This study investigates the ultrasound-assisted leaching of Li and Co from spent batteries using a deep eutectic solvent (DES) composed of polyethylene glycol and thiourea. The synergistic effect of ultrasound and DESs was explored to enhance the efficiency of Li and Co recovery. The experimental results demonstrated that ultrasound significantly accelerates the leaching process, achieving up to four times higher recovery rates compared to traditional methods. Optimal leaching conditions were identified at a solid-to-liquid ratio of 0.02 g/g, a temperature of 160 °C, and periodic ultrasound exposure. Under these conditions, the leaching efficiency reached 74% for Li and 71% for Co within 24 h. A kinetic analysis revealed that the ultrasound application shifts the rate-limiting step from a mixed control of mass transfer and chemical reactions to predominantly chemical reaction control, reducing the activation energy by approximately 27%.

The potential for barium sulphate nanoparticles to be used in a variety of important fields has sparked a lot of attention. Methods for obtaining this material by milling (top-down approach) are not very popular due to the difficulty of controlling the size and shape of particles, as well as changes in their physicochemical properties during milling. More promising is the bottom-up approach, which is the interaction of Ba²⁺ and SO₄²⁻ ions in a liquid environment. Direct precipitation is the simplest method; however, it does not allow control of the particle size. Microemulsions, microreactors membrane dispersion, as well as spinning disc reactors are used to overcome drawbacks of direct precipitation and allow control of particle size and shape. This is ensured mainly by intensive controlled micromixing of the precursors with concentrations close to saturated ones. The present review focuses on recent advances in the production of barium sulfate nanoparticles using various approaches, as well as their advantages and limitations. The issues of scaling up the techniques are also considered, and promising methods for obtaining BaSO₄ nanoparticles are also discussed.

The study investigates the application of high-voltage electrical pulses (HVEP) as a pretreatment to enhance the leaching efficiency of rare earth elements (REE) from coal ash (CA) produced from the combustion of Ekibastuz Basin coal in Almaty, Kazakhstan. HVEP treatment was applied to the finest (<40 µm) non-magnetic fraction of CA under controlled conditions, optimizing discharge current, voltage, and treatment duration. Leaching experiments with 1 M citric acid at various solid-to-liquid ratios, temperatures, and durations were conducted on both treated and untreated samples. Results indicated that HVEP-treated CA significantly improved REE recovery rates compared to untreated samples, with optimal conditions achieving 74% cerium, 79% yttrium, and 77% lanthanum recovery. The leaching of untreated CA under the specified conditions allowed no more than 28% REE to be extracted into the solution. The leaching process was found to follow first-order kinetics, with the chemical reaction of metal dissolution being the rate-limiting step.

This study investigates the optimization of an ammonia-based leaching process for the recovery of lithium and cobalt from spent LiCoO₂ cathodes, coupled with an energy-efficient ammonia stripping approach. Kinetic analysis revealed that both lithium and cobalt extraction follow pseudo-first-order kinetics, with activation energies of 76.54 kJ/mol and 97.22 kJ/mol, respectively, indicating a chemically controlled process. Optimal leaching conditions were established at 6 M NH₃, 1.5 M (NH₄)₂CO₃, liquid-to-solid ratio of 10:1, and 70 °C for 5 h, achieving 82.5% lithium and 96.1% cobalt recovery. The ammonia stripping process was optimized for energy efficiency, with operations at 95–98 °C providing the best balance between rapid NH₃ removal and energy consumption. At 98 °C, energy demand was reduced to ~282 kJ/mol, a sevenfold improvement over lower temperature operations. A stepwise separation strategy was developed, involving selective lithium precipitation at pH 10.7–10.8, followed by controlled ammonia stripping to precipitate cobalt at pH 8.8–9.0. This integrated approach offers a promising alternative to conventional acid-based recycling methods, combining high metal recovery with improved energy efficiency and reagent recyclability.

This paper introduces a novel method for synthesizing a cationic adhesion additive for road bitumen. The method involves condensing higher carboxylic acids and triglycerides of non-edible rapeseed oil with diethanolamine. The details of this innovative synthesis, the properties of the additive, and its action mechanism are shown in the results of this investigation. The surfactants in the synthesized products were identified by IR spectroscopy. They have significant practical implications. Different methods were used to investigate bitumen adhesion of acidic rock materials without and with additives. The results of the wetting angle study on the surface of rock materials changed from 19.81° to 80.33°, indicating a significant and remarkable improvement in its surface hydrophobicity. Moreover, the unique feature of the additive does not require dilution in organic solvents before use, which makes it highly practical for direct use.

Oil transportation becomes much more complicated due to the solidification of paraffins in them at low temperatures and the resulting increase in oil viscosity. To solve this problem, special additives as pour point depressants (PPDs) are used to prevent the agglomeration of paraffin crystals. In this work, 15 PPDs were obtained and tested, consisting of a solution of polyethylene in hexane and also, in some cases, from magnetic nanoparticles (MNPs) extracted from coal fly ash. The most effective result was observed with a mixture of 0.25% polyethylene in hexane and 2% MNPs, which managed to lower the oil’s pour point from 18 °C to −17 °C.