M. Alkattan et al., EXPERIMENTAL STUDIES OF HALITE DISSOLUTION KINETICS .1. THE EFFECT OFSATURATION STATE AND THE PRESENCE OF TRACE-METALS, Chemical geology, 137(3-4), 1997, pp. 201-219
The comprehensive understanding of halite dissolution facilitates asse
ssment of long-term radiogenic waste storage strategies, quantitative
description of evaporite deposit formation and optimization of industr
ial processes. To this end, the dissolution rate of compressed halite
powders was measured using the rotating disk method as a function of t
emperature, solute saturation state and the concentration of aqueous t
race metals. The results of these experiments were used to generate di
ssolution and transport rate constants, as well as activation energies
for these processes at temperatures from 25 degrees to 80 degrees C.
Results indicate that in the absence of trace metals, constant-tempera
ture halite dissolution rates vary linearly with the overall mineral s
aturation state. The presence of trace quantities of Fe and Zn were fo
und to negligibly affect halite dissolution, while trace quantities of
Co, Cr, Cd and Pb significantly lowered halite dissolution rates. At
constant trace-metal concentration, halite dissolution rates were foun
d to vary in the order: Fe approximate to Zn > Co > Cr > Pb > Cd. A co
mbined transition state theory/Langmuir adsorption model was developed
and demonstrated to effectively describe measured rates as a function
of solution composition.