Sorption properties of titanium phosphate ion-exchanger (Li-TiOP) towards Cu2+, Co2+, Mn2+, Ni2+ and Cr3+ ions in saturated LiNO3 solution were investigated. Solid samples were characterized by XRD, SEM, TG, DSC, NGSP and elemental analysis. Concentrations of elements in the solutions were determined by AAS and ICP MS methods. The adsorption isotherms for studied metal ions were calculated using the Langmuir, Freundlich, Temkin and Nikolsky models. Necessity for allowing for the solvated state of the sorbate is shown in studying the sorption of metal ions. Selectivity of Li-TiOP towards studied ions is found to be described in the following order of Cr3+ > Cu2+ > Mn2+ > Co2+ > Ni2+ for all models. The change in the thermodynamic parameters of the sorption process is associated with that in the ionic potential of the sorbent. Titanium phosphate effectively removes trace concentrations of metal ions from multi-component solutions, resulting in achievement of LiNO3 purity level of > 99.999 wt.%.

Разработан новый высокоэффективный метод получения тонкодисперсного порошка LiCoPO 4 с заданной морфологией из аммоний замещенного прекурсора NH 4 CoPO 4 ⋅H 2 O в расплаве нитрата лития. Показано, что морфология полученного продукта определяется морфологией используемого прекурсора и зависит от физико-химических условий его получения. Полученный LiCoPO 4 , а также его прекурсоры охарактеризованы методами РФА, СЭМ, БЭТ. Проведенные электрохимические испытания показали, что полученный порошок является электрохимически активным. Катодный материал на основе полученного LiCoPO 4 показал высокую удельную разрядную емкость 110 мА ч/г при плотности тока, соответствующей скорости заряда/разряда 1С, что обусловлено высокой дисперсностью и пластинчатой морфологией частиц синтезированного порошка. Предложенный метод отличается быстротой получения целевого продукта и не требует применения дорогостоящего оборудования, а также дополнительных стадий высокотемпературной кристаллизации и измельчения и может быть масштабирован до промышленного применения.

Разработаны составы сорбционных материалов на основе гидрофосфатов оксотитана(IV), модифицированные катионами циркония(IV) и содержащие одновременно катионообменные, представленные НРО \(_{4}^{{2 - }}\) -группами, и анионообменные, представленные ОН – -группами, функциональные центры. Проведена апробация полученных образцов при сорбции катионов/анионов сурьмы(III) из высокосолевого раствора. Показано, что сродство ионообменной матрицы к ионам сурьмы(III) усиливается с повышением содержания в ее составе функциональных групп. Такие составы могут рассматриваться как перспективные ионообменные материалы для эффективного извлечения радионуклидов сурьмы из многокомпонентных высокосолевых жидких радиоактивных отходов.

— We have proposed compositions of titanyl hydrogen phosphate-based sorption materials modified with zirconium(IV) cations and containing both cation and anion exchange functional centers, represented by НРО _4^2 - and OH – groups, respectively. The synthesized materials were tested in sorption of antimony(III) cations and anions from high-salt solutions. Increasing the concentration of functional groups in ion exchange matrices has been shown to increase their affinity for antimony(III) ions. Such compositions can be regarded as promising ion exchange materials for efficient extraction of antimony radionuclides from multicomponent high-salt liquid radioactive waste.

A new and highly efficient way of obtaining finely dispersed LiCoPO 4 powder is developed with a given morphology from ammonium substituted precursor NH 4 CoPO 4 ⋅H 2 O in a lithium nitrate melt. It is shown that the morphology of the obtained product is determined by the morphology of the used precursor and depends on the physicochemical conditions of its preparation. The obtained LiCoPO 4 and its precursors are characterized by means of XRD, SEM, and BET. Electrochemical tests show the resulting powder is electrochemically active. Cathode material based on the obtained LiCoPO 4 shows a high specific discharge capacity of 110 mA h/g at a current density corresponding to a charge/discharge rate of 1C, due to the high dispersion and lamellar morphology of the particles of the synthesized powder. The proposed procedure is characterized by the speed of obtaining the target product. It does not require the use of expensive equipment or additional stages of high-temperature crystallization and grinding, and can be scaled up to industrial use.

The results of studying of the nitric acid and NaOH + KOH alkalis’ mixture recovery from concentrated solutions in filter-press-type electrodialyzers with anion-exchange, cation-exchange, and bipolar membranes are presented. The necessity of the technological solutions preliminary purification from calcium and boron compounds was established, in order to obtain crystalline boric acid (H3BO3) and gypsum (CaSO4·2H2O). The possibility of obtaining, from purified concentrated salt solutions, acids and alkalis with a concentration of ~300–600 g/L suitable for reuse is shown. This can be provided only by the electrodialysis with anion- and cation-exchange membranes, while electrodialysis with bipolar membranes is complicated by noticeable contamination of both acidic and alkaline solutions with salts.

— The experimental data reported in this paper suggest that titanium(IV) oxyhydroxyphosphate-based ion-exchange materials are potentially attractive for extraction of heavy metal cations from solutions. We have studied the time-dependent ion exchange activity of titanium phosphates for Zn 2+ , Co 2+ , and Ni 2+ cations in relation to the liquid : solid ratio, temperature, and equilibrium pH of the cation exchange process. The results demonstrate that the selectivity of an ion exchanger for metal cations is determined by the ionic radii of the metals. Conditions for effective use of titanium phosphate materials for extraction of Zn 2+ , Co 2+ , and Ni 2+ cations from solutions (liquid : solid ratio, temperature, and pH) have been optimized experimentally.

The results reported in this paper suggest that titanium(IV) oxyhydroxyphosphates can be used for sorption extraction of valuable metal cations from solutions, followed by desorption and concentration of the metal cations and simultaneous regeneration of the titanium phosphate material for further use. Conditions for effective desorption processes (desorbing agent concentration and desorption time) have been studied and optimized. The sorption/desorption process effectiveness in the case of multistep use of the sorbent has been shown to decline as a result of steric hindrances associated with its dehydration. As the sorption properties of the sorbent degrade, it can be used for extraction of trace amounts of highly toxic metal cations and then buried.

The experimental data reported in this paper suggest that titanium(IV) oxyhydroxyphosphate-based ion-exchange materials are potentially attractive for extraction of heavy metal cations from solutions. We have studied the time-dependent ion exchange activity of titanium phosphates for Zn2+, Co2+, and Ni2+ cations in relation to the liquid : solid ratio, temperature, and equilibrium pH of the cation exchange process. The results demonstrate that the selectivity of an ion exchanger for metal cations is determined by the ionic radii of the metals. Conditions for effective use of titanium phosphate materials for extraction of Zn2+, Co2+, and Ni2+ cations from solutions (liquid : solid ratio, temperature, and pH) have been optimized experimentally.

The results of ceramic targets formation from powders of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 and Li 6.4 Al 0.2 La 3 Zr 2 O 12 solid electrolytes by cold pressing with subsequent high-temperature sintering are presented. Solid electrolyte powders of Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) with the NASICON structure and Li 6.4 Al 0.2 La 3 Zr 2 O 12 (LLZ) with the garnet structure with high Li-ion conductivity were synthesized by methods protected by patents in the RF, suitable for mass production. The conditions for the formation of dense single-phase targets (14 mm in diameter and 8-10 mm thick) from LATP and LLZ (cubic modification) solid electrolytes were established by X-ray diffraction analysis. The ionic conductivity, Li + ion transfer number and electronic conductivity of LATP and LLZ ceramic targets were determined by electrochemical impedance spectroscopy and potentiostatic chronoamperometry methods.

This paper demonstrates the feasibility of using titanium(IV) oxyhydroxyphosphate-based materials for sorption extraction of heavy metal cations from solutions. We have determined Pb2+ and Cd2+ sorption characteristics of ion exchangers, examined the kinetics of Pb2+ and Cd2+ sorption on the titanium phosphate materials, and assessed the effect of ionic radius on the affinity of the sorption matrices for metal cations. Conditions for effective use of the ion exchange materials for extracting Pb2+ and Cd2+ cations from solutions (liquid : solid ratio and pH) have been optimized experimentally.

Sorbents based on titanium(IV) compounds have been shown to be potentially attractive for quantitative removal of antimony(III) anions from liquid radioactive waste with complex chemical composition. Evidence is presented that titanium(IV) oxyhydroxyphosphates have enhanced affinity for antimony(III) cations. Selectivity of sorption matrices increases with increasing solution acidity and with an increase in the concentration of hydrogen phosphate groups in the composition of the material. Having enhanced affinity for negatively charged antimony(III) ions, titanium(IV) oxyhydroxides are potentially attractive for extraction of anionic species.

Lithium cobaltate with stoichiometric composition (LiCoO2) is synthesized by the sol–gel method. The physical parameters (particle size, specific surface area, and specific static conductivity) of studied samples are found and their dependence on the calcination temperature is revealed. The following three conduction mechanisms are shown to contribute to the conductivity value: frequency-independent σ0, ionic transport in the sample bulk σsv, and ionic transport at the electrode/ionic conductor interface σdl. The optimal modes of thermal treatment that allow the highly developed specific surface of LiCoO2 to be retained are determined.

The possibility to synthesize titanium phosphate from crystalline titanium salts has been shown for the first time. Optimal synthesis conditions have been found to provide preparation of monophase product of composition Ti(HPO4)2 · H2O or TiO(OH)H2PO4 · 2H2O by heterogeneous reaction of titanium-containing precursors with phosphoric acid. The process has been found to proceed for 3–5 h at stoichiometric consumption of the components and provides more environmentally benign and profitable conditions as compared with the known methods of synthesis.