Chemical Composition Of Minerals Research Articles

Dietary inclusion of pistachio wastes (Pistacia vera L.) to fattening male goat kids’ feeding: Chemical-mineral compositions, in vitro ruminal fermentation, in vivo digestibility, hemato-biochemical profile, and growth performance

Pistachio (PW, Pistacia vera L.) wastes are a collection of favorite materials that are produced in the pistachio processing factories, in combination with its industry derivatives of clusters, soft hull, leaves, hard shell, and kernel. Two experiments were carried out; in the 1st one, the chemical and mineral compositions, in vitro ruminal-digestive fermentation activities, and buffering capacity parameters were determined for PW and its derivatives. For the 2nd experiment, the nutritional effects of an aluminosilicate (AS) and polyethylene glycol (PEG), at 10 g/kg dietary dry matter (DM), on PW-based diets were investigated. However, forty Mahabadi male goat kids [5 months, 22 ± 2.0 kg body weight (BW)] were randomly divided into the four experimental diets: control (a basal diet without PW); PW (replaced 40 % of control ingredients with PW); PW + PEG (PW diet + 10 g PEG/kg DM); and PW + AS (PW diet + 10 g AS/kg DM). Crude protein content, dry matter digestibility (DMD), gas production, and metabolizable energy were increased (P < 0.001) in kernel rather than other treatments. Hard shell exhibited the lowest (P < 0.001) DMD and/or organic matter digestibility (at 24 and 96 h), and highest (P < 0.001) neutral detergent fiber, acid detergent fiber, and iron concentrations. In leaves, total phenolic and tannins, calcium, magnesium, and manganese had the highest (P < 0.001) concentrations versus other PW derivatives. Soft hull has the greatest (P < 0.001) acid-base buffering capacity among the evaluated derivatives. Dietary supplementation with 40 % PW decreased (P < 0.001) dry matter intake, final BW, average daily gain, nutrient digestibility, ruminal total volatile fatty acids, propionate, and acetate, but with an increase (P < 0.001) in those parameters in PW + PEG and PW + AS diets. Blood urea nitrogen and total protein decreased (P < 0.05) by dietary PW. The inclusion of 40 % PW in the diet reduced the growth performance and diet nutritive value, but improved plasma antioxidant status (total antioxidant capacity: and malondialdehyde). Addition of PW in goat kids’ diets with PEG or AS improved the digestibility and ruminal fermentation activities and enhanced growth performance. In conclusion, it is recommended to use PW at the dietary level of 40 % in fattening goat kids, provided that it is accompanied by adding AS or PEG to the diet.

Process Mineralogy of Lithium and Rubidium in the Diantan Polymetallic Mining Area, Tengchong, Southwest China

Highly differentiated granite often contains abundant key metal resources, such as lithium and rubidium. The Tengchong area of Yunnan hosts a large number of highly differentiated granites from the Cretaceous age. Among these, granite samples from the Diantan tin–lead–zinc polymetallic mining area exhibit Li contents exceeding 0.02% and Rb contents surpassing 0.1%. This suggests a promising potential for Li and Rb mineralization. However, the occurrence status and process mineralogical characteristics of Li and Rb remain unclear, directly impacting the assessment of the region’s comprehensive utilization potential for these key metals. This study focuses on representative granite samples from the Diantan mining area to conduct petrographic and process mineralogical research, examining single mineral chemical composition, physical properties, element occurrence state, and mineral embedding particle size. The results indicate that mica minerals primarily contain Li, while both feldspar and mica minerals are the main carriers of Rb. Zinnwaldite not only contains the highest Rb proportion among the samples but also plays a significant role in Li occurrence. Based on the dissociation characteristics, it is recommended to grind the material to a fineness of −0.075 mm, comprising 80% of the particles, before proceeding to the final flotation process. This would result in approximately 95% dissociation of the mica in the sample. Since mica is predominantly distributed between quartz and feldspar particles, with relatively low binding force, it facilitates mineral dissociation during the grinding process. Therefore, the actual beneficiation process may consider a moderately coarser grinding fineness based on the aforementioned findings.

Chemical evolution of major and minor minerals in rocks of the Arbarastakh complex (Aldan shield, Republic of Sakha, Yakutia)

The alkaline-ultrabasic carbonatite complex Arbarastakh is located in the southwestern part of the Siberian Craton. In addition to ultrabasic rocks such as pyroxenites and ijolites, various types of carbonatite dikes, phoscorites, and aillikites are present in the massif. Based on their modal and compositional characteristics, as well as the chemical composition of minerals, the rocks of the Arbarastakh complex have been divided into three groups: "aillikite", "phoscorite", and "alkaline-silicate and carbonatite" groups. The chemical compositions of olivines, phlogopites and spinellides indicate that aillikites are the least differentiated rocks in the complex. The compositional differences of micas from the "phoscorite" and "alkaline-silicate and carbonatite" groups support the liquation of the aillikite melt into two immiscible silicates and CPIO (carbonate-phosphate/iron-oxide-rich) melts. After liquation, for the "phoscorite" and "alkaline-silicate and carbonatite" groups, evolution follows fractional crystallization. Pyroxene-phlogopite-calcite and calcite carbonatites probably resulted from metasomatic alteration of silicate phases by apatite-dolomite carbonatites, which is confirmed by structural-textural features and the overlapping compositions of phlogopites, apatites and pyroxenes from calcite carbonatites and those from pyroxenites and ijolites.

Deformation and recrystallization of sulfide interlayers at the Golets Vysochaishii Gold-Ore Black-Shale Deposit

Research subject. The relationship of sulfide interlayers in silt-pelitic rocks with the cleavage of the axial surface at the Golets Vysochaishii gold-ore black-shale deposit (Bodaibo ore district). Methods. The structure of rocks was studied in out-crops, borehole cores, sanded samples, transparent and polished sections. The chemical composition of minerals was determined. Results. It was established that sulfide and sulfide-containing interlayers undergo deformation and recrystallization together with the host silt-pelitic rocks during plastic dynamometamorphic transformations of rocks. Conclusions. Metamorphic transformations of rocks took place in two stages. During the folding-thrust deformations of the first stage, a cleavage of rocks is formed, which leads to the splintering of sulfide interlayers with the orientation of the lenses along the cleavage. Metamorphic transformations of the second stage are manifested in sulfide and sulfide-containing interlayers in the collective recrystallization of their composing minerals with the replacement of surrounding rocks deformed at the previous stage. The second stage is characterized by changes in the mineral composition of rocks, manifested in the substitution of pyrrhotite with pyrite, increase in the iron content of chlorites and carbonates.

Hornblende in ultramafic-mafic rocks of the Khudolaz Complex of the Southern Urals: Crystallization conditions and petrological implications

Subject research. Morphology and chemical composition of amphiboles from ultramafic-mafic rocks of the Khudolaz complex. Methods. Morphological studies were carried out using optical (Carl Zeiss Axioskop 40A) and electron (Tescan Vega Compact) microscopes. The chemical composition of minerals was determined using CAMECA SX 100 and JEOL JXA-8230 electron probe microanalyzers. Results. The rocks under study are dominated by xenomorphic brown titanium hornblende crystals, formed mainly due to the reaction of clinopyroxene with a residual water-saturated melt at 920–1040°C. Euhedral brown hornblende, which crystallized directly from the residual water-saturated melt in the same temperature range, was found in small amounts. Green hornblende originated along the edges and cracks in brown hornblende crystals during the late magmatic stage and early hydrothermal stage (670–830°C) at the subsolidus transformation. At the hydrothermal stage (620–650°C and below), brown and green hornblende were partially replaced by actinolite and cummingtonite. Conclusions. The nature of changes in the composition of brown hornblende indicates similar petrogenesis conditions at the late magmatic stage in all intrusions of the Khudolaz complex. The process of transition from brown hornblende to green hornblende occurred with a gradual increase in oxygen fugacity (ΔNNO from –0.2…+0.4 to +0.9…+2.5), and was accompanied by decrease of Ti, Fe2+, Na and the increase of Si, AlVI, Mg, and K in the mineral structure. The low concentrations of F and Cl in hornblende crystals indicate their formation after migration of halogens from the melt.

High-temperature inter-mineral potassium isotope fractionation in ultrapotassic and granitic rocks: Implications for the potassium isotopic compositions of arc magmas

To constrain the mechanism and magnitude of inter-mineral K isotope fractionation during high-temperature magmatic processes, we conducted high-precision K isotope measurements on ultrapotassic and granitic rocks and mineral separates from the Qinling Orogenic Belt, China, as well as first-principles investigations of the corresponding K-bearing minerals. Our results show that the ultrapotassic rocks (−0.33 to −0.14‰) have considerably higher δ41K than the primitive mantle (−0.42 ± 0.08‰), confirming the previous conclusion that slab-derived fluids have contributed heavy K isotopic signatures to their mantle sources. Specifically, the K isotopic fractionation between biotite and microcline (Δ41Kbiotite-microcline = −0.11 to 0.05‰, with biotite and microcline ranging from −0.49 to −0.14‰ and − 0.48 to −0.12‰, respectively) agrees well with the calculated equilibrium isotopic fractionation scale. This evidence, together with the homogeneous mineral chemical compositions, suggests equilibrium K isotopic fractionation between biotite and microcline. Notably, amphiboles (δ41K ranging from −0.41 to 0.48‰) have heterogeneous K isotopic compositions and are generally heavier than coexisting microcline and biotite. In addition, the determined K isotopic fractionation between amphibole/plagioclase and microcline is inconsistent with the calculated results and is likely caused by the kinetic fractionation processes. To reveal the potential controls on the K isotopic compositions of arc magma, we utilized theoretical and measured K isotopic fractionation factors to model K isotopic fractionation behavior during amphibole crystallization. The results show that when Δ41Kamphibole-melt = 0.05‰, the fractional crystallization of amphibole shows negligible effect on the K isotopic composition of the residual melts. Even in the case of Δ41Kamphibole-melt = 0.24‰, fractional crystallization of amphibole exerts an insignificant control on the K isotopic composition of arc magma. Therefore, although amphibole may have heavier K isotopic compositions than the melts, its fractional crystallization may not distinctly decrease the K isotopic composition of residual melts.

Geomechanical research into surface coal mining in terms of geotechnical safety substantiation

Purpose. The purpose of the present study is to determine the geomechanical parameters for calculating the stability of side slopes by partial and general angle in the working front to ensure the completeness of coal mining in accordance with geotechnical rules and standards based on the regulations (EC-7) of the Kosovo Energy Corporation, which is the state corporation, producing not only electricity in the Republic of Kosovo. Methods. In the course of the present study, 60 additional drillings were carried out to a depth of 150 m up to green clay contact to determine the coal thickness. It was realized using a Type EK-650 drilling machine and a drilling diameter of 145/101 mm. To determine the angle φ and cohesion C, two methods were used, such as the Direct test and the Triaxial test. To obtain the most accurate results, a mathematical model was used to derive geomechanical parameters for calculating the slope geometry for the design geometry, where coal is mined to achieve a safety factor according to geotechnical standards. Findings. The regularities of changes in surface gloss of facing stone after its chemical treatment have been specified. It has been proved that all chemical impregnations increases stone gloss; the lower the initial indices of the natural stone surface gloss are, the greater stone changes are observed. In turn, that is caused by the fact that each type of natural stone has its own gloss limit. The regularities of lightness changes and surface saturation of natural facing stone after chemical treatment have been defined. They indicate that all agents reduce lightness and increase saturation of the natural stone surface (except Impregnation agent 3). According to the identified regularities, it is possible to control quality indices of the natural stone surface with simultaneous provision of uniform colour shade of a stone-faced building. The main problem arising during the study of surfaces of natural stone samples by means of infrared spectroscopy was inhomogeneity of its mineral-chemical composition over the sample area. As a result, various spectra have been obtained that are difficult to identify without the prepared reference samples. Complete infrared spectra of the natural stone surfaces of Pokostivskyi granodiorite and Bukivskyi gabbro. Both Pokostivskyi granodiorite and Bukivskyi gabbro have different infrared spectra within the analyzed range of wavelengths that can be explained by the difference in mineralogical composition of both natural stone types. Originality. A large number of physical-mechanical parameters were analyzed, including a mathematical model, with which the slope geometry was calculated using the design profiles and 9 methods. This has given satisfactory results based on Eurocode EC-7 which can be implemented in the field. Practical implications. To analyze the numerical and analytical methods for the design slope geometry, geotechnical Eurocodes were used according to two standards: Eurocode EC7-1 for geotechnical designs and Eurocode EC7-2 for field verification. They were tested on two factors: Category of terrain and Category of objects (excavator), to remove the coal cover using technology in compliance with the conditions in the field, such as the presence of surface water, underground waters and tectonics. This whole analysis is time consuming, so a safety factor has been determined based on the numerical analysis data.

Quality index control for building products made of natural facing stone

Purpose is to assess the influence of technological and natural factors on the decorative properties of natural facing stone to identify the regularities of changes in lightness and saturation of its surface. Methods. To assess the effect of technological and natural factors on the decorative properties of natural facing stone, methods of digital processing of images and infrared spectroscopy have been applied. The methods make it possible to obtain the data on the influence of mineralogical and chemical composition on the decorative properties of natural stone and characterize the physicochemical processes that occur during the natural stone processing by different methods. Findings. The regularities of changes in surface gloss of facing stone after its chemical treatment have been specified. It has been proved that all chemical impregnations increases stone gloss; the lower the initial indices of the natural stone surface gloss are, the greater stone changes are observed. In turn, that is caused by the fact that each type of natural stone has its own gloss limit. The regularities of lightness changes and surface saturation of natural facing stone after chemical treatment have been defined. They indicate that all agents reduce lightness and increase saturation of the natural stone surface (except Impregnation agent 3). According to the identified regularities, it is possible to control quality indices of the natural stone surface with simultaneous provision of uniform colour shade of a stone-faced building. The main problem arising during the study of surfaces of natural stone samples by means of infrared spectroscopy was inhomogeneity of its mineral-chemical composition over the sample area. As a result, various spectra have been obtained that are difficult to identify without the prepared reference samples. Complete infrared spectra of the natural stone surfaces of Pokostivskyi granodiorite and Bukivskyi gabbro. Both Pokostivskyi granodiorite and Bukivskyi gabbro have different infrared spectra within the analyzed range of wavelengths that can be explained by the difference in mineralogical composition of both natural stone types. Originality is in identifying the regularities of changes in lightness and saturation of the natural facing stone surface after its chemical treatment. Practical implications. The determined regularities of changes in lightness and saturation of the natural facing stone surface can help control the quality indices of the natural stone surface with the simultaneous provision of uniform colour shade of a stone-faced building.

Effect of isomorphic replacement of palygorskite on its heavy metal adsorption performance

Isomorphism is a common phenomenon in clay minerals, which is one of the main reasons for the change of mineral chemical composition and physical and chemical properties. In this study, four kinds of palygorskite with different degrees of isomorphic replacement of octahedral cations were selected. The microstructure and surface-interface properties of different Mg2+/Al3+ palygorskite were analyzed by X-ray diffraction, infrared spectroscopy, N2 adsorption-desorption method, X-ray fluorescence spectroscopy and other characterization methods, and the effects of isomorphic replacement on microstructure such as Mg content and surface-interface properties such as hydroxyl concentration and acid content were discussed. Taking Cu2+ as the target pollutant, the adsorption capacity of different palygorskite to Cu2+ was measured and discussed. Combining the surface hydroxyl concentration and acid amount of palygorskite, as well as the concentration, time and temperature of the reaction system, the rule of adsorption of the four palygorskite for Cu2+ was Mg-rich palygorskite (a-ATP) &amp;gt; palygorskite with equal Mg and Al (c-ATP) &amp;gt; Al-rich palygorskite (d-ATP) &amp;gt; palygorskite with the most Mg (b-ATP), demonstrating that when Mg was partially replaced by Al, palygorskite contained appropriate hydroxyl concentration and acid amount, resulting in the best adsorption effect for Cu2+ (29.2 mg/g). It is of great significance for resource utilization of palygorskite to reveal the regularity of heavy metal adsorption by isomorphic replacement of palygorskite.

DIATOMITES AND OPOKA FROM WESTERN KAZAKHSTAN DEPOSITS: LITHOGEOCHEMISTRY, STRUCTURAL AND TEXTURAL PARAMETERS, POTENTIAL OF USE

Link for citation: Smirnov P.V., Zhakipbayev B.E., Staroselets D.A., Deryagina O.I., Batalin G.A., Gareev B.I., Vergunov A.V. Diatomites and opoka from Western Kazakhstan deposits: lithogeochemistry, structural and textural parameters, potential of use. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 7, рр. 187-201. In Rus. The relevance. In recent decades, individual studies in the Republic of Kazakhstan have been aimed at expanding the potential of using rocks of large and industrial exploitation of silicite deposits for revising their physicochemical, mineralogical parameters, and assessing the prospects for expanding their use in new industries and technologies in the construction and technical industries, materials science based on deep chemical processing of mineral raw materials. The article presents new data on the chemical-mineralogical and structural parameters of diatomites from the Utesai deposit and opoka from the Taskala deposit of the Republic of Kazakhstan. The main aim: comprehensive analysis of the chemical-mineral composition and structural and textural features of rocks from two largest deposits of silicon raw materials in the Western part of Kazakhstan – the Utesai diatomite deposit and the Taskala opoka deposit. Objects: diatomites of the Utesai deposit and opoka of the Taskala deposits in the western part of the Republic of Kazakhstan. Methods: field research, lithological and petrographic analysis of thin sections, X-ray diffraction analysis, differential thermal analysis, scanning electron microscopy, X-ray fluorescence analysis. Results. The studied diatomites and opoka are characterized by a high degree of homogeneity; they are represented by typical phases for silicic rocks of the region – opal-CT, clay minerals with an admixture of quartz and feldspars. From the mineralogical point of view, the most obvious difference between the studied diatomites and the Trans-Urals is the significant content of kaolinite – over 10 %, while in the diatomites of the Trans-Urals, the main clay component is smectite and mixed-layer illite-smectite formations. The rocks under consideration are clayey diatomites and clayey flasks, the total content of basic oxides allows us to characterize raw materials as medium quality, most suitable for the production of foam glass materials, and, in particular, glass fiber, in the production of which alumina is an important functional component. At the same time, the significant content of clay and other impurities does not allow us to recommend such raw materials for the production of filter and sorbing materials.

Mineralogy and Р-T conditions for the formation of metasomatic rocks of the Voznesenskoye gold deposit (Southern Urals)

Research subject. Mineral associations, their chemical composition, and formation conditions of metasomatic rocks of the Voznesenskoye gold deposit located in the area of the Main Ural Fault in the Southern Urals.Methods. The chemical composition of minerals was studied using a Tescan Vega Compact scanning electron microscope equipped with an Oxford Instruments Xplorer 15 energy-dispersive analyzer. The formation P-T parameters were estimated using a chlorite geothermometer and a dolomite-calcite geothermobarometer.Results and conclusions. Two types of metasomatic rocks were identified: 1) propylites, which make up the outer zones of the metasomatic aureole, and 2) beresite-listvenites, common in its inner parts and hosting gold mineralization. The main propylite minerals were amphibole, orthoclase, albite, and ripidolite. Amphibole is represented by two generations, with the early generation comprising magnesian and actinolite hornblende and the late generation comprising actinolite. The crystallization temperature of ripidolite (307–313°С) corresponds to the temperature range of formation of propylites of the albite-actinolite facies. Beresite-listvenites (association: quartz, albite, chlorite, white mica, and carbonate) were formed at a temperature of 255–338°C and a pressure of 0.48–0.72 kbar. Gold ore mineralization was concentrated in the highest temperature zones of the halo of beresite-listvenite alterations. Such temperature conditions existed in dikes and their exocontact zones disturbed by ruptures. Light mica in beresite-listvenites is represented by sericite and phengite, and carbonate is a paragenesis of calcite and dolomite-ankerite. According to the composition and formation period, chlorite is differentiated into early ferruginous ripidolite and late pycnochlorite, depleted in Fe and enriched in Si, which is probably associated with a decrease in temperature during mineral formation and an increase in the activity of sulfide sulfur in the fluid. Along with an increase in the distance from the ore bodies, pycnochlorite exhibits greater contents of Si and lower contents of AlIV. The observed changes in the pycnochlorite composition are related to a decrease in temperature. The research results indicate the formation of the Voznesenskoye deposit under mesothermal conditions.

The Origin and Evolution of DMM-Like Lithospheric Mantle Beneath Continents: Mantle Xenoliths from the Oku Volcanic Group in the Cameroon Volcanic Line, West Africa

Abstract The lithospheric mantle as sampled by peridotite xenoliths in some continental settings resembles the source of mid-ocean ridge basalts (MORB). Whether this resemblance is a primary feature or the result of post-formation secondary processes remains controversial. Here, the age, origin and thermochemical evolution of fertile continental mantle are constrained based on the chemical composition of minerals in spinel-facies lherzolite and websterite xenoliths from the Wum maar and Befang cinder cone of the Oku Volcanic Group (Cameroon Volcanic Line, West Africa), combined with in-situ Sr isotope compositions of clinopyroxene and fabric investigation by Electron Backscatter Diffraction (EBSD). The majority of lherzolites (here assigned to Group I) consist of minerals with fertile composition (olivine Fo89, Al-rich pyroxenes, spinel Cr# 0.08–0.10). Clinopyroxene is LREE-depleted and has depleted 87Sr/86Sr (0.7017–0.7020). Crystal-preferred orientation determined by EBSD reveals that clinopyroxene, and sporadically both clino- and orthopyroxene, post-date the olivine framework. Subordinate Group II lherzolites also contain secondary clinopyroxene which is LREE-enriched and has higher 87Sr/86Sr (0.7033). In contrast, the scarce lherzolites of Group III are more refractory: they contain 72–78 vol.% olivine, Al-poor pyroxenes, and spinel with Cr# 0.18. Clinopyroxene (87Sr/86Sr 0.7021) is texturally coeval with olivine and orthopyroxene. Few lherzolites contain amphibole (87Sr/86Sr 0.7031) which post-dates the nominally anhydrous minerals. Most of the websterites (Group A) are aluminous (spinel Cr# 0.04–0.06) with LREE-depleted clinopyroxene having depleted 87Sr/86Sr ratios (0.7017–0.7020) similar to Group I lherzolites. Chemical characteristics of minerals coupled with the crystal-preferred orientation data suggests that Group I lherzolites originated in the spinel stability field by reactive intergranular percolation of an incompatible element-depleted MORB-like melt. Group A websterites likely formed as cumulates from that melt. The Group II lherzolites supposedly occur close to lithosphere-asthenosphere boundary and record interaction with lavas of the Cameroon Volcanic Line, whereas Group III lherzolites occur in the shallow part of the mantle profile and represent the protolith from which the Group I lherzolites were formed. Local crystallization of amphibole and concomitant recrystallization of the host lherzolite were driven by supply of water in an event post-dating the formation of LREE-depleted rejuvenated rocks. Migration of alkaline melts of the CVL apparently did not significantly affect the mineral and chemical composition of the lithospheric mantle, which allowed Group I lherzolites and Group A websterites to retain very low 87Rb/86Sr (average 0.002) and depleted 87Sr/86Sr ratios in clinopyroxene. This not only indicates their formation in the Paleoproterozoic (~2.0–2.25 Ga), possibly during the Eburnean orogeny at the margin of the Congo craton, but also indicates surprisingly little influence of the regionally recognized Pan-African event.

In vitro and in vivo investigation of Persian manna plant silage as an alternative forage for fattening lambs

The Persian manna plant (Alhagi maurorum, PMP) is a species with drought-resistant characteristics and distribution from Asia to America which is widely used in traditional medicine. As a result of recent droughts, many ranchers have become interested in using this plant for feeding their livestock. According to our knowledge, no scientific study has been done regarding the silage quality of PMP with natural-microbial additives. Rumen fluid may also be used as a low-cost and novel-natural microbial additive for improvement in silage quality. Therefore, we planned two in vitro and in vivo experiments to investigate PMP silage. In the first experiment, we ensiled PMP with molasses (M: molasses, 3%, 6%, and 9% of DM) plus rumen fluid (RF: rumen fluid, 3%, 6%, and 9% of DM) for 60 days with the aim of investigation of nutritional characteristics and its silage potential by in vitro methods. In the second experiment, we investigated the nutritional value of the selected superior silage from the in vitro section for animal experiments. The growth performance, nutrient digestibility, and ruminal fermentation parameters of forty male lambs were evaluated for substitution of 25%, 50%, 75%, and 100% forage with M6 +RF6 silage in a completely randomized design. Some mineral-chemical composition and digestive-fermentative parameters changed with ensiling PMP. The lowest NDF and ADF were observed in M6 +RF6 (P < 0.0001). Higher lactic acid production, total volatile fatty acids, aerobic stability, acid-base buffering capacity, metabolizable energy, Flieg point, and lower butyric acid, ammonia nitrogen, and pH were observed in M6 +RF6 compared to the control. Among the treatments, the highest dry matter intake, average daily gain, final weight, nutrient digestibility, and total volatile fatty acids were observed in lambs fed on the control diet. In total, PMP can be ensiled with molasses and rumen fluid well. As a result of the in vitro tests, a better nutritional value was relatively observed in M6 +RF6. The in vivo test also showed that M6 +RF6 can be substituted up to about 26% of the dietary DM without adverse effects on growth performance, nutrient digestibility, and ruminal fermentation parameters.

Association of Fe–Ti oxides in subalkaline dolerites of the Rai-Iz massif (Polar Urals)

The relevance of the research. Subalkaline dolerites, Fe–Ti oxides of which were studied in this work, occur within the largest deposits of chromium ores of the Rai-Iz massif. The study of the material composition and age of these rocks was carried out by the authors for the first time. The purpose of the research is to reveal the patterns of changes in the chemical composition of the main accessory minerals of rocks – titanomagnetite and ilmenite, and on the basis of the obtained data to evaluate the conditions for the formation of subalkaline dolerites of the massif. Research methodology. The chemical compositions of minerals were determined using microprobe analysis on a CAMECA SX 100 and scanning electron microscopy on a Jeol JSM-6390LV setup with an INCA Energy 450 X-Max 80 energy dispersive attachment. Raman spectra were obtained on a LabRam HR 800 Evolution spectrometer equipped with an Olimpus BX-FM microscope. The studies were carried out at the “Geoanalyst” сenter for the collective use of scientific equipment of the IGG, UB RAS. Results. The typomorphism of the chemical composition of titanomagnetite and ilmenite has been established for petrographic varieties of dolerites allocated on the massif. The T–fO2 parameters of dolerite formation were estimated and compared with metaultramafites. It is shown that titanomagnetite in amphibole dolerites undergoes maghemitization. The highest temperatures (1076–1126 °C) are recorded in pyroxene dolerites. The oxygen fugacity in these rocks is FMQ +0.6–+1 units. Hyalodolerite from the chilled margin of the pyroxene dolerite dike gives a temperature of 811–818 °C and an oxygen fugacity of 1.8 units above FMQ. The compositions of the associated ilmenite and titanomagnetite from amphibole dolerites correspond to fO2 = –2–0 units relative to FMQ and temperature 580–720 °C. The trend of change in T–fO2 parameters shows that the injection of the mafic melt occurred under conditions of metamorphism of ore-bearing ultramafic rocks. Conclusions. The formation of dolerite veins occurred under conditions of ultramafic rock metamorphism. The increased fugacity of oxygen at a relatively low temperature led to the maghemitization of titanomagnetite, rather than to the redistribution of components in the magnetite-ilmenite paragenesis.

Tungstates of the Boyovskoye tungsten deposit (Southern Urals)

The relevance of the work is due to the need for a mineralogical study of tungsten deposits in the Ural region, which have been mined since the end of the 19th century. The purpose of the work is the diagnostics and detailed description of tungstates from the Boyovskoye tungsten deposit located on the border of the Chelyabinsk and Sverdlovsk regions in the Southern Urals. Analytical studies were carried out in the Laboratory of Physical and Chemical Research Methods of the Institute of Geology and Geochemistry, UB RAS, Ekaterinburg. The chemical composition of minerals was analyzed in polished sections on a CAMECA SX 100 microanalyzer. Measurement conditions: accelerating voltage 15 kV, current 150 nA, electron beam diameter 2 μm. The pressure in the sample chamber is 2 ⋅ 10–4 Pa. The spectra were obtained on tilted wave spectrometers; the intensity was measured from analytical lines. Standard samples: scheelite, wolframite, galena, rutile and chromite. Raman spectra of minerals were obtained using a LabRam HR Evolution spectrometer (Horiba Scientific). A red laser, 532 nm, was used for analysis. As a result of the work, new data on the chemical composition of hubnerite and scheelite were obtained and their Raman spectra were presented. For the first time for the Boyovskoye tungsten deposit, a reliable diagnosis and description of lead tungstate – stolzite was made. The mineral was found in samples with veined quartz in association with muscovite, fluorite, hubnerite and scheelite. It fills cracks and voids in hubnerite, rarely overgrows scheelite or fills cracks in scheelite. It is a later mineral in relation to hubnerite and scheelite. Its chemical composition contains impurities of manganese, calcium, iron and titanium. The stolzite found by us is a mineral of the oxidation zone and, most likely, was formed due to the weathering of wolframite and galena, which is also present in quartz veins.

Gold source and ore-forming process of the Linglong gold deposit, Jiaodong gold province, China: Evidence from textures, mineral chemical compositions and sulfur isotopes of pyrite

The Linglong gold orefield is located northwest of the Jiaodong gold province, in the eastern North China Craton (NCC) area. It consists of over 10 gold mines with a total gold resource of approximately 1000 t, and gold mineralization occurs in gold-quartz veins. The Linglong gold deposit underwent four stages of ore-forming processes namely: Pyrite-quartz (stage I) – milky-white quartz vein with euhedral pyrites, Quartz-pyrite (stage II) – smoky quartz veins with euhedral-subhedral pyrites, Polymetallic sulfides (stage III) – quartz veins with large amounts of polymetallic sulfides (pyrite, pyrrhotite, sphalerite, galena), hematite, and native gold, and the Quartz–carbonate (stage IV) – calcite-quartz veins. This study focuses on the investigation of pyrites from three main mineralization stages (I-III), exploring their textures, in-situ major and trace element concentrations, and in-situ sulfur isotopic compositions.The study examined pyrite through various methods including BSE and EMPA major element, LA-ICP-MS trace element, and LA-MC-ICP-MS sulfur isotope analyses. Pyrite from three distinct stages of ore-forming processes were analyzed. Pyrites from stage I (Py-I) exhibited euhedral crystals with homogeneous brightness in the BSE, lacked mineral inclusions, porous microtextures, and oscillatory zones. Py-I possessed low contents of Au, Ag, As, Bi, Cu, Sb, Zn, Co, and Ni. Pyrites from stage II (Py-II) showed fine-coarse grains and euhedral-subhedral features with slight fractures, similar to Py-I, however, had the higher concentrations of As and Sb. Pyrites from stage III (Py-III) were found in the quartz-polymetallic sulfide veins and exhibited subhedral to anhedral features and more significant concentrations of metallic elements, particularly Au and As. The δ34S values of Py-I, Py-II and Py-III were in the ranges of 6.76‰–7.47‰, 6.11‰–7.27‰ and 6.07‰–8.33 ‰, respectively. Analysis of the texture and geochemical composition of pyrite suggested that invisible gold was primarily present in pyrite in the form of solid solution (Au+), accompanied by a small amount of nano-form gold. The ore-forming fluids that led to this mineralization were mostly derived from mantle-derived mafic magma mixed with some minor metamorphic sedimentary material. A decrease in fluids temperature, water–rock interactions and fluid boiling led to the depositions of sulfides and gold. In the Late Mesozoic, lithospheric delamination of the eastern block of the NCC triggered decompression and melting of the upwelling asthenospheric mantle resulting in partial melting of the lithospheric mantle. This lithospheric mantle-derived mafic magma provided the ore-forming fluids for large-scale gold mineralization in the Jiaodong gold province.

Recognition of the Xiayu intermediate-sulfidation epithermal Ag-Pb-Zn-Au(-Cu) mineralization in the East Qinling polymetallic ore belt, China: Constraints from geology and geochronology

Porphyry Cu deposits are often temporal-spatial-genetically associated with epithermal polymetallic (Ag-Pb-Zn-Au-Cu) veins in some important metallogenic belts, forming a porphyry–epithermal ore systems. However, the genetic type of the large-scale vein-type Ag, Pb, Zn and Au mineralization in the world-class East Qinling porphyry Mo ore belt (Central China) has not been delineated. Here, we provide a case study of the Xiayu orefield as an example for a typical intermediate-sulfidation epithermal Ag-Pb-Zn-Au(-Cu) deposit. The Xiayu Ag-Pb-Zn-Au(-Cu) orefield, the largest Ag producer in the East Qinling ore belt, contains the Haopinggou Ag-Pb-Zn-Au, Shagou Ag-Pb-Zn, Tieluping Ag-Pb(-Cu), and Houzhanggou Ag(-Cu) deposits, which share similar geological characteristics. The Ag-Pb-Zn-Au(-Cu) mineralization occurs as open-space fillings, veins and local hydrothermal breccias and stockworks, infilled with carbonates (siderite, ankerite, and calcite), quartz, pyrite, sphalerite, galena, chalcopyrite, tetrahedrite, electrum, silver minerals (argentiferous tetrahedrite, stromeyerite, pyrargyrite, polybasite, argentite and native silver). The vein crosscutting and overprinting relationships indicate four hydrothermal stages: (I) siderite-pyrite-quartz-electrum ± magnetite, (II) dark-brown sphalerite-siderite-quartz ± galena, (III) galena-tetrahedrite-chalcopyrite-silver minerals-ankerite-quartz ± light-brown sphalerite, and (IV) ankerite-calcite-chalcedony-fluorite. Mineral zoning at the orefield-scale is recognized from north to south: pyrite, sphalerite-galena, and tetrahedrite-native silver, which corresponds to ore metal zoning from Au ± Zn to Zn-Pb-Ag and Cu-Ag.The Haopinggou granite porphyry consists of the megacrystic granite porphyry (P1) and granite porphyry (P2), which were emplaced at 134.6±1.2 Ma and 125.9±0.7 Ma, respectively. Anhedral monazite (Mon1) encapsulated in pyrite and siderite from stage I of the Haopinggou and Shagou deposits constrains the early hydrothermal activity at 133.3±1.0 Ma. U-Pb dating of syn-ore monazite (Mon2) and xenotime (intergrown with electrum, galena, sphalerite and quartz) from the Shagou, Haopinggou, and Tieluping deposits constrains the Ag-Pb-Zn-Au(-Cu) mineralization age to be 125.7±1.8 Ma to 123.3±1.7 Ma. The consistency of the magmatic and mineralization ages indicates that the magmatic-hydrothermal process may have played an important role in the Ag-Pb-Zn-Au(-Cu) mineralization. Gold distribution, mineral association, and geochronological data, all suggest that the Au and Zn-Pb-Ag ores were formed from the same mineralization event rather than two discrete mineralization events as previously suggested. Considering the geological characteristics, metal zoning, mineralization ages, mineral chemical composition and published data of fluid inclusion, we conclude that the Xiayu Ag-Pb-Zn-Au(-Cu) veins belong to typical intermediate-sulfidation epithermal mineralization and further propose a porphyry–breccia–intermediate-sulfidation epithermal Ag-Pb-Zn-Au(-Cu) mineralization system. It is the first reported intermediate-sulfidation epithermal mineralization in the East Qinling ore belt, which implies that the epithermal mineralization may have been developed in the world-class East Qinling porphyry Mo ore belt.

Mineralogy of ores of the Vosneenskoe gold deposit (Southern Ural)

The mineralogical features of the ores of the Voznesenskoye gold deposit located in the zone of the Main Ural Fault at the northern end of the Magnitogorsk megazone of the Southern Urals have been studied. The chemical composition of minerals was determined using a Tescan Vega Compact scanning electron microscope with an Oxford Instruments Xplorer 15 energy dispersive analyzer. Two stages of ore formation have been identified and characterized. On the early of them, arsenic pyrite (0.38–0.84% As), which is the main mineral of ores, was first formed, and later sulfurous arsenopyrite (S/As = 1.12–1.19), molybdenite enriched in Fe (7.25–8.07%), and chalcopyrite. Using an arsenopyrite geothermometer, it was found that the formation of sulfides at an early stage occurred approximately in the temperature range of 318–380°C. At a late stage, an association was formed that united pyrite containing Sb (0.28–0.31%), Zn-Fe-tetrahedrite (Cu9.1–9.4 (Fe1.2–1.3 Zn1.1–1.4)2.4–2.6 (As0.2–0.4 Sb3.7–4.1)4.2–4.3 S12.9–13.2) and native high-grade gold (952–997‰) with impurities Ag and Cu. Minerals of this association, which have an insignificant distribution, are found in crushing zones developed in arsenic pyrite. In terms of chemical composition, the studied tetrahedrite is close to the fahlores of the subepithermal mineralization of the Mikheevka porphyry Cu deposit. Based on the results of the studies performed, a preliminary conclusion was made that the Voznesenskoye deposit belongs to the subepithermal type of gold mineralization.

Can Alhaji maurorum as a halophyte plant be ensiled with molasses and Saccharomyces cerevisiae well?

Alhagi maurorum (Caspian Manna, AM) is a species of legume found commonly in the semi-arid region of the world. Nutritional aspects of silage prepared from AM have not been scientifically investigated so far, therefore, in this study, chemical-mineral composition, gas production parameters, ruminal fermentation parameters, buffering capacity, and silage characteristics of AM were investigated by standard laboratory methods. Fresh AM was ensiled in the mini-silos (3.5 kg) and treated with (1) no additive (control), (2) 5% molasses, (3) 10% molasses, (4) 1 × 104 CFU of Saccharomyces cerevisiae [SC]/g of fresh silage, (5) 1 × 104 CFU of SC/g of fresh silage + 5% molasses, (6) 1 × 104 CFU of SC/g of fresh silage + 10% molasses, (7) 1 × 108 CFU of SC/g of fresh silage, (8) 1 × 108 CFU of SC/g of fresh silage + 5% molasses, and (9) 1 × 108 CFU of SC/g of fresh silage + 10% molasses for 60 days. The lowest concentrations of NDF and ADF were related to treatments no. 6 and 5, respectively (p < 0.0001). The ash content as well as sodium, calcium, potassium, phosphorus and magnesium were highest in treatment no 2. Silages containing 10% molasses (no. 3) had the highest and lowest lactic (p < 0.0001) and butyric (p < 0.0001) acids, respectively. The highest amount of potential gas production was observed in treatments no. 5 and 6, respectively (p < 0.0001). Total yeast was decreased with increasing molasses in the silages (p < 0.0001). Acid-base buffering capacity was also highest in treatments no. 6 and 5, respectively (p = 0.0003). In general, due to the fibrous nature of AM, it is recommended to add molasses at levels of 5 or 10% when ensiling. The silages containing SC at a lower level (1 × 104 CFU) along with higher levels of molasses (10% of DM) had better ruminal digestion-fermentation characteristics compared to other silages. Also, the addition of molasses improved the internal fermentation characteristics of AM in the silo.

Geochemical and mineralogical characterization of phosphogypsum and leaching tests for the prediction of the mobility of trace elements.

Phosphoric acid manufacturing generates large amounts of phosphogypsum (PG); a by-product generally disposed in the surface or evacuated in the seawater without any pretreatment. Phosphogypsum may host non-negligible amounts of valuable elements such as rare earth elements (REEs), which are critical elements on the global market. Surface disposal of PG may be a sustainable option to allow further processing in order to recover valuable elements. However, surface disposal exposes PG to atmospheric conditions (e.g., water, oxygen) which may increase their reactivity and accelerate the release rate of chemical species. This study aims to evaluate the trace element release rate from PG at atmospheric conditions. The studied PG samples were collected from a Moroccan phosphate treatment plant. The samples were characterized for their (i) chemical composition using inductively coupled plasma optical emission spectrometry (ICP-OES) for major elements and inductively coupled plasma mass spectrometry (ICP-MS) for trace elements; (ii) mineralogical composition by X-ray diffraction (XRD), scanning electron microscope equipped with energy-dispersive spectrometer (SEM-EDS), laser-induced breakdown spectroscopy (LIBS), and the mineral chemical composition was analyzed by electron probe microanalyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS); and (iii) chemical species release rate using leaching tests over 24h at 25 and 60°C. Chemically, the PG samples were mainly composed of Ca (23.03-23.35 wt.%), S (17.65-17.71 wt.%), and Si (0.75-0.82 wt.%), and non-negligible amounts of trace elements: REE (344-349ppm), Cd (3.5-7.4ppm), U (9.3-27.4ppm). Mineralogically, the PGs are mainly formed by gypsum (94.2-95.9 wt.%) and quartz (1.67-1.76 wt.%). In terms of chemical species release, the PGs showed a higher reactivity at 60°C compared to room temperature with a higher release rate at the beginning of the leaching tests. Quantitatively, the PG samples released 3.57-4.11µg/L/day of REE, 3.18-17.29µg/L/day of U, and 1.67-5.49µg/L/day of Cd. Based on the leaching results, we concluded that the trace elements (e.g., U, Cd, REE) are incorporated in PG crystal lattice, which may explain their low concentrations in the leachates. Consequently, total digestion of PG matrix is required to solubilize REE.