Solubility of Barium Sulfate in Water at Elevated Temperatures and Pressures

Abstract

There are few measurements of barium sulfate (BaSO4) solubility in water above 373 K available in the literature. BaSO4 solubility data at water saturation pressure are scare. The pressure dependence on BaSO4 solubility has not previously been comprehensively reported for the pressure range 100–350 bar. In this work, an experimental apparatus was designed and built to measure BaSO4 solubility in aqueous solutions under high-pressure (HP), high-temperature (HT) conditions. The solubility of BaSO4 was experimentally determined in pure water over the temperature range from T = (323.1 to 440.1) K and pressures ranging from p = (1 to 350) bar. Most of the measurements were done at water saturation pressure: six data points were done above the saturation pressure (323.1–373.1 K) and 10 experiments were conducted at water saturation (373.1–440.1 K). The reliability of the extended UNIQUAC model and results generated in this work was demonstrated by comparing with the scrutinized experimental data reported in the literature. The model gives a very good agreement with BaSO4 equilibrium solubility data, demonstrating the reliability of the extended UNIQUAC model. The accuracy of the model at high temperature and saturated pressure due to data insufficiencies is discussed.

Barium Sulfate Solubility in Aqueous Solutions Containing Chlorides or Nitrates

“…These existing experimental data are limited to a small range of temperatures at ambient pressure and a few electrolyte composition ranges. − The majority of measurements were performed at 25 °C in a ternary system up to 0.5 m. However, the thermodynamic model parameters were determined based on these available data. A comprehensive summary of the published research on BaSO 4 solubility in our previous work , suggests that further experimental measurements with more ions are needed to develop a fine-tuned Extended UNIQUAC parameter set. The existing data in the CaCl 2 /MgCl 2 aqueous solution − are insufficient to confirm the accuracy of the model.…”