MODELING THE COMPENSATION EFFECT FOR DIFFERENT BAUXITE TYPES LEACHING IN NaOH SOLUTION

This article presents the results of experimental investigations of the leaching process kinetics for different types of bauxite: gibbsite [image omitted], boehmite [image omitted], diaspore [image omitted], and gibbsite/boehmite and boehmite/diaspore mixtures. The process kinetics were investigated under isothermal conditions, while selection of the kinetic models for linearization of experimental isotherms =f(t) was performed by using Sharp's method of reduced halftime or reaction t/t0,5. As the results of the kinetic parameters evaluation, the linear dependence of activation energy on the density of bauxite types, with the correlation coefficient of R2=0.978, was detected. Also, the linear dependence of the Arrhenius parameters logarithm on activation energy was confirmed lnA=f(Ea). The resulting degree of the correlation for this dependence was R2=0.999, which led to the conclusion that such a dependence should be considered as a potential compensation effect of the investigated system. This brings new possibilities for making decisions concerning the leaching rate depending on the mineralogical form of the starting bauxite.