Hydrothermal treatment of sphalerite and pyrite particles with CuSO4 solution

Kritskii A., CELEP O., YAZICI E. Y., DEVECİ H., Naboichenko S.

Minerals Engineering, cilt.180, 2022 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 180
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1016/j.mineng.2022.107507
  • Dergi Adı: Minerals Engineering
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Anahtar Kelimeler: Hydrothermal treatment, Sphalerite, Pyrite, Sulfide minerals, Kinetics, Mechanism, Copper sulfate, Sulfuric acid media, Autoclave, COPPER
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

© 2022The nature of the hydrothermal reaction between sphalerite (ZnS) and pyrite (FeS2) particles and copper sulfate (CuSO4) solution was investigated in this study. The effects of temperature (443–523 K), CuSO4 (0.08–0.96 mol/L) and H2SO4 (0.05–0.6 mol/L) concentrations, reaction time (1–120 min), stirring speed (40–100 rpm) and particle size (10–100 μm) on the conversion of sphalerite and pyrite were studied. The ZnS conversion was significant already at 443 K and the most complete conversion was observed at T > 503 K after 120 min of treatment. For FeS2, conversion of about 50 % was achieved only at T > 523 K. It has been experimentally shown that the FeS2 treatment is a multistage process as the analysis of reaction kinetics suggests. The shrinking core model (SCM) was applied for describing the kinetics of the conversion process. Two stages of minerals’ transformation were conditionally identified: 1–600 s (Stage 1) and 1200–7200 s (Stage 2). Stage 1 is responsible for primary interaction between the minerals and CuSO4 solution on the surface of the solid and the formation of a thin layer of Cu1-xS sulfides, while in Stage 2 a denser layer of Cu1-xS forms, which indicates a diffusion-controlled step. The reaction orders with respect to CuSO4 and H2SO4 as well as activation energies were calculated for the hydrothermal treatment of ZnS and FeS2 with CuSO4 solution, respectively for Stages 1 and 2. The reaction mechanisms in both stages were proposed, and some inconsistencies that were reported in previous studies were explained.