DISSOLUTION KINETICS OF NATURAL FES2 IN CARBON-TETRACHLORIDE AND WATER-CARBON TETRACHLORIDE MEDIA SATURATED BY CHLORINE

The dissolution kinetics of natural pyrite samples in Cl-2-saturated c arbon tetrachloride and water-carbon tetrachloride media have been inv estigated, The effects of pyrite particle size, reaction time, tempera ture, stirring speed and water-to-carbon tetrachloride ratio were stud ied. The dissolution rate of pyrite in these media increased with incr ease in temperature and decrease in particle size, In water-carbon tet rachloride medium, the rate was independent of the stirring speed, How ever, in carbon tetrachloride medium alone, the increase in the stirri ng speed significantly increased the dissolution rate, The experimenta l data were analyzed on the basis of unreacted shrinking core model, I t has been found that the dissolution is controlled by diffusion throu gh the ash layer in carbon tetrachloride and that it is chemically-con trolled in water-carbon tetrachloride medium. The activation energies for the diffusion- and the chemically-controled steps were 32.3 and 22 .3 kJ mol(-1), respectively.