Metals recovery from multimetal sulphide concentrates (CuFeS2–PbS–ZnS): combination of thermal process and pressure leaching

Kinetics of Chalcopyrite Leaching by Hydrogen Peroxide in Sulfuric Acid

In ores, chalcopyrite is usually associated with other sulfide minerals, such as sphalerite, galena, and pyrite, in a dispersed form, with complex mineralogical structures. Concentrates obtained by flotation of such ores are unsuitable for pyrometallurgical processing owing to their poor quality and low metal recovery. This paper presents the leaching of chalcopyrite concentrate from the location “Rudnik, Serbia”. The samples from the flotation plant were treated with hydrogen peroxide in sulfuric acid. The influences of temperature, particle size, stirring speed, as well as the concentrations of hydrogen peroxide and sulfuric acid were followed and discussed. Hence, the main objective was to optimize the relevant conditions and to determine the reaction kinetics. It was remarked that the increase in temperature, hydrogen peroxide content, and sulfuric acid concentration, as well as the decrease in particle size and stirring speed, contribute to the dissolution of chalcopyrite. The dissolution kinetics follow a model controlled by diffusion, and the lixiviant diffusion controls the rate of reaction through the sulfur layer. Finally, the main characterization methods used to corroborate the obtained results were X-ray diffraction (XRD) as well as qualitative and quantitative light microscopy of the chalcopyrite concentrate samples and the leach residue.

Successful sulfur recovery in low sulfurate compounds obtained from the zinc industry: Evaporation-condensation method

The improvement of an evaporation-condensation method allows for successful recovery of elemental sulfur from sulfide concentrates from the zinc industry. Elemental sulfur can be obtained with this method in samples with a low (60%) sulfur content. The effects of heating temperature between 150°C and 250°C and heating time up to 120min on the recovery of sulfur are also studied. Elemental sulfur obtained in this way is of high purity and therefore, there is no need for further purification. The treatment of these industrial residues would help removing sulfur from the environment.