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<p>Nickel extraction from lateritic ores is increasingly vital due to the growing demand for battery materials. This study investigates the kinetics of nickel precipitation as mixed hydroxide precipitate (MHP) from pregnant leach solution (PLS) derived from Southeast Sulawesi laterite ore after iron removal. The research focuses on the effects of pH, temperature, and potassium hydroxide (KOH) concentration on nickel recovery efficiency, aiming to develop a reliable kinetic model. PLS was obtained via sulfuric acid leaching of pre-roasted laterite, followed by iron removal using calcium carbonate at pH 3. Nickel was then precipitated using varying concentrations of KOH under controlled pH and temperature. Experiments were conducted over a pH range of 7–9, temperatures of 30–90&#xa0;°C, and KOH concentrations of 10–20%. A nonlinear least squares method was applied to determine the reaction order and rate constants. The highest nickel recovery (85.04%) occurred at a pH of 9 and a temperature of 60&#xa0;°C with 20% KOH. Kinetic analysis revealed non-integer reaction orders decreasing with temperature, indicating a shift from nucleation-limited to diffusion- or surface-controlled mechanisms. Interestingly, rate constants decreased with temperature, likely due to competing effects of solubility and phase transformation. The kinetic model showed strong agreement with experimental data (<i>R</i><sup>2</sup> &gt; 0.98). XRD analysis confirmed that the MHP comprised mainly Ni(OH)<sub>2</sub> and Co(OH)<sub>2</sub> with amorphous structural features. These findings enhance understanding of MHP formation mechanisms and support the optimization of nickel recovery processes from lateritic ores.</p>

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Kinetics of Ni Precipitation as Mixed Hydroxide Precipitate (MHP) from Southeast Sulawesi Laterite Ore Pregnant Leach Solution

  • 期刊论文

  • 发表日期：

    2025年7月17日

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  • Gyan Prameswara,
  • Yohandri Bow,
  • Flaviana Yohanala Prista Tyassena,
  • Himmah Sekar Eka Ayu Gustiana,
  • Iga Trisnawati,
  • Gledys Yulianingsih,
  • Yusdianto,
  • Herlina Rahim,
  • Andi Arninda,
  • Dewi Purnama Sari,
  • Wahyu Budi Utomo,
  • Fajriyati Mas’ud,
  • Anerasari Meidinariasty,
  • Adi Syakdani,
  • Dilia Puspa,
  • Muhammad Iqbal Al Fuady

摘要

Nickel extraction from lateritic ores is increasingly vital due to the growing demand for battery materials. This study investigates the kinetics of nickel precipitation as mixed hydroxide precipitate (MHP) from pregnant leach solution (PLS) derived from Southeast Sulawesi laterite ore after iron removal. The research focuses on the effects of pH, temperature, and potassium hydroxide (KOH) concentration on nickel recovery efficiency, aiming to develop a reliable kinetic model. PLS was obtained via sulfuric acid leaching of pre-roasted laterite, followed by iron removal using calcium carbonate at pH 3. Nickel was then precipitated using varying concentrations of KOH under controlled pH and temperature. Experiments were conducted over a pH range of 7–9, temperatures of 30–90 °C, and KOH concentrations of 10–20%. A nonlinear least squares method was applied to determine the reaction order and rate constants. The highest nickel recovery (85.04%) occurred at a pH of 9 and a temperature of 60 °C with 20% KOH. Kinetic analysis revealed non-integer reaction orders decreasing with temperature, indicating a shift from nucleation-limited to diffusion- or surface-controlled mechanisms. Interestingly, rate constants decreased with temperature, likely due to competing effects of solubility and phase transformation. The kinetic model showed strong agreement with experimental data (R2 > 0.98). XRD analysis confirmed that the MHP comprised mainly Ni(OH)2 and Co(OH)2 with amorphous structural features. These findings enhance understanding of MHP formation mechanisms and support the optimization of nickel recovery processes from lateritic ores.