Kinetics of atmospheric leaching molybdenum from metalliferous black shales by air oxidation in alkali solution

Kinetics of atmospheric leaching molybdenum from metalliferous black shales by air oxidation in alkali solution was investigated. The effects of temperature and sodium hydroxide concentration on the rate of molybdenum leaching were studied. The results of the kinetic analysis of the leaching data for various experimental conditions indicated that the reaction is controlled by diffusion with the activation energy of 15 kJ/mol higher than 65 °C, and controlled by chemical reaction with the activation energy of 57 kJ/ mol lower than 65 °C and molybdenum recovery of about 90% can be reached in about 30 min. In addition, increasing concentration of sodium hydroxide has a positive effect on the dissolution of black shales and reaction order with respect to sodium hydroxide concentration were approximately1.9 lower than 65 °C and 1.8 higher than 65 °C, respectively.