In addition to the synthetic particle systems, two tailings from an iron mine and a copper mine in the northern United States are analyzed. The composition of the tailings is listed in Table in mass fractions quantified by wavelength dispersive X-ray fluorescence (WDXRF) (S4 Explorer, Broker, Bruker Co, Billerica, USA). Since no explicit reaction equations can be established for multi-component mixtures, the calculation is based on the identical amount of acid for anhydrite. Thus, for anhydrite and for both tailings, 5 % w/w and 𝑆𝑡 1.0 corresponds to a molar HCl concentration of 0.75 M. Accordingly, 𝑆𝑡 0.5 also corresponds to half the acid concentration. It should also be mentioned that the proportion of CaO within the copper tailing consists of gypsum, which corresponds to anhydrite.