The Phase Stabilities of Magnesium Hydroxychlorides

Molten Chloride Thermophysical Properties, Chemical Optimization, and Purification

“…Very similar behaviors to produce hydroxychloride during salt dehydration had been found in CaCl2 salt as well [16,17,[31][32][33][34][35]. To mitigate the risks of the corrosive hydroxychloride species, multiple methods for salt dehydration and purification have been proposed, such as thermal treatment by controlled heating [26,29,43,31,[36][37][38][39][40][41][42], reduction by elemental Mg [19,22,23,25], dehydration with ammonium chloride [14,29,42,44,45], and carbochlorination with CO, Cl2, and/or CCl4 to remove oxide species [13,14,46,47]. Because the targeting CSP industry needs a significant amount of salt inventory (>10,000 Mt) for each power plant, it is our intent to investigate the most cost-effective and scalable salt purification process.…”

“…36 Figure 14 plots the post-purification MgOHCl content as a function of sparging gas flow rate at different Mg addition level. Except the possible outliers at 50 sccm with 0.1 wt.% Mg, 37 there is generally a lower MgOHCl content if sparging is used, but there is no significant difference between 50 sccm and 200 sccm of sparging. The role of Mg seems inconclusive.…”

“…However, this is a speculation only. But, both possibilities suggest that clogging must be considered in the melter design 37. The outliers are possibly due to an expired chemical used for titration.…”

Effect of alcohol leachable chloride on strength of magnesium oxychloride cement

“…After the drop is over, the system was left for 3 days to transform colloid particles to crystal particles. The crystal particles were collected by filtration, and washed with absolute ethanol 17,29,30 . After washing, the final product was dried at 40°C under vacuum.…”

“…The former (especially two oxychloride crystalline phases) is the binder phases of MOC, thus, many researches have been conducted on their characteristics and their influence on the performances of MOC materials. It has been shown that both 5‐phase and 3‐phase appear as well as crystallized acicular crystals in scroll‐tubular whisker form 24‐26 and have the similar crystal structure, 27‐28 and 3‐phase is thermodynamically more stable than 5‐phase 29‐30 . But, it is generally believed that the 5‐phase whiskers and their resulting microstructure give cured MOC pastes high strength and great binding power 25,26 .…”