| Autor: |
Usuki T; Faculty of Science, Yamagata University, Yamagata 990-8560, Japan., Khomenko M; ILIT RAS-Branch of the FSRC 'Crystallography and Photonics' RAS, 140700 Moscow, Russia.; Laboratory of Biophotonics, Tomsk State University, 634050 Tomsk, Russia., Sokolov A; Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France., Bokova M; Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France., Ohara K; Faculty of Materials for Energy, Shimane University, 1060, Nishi-Kawatsu-Cho, Matsue, Shimane 690-8504, Japan., Kassem M; Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France., Tverjanovich A; Institute of Chemistry, St. Petersburg State University, 198504 St. Petersburg, Russia., Bychkov E; Laboratoire de Physico-Chimie de l'Atmosphère, Université du Littoral Côte d'Opale, 59140 Dunkerque, France. |
| Abstrakt: |
Oxidative recycling of metals is crucial for a circular economy, encompassing the preservation of natural resources, the reduction of energy consumption, and the mitigation of environmental impacts and greenhouse gas emissions associated with traditional mining and processing. Low-melting gallium trichloride appears to be a promising oxidative solvent for rare-earth metals, transuranium elements, platinum, pnictogens, and chalcogens. Typically, oxidative dissolution with GaCl 3 occurs at relatively low temperatures over a few days, assuming the presence of tetrahedral Ga-Cl entities. While supercritical gallium trichloride holds the potential for advanced recycling, little is known about its structure and viscosity. Using high-energy X-ray diffraction and multiscale modeling, which includes first-principles simulations, we have revealed a dual molecular nature of supercritical gallium trichloride, consisting of tetrahedral dimers and flat trigonal monomers. The molecular geometry can be precisely tuned by adjusting the temperature and pressure, optimizing the recycling process for specific metals. The derived viscosity, consistent with the reported results in the vicinity of melting, decreases by a factor of 100 above the critical temperature, enabling fast molecular diffusion, and efficient recycling kinetics. |
