ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Ammonia leaching of MoO₃ concentrate: finding the reaction mechanism and kinetics analysis

Mahtab Vosough, Gholam Reza Khayati, and Shahriar Sharafi

Department of Materials Science and Engineering, Shahid Bahonar University of Kerman, Kerman, Iran

E-mail: vosoughm@yahoo.com

Received: 30 June 2021  Accepted: 19 January 2022

Abstract:

In this study, the leaching kinetics of Mo from molybdenum trioxide concentrate was investigated in an alkaline medium-ammonia solution. The influence of temperature, time, pulp concentration, and particle size at various levels was studied on Mo dissolution rate. Elemental analyses of solid and liquid specimens were achieved by X-ray fluorescence and inductively coupled plasma optical emission spectroscopy. Scanning electron microscope, X-ray diffraction, and Fourier transform infrared (FTIR) spectroscopies characterized the structure, phase analysis, and chemical bonds decomposition. The experimental data were fitted with proposed models, and the reaction control step was defined diffusion. The kinetic model was extracted as: \(1 - \frac{2}{3}\chi - (1 - \chi )^{\frac{2}{3}} = 4 \times 10^{ - 11} ({\text{SC}})^{ - 2.2326} ({\text{PS}})^{ - 1.4598} \exp \left( {\frac{ - \,44.53}{{RT}}} \right)t\). The dissolution efficiency of molybdenum in the concentration of ammonia 25%, temperature 25 °C, time 60 min, solid-to-liquid ratio (pulp concentration) 5 wt%, and the particle size of 38 μm equal to 98.8% was selected as the optimal value for leaching of molybdenum.

Keywords: Molybdenum trioxide; Kinetic model; Leaching; Activation energy

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02098-z

Chemical Papers 76 (5) 3227–3237 (2022)