Kinetic study of abstraction of ethyl xanthate ions by oxidized chalcocite surface

The results of potassium ethyl xanthate (EtXK) consumption measurements by synthetic chalcocite (Cu₂S grain-sized classes of 60–75 μm and 120–200 μm, respectively) are presented. These measurements were done in a modified circulation apparatus in an argon or oxygen atmosphere at pH=9.5. The experimental results were compared with theoretical results predicted by a mathematical model based on the assumption that the EtX^? ions were immobilized as a result of a chemical reaction (or reactions), e.g., of an ion-exchange type, taking place within the oxidation product layer (OPL), formed on the Cu₂S surface.The experimental and theoretical results are in good agreement especially for small values of Q₀ (Q₀ is the initial mass of the EtX^? in solution per mass unit of Cu₂S). In this case both the theoretical and experimental results show that the EtX^? concentration in solution decays exponentially with time.