Abstract: The kinetics of formation reaction of Zn2SiO4 during roasting the sphalerite concentrate with high silica was investigated. The effects of temperature, particle size on the formation rate of Zn2SO4 were also studied. The results show that the kinetics of formation reaction of Zn2SiO4 fits a shrinking core model, and the control step is solid film diffusion. The activation energy was calculated to be 406 kJ/mol and the rate constants were determined. Thus a general kinetic rate equation was developed. The effective method of controlling rate formation of Zn2SiO4 is to increase properly the particle size and lower the temperature to 860 ℃ or so.
Kinetics of formation reaction of Zn2SiO4 during roasting high silica-containing sphalerite concentrate
Abstract:
The kinetics of formation reaction of Zn 2SiO 4 during roasting the sphalerite concentrate with high silica was investigated. The effects of temperature, particle size on the formation rate of Zn 2SO 4 were also studied. The results show that the kinetics of formation reaction of Zn 2SiO 4 fits a shrinking core model, and the control step is solid film diffusion. The activation energy was calculated to be 406?kJ/mol and the rate constants were determined. Thus a general kinetic rate equation was developed. The effective method of controlling rate formation of Zn 2SiO 4 is to increase properly the particle size and lower the temperature to 860?℃ or so. [
Fig.4 Relationship between formation rate of Zn2SiO4 and reaction time (Solid line—Experimental curve;Dotted line—Calculated curve by general kinetic Eqn. (2) of diffusion control)