Platinum extraction from different secondary sources has been experimentally tested by many researchers. In this article, dissolution of platinum in aqua-regia solution from two types of spent catalysts (reforming and nitric acid production) was kinetically studied. A variety of kinetic models for heterogeneous solid-liquid reactions, including homogeneous diffusion model, shrinking core model,...

in this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°c to 50°c. in the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential wer...

The leaching kinetics of smithsonite ore in acetic acid solutions, an environmental friend, and natural reagent was investigated. The influence of parameters such as reaction temperature, particle size, solid-liquid ratio and acid concentration was studied in order to reveal the leaching kinetics of smithsonite ore. In this study, experimental and statistical methods were carried out in order t...

Unsatisfiable core analysis can boost the computation of optimum stable models for logic programs with weak constraints. However, current solvers employing unsatisfiable core analysis either run to completion, or provide no suboptimal stable models but the one resulting from the preliminary disjoint cores analysis. This drawback is circumvented here by introducing a progression based shrinking ...

This communication reports the reduction mechanism and kinetics of CoO-NiO/Al2O3 oxygen carrier using methane as the reduction gas. Kinetics experiments are performed in a novel fluidized bed CREC riser simulator under turbulent fluidized bed reaction conditions. A shrinking-core model is used for the kinetic modeling assuming spherical grains of the oxygen carrier particles. The XRD analysis s...

  Abstract   The effect of mechanical activation using an attrition mill on the particle size of an ilmenite concentrate and its effect on the ability of the concentrate for Iron separation during hydrochloric acid leaching and the kinetics of the dissolution process have been investigated. It was observed that mechanical activation in an attritor significantly enhances the dissolution of iron ...