This article studies the geological structure, mineralogical composition, genesis, and sorption properties of Khonguruu zeolite deposit (Republic of Sakha, Russia). Although it is one of the largest developed deposits in Russia, detailed studies of the mineral composition and physicochemical properties have not been conducted previously, which limits its industrial potential. Zeolites were studied with X-ray diffraction (XRD), scanning electron microscopy (SEM), differential thermal analysis (DTA), X-ray fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and cation exchange capacity (CEC) analyses. Experiments on the sorption of radioactive cesium were also carried out. Zeolites formed four beds with an average content of 50-85%. The main focus of this study is on the detailed investigation of its mineral composition. These data, together with the analyses of ion-exchange complexes and color, provided an opportunity to distinguish between different types of zeolites. The zeolite minerals are represented by heulandite-1, heulandite-2 and, to a lesser extent, clinoptilolite. For the first time, a significant presence of amorphous silica was demonstrated in zeolite samples and used for correction of the crystallochemical formula of zeolites. On the basis of exchangeable cations composition, two main types of zeolites were found at the deposit: alkaline and alkaline-earth. The CEC of the zeolites ranged from 139 to 214 cmolc kg-1 and high 137Cs sorption. The zeolites have a volcanogenic-sedimentary genesis and were formed from ash material of basic and acidic composition in coastal sea waters with alternating conditions of low and high salinity. Based on the data obtained, it can be concluded that the alkaline raw material can be used as a sorbent for wastewater treatment.

This work is devoted to the study of the effect of acid treatment on the structural and textural properties of natural zeolite and its sorption activity with respect to radioiodide. To carry out the experiments, natural zeolite was treated with nitric acid of various concentrations at 20 and 90 degrees. The following methods were used to study the samples: XRD, SEM, DTA, XRF, FTIR, BET, and CEC analyses. Experiments on the sorption and desorption of radioiodide were carried out. The obtained results indicate that acid treatment results in the gradual leaching of aluminum from the crystal lattice and a significant increase in the specific surface area and microporosity of the zeolite. At the same time, the morphology of clinoptilolite is not significantly changed. Additional studies have shown that acid treatment leads to the hydrophobization of zeolite channels and the formation of an amorphous aluminosilicate phase, which makes a significant contribution to the increase in the specific surface area and microporosity. It was found that, with an increase in the degree of dealumination of the zeolite, there is an increase in the sorption properties with respect to radioiodide. The maximum values of sorption capacity were obtained after treating the zeolite with a 1 M nitric acid solution at 90 °C. With a further increase in the concentration of acid, critical changes in the structure of the zeolite occur, leading to a sharp decrease in the sorption capacity. Iodide sorption is not associated with physical adsorption in the micropores of the zeolite and the newly formed amorphous phase. The main mechanism of the sorption appears to be the interaction with silanol and bridging hydroxyl groups on the surface of the zeolite and the amorphous aluminosilicate phase.

During the development of the disposal concept in a crystalline massif of the Russian Federation, a question arose regarding the selection of the most suitable types of bentonite for a buffer layer. Data on the composition, structure, surface, and adsorption properties of four promising deposits have been obtained. The correlations between genesis and specific surface area (SSA) revealed in this study indicate that bentonites of volcanogenic-sedimentary origin have lower SSA in comparison with those of sedimentary and hydrothermal origin. The main contribution to the charge of the 2:1 layer is made by isomorphic substitutions in the tetrahedral sheet, which directly affects the sorption properties of bentonites. The influence of smectite structure on adsorption properties have been described. In particular, the dependencies between the layer charge and cation exchange capacity (CEC) have been analyzed. At the same time, the research indicates that, unlike the CEC, the specific surface area of a deposit is determined by its geological history. Special attention is being paid to refining methodological approaches for deriving crystal chemical formulae of smectites, which will be needed in the future for modelling changes in bentonite over a long-term perspective.

This work is concerned with classification and study of the composition and properties of hydrothermal zeolites from the Yagodninskoe deposit, (Kamchatka) which were formed in volcanic rocks. The study involved X-ray phase analysis and X-ray fluorescence, optical and scanning electron microscopy. We determined specific syrface AREA the pore size distribution, as well as cation exchange capacity in zeolites. The study resulted in the identification of four main rock types at the deposit: the original unaltered perlites, zeolites rock, zeolitized tuffs, as well as poorly zeolitized tuff breccias. The Content of zeolite group minerals reaches 70

This work is devoted to the development of a method of obtaining a sorbent for cleaning water surfaces of oil films using a sorbent based on natural glauconite modified with a ferromagnetic component and hydrophobisator. The optimum content of modifying agents as well as the modes of thermal activation which provide high buoyancy to the sorbent, and the maximum degree of oil extraction from the surface of seawater have been established. The influence of modification on the structure and properties of glauconite is shown. The principle of action of a hydrophobic sorbent with magnetic properties on the example of interaction with oil is described. A series of methods was used: X‐ray diffraction, X‐ray fluorescence method, thermal analysis, scanning electron microscope and determination of specific surface area by nitrogen adsorption. It is shown that the glauconite under study is represented by globular alluminosilicates of illite/glauconite-smectite composition with increased iron content, which is characteristic of "immature” glauconites. The maximum rate of petroleum and engine oil absorption by the sorbent, which is observed due to hydrophobic interactions, was recorded during the first 5 min. It was found that the best sorption properties in relation to petroleum and engine oil are possessed by thermally activated glauconite sorbent with the addition of 5

The sorption parameters of natural zeolites of various genesis, as well as synthetic X-type zeolite towards 137 Cs and 90 Sr radionuclides, were explored. Mineral and chemical compositions, values of the specific surface area and porous structure are reported for the examined samples. The distribution coefficients of trace amounts of radionuclides 137 Cs in 0.1 and 1.0 M sodium nitrate solution and those of 90 Sr in 0.01 M calcium chloride solution were found. A sample of hydrothermal zeolite from the Yagodninskoe deposit (Kamchatka Territory) was shown to be of the maximum sorption parameters towards cesium and strontium. It was concluded that the cation exchange capacity, the chemical composition of exchange sites, and the size of the channels in the zeolite crystal lattice are the factors determining the sorption activity of zeolites towards 137 Cs and 90 Sr radionuclides.

Ссылка для цитирования: Цеолитсодержащий трепел Хотынецкого месторождения (Орловская область): минеральный состав, сорбционные свойства, условия образования/ П.Е. Белоусов, Н.Д. Карелина, И.А. Морозов, М.А. Рудмин, В.В. Милютин, Н.А. Некрасова, А.О. Румянцева, О.В. Закусина, В.В. Крупская // Известия Томского политехнического университета. Инжиниринг георесурсов. – 2023. – Т. 334. – № 5. – С.70-84. Актуальность работы обусловлена необходимостью развития минерально-сырьевой базы месторождений высококачественного сорбционного сырья России, а также изучения свойств природных сорбентов с целью их дальнейшего применения на практике. Целью работы является изучение особенностей геологического строения, условий образования, минерального состава и сорбционных свойств цеолитсодержащего трепела Хотынецкого месторождения. Объектом исследования является Хотынецкое месторождение цеолитсодержащего трепела, изученное полевым отрядом Института геологии рудных месторождений, петрографии, минералогии и геохимии РАН в 2019–2020 гг. Методы: рентгенофазовый и рентгенофлуоресцентный анализ, ИК-спектроскопия, оптическая и сканирующая электронная микроскопия, определение удельной поверхности и распределения пор по размерам, емкость катионного обмена, эксперименты по сорбции цезия, стронция и меди. Также была проведена палеотектоническая реконструкция. Результаты. Продуктивная толща Хотынецкого месторождения состоит из трех пачек, основными полезными компонентами которых являются минералы группы цеолита, опал-кристобалита и смектита. Их содержание достигает 80 %. Образование месторождения происходило в три этапа и связано с первичным накоплением кремнезема в прибрежных морских водах, сносом терригенного глинистого материала с близлежащей суши, дальнейшим уплотнением и переработкой накопленного материала на стадии диагенеза. Образование клиноптиллолита связано с повышением рН и растворением опал-кристобалитового и глинистого материала в результате вторичного воздействия низкотемпературных глубинных растворов. Проведенные эксперименты показали, что данное сырье обладает высокими сорбционными характеристиками по отношению к цезию и меди и может применяться в качестве компонента сорбционных смесей и барьеров для очистки загрязненных вод.

Изучены сорбционные характеристики природных цеолитов различного генезиса, а также синтетического цеолита типа Х по отношению к радионуклидам 137 Cs и 90 Sr. Для изученных образцов приведены их минеральный и химический составы, значения удельной поверхности и пористой структуры. Определены значения коэффициентов распределения микроколичеств радионуклидов 137 Cs в 0.1 и 1.0 М растворе нитрата натрия и 90 Sr в 0.01 М растворе хлорида кальция. Показано, что максимальными сорбционными характеристиками по отношению к цезию и стронцию обладает образец гидротермального цеолита Ягоднинского месторождения (Камчатский край). Сделан вывод о том, что факторами, определяющими сорбционную активность цеолитов по отношению к радионуклидам 137 Cs и 90 Sr, являются величины емкости катионного обмена, химический состав обменных центров, а также размер каналов в кристаллической решетке цеолитов. Ключевые слова: цеолиты, клиноптилолит, состав, сорбция, радионуклиды, цезий, стронций.

The sorption parameters of a number of natural materials, diatomite, tripoli, and bentonite rock, were studied in relation to the 137Cs, 90Sr, and 233U radionuclides. It was shown that the efficiency of 137Cs and 90Sr sorption is directly proportional to the content of the clay component (illite and smectite minerals) in the sample and to the cation-exchange capacity (CEC), which indicates the ion exchange sorption mechanism of these radionuclides. The sorption parameters of the studied samples with respect to 137Cs and 90Sr decrease in the series bentonite rock > diatomite > tripoli. The 137Cs distribution coefficients (Kd) of bentonite rock and diatomite samples in the NaNO3 concentration range of 0.1–1.0 mol/dm3 are more than 103 cm3/g, which evidences high sorption-selective parameters of these rocks with respect to 137Cs. The Kd values of 90Sr on all the studied sorbents upon sorption from tap water are 1–2 orders of magnitude lower than the sorption of 137Cs, which is caused by the competitive sorption of calcium ions. The main mechanism of 233U sorption is physical adsorption on the surface of minerals, which is proportional to the specific surface area of minerals. The Kd values of 233U for all studied sorbents are relatively low and are in the range of 48–160 cm3/g. It was shown that natural sorbents, bentonite clays and diatomites, can be used as effective geochemical barriers to prevent the migration of cesium and strontium radionuclides from radioactive waste storages.

This paper is a study of volcanogenic bentonite. We examine the geological structural settings of the deposits, the paleogeographic environment of sedimentation, structural and textural features of the rocks, and their diagnostic features. We have identified ore-controlling factors in the generation of volcanogenic and hydrothermal bentonite. Comparative analysis has been performed of the original volcanogenic material sampled at deposits in Russia and abroad. The Dash-Salakhly deposit (Republic of Azerbaijan) and a bentonite-bearing province on Sakhalin Island were studied to find how bentonites of different genesis were formed. These studies provide evidence that the composition of the parent material for bentonite varies in a wide range, between basalt and rhyolite. The main factor that controls the generation of bentonite is the type of the sedimentation basin and physicochemical conditions rather than the composition of the parent material.

Experimental samples of bipolar ion-exchange membranes were obtained by applying liquid sulfocation exchanger LF-4SK containing bentonite clays treated with stearic acid to an anion-exchange membrane-substrate with quaternary ammonium groups MA-41. The effect of the amount of added bentonite (1, 2, 3 wt%) on the characteristics of membranes was studied. Silicon and hydroxyl of the included bentonite accelerate the dissociation of water molecules, which leads to increasing the concentration of hydrogen and hydroxyl ions during bipolar electrodialysis. Surface modification of bentonite particles with stearic acid improves the dispersion of the clay in the polymer solution. The physico-mechanical characteristics of experimental ion-exchange membranes containing bentonite treated with stearic acid are compared with a membrane containing natural untreated bentonite. The total exchange capacity, density, moisture capacity, as well as tensile strength and relative elongation were determined. The injection of a hydrophobizer into the membrane leads to a decrease in moisture content, an increase in the total exchange capacity and density of the cation-exchange layer compared to a membrane containing bentonite in its original form. The conversion of sodium sulfate (concentration 0.5 mol/dm(3)) was carried out with experimental bipolar ion-exchange membranes. The use of a bipolar membrane containing bentonite treated with stearic acid (3%) in the cation-exchange layer leads to an increase in the productivity of the process and a decrease in energy costs compared to a commercially available heterogeneous ion-exchange membrane with similar functional groups and not containing catalytic additives. A scheme for obtaining experimental bipolar membranes is proposed, which consists of the following stages: preparation of bentonite; treatment of bentonitewith stearic acid; preparation of anion-exchange membrane-substrate MA-41; coating the membrane-substrate with of a cation-exchange layer.

This investigation aims to design controlled-release nanocomposites based on mechanical activation of a mixture of glauconite and nitrogen nutrients in a 1:1 ratio. The methods include mechanochemical preparation of composites, X-ray diffraction analysis, scanning electron microscope with energy-dispersive X-ray spectroscopy (SEM–EDS), high-resolution transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), differential thermal analysis (thermo-gravimetric analysis and differential scanning calorimetry, TG-DSC), and soil column leaching experiments with the prepared nanocomposites for 56 days and growth of oat (Avéna satíva) using manufactured nanocomposites were tested. The nanocomposites display increasing intercalation between nitrogen substances and glauconite with increasing duration of the operation. The amount of intercalated nitrogen in the glauconite interlayer increases from 21.2 to 23.1% as the operation time increases from 3 to 14. The adsorbed nitrogen on glauconite flakes thickens with time. Analytical results record the frequent structural modifications of the nanocomposites. A substantial increase in the interlayer thickness of the unit structure of glauconite compared to its original state indicate the intercalation of urea into the structure of glauconite. Nitrogen occurs as intercalations in the exchangeable site (interlayer space) of the glauconite unit structure, remains an absorbed part within micro-flakes, or may be adsorbed on the surface of mineral particles. Soil leaching experiments, spanning over 56 days, reveal the release of nitrogen and potassium initially at a fast rate, which slows down with time. The nanocomposites leach nutrients at a slower rate than the urea sample. The plant height grows faster with the application of urea than nanocomposites. However, the reduced release of nitrates and ammonium from the nanocomposites decreases the leaching of nutrients downstream to soil layers. It prohibits the emission of greenhouse gases like nitrous oxides into the atmosphere. Therefore, the nanocomposites are classified as polyfunctional controlled-release fertilizers saving 50% of the urea. Further, the simultaneous release of potassium makes the composite a complex controlled-release fertilizer.

The article is devoted to analysis of the glauconite resource base in Russia. The geotectonic and lithological-paleogeographic positions of deposits and large glauconite occurrences, and their formation conditions are considered. Based on the structural position, age, and spatial localization of deposits and occurrences, glauconite provinces are identified and the most promising areas for expanding the glauconite resource base in the Russian Federation are identified. Information on reserves in deposits, the degree of their development, and production volumes is given. An overview of the main producer countries and glauconite production volumes in the world is presented. The geological structure and quality of raw materials in the Karinsk glauconite deposit are described. In tectonic terms, the glauconite deposits and occurrences in Russia are confined to the central parts of plates and platforms, foredeeps, and orogenic belts. The majority of glauconite deposits and occurrences are found in the Upper Cretaceous and Paleogene (Late Jurassic or Early Cretaceous in some cases) rocks. Predicted glauconite resources in the Russian Federation are more than 2.5 Gt. The most promising sites include the areas of western Siberia, as well as Moscow and Kirov districts in the European part of Russia.

The effect on the characteristics of the electrodialysis process of the acid activation of bentonite included in the cationexchange layer of an experimental bipolar membrane obtained by applying a liquid LF-4SK cation-exchange layer containing bentonite particles onto an anion-exchange membrane-substrate MA-41 was studied. Acid activation of bentonite was carried out with nitric acid (C = 1 and 4 mol/dm3) for 6 hours at temperatures of 20 and 90 °C. The conversion of sodium sulphate (C = 0.5 mol/dm3) was carried out in a six-section electrodialysis apparatus with experimental bipolar membranes containing bentonite in its original form and after acid activation. It has been shown that the addition of bentonite treated with nitric acid (C = 4 mol/dm3, t = 90 °C, t = 6 h) to the cation-exchange layer of a bipolar membrane leads to an increase in productivity, current efficiency and a decrease in energy costs compared to a membrane containing bentonite in its original form. Experimental bipolar membranes made on the basis of MA-41 and a liquid sulphonic cation exchanger containing acidactivated bentonite clays make it possible to obtain an acid and alkali performance omparable to that of the MB-3 bipolar membrane.

The present study examines the sorption of Cs (I) and Sr (II) on organic sorbents in the pH range from 2 to 10, as well as the mechanisms of their binding. In order to determine the influence of the physical properties and the quantity of functional groups of the organic sorbents on sorption, experiments were carried out on organic materials of varying degrees of metamorphism: high-moor peat, hard and brown coals and shungite. A detailed description of their mineral composition, cation exchange capacity, buffering capacity and elemental composition of sorbents is provided. XRD, XRF, SEM and BET adsorption methods were used for assaying. As a result of the conducted research, it can be concluded that Sr (II) showed a higher sorption per unit specific surface area than Cs (I) in the studied range of concentrations and pH values. Sr (II) sorption decreases in the following order: high-moor peat > brown coal > shungite > hard coal. The sorption of Cs (I) is highest on brown coal and lesser for high-moor peat, shungite and hard coal. It is suggested that Cs (I) and Sr (II) can be fixed on carboxyl functional groups and Cs (I), possibly, in insignificant amounts on phenolic hydroxyls of all four studied organic sorbents.

This article studies the geological structure, mineralogical composition, genesis and industrial properties of bentonite of the 10th Khutor deposit (Republic of Khakassia, Russia). The deposit is confined to the coal-bearing formation of Carboniferous age and is one of the main sources of bentonite for the metallurgical and foundry industries in Russia. The samples were collected during several field seasons and were studied with XRD, SEM, DTA, XRF, FTIR, BET and CEC analysis. The deposit consists of 6 productive layers with montmorillonite of alkaline-earth type varying in content from 38 to 72%. The formation of bentonites is associated with the alteration of volcanic ash of rhyodacite and dacite composition in zones of shallow sea water - bays and lagoons. The specific conditions of the formation, like an evaporitic depositional environment with high concentrations of soluble salts and burial diagenesis, as evidenced by seams and packs of hard coal, affected the textural and surface properties of the bentonite and caused the observed low microporosity and limited illitization.

The aim of this work is to study the characteristics of the electrodialysis of a sodium sulphate solution with experimental bipolar membranes based on the MA-41 anion exchange membrane and a liquid sulphonated cation-exchanger modified with bentonite clays. The conversion of sodium sulphate was conducted by electrodialysis with bipolar membranes obtained by applying a liquid sulphonated cation-exchanger containing particles of bentonite clay to the MA-41 anion-exchange membrane. To increase the performance of membranes in terms of hydrogen and hydroxyl ions, we carried out organomodifications of bentonite with alkyldimethylbenzylammonium chloride and stearic acid at various concentrations. The bipolar membrane with the addition of bentonite modified with alkyldimethylbenzylammonium chloride (2 wt%) showed a higher performance in terms of H+-ions. The bipolar membrane with bentonite modified with stearic acid (3 wt%) added to its cation-exchange layer is the most effective in terms of obtaining a f lux of OH--ions. It was shown that a combination of alkyldimethylbenzylammonium chloride (2 wt%) and stearic acid (3 wt%) used to modify bentonite can increase the performance of the bipolar membrane during the conversion of sodium sulphate, both in terms of the acid and alkali.

Experimental samples of bipolar ion-exchange membranes made of a liquid sulfonic cation exchanger (LF-4SK) with bentonite clays (natural and organomodified) and an anion-exchange membrane MA-41 were obtained. A quaternary ammonium salt, alkyldimethylbenzylammonium chloride (surfactant), was used as an organomodifier. As a result of the treatment of bentonite with a surfactant, its surface becomes organophilic and more compatible with the organic polymer, and the interplanar distance also increases. Experimental bipolar membranes have better characteristics in terms of generation of hydrogen and hydroxyl ions during the conversion of sodium sulfate than heterogeneous bipolar membranes with similar functional groups in the cation- and anion-exchange layer, which are commercially available.The bipolar membrane with the addition of organoclay (2% wt.) showed a higher productivity in terms of H+ - ions in comparison with the membrane containing natural, unmodified bentonite samples in the cation-exchange layer. The use of organomodified bentonite in the cation-exchange layer of the prototype membrane has increased the concentration of target products and significant decreased in energy consumption per unit of the target product. The effect of bentonite clay on the characteristics of the bipolar membrane is explained by the presence of hydroxyl and silicon groups in the clay, which are catalysts for the dissociation of water molecules. A technological scheme has been developed for obtaining an experimental bipolar bentonite-modified membrane, the main stages of which are: preparation of bentonite (drying and grinding); treatment of bentonite clay with alkyldimethylbenzylammonium chloride; treatment of organoclay suspension and liquid sulfonic cation exchanger LF-4SK with ultrasound; application of the resulting suspension onto a substrate membrane - an anion-exchange membrane with quaternary ammonium groups MA-41.

10th Khutor deposit is located in the Republic of Khakassia and confined to the coal-bearing formation of Carboniferous age within the development of continental tuff-sandy-argillaceous sediments. In terms of mineral composition, bentonites are mainly composed of Al-rich montmorillonite. The content of montmorillonite reaches a maximum of 70-75%, with an average content of 55 to 70%. It is one of the main sources of bentonite for the metallurgical and foundry industries in Russia. One of the distinctive features of bentonites from the 10th Khutor deposit is that despite the age of the deposit, about 350 million years, and the presence of an initial phase of metamorphism, as evidenced by the formation of hard coal, these bentonites retained the ability to swell and have high thermal stability. The formation of bentonites is associated with the decomposition of volcanic ash of rhyodacite and dacite composition in zones of shallow seawater - bays and lagoons. The properties of bentonite were influenced by the initial stage of metamorphism. The main purpose of this work was to establish the conditions for the formation of this deposit, as well as to study the features of the mineral composition and physicochemical properties of these raw materials. In addition to fundamental issues, the aim of the work was applied research on the properties and quality of bentonites.