Leaching behaviour of a complex zinc ore in a mixed citric-oxalic acid medium: Interaction effect and statistical modelling

Demirci S., Çetinkaya Z.

PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING, cilt.62, sa.6, ss.1-18, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 62 Sayı: 6
  • Basım Tarihi: 2026
  • Doi Numarası: 10.37190/ppmp/241887
  • Dergi Adı: PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING
  • Derginin Tarandığı İndeksler: Applied Science & Technology Source, Scopus, Science Citation Index Expanded (SCI-EXPANDED)
  • Sayfa Sayıları: ss.1-18
  • Çukurova Üniversitesi Adresli: Evet

Özet

Zinc leaching from a complex zinc ore using a mixture of citric and oxalic acids was investigated through response surface methodology (RSM) with a modified central composite design (CCD). The effects of solid content (2.5–12.5% w/v), citric acid stock solution concentration (0.25–1.25 M), oxalic acid stock solution concentration (0.05–0.25 M), leaching time (15–120 min), and temperature (30–70°C) were evaluated. Based on the F-values of the linear terms, the apparent order of influence was oxalic acid stock concentration > temperature > leaching time > citric acid stock concentration > solid content. This ranking represents linear main effects rather than overall variable importance, as significant interactions were also identified. Oxalic acid exhibited a strong negative linear effect, indicating that increasing its concentration did not improve Zn recovery. The highest experimental Zn recovery (67.98%) was obtained at 10% (w/v) solids, 1.0 M citric acid, 0.10 M oxalic acid, 30 min, and 60°C. Numerical optimization predicted a maximum Zn recovery of 81.42% at 10% (w/v) solids, 1.0 M citric acid, 0.10 M oxalic acid, 90 min, and 60°C. Three independent validation experiments yielded an average Zn recovery of 78.77 ± 1.10% (n = 3), corresponding to a relative prediction error of 3.25%. These findings demonstrate the effectiveness of RSM-based optimization and suggest that increasing oxalic acid concentration in the mixed-acid system may reduce Zn recovery