Electrical Conductances and association constants in dilute aqueous NdCl\textsubscript{3} solutions from 298 to 523 K along an isobar of 25 MPa

TL;DR

This study measures electrical conductances and association constants of dilute NdCl3 solutions in water from 298 to 523 K at 25 MPa, using advanced modeling to analyze the data and compare with existing models.

Contribution

It provides new experimental data and modeling approaches for electrical conductance and association constants of NdCl3 in water at high temperatures and pressures.

Findings

Limiting conductances agree with predictive models.

Only the first association constant could be reliably determined below 373 K.

Both association constants could be derived above 373 K and align with previous studies.

Abstract

Electrical measurements were performed in dilute aqueous NdCl3 solutions from 298 to 523 K along the 25 MPa isobar to obtain limiting conductances and association constants. The specific conductance data were estimated using a continuous flow cell and a Markov Chain Monte Carlo (MCMC) correction algorithm. The limiting conductances for the salts in water were derived by regressing the mean spherical approximation (MSA) conductance model and speciation analyses based on the MCMC algorithm and the Deep Earth Water (DEW) model. The limiting conductances derived from the experimental data agree well with a predictive correlation proposed by Smolyakov, Anderko, and Lencka. Only the first association constant between neodymium and chloride could be derived at low temperatures (< 373 K) due to the apparent large statistical uncertainty of the second association constant. Above 373 K, both association constants could be derived and show a reasonable agreement with Migdisov and Williams-Jones and Gammons et al.