Phase equilibria, structural and thermodynamic properties of phases in the nickel (II) methanesulfonate – Water, cobalt (II) methanesulfonate – Water and manganese (II) methanesulfonate – Water systems

Phase Equilibria in Water–Methanesulfonic Acid–Copper (Zinc) Methanesulfonate: Experiments and Modeling

“…Saturated vapor pressure measurements were performed by a static method at temperatures 15 °C/288.15 K, 25 °C/298.15 K, and 35 °C/308.15 K on an original apparatus, which was described in our previous works. − Because methanesulfonic acid is not volatile, according to Clegg and Brimblecombe, as well as its salts, the total pressure above a ternary solution would be almost the same as the saturated water vapor pressure (within the uncertainty stated for the method). The temperature of a vessel during measurement was maintained with a 0.02 K precision using a liquid thermostat (Julabo F25-MC) controlled by a second Pt resistance thermometer connected to the bridge.…”

“…Argon gas was supplied using liquid argon (99.993% assay). All required parameters, such as nebulizer, auxiliary gas flow rates, RF (radio frequency) power, number of replicates, and integration time, were optimized in a previous work before analysis (see supplementary for Belova et al). The weighted sample (ca.…”

“…Ternary PSC parameters were optimized using both SLE and VLE data reported in the present work. Parameterization of the model was performed in the MATLAB environment using scripts by Maliutin et al for optimization. The following objective function was minimized to obtain parameter values (eq ): F ( X 1 , ... , X n , θ 1 , ... , θ k ) = ∑ x ∑ i = 1 ... n w x false( X i exp − X i calc ( θ 1 , ... , θ k ) false) 2 where X i exp represents the thermodynamic properties determined in an experiment (water activity a w for VLE or molality m for SLE), X i calc true( θ 1 , ... , θ k true) represents the corresponding values, calculated with the chosen model, θ 1 , ..., θ k stands for the model parameters being optimized, and w x represents the weight coefficients.…”

“…An isothermal solubility method was used to obtain solubility data at 298.15 K. The methodology was similar to those described in Belova et al and Belova et al Initial mixtures were prepared from water, acid, and corresponding tetrahydrate (see Table ), except those for the Zn­(CH 3 SO 3 ) 2 ·12H 2 O solubility area, where small amounts of diluted acid were added to Zn­(CH 3 SO 3 ) 2 ·12H 2 O crystals. In the latter case, Zn(CH 3 SO 3 ) 2 ·12H 2 O stoichiometry was estimated from modeling and a batch composition was calculated as ∼1 to 3 mixture of liquid and Zn­(CH 3 SO 3 ) 2 ·12H 2 O.…”

“…As for the model of choice, on the one hand, the Pitzer model is one of the most widespread models for electrolyte solutions used, e.g., in the works by Charykova et al, Vielma, Kobylin et al, and Justel et al, and there is a compatibility with systems with some other anions (e.g., sulfate in the works by Charykova et al, Vielma, Kobylin et al, and Justel et al or nitrate in the works by Filippov et al and Sadowska& Libuś), making it possible to look for mixed acid MSA leaching agents. On the other hand, the Pitzer model has a limited workability for concentrated acid solutions, whereas the Pitzer–Simonson–Clegg model allows to predict properties for up to 40 mol·kg –1 MSA solutions in water, as it was reported by Belova et al There are binary parameters for the copper and zinc methanesulfonate–water system within this framework in Belova et al, as well as for some other 3d-metal methanesulfonate–water systems in Belova et al Thus, the goal of this work was to obtain a thermodynamic model that allows us to calculate adequately VLE and SLE in Cu­(CH 3 SO 3 ) 2 –CH 3 SO 3 H–H 2 O and Zn­(CH 3 SO 3 ) 2 –CH 3 SO 3 H–H 2 O systems at least at 298.15 K and check solubility constants obtained previously in limiting binary water–salt systems.…”