The article presents the research results for the synthesis of inorganic sorbents based on manganese oxide compounds. It shows the results of the lithium sorption from brines with the use of synthesized sorbents. The effect of temperature, the molar ratio of Li/Mn, and the duration for obtaining a lithium-manganese precursor and its acid treatment was studied. The sorption characteristics of the synthesized sorbents were studied. The effect of the ratio of the sorbent mass to the brine volume and the duration of the process on the sorption of lithium from brine were studied. In this case, the sorbent recovery of lithium was ~86%. A kinetic model of the lithium sorption from brine on a synthesized sorbent was determined. The kinetics of the lithium sorption was described by a pseudo-second-order model, which implies limiting the speed of the process due to a chemical reaction.

The growing global demand for lithium, driven by its pivotal role in battery production, highlights the need for alternative technologies to recover this metal from low-grade and anthropogenic raw materials. This study investigates lithium extraction from aluminosilicate tailings of rare-metal production by sulfate roasting with concentrated sulfuric acid, followed by aqueous and hydrochloric acid leaching. Mineralogical analysis confirmed lithium mainly in muscovite and biotite (isomorphic substitutions) and partly as spodumene within the aluminosilicate matrix. The optimal parameters of thermochemical treatment were determined as 300 °C for 1 h at a liquid-to-solid ratio of 1:6. Subsequent aqueous leaching (90 °C, 1 h, L/S = 6:1) achieved a lithium recovery of 82.3%, while HCl proved less effective. Using response surface methodology (RSM) and a central composite design (CCD), a regression model was developed predicting up to 93.4% lithium extraction at 90 °C, a liquid-to-solid ratio of 10:1, and a leaching duration of 75 min. The calculated values showed good agreement with experimental data obtained at 90 °C, L/S = 10:1, and 30 min leaching, yielding 91.92% lithium recovery. These results confirm the efficiency of the proposed thermochemical approach and provide a scientific foundation for its further development and industrial scale-up.

Lithium is the most important raw material for the production of modern electronics and electric vehicles. Today, it is impossible to imagine any mobile device without lithium batteries. The role of lithium in the global economy is only growing. The production of electric vehicles and batteries contributes to the reduction of carbon dioxide emissions. Nevertheless, end-of-life lithium-ion batteries pose a danger to the ecosystem. The article presents technological developments in the field of lithium extraction. The main sources of lithium are pegmatites, continental and geothermal brines, as well as clays, seawater and industrial brines. The main commercial lithium product is lithium carbonate (Li2CO3), which is obtained mainly from the mining, extraction and processing of spodumene ores and saltlake, oilfield brines. The effective role of lithium in addressing important issues such as pollution, climate change and the increasing depletion of natural resources used to produce lithium-ion batteries for these electric vehicles is also discussed.

Niobium, with its unique properties, plays a key role in high-tech industries, but its recovery from secondary sources remains poorly studied. The kinetics of niobium leaching from niobium-containing middlings obtained via the water treatment of dust chamber sublimations of titanium chlorinators is considered in this study. The leaching process was conducted using a fluoride–sulphuric acid solution. The experiments were performed at 25–90 °C in agitation mode. Kinetic data were analysed using compression-core and mixed-control models, which made it possible to establish the limiting stages of the process. A mixed mechanism, including a chemical reaction on the surface and diffusion through a layer of products with an activation energy of 30.05 kJ/mol, was established. The niobium recovery degree increased from 35.25 to 93.5% as the temperature increased, highlighting its effect on the process. The insoluble residue, rich in titanium, and the liquid phase with niobium and zirconium have the potential for further processing. The results provide the basis to optimise technologies intended to recover niobium from man-made raw materials, contributing to an increase in resource efficiency.

This paper presents the results of a study on the physicochemical parameters of the lithium sorption process from hydromineral raw materials using synthesized sorbents. The physicochemical parameters of lithium sorption from brine, including the enthalpy change (ΔH, kJ/mol), entropy change (ΔS, kJ/mol·K), and Gibbs free energy (ΔG, kJ/mol), were investigated. The enthalpy value ΔH = -0.698 kJ/mol indicates that the process is exothermic, as it is accompanied by heat release. The positive value of entropy ΔS = 0.0122 kJ/(mol·K) indicates a low degree of order and increased randomness at the interface between the manganese dioxide-based sorbent and the brine during lithium absorption. The negative Gibbs free energy (ΔG) values, ranging from -4.401 to -4.769 kJ/mol at temperatures of 303–333 K, confirm that the lithium sorption process on the manganese oxide sorbent is spontaneous and can proceed without external influence. Additionally, the activation energy value Ea = -0.592 kJ/mol suggests a decrease in the sorption rate as the temperature increases. Using a modified Arrhenius-type equation, the adhesion probability S* was determined to be 0.188. This value indicates the predominance of the chemisorption mechanism in the lithium sorption process.

This paper presents the results of lithium extraction from a lithium-containing precipitate obtained by the sulfation roasting of rare-metal production tailings, leaching of the sulfate roast product, and subsequent precipitation. Unlike the conventional sulfuric acid process, in the present study, lithium is chemisorbed from the solution obtained after leaching the sulfate calcine onto freshly precipitated aluminum hydroxide, which is subsequently calcined, followed by lithium desorption (aqueous leaching). During the preparation of the precipitate for the formation of the freshly precipitated aluminum hydroxide sorbent, the aluminum impurity naturally present in the solution was utilized, while the lithium to be recovered was present in the solution in the form of a sulfate compound. Data were obtained on the leaching (desorption) of lithium from freshly precipitated precipitates in which lithium was present in the form of a sulfate compound. Aqueous leaching was investigated for the precipitate in the wet state, after drying at 105 °C, and after calcination at 275–350 °C under atmospheric pressure in a thermostatic cell at 30 °C, as well as under autoclave conditions at 200 °C. The results showed that calcination significantly enhanced lithium extraction, while autoclave leaching further improved recovery. The effects of the solid-to-liquid (S:L) ratio, leaching time, and temperature on lithium extraction from the calcined precipitate were evaluated. The optimum conditions were aqueous leaching of the precipitate calcined at 275–350 °C with an S:L ratio of 1:10–1:15, a leaching time of 0.5–1 h, and a temperature of 55–98 °C. Autoclave leaching was also effective for precipitates dried at 105 °C and calcined at 350 °C. Under the optimum conditions, lithium extraction reached 92–96% during atmospheric leaching and approximately 98–100% under autoclave conditions. Concentration of the lithium-bearing solution produced a lithium-containing carbonate precipitate with 1.43 wt.% Li, corresponding to 3.07 wt.% Li₂O.