TY  - JOUR
A1  - Steding, Svenja
A1  - Kempka, Thomas
A1  - Kühn, Michael
T1  - How insoluble inclusions and intersecting layers affect the leaching process within potash seams
JF  - Applied Sciences : open access journal
N2  - Potash seams are a valuable resource containing several economically interesting, but also highly soluble minerals. In the presence of water, uncontrolled leaching can occur, endangering subsurface mining operations. In the present study, the influence of insoluble inclusions and intersecting layers on leaching zone evolution was examined by means of a reactive transport model. For that purpose, a scenario analysis was carried out, considering different rock distributions within a carnallite-bearing potash seam. The results show that reaction-dominated systems are not affected by heterogeneities at all, whereas transport-dominated systems exhibit a faster advance in homogeneous rock compositions. In return, the ratio of permeated rock in vertical direction is higher in heterogeneous systems. Literature data indicate that most natural potash systems are transport-dominated. Accordingly, insoluble inclusions and intersecting layers can usually be seen as beneficial with regard to reducing hazard potential as long as the mechanical stability of leaching zones is maintained. Thereby, the distribution of insoluble areas is of minor impact unless an inclined, intersecting layer occurs that accelerates leaching zone growth in one direction. Moreover, it is found that the saturation dependency of dissolution rates increases the growth rate in the long term, and therefore must be considered in risk assessments.
KW  - salt dissolution
KW  - reactive transport
KW  - heterogeneity
KW  - density-driven
KW  - convection
KW  - PHREEQC
KW  - porous media
Y1  - 2021
U6  - https://doi.org/10.3390/app11199314
SN  - 2076-3417
VL  - 11
IS  - 19
PB  - MDPI
CY  - Basel
ER  -