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When considering resource shortages and environmental pressures, salvaging valuable metals from the cathode materials of spent lithium-ion batteries (LIBs) is a very promising strategy to realize the green and sustainable development of batteries. The reductive acid leaching of valuable metals from cathode materials using methanol as a reducing agent was studied. The results show that the leaching efficiencies of Co and Li are 99% under optimal leaching conditions. The leaching kinetics of cathode materials in a H

Inexpensive electrolyte systems and readily available rare-earth (RE) precursors are necessary for the facile recovery of RE metals at the lowest temperature, which will allow the sustainable devel...

The density, conductivity, and viscosity of the 1,3-dimethyl-2-imidazolinone and lithium nitrate (DMI– LiNO3) solvated ionic liquid were measured as a function of temperature. Additionally, the electrochemical mechanism and electrodeposition of neodymium from the DMI–LiNO3 solvated ionic liquid were investigated. Cyclic voltammetry results indicate that the electrochemical reduction of Nd(III) is irreversible and proceeds via one-step with three-electron transfer, which is controlled by diffusion with a diffusion coefficient of 5.08×10−8 cm2/s. Energy- dispersive X-ray spectrometry and X-ray photoelectron spectroscopy data confirm that the electrodeposit obtained after electrodeposition at −4 V (vs Ag) using the DMI–LiNO3–Nd(CF3SO3)3 solvated ionic liquid contains metallic neodymium.

This study aims to design and implement an efficient cooling system to reduce the shutdown pot's cooling time in the smelter's delining room. This cooling process requirement is a result of the usual delay between the cut-down of a pot and the start of the pot demolition process that would have to be left to cool down from a temperature of about 960 °C to a temperature with which the delining team can physically handle it. As the cooling process is currently carried out in a free convection environment, the process takes five to nine days, causing the pot to spend a significant amount of time in the repair room. On the other hand, environmental regulation does not allow aluminum smelting plants to leave the hot pot in the open air; it has to be in a room enclosure. In developing a cooling technique that reduces the pot's cooling time and flue gas releases after shutting down, it is essential to ensure that the mechanical integrity of the potshell is maintained. To this effect, this study was kicked off by experimental studies to deduce the effect of various cooling parameters on the potshell material's microstructure and mechanical properties. Subsequently, 3D Finite Element Heat Transfer (FEHT) models of the DX technology pot were developed. On-site measurements were carried out on the DX pot at the plant and used to validate the models and validate the cooling techniques' effectiveness and their efficiency in reducing energy consumption. The models developed are useful in working out suitable and sustainable heat transfer mechanisms for efficient potline management to achieve acceptably low social and environmental impacts.

Urea/1-ethyl-3-methylimidazolium chloride (urea-EMIC) was developed to electrodeposit Cu from Cu2O at room temperature. Density, viscosity and conductivity of this urea-EMIC system were obtained. The cyclic voltammograms illustrated that the electroreduction of copper ion (Cu(I) ion) involves a quasi-reversible and one-step single electron transfer process. Chronoamperometric studies showed that the copper electrodeposition proceeds a three-dimensional (3D) progressive model. With an increase in temperature, on voltammograms the onset potentials for copper ion reduction shifted anodically and the diffusion coefficient determined using chronoamperometry increased from 5.40 × 10−11 m2 s−1 at 333 K to 1.02 × 10−10 m2 s−1 at 363 K. Also, potentiostatic electrolysis was conducted on tungsten substrates at − 0.65 V (vs. Ag) and 363 K. Then spherical metallic copper electrodeposits were obtained.

Samples of (LiF−CaF2)eut−xSmF3(−xGdF3) (x=0.03−0.50) were prepared by spontaneous cooling as well by very fast cooling (using the rapid solidification processing (RSP) method) which provide two types of sample morphology: riffle-like and sphere-like fragments. All types of samples were studied by XRD, optical absorption and fluorescence spectroscopy. The presence of LiF stabilises the cubic cell dimension, and the content of lanthanide fluorides presents influence on phases formed, as well as the crystallinity of the system, in both the spontaneously and rapidly-cooled systems. The photoluminescence properties of the investigated systems are dependent on the lanthanide fluoride content. The intensity of the emission bands, corresponding to the Sm3+ ion, reaches the maximum when the Sm content is x(SmF3)=0.03. An even stronger dependence is observed of optical properties on the morphology of the samples, i.e. whether the samples are spontaneously cooled or processed by the RSP method followed by mechanical grinding. Mechanical grinding enhances the luminescent properties and leads to higher emission intensities. It is also shown that the photoluminescent spectroscopy is suitable for detection/approval of lowered local symmetry via significant splitting of spectral bands.

To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea−1-ethyl-3- methylimidazolium fluoride (urea−[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb in this electrolyte was studied. The density, viscosity and conductivity of this electrolyte were investigated before electroextraction. The electrochemical behavior of Pb in the urea−[EMIM]F system was recorded via cyclic voltammograms, chronoamperometry and potentiostatic electrolysis. The results illustrate that Pb can be electrochemically extracted from PbO in this system at room temperature and that Pb reduction involves a quasireversible process and follows a one-step and two-electron transfer process. The reduction of Pb proceeds with a three-dimensional (3D) progressive model. With an increase in temperature, the onset potentials for Pb reduction shift anodically. The diffusion coefficient of Pb(II) is determined to be 6.88×10−10 cm2/s at 353 K. Additionally, spherical Pb particles are obtained after electrodeposition in the urea−[EMIM]F system via potentiostatic electrolysis.

A three-dimensional numerical model has been developed to quantify the predominant phenomena roles on dynamics alumina particles between an electrolytic bath and the vicinity of gas bubbles. At the particle scale, the bath, regarded as turbulent flow, was modeled by a steady plane shear flow and solved using a lattice Boltzmann method. The coupling between the fluid and particle phases is carried out using an immersed boundary method to tackle the interface. This numerical scheme resolves the hydrodynamic perturbation induced by the alumina particles, and hence their interactions are described by Lagrangian particle tracking. The hydrodynamic effects combined with mechanical and thermal responses on the computation of the fluid system's stress intensity factors were investigated. An excellent convergence and accuracy were achieved for the transport and interaction of the alumina particle model.

The conversion of CO2 into carbon materials and oxygen gas has great significance for reducing the greenhouse gas concentrations of Earth and realizing in situ utilization of Mars’ atmosphere. In this work, LiF-Li2O melts containing CO2 were electrolyzed using a Ni cathode and Pt anode at 850°C. Carbon materials with different morphologies were deposited on the cathode and oxygen evolution was detected in anode gas. The products were characterized by Raman spectroscopy, x-ray diffraction, scanning electron microscopy and gas chromatography. The results demonstrated that CO2 was firstly captured and converted into the carbonate in LiF-Li2O melts, and subsequently electrolyzed. The morphologies of the carbon material obtained on the cathode were dependent on the electrolysis potentials. The rate of CO2 and O2 production in the anode gas was related to the reaction process, current density, and potentials. Electrochemical decomposition of CO2 into carbon materials and oxygen gas in a fluoride melt was proved to be feasible.

A facile procedure is reported for the synthesis of various 2-bromo-1-phenyl-5,6-dihydro-3H,7aH-benzo[b]pyrrolo[2,1-c][1,4]oxazin-3-ones via a radical bromination-induced ipso cyclization–ortho cyclization sequence of N-arylpropiolamides in the presence of TBAB and oxone. The radical cyclization sequence involves a radical bromo α-addition into the alkyne, ipso-cyclization, and ortho-trapping of the spirocyclic intermediate.

Solubility of CO2 in molten Li2CO3-LiCl was measured by a pressure differential method, and the enthalpy change of the solution was calculated on that basis. The relationships between the solubility and the enthalpy change, and the temperature and the composition of the melts were discussed. The results showed that when the temperature was 873?923 K and the Li2CO3 content was 10?50 mol%, the solubility of CO2 increased with decreasing temperature and/or increasing Li2CO3 content. The maximum solubility was 3.965 ? 10?7gCO2/gmelt at 873 K when the content of Li2CO3 was 50 mol%. The solution of CO2 was exothermic. With increasing temperature and Li2CO3 content, more enthalpy was needed for CO2 solution.

A model was built to simulate liquid aluminum leakage during the casting process, including transient trough flow, orifice outflow, and spread, to prevent the explosion. A comparison between the simulation data and the theoretical calculation results verifies that the model has remarkable adaptability and high accuracy. Although the height of liquid aluminum in the mixing furnace and outlet radius are changed, the molten aluminum will not leak during the casting process. The aluminum in the trough moves forward in a wave-like motion and causes a leakage. The spread of the leaked aluminum resembles a long strip on the ground. The leakage amount and spread area of liquid aluminum increase with increasing the height of liquid aluminum in the mixing furnace.

To investigate the electrochemical reduction mechanism of Ta(V) in ethylene carbonate and aluminum chloride (EC−AlCl3) solvate ionic liquid, cyclic voltammetry experiments were conducted on a tungsten working electrode. Four reduction peaks were observed in the cyclic voltammogram of the EC−AlCl3−TaCl5 ionic liquid. The reduction peaks at −0.55, −0.72, and −1.12 V (vs Al) were related to the reduction of Ta(V) to tantalum metal by three stages including the formation of Ta(IV) and Ta(III) complex ions. The reduction of Ta(III) to tantalum metal was an irreversible diffusion-controlled reaction with a diffusion coefficient of 3.7×10−7 cm2/s at 323 K, and the diffusion activation energy was 77 kJ/mol. Moreover, the cathode products at 323 K were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray photoelectron spectroscopy. The results showed that tantalum metal and tantalum oxides were obtained by potentiostatic electrodeposition at −0.8 V for 2 h.

The molten mixtures of alkali metal fluorides and aluminum fluoride are applied as aluminum electrolytes or brazing fluxes. However, the presence of Al2F7− in such molten systems is disputed. In the present study, MF–AlF3 (M = K, Cs) systems with molar ratios

Cobalt chloride and neodymium chloride were dissolved in the urea and choline chloride deep eutectic solvents (DESs), and the electrochemical mechanisms of Co-Nd alloy codeposition were investigated under ambient conditions. Results from cyclic voltammetry indicated that the deposition of metallic Co on the tungsten electrode proceeds by an apparent two-electron transfer irreversible process at − 1.02 V (vs Ag). It is impossible to deposit pure Nd in urea and choline chloride DESs, whereas Co-Nd alloys can be codeposited from electrolytes with both Co(II) and Nd(III) ions. Furthermore, chronoamperometric experiments demonstrated that the electrochemical deposition of metallic Co can be considered as a three-dimensional (3-D) progressive nucleation process, while Co-Nd alloys were formed by instantaneous nucleation with diffusion-controlled growth. The average value of the diffusion coefficient of Co(II) ions in the urea and choline chloride DESs containing 3.8 × 10−5 mol/cm3 CoCl2 at 373 K was calculated to be 1.98 × 10−7 cm2/s. Moreover, analysis by scanning electron microscopy and energy dispersive X-ray spectroscopy suggested that a flat and uniform film consisting of Co (96.26 wt pct) and Nd (3.74 wt pct) was prepared by electrodeposition on a Cu substrate.

Copper and copper-zinc alloys were electrochemical prepared from Cu2O-ZnO mixed oxides in urea and 1-butyl-3-methylimidazolium chloride deep eutectic solvent at 383 K. The electrochemical reduction and nucleation mechanism of copper and copper-zinc alloys were investigated by cyclic voltammetry and chronoamperometry. Cyclic voltammetry showed that copper species [Cu2ClO·urea]− was reduced to copper at − 0.68 V (vs. Ag), while zinc species [ZnClO·urea]− was reduced to zinc and formed copper-zinc alloy at − 1.8 V (vs. Ag). Chronoamperometry indicated that copper particles were electrodeposited by progressive nucleation with diffusion-controlled growth process in urea-BMIC-Cu2O solutions, and the average diffusion coefficient of copper complex ions was determined to be 2.79 × 10−8 cm2 s−1. On contrast, the electrodeposition of copper-zinc alloy proceeded via combination of 3D instantaneous and progressive nucleation. On the other hand, copper and copper-zinc alloys were electroplated on to a stainless steel substrate and characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy.

To develop Martian soil simulant, basalts of the Chahar volcanic group in Wulanchabu, Inner Mongolia, China were selected as the simulant initial materials, which were ground and sorted to a predetermined particle size ratio, and small amounts of magnetite and hematite were added. The main phases of NEU Mars-1 simulant were plagioclase, augite and olivine. The glass transition and crystallization temperatures of NEU Mars-1 were 547.8 and 795.7 °C, respectively. The complex dielectric constant, magnetic conductivity (0.99–1.045), and dielectric loss tangent angles (0.0025–0.030) of NEU Mars-1 were all stable in the frequency range of 2–18 GHz. Mossbauer spectroscopy results showed that the mass ratio of Fe2+ to Fe3+ in the simulant was 77.6:22.4. The NEU Mars-1 Martian soil simulant demonstrated particle size ratio, chemical composition, phase composition, thermal stability, and dielectric property similar to Martian soil, and can be used as the substitute material to extract oxygen and metals with in-situ resource utilization technologies.