Primary Aluminosilicate Research Articles

ГЕОХИМИЧЕСКИЕ ПОСЛЕДСТВИЯ ЗАХОРОНЕНИЯ УГЛЕКИСЛОГО ГАЗА В ТЕРРИГЕННЫХ КОЛЛЕКТОРАХ

The paper is aimed at the research practice on identifying the features of interaction in the water-rockcarbon dioxide system in relation to terrigenous reservoirs, widely occurring in hydrogeological basins in the territory of the Russian Federation and potentially suitable for the placement of carbon dioxide. As the CO2 solution is saturated, along with an increase in total dissolved solids there is a naturally-determined increment in the volume of transition of ions into their complex forms. The main macro components (Ca2+, Mg2+, Na+, K+, (SO4)2–, Cl– ) migrate mainly in the form of their own ions, with a decrease in their fraction by an order of 1–3 % with an increase in mineralization. Ions such as Fe, Al3+, Mn3+, (NO3)–, (HCO3)–, SiO2, (NH4)+, (NO2)– are prone to transition into the form of complex compounds, the fraction of which in the total volume increases with the amount of saturation of solution with carbon dioxide. When CO2 is injected into the terrigenous reservoir, there is a natural decrease in the solution pH, absence of precipitation of carbonates and minimal changes in the rock porosity. The observed process of dissolution of primary aluminosilicate minerals (albite, anorthite, potassium feldspar) is characteristic of most of the considered mineralogical varieties of reservoirs, when they are saturated with CO2. This process is accompanied by deposition of secondary mineral phases in the form of montmorillonites, illites, chlorites, etc. Taking into account the low rates of these reactions, no significant changes in reservoir properties are noticed.

Calcium wastes as an additive for a low calcium fly ash geopolymer

A geopolymer is a low-carbon cement based on the utilization of waste ash in alkali-activated conditions. Coal fly ash is widely used as a source material for geopolymer synthesis since it contains a sufficient amount of reactive alumina and silica for geopolymerization. Geopolymer products are known to have beneficial fire resistance and mechanical properties. Class F or low-calcium fly ash (LCFA) is generally used as a primary aluminosilicate source; however, heat curing is required to complete the reaction and hardening process and achieve a strong composite. Furthermore, calcium additives are often required to improve the strength of LCFA geopolymers. This paper presents the potential of reusing calcium waste for this purpose. Three calcium wastes, namely calcium carbide residue (CCR), limestone waste, and waste cement (WC) slurry in powder form were used as additives and compared with the use of ordinary Portland cement (OPC). LCFA was replaced with the calcium additives at 20%. However, 20% CCR resulted in flash setting, hence 5% CCR was used instead. A durability test using 3% HCl solution was also performed. The results showed that the reactivity of calcium additives played an important role in strength development. In the calcium–aluminosilicate–alkali system, calcium silicate hydrate (CSH) and calcium aluminosilicate hydrate (CASH) were formed. The maximum strength of 21.9 MPa was obtained from the OPC/LCFA geopolymer, and 3% HCl solution had a deleterious effect on the strength. OPC and CCR were favorable reactive sources of calcium compounds to blend with LCFA. From the thermogravimetric results, lower thermal weight changes with higher strength gains were achieved. Low CaCO3 decomposition at 750 °C according to the TGA curves indicated the more formation of thermally stable CSH and high compressive strength of Ca/LCFA geopolymers.

Water chemistry variation in tropical high‐mountain lakes on old volcanic bedrocks

AbstractWater chemistry and its ecological implications have been extensively investigated in temperate high‐mountain lakes because of their role as sentinels of global change. However, few studies have considered the drivers of water chemistry in tropical mountain lakes underlain by volcanic bedrock. A survey of 165 páramo lakes in the Cajas Massif of the Southern Ecuador Andes identified 4 independent chemical variation gradients, primarily characterized by divalent cations (hardness), organic carbon, silica, and iron levels. Hardness and silica factors showed contrasting relationships with parent rock type and age, vegetation, aquatic ecosystems in the watershed, and lake and watershed size. Geochemical considerations suggest that divalent cations (and related alkalinity, conductivity, and pH) mainly respond to the cumulative partial dissolution of primary aluminosilicates distributed throughout the subsurface of watersheds, and silica and monovalent cations are associated with the congruent dissolution of large amounts of secondary aluminosilicates localized in former hydrothermal or tectonic spots. Dissolved organic carbon was much higher than in temperate high‐mountain lakes, causing extra acidity in water. The smaller the lakes and their watersheds, the higher the likelihood of elevated organic carbon and metals and low hardness. The watershed wetland cover favored metal levels in the lakes but not organic carbon. Phosphorus, positively, and nitrate, negatively, weakly correlated with the metal gradient, indicating common influence by in‐lake processes. Overall, the study revealed that relatively small tropical lake districts on volcanic basins can show chemical variation equivalent to that in large mountain ranges with a combination of plutonic, metamorphic, and carbonate rock areas.

Production of green bricks from low-reactive copper mine tailings: Durability and environmental aspects

In response to the net-zero emissions plan for 2050, geopolymerization of mine tailings (MT) has attracted massive attention from construction material researchers and engineers. To successfully recycle or reuse MT through geopolymerization, it is essential to have a reliable understanding of the environmental and durability aspects of the geopolymer products. This study investigates the durability and leaching behavior of geopolymer bricks produced from low-reactive copper MT as the primary aluminosilicate precursor and slag as the supplementary cementitious material (SCM). Durability tests include fourteen (14) wet-dry cycles and fifty (50) freeze–thaw cycles, respectively. After the durability test, the weight loss and unconfined compressive strength (UCS) of the geopolymer brick specimens were measured. The leaching study was conducted following TCLP guidelines by immersing the geopolymer brick specimens in solutions with pH = 4 and 7, and measuring the concentration of contaminants in the solution after 120 days. After the leaching test, the wet and dry UCS of the geopolymer specimens were measured. In addition, microscopic studies including SEM/EDX and XRD were performed to study the microstructural changes and the phase composition. The results show a substantial loss in UCS after the durability tests. However, the weight loss is small compared with conventional cementitious materials. Most importantly, the contaminants in the MT are successfully stabilized within the geopolymer framework.

Microbial Alkalinity Production and Silicate Alteration in Methane Charged Marine Sediments: Implications for Porewater Chemistry and Diagenetic Carbonate Formation

A numerical reaction-transport model was developed to simulate the effects of microbial activity and mineral reactions on the composition of porewater in a 230-m-thick Pleistocene interval drilled in the Peru-Chile Trench (Ocean Drilling Program, Site 1230). This site has porewater profiles similar to those along many continental margins, where intense methanogenesis occurs and alkalinity surpasses 100 mmol/L. Simulations show that microbial sulphate reduction, anaerobic oxidation of methane, and ammonium release from organic matter degradation only account for parts of total alkalinity, and excess CO2 produced during methanogenesis leads to acidification of porewater. Additional alkalinity is produced by slow alteration of primary aluminosilicate minerals to kaolinite and SiO2. Overall, alkalinity production in the methanogenic zone is sufficient to prevent dissolution of carbonate minerals; indeed, it contributes to the formation of cemented carbonate layers at a supersaturation front near the sulphate-methane transition zone. Within the methanogenic zone, carbonate formation is largely inhibited by cation diffusion but occurs rapidly if cations are transported into the zone via fluid conduits, such as faults. The simulation presented here provides fundamental insight into the diagenetic effects of the deep biosphere and may also be applicable for the long-term prediction of the stability and safety of deep CO2 storage reservoirs.

Principal Parameters Controlling Water Composition in Saline and Brackish Lakes in Eastern Transbaikalia

Extensive field hydrogeochemical data and thermodynamic simulations demonstrate that the composition of lacustrine waters is controlled not only by evaporation but also by interaction between the waters and rocks. This interaction begins in the catchment areas of the lakes and continues in these lakes themselves, because the waters (regardless of their salinity) do not occur in equilibrium with many of the endogenic minerals. These processes are the most intense in soda lakes, as follows from the highest pH of their waters (9.0–10.7). These values provide evidence that these waters most intensely interact with primary aluminosilicates. The two processes responsible for sulfur behavior in these lakes are sulfate reduction and sulfide oxidation. Different geochemical environments produced in lakes of different type are favorable for the selective enrichment of some elements, which are mobile in these environments and whose concentrations can significantly increase.

Mechanisms of the Formation of Sodium Bicarbonate Groundwaters in the Southeast of West Siberia

The research data are presented on the chemical and isotope composition of sodium bicarbonate groundwaters in the southeast of West Siberia. It is shown that the studied waters occur ubiquitously within Mesozoic–Cenozoic sedimentary deposits at a depth roughly from 50–300 m to 1.0–2.3 km. Various geochemical characteristics and conditions of occurrence made it possible to distinguish five types of waters: (I) fresh, (II) brackish, (III) high-alkaline low-saline, (IV) coal-deposit saline, and (V) carbonated waters. Types I and II are characterized by regional occurrence and a quite typical chemical composition. Types III–V have specific compositions and occur locally throughout the region. The genesis of all types of bicarbonate waters was determined as infiltration based on isotope data (δ18O, δD, and δ13С). Type IV is characterized by a positive “oxygen shift” and the carbon source is biogenic, except for type V. Calculations of equilibrium in the water-host minerals system showed that all bicarbonate waters were nonequilibrium for a number of primary aluminosilicate minerals and equilibrium for a wide variety of carbonates and clays. It was found that the amount of water-equilibrium minerals increased from type I to type IV with increasing water total dissolved solids (TDS) and pH values. The studies identified the governing characteristics of the formation of secondary minerals and hence of bicarbonate waters, including the main (pH value, Si, Ca, HCO3, and Al) and additional parameters of the medium (organic matter and gases). The same mechanism for all types of bicarbonate waters was determined: dissolution of water-nonequilibrium aluminosilicate minerals of sedimentary deposits and simultaneous precipitation of carbonates. The diversity of manifestations of bicarbonate waters is related to different interaction times in the water–rock system (types I and II), even during the bicarbonate stage, as well as additional overprinting of environmental features, i.e., the occurrence of supplementary sources of CO2 and organic matter for types IV and V, respectively, or their absence for type III. The presented formation schemes for different types of bicarbonate waters were also confirmed by the data of 18O and 13С isotope studies.

In situ remediation of Cd(II) contaminated paddy fields with activated Ca[sbnd]Si mineral material derived from Potash feldspar and its mechanism

Continuous rice cultivation and excessive use of chemical fertilizers result in soil acidification and heavy metal pollution in southern China. An activated CaSi mineral remediation material (CSRM) was innovatively prepared by two-stage modification (calcination with mixed salts and the hydrothermal activation) of primary aluminosilicate Potash feldspar. Based on the excellent results of previous pot experiments, this material was used for in situ remediation of cadmium contaminated paddy fields. Adding 4500 kg/hm2 of the material, the cadmium contents in rice and the available cadmium contents in soil was reduced significantly by 41.43%–73.32% and 16.67%–31.13%, accompanied by the increase of soil pH 0.68–0.82 and rice yield 4.24%–11.22%. To further study the remediation mechanism of cadmium, the composite was used for Cd(II) removal in aqueous solution, in combination with SEM, EDX, XPS, XRD, XRF, and BET analysis. The adsorption isothermal data was more suitable with the Langmuir model, and the kinetics can be well described by the pseudo-second-order model. The isothermal study also demonstrated an adsorption process on homogeneous surface along with monolayer adsorption and the maximum capacity obtained from the Langmuir model was 273.2 mg/g at 328 K. By instrumental analysis, it could be known that stable carbonates and silicates were formed by the interaction of materials with cadmium ions, and this process was feasible, spontaneous and endothermic. Ion exchange was found to be the most important chemical process, followed by precipitation, surface complexation and adsorption. The porosity of clay was another significant reason for the removal of heavy metals by adsorption mechanism.

Hydrogeochemistry of authigenic mineral formation in Upper Jurassic sediments (the Nadym-Taz interfluve area, Arctic regions of Western Siberia)

This paper presents a novel numerical modelling approach to physicochemical evolution of water – rock interactions in Upper Jurassic sediments in the Nadym–Taz interfluve (Arctic regions of Western Siberia). The results show that the authigenic mineral formation proceeds continuously and strictly successively (kaolinite – montmorillonite – illite – mica – chlorite – albite – microcline), involving definite geochemical parameters of the medium (pH, concentrations of SiO2, Al, Na, K, Ca, Mg in solution). For example, the widely spread kaolinite cement forms in the medium with near neutral pH (on average, рH = 7.2) with silica concentration in solution 15–20 mg/dm3, while the formation of authigenic illite begins at silica concentration of 25–40 mg/dm3 and pH about 7.3–7.4. Despite rather low salinity (up to 63 g/dm3) of the investigated groundwater and long-term interaction of water with the rocks (spanning ca. 165 Ma), the equilibrium with primary (endogenous) minerals such as albite, anorthite, microcline is practically unobserved. At the same time, the groundwater is in equilibrium with mica, illite, Ca–, Na– and Mg–montmorillonites, kaolinite, more rarely with Mg–chlorite. The state of groundwater equilibrium with primary aluminosilicate minerals is always challenged by a carbonate barrier, so rocks carbonatization in various degree is observed almost everywhere.

ОСОБЕННОСТИ ВЗАИМОДЕЙСТВИЯ В СИСТЕМЕ ВОДА–ПОРОДА НА ТЕРРИТОРИИ ВОДОСБОРА ОЗЕРА ИМАНДРА (КОЛЬСКИЙ ПОЛУОСТРОВ)

Актуальность исследования обусловлена тем, что при оценке эколого-геохимического состояния природной среды необходимо учитывать соотношение природных и техногенных процессов, протекающих во всех ее компонентах (почве, воде, воздухе и т. д.). Так, основным природным процессом, определяющим обогащение вод химическими элементами, является их взаимодействие с горными породами. Однако на процессы в системе вода–порода значительное влияние может оказывать техногенный фактор. В этой связи глубокое понимание особенностей гидрогеохимических процессов в пределах территорий, подверженных значительному техногенному воздействию, является важной задачей современной экогеохимии. Цель: исследование особенностей взаимодействия вод с горными породами в условиях техногенной трансформации природной среды района озера Имандра Кольского полуострова. Объекты: подземные и поверхностные воды водосбора озера Имандра (Кольский полуостров). Методы. Макрокомпонентный состав вод определялся методами ионной хроматографии, титриметрии, пламенной фотометрии, потенциометрии, фотоколориметрии, турбидиметрии. Для определения микрокомпонентов в составе вод использовался масс-спектрометр с индуктивно-связанной плазмой NexION 300D. Насыщенность вод к вторичной минеральной фазе оценивалась по величине индекса насыщения (SI), рассчитанной с помощью программного продукта PHREEQC. Результаты. Установлено, что в пределах водосборной территории озера Имандра распространены низко минерализованные природные воды преимущественно гидрокарбонатного кальциевого состава с нейтральной и слабощелочной средой. Специфика химического состава вод западной и восточной частей рассматриваемой территории определяется совокупным влиянием природных и антропогенных факторов. Так техногенное влияние комбината «Североникель» подтверждают повышенные концентрации никеля и меди в поверхностных водах западной части территории. Рассмотренные природные воды неравновесны с первичными алюмосиликатными минералами и насыщены гидроксидами, оксидами железа и алюминия и, в меньшей степени, меди, каолинитом, и, в отдельных точках, иллитом, Ca- и Mg-монтмориллонитом. С позиций эволюционного развития высокая интенсивность водообмена на рассматриваемой территории является фактором, обусловливающим нахождения системы вода–порода на начальных стадиях. Наличие в составе равновесной минеральной фазы оксидов и гидроксидов меди свидетельствует о влиянии техногенных факторов на процессы взаимодействия в системе вода–порода.

Ecologo-Geochemical Conditions of the Water Bodies Within the Damodar River Basin (India) During a Low-Water Period

Ecologo-geochemical conditions of surface water and groundwater are considered in the case of one of the industrially most developed states of India, West Bengal, within the Damodar river basin near Damodar City. The observations were made in the pre-monsoon period of March 2019, a period with the worst conditions of wastewater dilution. To analyze total chemical composition of water samples, a standard set of analytical methods was used; trace elements were analyzed by inductively coupled plasma mass spectrometry. Data obtained indicate both the unsatisfactory water quality and the intense self-purification processes. The waters under study are, in general, characterized as freshwaters (except for the stream receiving wastewater from the chemical plant where the water is “brackish”), HCO3–Ca or HCO3–Na (except for the water in the stream near the chemical plant, which is Cl–Na, and groundwater, which is Cl–Ca). In most cases, the waters are oversaturated with carbonates, compounds with humic acids, quartz and undersaturated with primary aluminosilicates. The main ollutants are organic compounds according to the values of permanganate demand and chemical oxygen demand, Al, F–, NH4+, Fe, and Mn. Phosphates, As, Pb, and some other chemical elements are also present in significant concentrations It is shown that most pollutants settle in bottom sediments of the streams receiving wastewater from industrial enterprises within a few kilometers from the wastewater discharge points. The mechanism of water selfpurification is, possibly, associated with co-precipitation and sorption of a great number of substances on particles of poorly soluble carbonates and hydroxides of Ca, Fe and some other metals at relatively high pH values associated with the consumption of carbon dioxide by microorganisms.

Sodium-bicarbonate groundwaters in southeastern West Siberia, Russia: Compositions, types, and formation conditions

Sodium-bicarbonate HCO3–Na (sodic) groundwaters exist throughout southeastern West Siberia at approximate depths from 50–300 m to 1.0–2.3 km in Mesozoic-Cenozoic sediments. They belong to five main types of fresh (I), brackish (II), high-pH low-saline (III), coal-related saline (IV), and carbonated (V) waters that differ in composition, as well as in depth and lateral extent. Waters of types I and II are of regional extent and common chemistry, while those of three other types have specific compositions and are restricted to local areas. Isotope data (δ18O, δD, δ13C) indicate that waters of all five types originated by the infiltration mechanism; type IV water has an enriched oxygen isotope composition; all water types except V have biogenic carbon sources. As shown by thermodynamic calculations, all HCO3–Na waters are nonequilibrium with many primary aluminosilicate minerals bur are equilibrated with carbonates and clay minerals. The number of minerals equilibrated with these waters increases progressively from type I to IV with salinity and pH. The obtained data allow reconstructing the formation of sodic waters of different types in the context of the evolution in the system ‘water – rock – gas – organic matter’. The formation scenario is the same for all types of water: dissolution of sedimentary aluminosilicate minerals which are not in equilibrium with the waters and concurrent precipitation of carbonates. Waters in the zone of slow water exchange at depths from 100 to 300 m acquire the HCO3–Na compositions, with TDS >0.7–0.8 g/L and рH >7.6. The diversity of the waters results from difference in their residence time, even during the formation of HCO3–Na chemistry (types I and II), and from environment effects: presence of inorganic CO2 (V) and organic carbon (IV) sources or their absence (III).

Hydrogeochemistry of the authigenic mineral-forming processes (a case study of Oxfordian deposits in the Ob-Irtysh interfluve)

Results of the pioneering numerical physicochemical modeling of interactions in the water – rock system on the example of Oxfordian deposits in southern regions of the Ob-Irtysh interfluve (southeastern regions of Western Siberia) are presented.It has been established that, despite the groundwaters having low salinity (up to 46 g/dm3) of and their persistent interactions with rocks (during tens, or probably hundreds of millions of years), they practically have no equilibrium with primary (endogenous) minerals: albite, anortite, microcline.At the same time, groundwater is in equilibrium with micaceous minerals, Ca-, Na - and Mg-montmorillonites, kaolinite, Mg-chlorite. There is always a carbonate barrier in the way of groundwater attaining an equilibrium with primary aluminosilicate minerals. As a result of the detailed petrographic studies, the genetic series of authigenic minerals of the diagenetic and catagenetic phases were established in the studied silty-sandy rocks. Relict diagenetic minerals are represented by glauconite, pyrite, siderite, calcite of the first generation of precipitation, kaolinite, anatase and leucoxene. Catagenetic minerals are considerably dominated by calcite of the second and third generations of precipitation, quartz, kaolinite, whereas siderite, chlorite, albite, dolomite are developed in minor amounts. The results of petrographic studies have corroborated the thermodynamic calculations.

Role of water-rock interactions in the formation of the composition of radon waters of the Zaeltsovsky field (the southern part of West Siberia)

Results of thermodynamic calculations of the interactions of radon waters from the Zaeltsovsky field with the minerals of host rocks are presented for the first time. It was established that waters under study are supersaturated with respect to calcite and siderite, and to a smaller extent with respect to magnesite and dolomite. No saturation of radon waters with respect to primary aluminosilicate minerals (albite, anortite, microcline, ferrosilite) is observed. The points are located in the fields of stability of clayey minerals (kaolinite, Ca- and Mg-montmorillonite, Fe-sepiolite), gibbsite and leptochlorite. In the evolution of the water-rock system, they correspond to the siallite type of interaction with rocks.

Lateral Zoning of Groundwater Chemistry and Authigenic Mineralogy in the Oxfordian Regional Reservoir of the Nadym–Taz Interfluve

Abstract —This is a pioneering study on lateral zoning of groundwater chemistry and authigenic mineralogy in the Oxfordian regional reservoir of the Nadym–Taz interfluve. According to thermodynamic calculations, the nonequilibrium–equilibrium water–rock system lacks equilibrium with primary magmatic minerals, such as albite, anorthite, and microcline, though the water is moderately saline (up to 63.3 g/L) and has been in interaction with rocks for ~165 million years. Authigenic minerals form continuously and successively (kaolinite–montmorillonite–illite–micas–chlorite–albite–microcline) from waters that have certain рH and contents of SiO2, Al, Na, K, Ca, and Mg. The equilibrium of groundwater with primary aluminosilicate minerals impinges on a carbonate barrier, and almost all rocks are more or less strongly carbonatized. Authigenic mineral assemblages from the southern Nadym–Taz interfluve include kaolinite unlike those from the northern part of the region, where albitization is more common. Authigenesis generally decays in the eastern direction.

The chemical and isotopic compositions of thermal waters and gases in the Republic of Buryatia, Russia

The chemical and isotopic compositions of waters and associated gases in the Republic of Buryatia are investigated in this report. Results show the thermal waters are predominantly enriched in N2. They are alkaline, low salinity and have high concentrations of HCO3-, SO42-, F, Si but low values for Ca2+, Mg2+, K+. According to isotopic composition, the thermal waters are meteoric in origin. Despite the low salinity, the thermal waters are in equilibrium with calcite, magnesite, fluorite, albite, laumontite and other minerals but are not equilibrium with respect to primary aluminosilicates. This indicates that the thermal waters and water-bearing rocks represent the equilibrium-nonequilibrium system.

Chemical equilibrium of groundwater with minerals of the host rocks in Upper Jurassic sediments (Arctic regions of Western Siberia)

The results of thermodynamic calculations for a water-rock system in the Upper Jurassic deposits of the Arctic regions of Western Siberia are presented. In the area under investigation the groundwaters have been identified with mineralization up to 63.3 g/L and various chemical composition and genesis. Despite the long interaction with the rock (150-160 ma) equilibrium with endogenous minerals (albite, microcline and anorthite) is practically not observed. At the same time, groundwaters are in equilibrium with clay minerals and micas, such as: Caand Na-montmorillonites, kaolinite, paragonite, margarite, illite, muscovite and Mg-chlorite. The establishment of a balance of groundwater with primary aluminosilicate minerals is also affected by interactions with carbonate minerals. The differences in composition of groundwater in equilibrium with certain aluminosilicates and carbonates indicate that the mineral changes are formed from a solution of a strictly defined chemical composition in an appropriate geochemical environment.

Geochemistry of Soda Waters of the Chulym–Yenisei Artesian Basin (West Siberia)

Abstract —Results of studies of soda waters of the Chulym–Yenisei artesian basin are presented. It is shown that these waters are ubiquitous within Cretaceous or Jurassic sediments at depths of ~100–300 m to 1.5–2.3 km. According to the formation conditions, mineralization, and pH, they are divided into three groups: Type I waters spread to a depth of 600 m and have pH = 7.4–8.4 and TDS ≤ 0.5 g/L, type II waters occur at depths of 0.6–2.3 km and are characterized by pH = 8.0–8.9 and TDS = 0.7–4.1 g/L, and type III waters (“Omega”) form a local segment among type II waters and have a unique composition: high alkalinity (pH = 9.0–10.3) and low mineralization (TDS = 0.2–0.6 g/L). We focus special attention on type III waters and present results of studies of their microcomponent, gas, and isotope compositions. The cause of their low salinity and high pH is explained for the first time. Taking into account the isotope data (δD, δ18O, and δ13C), we have established the infiltration origin of soda waters of the three types and the biogenic source of their carbon dioxide. Calculations of equilibria in the water–host-mineral system have shown that all soda waters are in disequilibrium with many primary aluminosilicate minerals but are in equilibrium with a wide range of carbonates and clays. In passing from type I to type III waters, the number of minerals in equilibrium with water continuously increases (albite, microcline, muscovite, and biotite). Taking into account the data obtained, we present schemes of formation of different types of soda waters in the studied basin at different stages of the evolution of the water–rock– gas–organic-matter system and estimate the time of each stage.

High-recycled-content hydraulic cements of alternative chemistry for concrete production

ABSTRACTSustainable hydraulic cements based on alkali aluminosilicate chemistry were developed with market-limited wastes acting as the primary aluminosilicate precursors. Two sets of formulations were developed with waste brick or impounded coal ash used at relatively large volume as aluminosilicate precursors. Supplementary materials were used to produce raw materials of viable chemistry. Blends of raw materials were transformed into hydraulic cements by input of mechanical energy without resorting to elevated temperatures. The resultant hydraulic cements exhibited viable strength development characteristics. FTIR, SEM, EDS and NMR analyses were conducted in order to gain insight into the structure of the hydraulic cements and their hydration products. The results pointed at the prevalence of calcium aluminosilicate hydrates among the products of hydration which thoroughly bound the non-hydrated cores of cement particles.

Underground water in Sukhodol Bay area (South Primorye)

The paper describes the specific chemical groundwater composition in Sukhodol Bay (eastern Ussuri Bay). The equilibrium between groundwater and carbonate-aluminosilicate minerals in water-bearing rocks was calculated. It was established that a fraction of the studied water was calcite saturated. However, dolomite and magnesium undersaturated groundwater is non-equilibrium with primary aluminosilicates.