Experimentally Determined Phase Diagram for the Barium Sulfide-Copper(I) Sulfide System Above 873 K (600 °C)

2021

Preprint

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The high temperature thermodynamic properties of chalcogenides materials based on BaS remain elusive, and herein the La2S3 pseudo binary system is investigated above 1573 K. The liquid properties of BaS-La2S3 are measured by means of high resolution in-situ visualization coupled with thermal arrest measurements in a thermal imaging furnace. This enables to report for the first observation of such melts in a containerless setting. The melting points of BaS and La2S3 are revisited at 2454 K and 2004 K respectively. La2S3 demonstrates a high stability in its liquid state, in strike difference with the sublimation observed for BaS. BaS is however partially stabilized with the addition of few percents of La2S3.The remarkable chemical and thermal stability of La2S3-rich samples, contrasts with the partial decomposition and high vapor pressure observed for BaS-rich samples. Observations and analysis of the solidified samples suggests three different solid solutions. Solid and liquid densities are investigated along the different compositions, supporting a first estimate of the volumetric thermal expansion coefficient for La2S3.

Section: Bas and La 2 Ssupporting

confidence: 90%

Section: Bas-rich and La 2 S 3 -Rich Liquid Behaviormentioning

confidence: 81%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Liquid State Properties and Solidification Features of the Pseudo Binary BaS-La2S3

Boury

2021

Preprint

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“…The position of Ba in the periodic table makes BaS the most ionic alkaline rare earth sulfide with a band gap of 2.1 eV 4 suggesting application in iono-conduction 5 . The standard melting point of BaS has been reported several times at 2508, 2480, 2475, 2470 and 2430 K (respectively 6 – 10 ). Livey et al 9 mentioned an important volatility for BaS at high temperature impeding the obtention of a stable thermal trace or a good optical visualization.…”

Section: Introductionmentioning

confidence: 99%

Liquid state properties and solidification features of the pseudo binary BaS-La2S3

Boury

2021

Sci Rep

Self Cite

The high temperature thermodynamic properties of chalcogenides materials based on BaS remain elusive. Herein the pseudo binary BaS-La2S3 is investigated above 1573 K. The liquid properties of BaS-La2S3 are measured by means of high resolution in-situ visualization coupled with thermal arrest measurements in a thermal imaging furnace. This enables to report the first observation of such melts in a container-less setting. The melting points of BaS and La2S3 are revisited at 2454 K and 2004 K respectively. La2S3 demonstrates a high stability in its liquid state, in strike difference with the sublimation observed for BaS. BaS is however partially stabilized with the addition of few percents of La2S3. The remarkable chemical and thermal stability of La2S3-rich samples contrasts with the partial decomposition and high vapor pressure observed for BaS-rich samples. Observations and analysis of the solidified samples suggest three different solid solutions. Solid and liquid densities are investigated along the different compositions, supporting a first estimate of the volumetric thermal expansion coefficient for La2S3.

Selective Sulfidation and Electrowinning of Nickel and Cobalt for Lithium Ion Battery Recycling

Stinn

The Minerals, Metals &Amp; Materials Series

2021

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Processes for recycling lithium ion batteries (LIB), in particular complex chemistries such as those containing nickel-manganese-cobalt oxide (NMC) cathodes, are hindered by tradeoffs between capital cost, process sustainability, and materials recovery. Most metal separations in primary and secondary production of critical elements rely on anion exchange chemistries. Herein, we explore the application of a novel oxide-sulfide anion exchange methodology to facilitate LIB recycling. Beginning with selective sulfidation of NMC cathode oxides, we demonstrate that lithium may be stabilized as a sulfate, manganese as an oxysulfide, and nickel and cobalt as sulfides from the mixed metal feed, potentially facilitating isolation of lithium via leaching and nickel-cobalt via flotation. Following, we explore molten sulfide electrolysis as a method of process intensification, combining separation and reduction into a single unit operation for difficult to separate metals such as cobalt and nickel. We demonstrate selective reduction of cobalt from mixed nickel-cobalt sulfide, as produced in selective sulfidation of waste NMC cathodes, using a barium-lanthanum sulfide supporting electrolyte. Our preliminary results suggest that selective sulfidation as a pretreatment for selective molten sulfide electrolysis is a promising avenue for separation of critical elements from complicated materials feeds, such as those found in lithium ion battery recycling streams.