Recycling Lithium from Waste Lithium Bromide to Produce Lithium Hydroxide

Lithium resources face risks of shortages owing to the rapid development of the lithium industry. This makes the efficient production and recycling of lithium an issue that should be addressed immediately. Lithium bromide is widely used as a water-absorbent material, a humidity regulator, and an absorption refrigerant in the industry. However, there are few studies on the recovery of lithium from lithium bromide after disposal. In this paper, a bipolar membrane electrodialysis (BMED) process is proposed to convert waste lithium bromide into lithium hydroxide, with the generation of valuable hydrobromic acid as a by-product. The effects of the current density, the feed salt concentration, and the initial salt chamber volume on the performance of the BMED process were studied. When the reaction conditions were optimized, it was concluded that an initial salt chamber volume of 200 mL and a salt concentration of 0.3 mol/L provided the maximum benefit. A high current density leads to high energy consumption but with high current efficiency; therefore, the optimum current density was identified as 30 mA/cm2. Under the optimized conditions, the total economic cost of the BMED process was calculated as 2.243 USD·kg−1LiOH. As well as solving the problem of recycling waste lithium bromide, the process also represents a novel production methodology for lithium hydroxide. Given the prices of lithium hydroxide and hydrobromic acid, the process is both environmentally friendly and economical.

InSAR surface deformation and numeric modeling unravel an active salt diapir in southern Romania

Salt diapirism is often associated with potential hydrocarbon energy resources, and detecting active diapirs can strongly affect the prospect to discover new gas and oilfields. Here we use InSAR techniques as a proxy to evaluate surface deformation in the Diapiric Fold Zone located in the East Carpathians Bend. Significant surface uplift (~ 5 mm/year) is identified in a relatively small region not previously known for the presence of an actively rising salt diapir. Using high-resolution two-dimensional thermomechanical numerical simulations of salt diapirs intrusions, we show that that the observed surface deformation can be induced by a relatively small salt diapir (1–2 km in diameter) rising from an initial salt layer located at < 7 km depth. We constrain the salt diapir viscosity by comparing the InSAR surface deformation pattern with results from numerical simulations and our best fitting model is obtained for a salt viscosity of 1 × 1017 Pa s. The best fitting model reveals the presence of a relatively small salt diapir that has not pierced yet the entire sedimentary layer and is located just 1–2 km below the surface.

Salt morphologies and crustal segmentation relationship: new insights from Western Mediterranean Sea and other salt passive margins

&lt;p&gt;Salt tectonics at salt-bearing margins is often interpreted as the combination of gravity spreading and gravity gliding, mainly driven by differential sedimentary loading and margin tilting, respectively. Nevertheless, in the Western Mediterranean Sea, the classical salt tectonics models are incoherent with its morpho-structural setting: the Messinian salt was deposited in a closed system, formed several Ma before the deposition, horizontally in the entire deep basins, above a homogenous multi-kilometre pre-Messinian thickness. The subsidence is purely vertical in the deep basin, implying a regional constant initial salt thickness, the post-salt overburden is homogenous and the distal salt deformation occurred before the mid-lower slope normal faults activation. Instead, the compilation of MCS and wide-angle seismic data highlighted a clear coincidence between crustal segmentation and salt morphology domains. The geometrical variation of salt structures seems to be related to the underlying crustal nature segmentation. Regional thermal anomalies and/or fluid escapes, associated with the exhumation phase, or the mantle heat segmentation, could therefore play a role in adding a further component on the already known salt tectonics mechanisms. The compilation of crustal segmentation and salt morphologies in different salt-bearing margins, such as the Santos, Angolan, Gulf of Mexico and Morocco-Nova Scotia margins, seems to depict the same coincidence. In view of what is observed in Western Mediterranean Sea, the heat segmentation influence in the passive margins should not be overlooked and deserves further investigation.&lt;/p&gt;

Preparation of metallic cobalt powders by thermolysis of cobalt (II) acetate, oxalate and formate

The thermal decomposition of cobalt (II) formate, acetate, and oxalate was studied by synchronous thermal analysis. It is established that in all cases the final product is metallic cobalt. Thermogravi- metric analysis combined with differential scanning calorimetry and mass spectroscopy made it possi- ble to establish thermolysis schemes and gaseous products of salt decomposition. The conditions for obtaining powdered metallic cobalt from carboxylic acid salts are determined. It was determined by electron microscopy that the particle size and structure of metal powders depend on the type of initial salt.

Regulation of Ethyl Carbamate of Saccharomyces cerevisiae in Chinese Luzhou-Flavor Liquor Fermentation

The carcinogen ethyl carbamate (EC) in alcoholic beverages mainly comes from the spontaneous reaction of ethanol and urea, and urea is produced by the breakdown of arginine by arginase in Saccharomyces cerevisiae. Regulating activity of arginase and decreasing urea content are beneficial to reduce EC in liquor. In this study, Saccharomyces cerevisiae isolated from Daqu was fermented under a series of stress conditions to evaluate the content changes of EC and its precursors. Temperature and pH below 25 °C and pH 4.0, ethanol concentration of 4–6% and a certain initial salt concentration could reduce arginine consumption and urea production by decreasing transcription level of arginase and increasing transcription level of urea carboxylase, and eventually lead to the reduction of EC. These methods will help to improve the strategy of EC control in Chinese liquor.

Characterization and Performance Analysis of an Adsorptive Polyacrylonitrile based Hydrogel for Heavy Metals Removal

Adsorption is a key technology for heavy metals removal from industrial effluents. The use of adsorbent polymers is considered to be an attractive solution for wastewater treatment due to their high selectivity for certain heavy metals. Through the current study, an adsorptive polyacrylonitrile based hydrogel blend was used to examine heavy metals removal in simulated effluents incorporating chromium and nickel. Moreover, Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) in conjunction to an Energy Dispersive X-Ray Spectroscopy (EDX) were used for characterization of the polymeric blend structure. Finally, for surface evaluation, the specific surface area and the pore size distribution Brunauer-Emmett-Teller (BET) analysis techniques were used together with electrical conductivity measurements. The obtained results from FTIR showed the appearance of the original bands of raw materials (polyacrylonitrile (PAN), polyvinyl alcohol and polyaniline (PAni) and the change of the peaks position confirmed the hydrolysis and combination of starting materials into the polymeric blend. Surface morphology studies showed that this gel has porous surface with an average pore size and surface area of 0.73 nm and 17.3 m2 /g, respectively. Moreover, Electrical conductivity measurements indicated the presence of PAni in the polymeric blend assisted in the increase in conductivity of PAN. Finally, the different parameters of the polymeric hydrogel blend were investigated through swelling water ratio (SWR) and conventional adsorption processes at different operating conditions such as; initial salt concentration, pH and contact time. The maximum chromium adsorption results were (12.44 mg/g for 10 mg/L initial salt concentration), (10.46 mg/g for 5.5 pH) and (4.91 mg/g for 1 hr. contact time). Whereas, the maximum nickel adsorption was (7.67 mg/g for 20 mg/L initial salt concentration), (7.57 mg/g for 7 pH) and (6 mg/g for 2 hrs. contact time).

SaltNet: A production-scale deep learning pipeline for automated salt model building

One of the most important steps in velocity model building for seismic imaging in salt basins such as the Gulf of Mexico is the iterative refinement of the salt geometry. Traditionally, this step is difficult to automate, and production workflows require extensive domain expert intervention to accurately interpret the salt bodies on images migrated with an incorrect intermediate velocity model. To alleviate this problem, we propose an end-to-end semisupervised deep learning pipeline, SaltNet, capable of fully automated salt interpretation during initial model building iterations. We show that the method can be used to build the initial salt model (top of salt-1 and base of salt-1 or salt body-1 iterations) without domain expert intervention while achieving accuracy close to that of a human expert. Unlike existing convolutional neural network (CNN)-based salt interpretation applications, this method is designed to work on noisy low-resolution real-data seismic images that are typically encountered during the initial model building stage. It is also generalizable to migrated images from previously unseen surveys. This is achieved by training a suite of deep high-capacity CNN models with a multiview semisupervised learning scheme that leverages data and model distillation concepts to make these models robust to potentially large domain differences that images from a new target survey may exhibit. Consequently, CNN models achieve human-level interpretation accuracy on such new surveys without the need to manually interpret any portion of the target survey. Results from a field test on a Gulf of Mexico survey show excellent agreement between migrated images generated by the conventional interpreter-picked and SaltNet-picked initial salt model.

Obtaining the conductive SnO2 films by chemical bath deposition method

Thanks to such unique properties as transparency and conductivity tin dioxide often utilize as transparent contact layer to produce displays, solar cells, and sensor devices. Hydrochemical method of deposition SnO2 films is a perspective due to its simplicity, and economical efficiency. The ionic equilibria analysis was carried out and the boundary conditions of Sn(OH)2 solid phase formation in the «Sn2+ – H2O – OH‾» system calculated. It was established, that tin(II) hydroxide may be obtain in the range 2 < pH < 12. Preliminary results allow to determinate an optimal mixture sourness interval 1 < pH < 5. Revealed, that the thickness of the Sn(OH)2 films strongly depends on the solution pH. Maximum value of 488 nm reached at pH = 8. Conductive SnO2 layers were obtained on a glass and sitall substrates with simultaneously presence of antimony chloride and ammonium fluoride followed by annealing in air. The thickness vs temperature and thickness vs tin initial salt concentration dependences were installed. The uniform tin hydroxide layers with a thickness of ~74 nm may be synthesized under pH = 2 conditions. By the electron microscopy method the average particle size was established changing from 200 to 400 nm for as-synthesized films, to ~20 nm for annealed which indicates the nanostructure nature of the films. The morphology, elemental composition and conductive properties of deposited films were investigated before and after heating stage. Studying the annealing temperature influence at the film resistance were identified a three temperature ranges within which the films sharply differ in their conductive properties, which is associated with phase and structural transformations in them. Shown, that the most conductive SnO2 films with the omic resistance 3-5 kOm/sm were obtained at the temperature range 620-870 K.

Effect of Initial Salt Composition on Physicochemical and Structural Characteristics of Zero-Valent Iron Nanopowders Obtained by Borohydride Reduction

The effect of initial salt composition on characteristics of zero-valent iron nanopowders produced via borohydride reduction was studied. The samples were characterized by X-ray diffraction, scanning and transmission electron microscopy, and low-temperature nitrogen adsorption. The efficiency of Pb2+ ions removal from aqueous media was evaluated. The use of ferric salts led to enhanced reduction kinetics and, consequently, to a smaller size of iron particles in comparison with ferrous salts. A decrease in the ionic strength of the synthesis solutions resulted in a decrease in iron particles. The formation of small highly-reactive iron particles during synthesis led to their oxidation during washing and drying steps with the formation of a ferrihydrite phase. The lead ions removal efficiency was improved by simultaneous action of zero-valent iron and ferrihydrite phases of the sample produced from iron sulphate.