 1, respectively.