Complex Mineral Research Articles

Sorption-desorption of rare earth metal cations by ferromanganese crusts of Govorov’s guyote of the Magellanic Mountains of the Pacific Ocean

The article presents the results of experimental studies on the sorption and desorption of rare earth metal (REM) cations by cobalt-rich ferromanganese crusts (CMC) of Govorov’s guyot. It has been established that the sorption of REM cations occurs on the ore minerals KMK – Fe-vernadite, vernadite, Mn-feroxygite, goethite. The crusts are characterized by a high exchange capacity – 1.78–3.57 mg-eq/g, which increases in a series: (Dy Gd Lu Sm Nd Y, La Eu) Ce. The sorption of REM cations proceeds by an ion exchange equivalent irreversible mechanism. The exchange complex of ore minerals consists of Na+, K+, Ca2+, Mg2+ cations, which contribute 97‒98% to their total capacity. The crusts are characterized by the group sorption of REM cations from multicomponent aqueous solutions of metal salts. The selectivity of ore manganese and ferruginous minerals of crusts to REM cations is significantly higher than to the main cations of ocean water. From experimental data on the desorption of sorbed REM cations with NaCl solution, their irreversible absorption by ore minerals follows, and the strengthening of the chemical bond of sorbed REM cations with the main structural elements of these minerals over time. An important property of ore minerals, primarily manganese minerals, is their chemical and structural stability in aqueous solutions of electrolytes. This suggests the repeated use of ferromanganese crusts as sorbents of REM cations.

Effect of vitamin-mineral complex with probiotic on histological structure of gastrointestinal tract tissues of budgerigars

Purpose: to evaluate the effect of a vitamin-mineral complex with a probiotic on the histological structure of the gastrointestinal tract tissues of budgerigars in dynamics.Materials and methods. The object of the study were budgerigars aged from 60 to 180 days. According to the principle of pairs-analogues, 3 experimental and a control group of 20 birds each were formed from clinically healthy budgerigars. For the purpose of the experiment, complete granules were created containing a basic grain-seed diet and a complex consisting of a probiotic, vitamins and minerals. Bacillus Subtillis 5 mg per 100 g of live weight was used as a probiotic. For histological and histochemical studies, tissue pieces measuring 0.5 x 0.5 x 0.5 cm were selected. In each section, an assessment of at least 10 fields of vision was given.Results. As a result of the experiment, lasting 45 days, a gradual increase in the probiotic mass was noted in the gastrointestinal tract of budgerigars on the 15th and 30th day. Complete release of the body from the probiotic was observed on the 30th day after stopping the administration of the granulated complex. No changes in the histological structure of the liver were revealed. Positive changes in the intestine and stomach were noted, such as an increase in the density of villi and the height of the epithelium, folds, crypts and tubular glands. These changes are reversible, due to the temporary effect of the vitamin and mineral complex with a probiotic.

Study on the effect and mechanism of coarse magnetite on the flotation of fine-grained hematite

Lean hematite ore is one of the refractory iron ores in China due to its fine crystal size, deep oxidation degree and complex mineral composition. With the deep mining of mine ore, the disseminated particle size of iron minerals is finer, and the ore properties are more complex and difficult to be separated. Therefore, the research on high-efficiency beneficiation technology of fine-grained lean hematite ore is the requirement and important direction of the development of refractory iron ore beneficiation. In this paper, the carrier flotation method is used to comprehensively recover hematite, and the addition of coarse-grained magnetite can effectively improve the recovery rate of fine-grained hematite. The flotation results show that when the ratio of magnetite to hematite is 1: 1, the recovery rate of iron ore can reach more than 96.34%, and the efficient recovery is realized. Based on the results of pure mineral test, the carrier flotation test of Anshan lean hematite ore was carried out. The results show that the reverse flotation concentrate product with TFe grade of 67.88% and total iron recovery of 84.81% can be obtained, and the TFe grade of the reverse flotation tailings is 24.20%. It can be seen that compared with the traditional process, the grade of carrier flotation tailings is 2.37 percentage points lower than that of the original reverse flotation tailings; the carrier reverse flotation process can effectively improve the recovery rate of iron concentrate. In addition, the theoretical analysis of carrier flotation was carried out by contact angle, zeta potential, mineral phase microscope, SEM and XPS. It was found that the collision probability between fine mineral particles and bubbles was low, which limited the recovery of fine mineral particles in the flotation process. Fine-grained hematite can be non-selectively attached to the carrier particles, thereby affecting the adsorption of starch on it, thereby improving the recovery rate of fine particles; The carrier reverse flotation can further improve the flotation efficiency by gravity and shear force. Carrier reverse flotation provides a new idea for effective recovery of iron ore.

Consideration of spectral interference in total reflection X-ray fluorescence analysis using a limited number of calibration samples: Case study of ocean polymetallic nodules

A novel approach for quantitative analysis in total-reflection X-ray fluorescence (TXRF) which can be employed for the samples with complex matrices inducing overlapping spectral signals in the scenario of limited availability of standard samples is proposed. The approach is based on the least squares (LS) decomposition of real spectra into the weighted sum of simulated individual element subspectra and requires only a single sample of matrix-matched reference material. Oceanic polymetallic nodules and crusts, having complex mineral matrix and containing high concentrations of overlapping elements, were chosen to demonstrate the feasibility of the approach in quantification of 11 elements. The comparison of the results obtained with LS decomposition, internal standard and linear calibration with three standard samples was performed. It was demonstrated that the performance of the proposed approach and of the linear calibration was better than that of internal standard for most of the elements; however, the proposed method requires only a single standard sample.

Rinse aid with bischofite: prevention of caries and gingivitis in adolescents

The frequency of using liquid complementary hygiene products has been increasing significantly in recent years. This trend is typical not only for adults, but also for children. The ease of use of rinses, foams, suspensions largely contributes to the growth of their popularity. As substances having a complex effect, researchers have long been interested in mineral complexes, among which calciumand magnesium-containing compounds are of particular importance [2, 3]. Such natural minerals as carnalite, kieserite, and bischofite are of particular interest. The effectiveness of the anti-carious, anti-plaque and anti-inflammatory effects of preventive drugs was evaluated: irrigator liquid + mouthwash WATERDENT Anti-caries and baby foam for the oral cavity WATERDENT Happy Smile during the rehabilitation period in children with permanent bite. Materials and methods. An open comparative study of the effectiveness of the use of liquid for the irrigator + mouthwash WATERDENT «Anticaries» and baby foam for the oral cavity WATERDENT Happy Smile was conducted. To assess the effectiveness of the hygiene products used, the following clinical indicators were selected: the caries intensity index (KPI), the Green – Vermillion simplified index (IG-U), the PMA index and the Mulleman – Cowell index. Clinical parameters were determined before and after the use of the compared hygiene products in groups after 1 month. During the study, laboratory saliva parameters were monitored: saliva pH, total protein, determination of saliva Ca and Md. 3 groups of participants were recruited from among those who applied for help at the UMMU dental clinic. All volunteers were somatically healthy children aged 12–18 years with different caries activity and catarrhal gingivitis, randomly distributed by gender and age. Statistical data processing was carried out in Microsoft Excel and Statist programs. Results. The evaluation of clinical tests in the groups showed a significant change in the indices of PMA and Grinn – Vermilion (р ≤0,05) in patients of the main group and a statistically significant improvement in the index of Grinn – Vermilion (р ≤ 0,05) in patients using foam (comparison group), while in the control group there were no dynamics of statistically significant changes in clinical indicators. An increase in the level of calcium in saliva in patients who used Irrigator Liquid + mouthwash WATERDENT Anti-caries from 2.30 to 2.95 characterizes the high mineralizing potential of bischofite, which is part of its composition, and its karyoprophylactic property. An assessment of laboratory data in the main and comparison groups at the beginning of the experiment and after 1 month showed a significant change in total protein values from 2.94 to 2.26 and 2.72 to 2.09 g/l, respectively, for these groups (p <0.05), which shows the positive effect of these products on hygiene, on changes in saliva properties and karyoprophylactic potential. Conclusions. Clinical and laboratory studies of the use of Liquid for irrigator + rinse WATERDENT Anti-caries and baby Foam for the oral cavity Waterdent Happy Smile confirm the claimed consumer properties of these products: anti-carious, anti-plaque and anti-inflammatory effects and can be recommended in comprehensive individual hygienic oral care for children.

Alkaline Mineral Complex Water Attenuates Transportation-Induced Hepatic Lipid Metabolism Dysregulation by AMPKα-SREBP-1c/PPARα Pathways

Transportation, an unavoidable process in livestock farming, causes metabolic disorders in the body, which then lead to endocrine disruption, being immunocompromised, and growth suppression. Lipid metabolism dysregulation is a critical phenotype induced by transportation. The liver is a vital organ in lipid metabolism, with a role in both lipid synthesis and lipolysis. However, the specific mechanisms by which transportation affects hepatic lipid metabolism remain unclear. This study employed rats as a model to investigate the effects of transportation on hepatic lipid metabolism. Rats subjected to transportation showed altered serum lipid profiles, including decreased serum triglyceride (TG), low-density lipoprotein cholesterol (VLDL-C), and non-esterified fatty acid (NEFA) immediately after transportation (IAT) and serum total cholesterol (TC) on day 3, and increasing serum TG, TC, and low-density lipoprotein cholesterol (LDL-C) on day 10. Meanwhile, fatty droplets in the liver were also reduced at IAT and increased on days 3 and 10. Notably, transportation also affected hepatic-lipid-metabolism-related enzyme activities and signaling pathways, such as increased AMP-activated protein kinase alpha (AMPKα) phosphorylation and modulations in key proteins and genes related to lipid metabolism, decreased hepatic acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) activities at IAT, and increased carnitine palmitoyl transferase 1 alpha (CPT-1α) at IAT and ACC and CPT-1α activities on days 3 and 10. Supplementation with alkaline mineral complex water (AMC) before and after transportation mitigated the adverse effects on hepatic lipid metabolism by modulating the AMPKα-SREBP-1c/PPARα pathway, enhancing lipid synthesis, and reducing the oxidative catabolism of fatty acids. AMC inhibited the transportation-induced activation of AMPKα and restored the balance of lipid-metabolism-related enzymes and pathways. These findings highlight AMC’s potential as a therapeutic intervention to alleviate transportation-induced lipid metabolism disorders, offering significant implications for improving animal welfare and reducing economic losses in livestock farming.

Diagenesis of marine-continental transitional shale from the Upper Permian Longtan Formation in southern Sichuan Basin, China

Abstract Upper Permian Longtan Formation transitional shale has become an important exploration layer, but the Longtan Formation shale (LFS) has a complex mineralogical composition, which affects the subsequent diagenesis and diagenetic evolution, and restricts the subsequent geologic exploration of shale gas. In this article, the observation of drilling cores, argon ion polishing-scanning electron microscope, Vitrinite reflectance, and X-ray diffractometer were used to analyze the type and characteristics of diagenesis of the LFS and clarify the stage of diagenetic evolution. The results show that the main diagenesis in the LFS is compaction, cementation, thermal maturation of organic matter (OM), dissolution, and transform of clay minerals. Among them, OM hydrocarbon generation, clay mineral transformation, and dissolution are pore-enhancing diagenetic events. Compaction and cementation are pore-reducing diagenetic events. The transitional and marine shales have similar characteristics of diagenesis, but there are big variations in the diagenesis of OM hydrocarbon, authigenic quartz, and siderite. The complex depositional environments of the marine-continental transition environment have resulted in a variety of rock types, which in turn influenced the diagenesis types and diagenetic evolution process. Compared with the transitional shales of the Shanxi and Taiyuan formations in the South China North Basin, the LFS are characterized by high clay content, low quartz content, complex mineral compositions, and a higher degree of thermal evolution.

Mineral effects on methane hydrate formation and distribution in sand sediments

Methane hydrate is a promising energy resource widely occurring in the world, but the formation and distribution of methane hydrate in marine sediments with complex minerals remains unclear. Due to the small pore space and fine-grained size of clay minerals, the contact relationship between methane hydrate and clay mineral surface under excess water has not been characterized fully, which is required to investigate the mineral effect on methane hydrate formation. In this study, cryo-SEM was applied to observe the distribution of methane hydrate synthesized in pure quartz sands and the quartz sands mixed with montmorillonite or illite separately. According to the results of the research, methane hydrate dispersedly forms in the pore space away from and on the surface of quartz under a local excess water condition. In addition, methane hydrate occurs away from montmorillonite in pores with excess water and contacts the edge of montmorillonite under a local excess-gas condition. Moreover, methane hydrate was only observed to form away from illite aggregates in the pore with residual water. Montmorillonite and illite influence the preferable distribution of methane hydrate to occur away from mineral surface in excess water condition. In the sediments composed of different minerals, methane hydrate forms stochastically in the pore space and grows up individually. As a result, the findings of this study significantly expand the understanding of the formation and distribution of methane hydrate in marine sediments and the prediction of physical properties of hydrate-bearing sediments, and provide insights into natural gas hydrate exploration and production.

INNOVATIVE METHODS FOR PROCESSING COPPER ORES IN KAZAKHSTAN: A COMPREHENSIVE APPROACH TO ENHANCING THE EFFICIENCY OF VALUABLE COMPONENT EXTRACTION

This article presents an innovative approach to processing copper ore from one of the deposits in Kazakhstan, aimed at enhancing the efficiency of copper extraction from materials with a complex mineral composition. The described methodology includes several key stages: comprehensive analysis of the ore's material composition, gravity and flotation beneficiation, as well as hydrometallurgical processes. During the study, the ores underwent preliminary preparation, including crushing and grinding to the required fineness. Experiments on gravity and flotation beneficiation demonstrated that optimizing the parameters of these processes significantly increases the yield of copper concentrate. Additionally, sulfuric acid leaching conducted showed high efficiency in extracting copper from the ground ore. The research results confirm that a comprehensive approach to copper ore processing ensures high efficiency in extracting valuable components and opens up prospects for the sustainable and economically viable utilization of complex copper ores

Mineralogical Characterisation of Copper Slag and Phase Transformation after Carbocatalytic Reduction for Hydrometallurgical Extraction of Copper and Cobalt

Copper smelting slag is a significant potential resource for cobalt and copper. The recovery of copper and cobalt from copper slag could significantly augment the supply of these metals, which are essential to facilitating the transition to green energy while simultaneously addressing environmental concerns regarding slag disposal. However, the complex mineral composition of copper slag poses an enormous challenge. This study investigated the mineralogical and chemical characteristics of copper slag, which are vital for devising the most effective processing techniques. XRD and FESEM-EDS were employed to examine the morphologies of copper slag before and after the reduction process. The effects of borax and charcoal (carbocatalytic) reduction on phase transformation were evaluated. The XRD analysis revealed that the primary phases in the copper slag were Fe2SiO4 and Fe3O4. The FESEM-EDS analysis verified the presence of these phases and yielded supplementary details regarding metal embedment in the Fe2SiO4, Fe3O4, and Cu phases. The carbocatalytic reduction process expedited the transformation of copper slag microstructures from crystalline dendritic to amorphous and metallic phases. Finally, leaching experiments demonstrated the potential benefits of carbocatalytic reduction by yielding high extractions of Cu, Co, and Fe.

Chemical and mineralogical constitution of redoximorphic features and mechanism of formation of Plinthosols from the Araguaia River plain, Brazil

ABSTRACT Currently in Brazil, large grain cultivation projects on Plinthosols are a reality, however, there is little or no knowledge of the real mechanism of formation of the plinthite feature, in addition to what is reported in the literature as being a product of oxidation-reduction processes of iron element. This study evaluates iron redoximorphic features and investigates their chemical and mineralogical composition in two profiles of Plinthosols from the Araguaia River plain (P1 and P2). The study strengthens the understanding of the pedogenetic processes involved in the formation of mottles and plinthite. In this sense, it assesses whether the formation mechanisms corroborate the literature. Soil features were sampled in the upper right and left position at the initial plinthic horizon, upper right and left position at the main plinthic horizon, and lower right position at the base horizon of the plinthite zone in the profile. Separated samples comprising the soil matrix, mottles, and plinthite under natural moisture conditions were ground into powder form for chemical determinations by X-ray fluorescence (XRF), sulfuric acid attack (H 2 SO 4 ), sodium dithionite-citrate-bicarbonate (DCB), and ammonium acid oxalate; and mineralogical determinations by X-ray diffraction. Iron contents in all determined forms were always higher in the plinthite feature, intermediate in the mottle feature, and lower in the soil matrix feature. Most of the Fe in all redoximorphic features is included in the structure of primary minerals and their derivatives (vermiculite, illite, and VHEs). Only part of the iron present (about 35.40 % in P1 and 41.98 % in P2) is detected in the form of oxides such as goethite and hematite, which could be formed in redox processes. The mottle and plinthite features under study are not the product of the classic process of segregation, mobilization, and accumulation of iron as a consequence of redox processes. These features were formed or emerged as a result of a relatively slow and constant weathering process of their source material, which is gradually decomposed in an aqueous medium, releasing most of its components. These components include iron and more mobile elements such as bases and silicon, which leave the system through drainage water, and of which a small part may eventually recombine to form new less complex minerals such as kaolinite and oxides.

Coupled transformation pathways of iron minerals and natural organic matter related to iodine mobilization in alluvial-lacustrine aquifer

The complex of natural organic matter (NOM) and iron minerals in sediment is the main host and source of groundwater iodine. However, the transformation pathways of the complex remain unclear. The groundwater and sediment from the Hetao Basin were collected in this study to analyze multi-isotopes, NOM molecular characteristics, and iron mineral phases. The results showed that high-iodine groundwater was mainly observed in the discharge area, where biodegradation of NOM, sulfate reduction and methanogenesis occurred. Compared to the shallow clayey sediments, the confined sandy sediments had lower iodine content, a lower fraction of crystalline iron oxides, and a higher fraction of carbonate associated Fe(II) minerals, suggesting that the release of sediment iodine in the aquifer is related to the transformation of sediment Fe(III) hydroxides/oxides. Moreover, the molecular features of high-iodine groundwater NOM and sandy sediment NOM were characterized by a higher proportion of refractory compounds, suggesting that the reductive transformation of sediment Fe(III) hydroxides/oxides is fueled by degradable organic compounds. The microbial Fe-reducing and/or sulfate-reducing processes cause the enrichment of groundwater iodine in the form of iodide via the transformation of iodine species. These findings provide new insights into the genesis of high-iodine groundwater.

Gas–Liquid Mixability Study in a Jet-Stirred Tank for Mineral Flotation

Micro- and nano-bubble jet stirring, as an emerging technology, shows great potential in complex mineral sorting. Flow field characteristics and structural parameters of the gas–liquid two-phase system can lead to uneven bubble distribution inside the reaction vessel. Gas–liquid mixing uniformity is crucial for evaluating stirring effects, as increasing the contact area enhances reaction efficiency. To improve flotation process efficiency and resource recovery, further investigation into flow field characteristics and structural optimization is necessary. The internal flow field of the jet-stirred tank was analyzed using computational fluid dynamics (CFDs) with the Eulerian multiphase flow model and the Renormalization Group (RNG) k − ε turbulence model. Various operating (feeding and aerating volumes) and structural parameters (nozzle direction, height, inner diameter, and radius ratio) were simulated. Dimensionless variance is a statistical metric used to assess gas–liquid mixing uniformity. The results indicated bubbles accumulated in the middle of the vessel, leading to uneven mixing. Lower velocities resulted in low gas volume fractions, while excessively high velocities increased differences between the center and near-wall regions. Optimal mixing uniformity was achieved with a circumferential nozzle direction, 80 mm height, 5.0 mm inner diameter, and 0.55 radius ratio.

Tracing the Oxidizing State and Element‐Mobilizing Fluids in Continental Subduction Zones: Insights From the Granitic Melt‐Eclogite Interface

AbstractFluids in subduction zones significantly influence element mobility, isotope fractionation, and mass transfer. However, unraveling the source, composition, and redox state of fluids in continental subduction zones poses a significant challenge. This study focuses on a granitic melt‐eclogite contact interface, along with adjacent granite and eclogite from the Sulu ultrahigh‐pressure metamorphic belt in East China. The interface exhibits complex mineral assemblages, enriched rare earth elements (REEs), and high field strength elements (HFSEs). Zircon grains from the interface show an age of ∼217 ± 9 Ma, slightly later than peak metamorphism, along with the presence of coesite inclusions. These findings suggest that the interfacial fluid likely formed from the mixing of granitic anatectic melt and aqueous fluid from the eclogite during the initial exhumation of the Sulu terrane. The interaction resulted in the eclogite acquiring substantial REEs and HFSEs, suggesting the interfacial fluid's effective element‐transporting capability and potential supercritical fluid properties. Zircon Ce anomaly and Fe3+/Fe2+ oxybarometer data indicate a highly oxidizing interfacial fluid, analogous to arc magmas in oxygen fugacity. This led to the preferential loss of isotopically heavier Cr from the eclogite during fluid‐eclogite interaction, evidenced by heavier Cr isotopic compositions in the interface (δ53Cr = −0.04 to −0.05‰) compared to adjacent eclogite (δ53Cr as low as −0.11‰). In summary, our results highlight the presence of strong oxidizing and element‐mobilizing fluids in continental subduction zones, offering insights into supercritical fluid recognition and the genesis of oxidizing arc magmas in subduction zones.

Re-examination of vesbine in vanadate-rich sublimate-related associations of Vesuvius (Italy): Mineralogical features and origin

Abstract A set of 23 vesbine-bearing samples from Vesuvius volcano (Italy), preserved in the collection of the Royal Mineralogical Museum of Naples, University Federico II (RMMN), have been investigated to identify the mineral assemblages and their mode of formation. In the late 19th century, fumarole-related yellow patinas coating some historical lavas from Vesuvius were believed by Scacchi to contain a new element, vesbium, similar to vanadium in a mineral he called vesbine. Subsequent studies rejected vesbium and showed that vesbine was a poorly defined mixture of copper vanadates and halides. The vesbine samples studied here consist of yellowish to yellow-green-blue encrustations on Vesuvius lavas and have been analyzed by combined optical microscopy, SEM-EDS, XRPD, FTIR, and TEM-HRTEM-EDS. Results reveal complex mineral associations, including vanadates, halides, carbonates, oxides, silicates, tungstates/molybdates, and sulfates. The vanadates correspond to mottramite, volborthite, and vanadinite; subordinate amounts of descloizite were detected by XRPD and FTIR investigations. Several additional non-essential elements have been detected in the vanadates, including Mn, Zn, and As. The occurrence of wulfenite- and stolzite-rich phases indicates the presence of Mo and W, along with Pb, in the mineralizing fluids. Mn-rich phases, commonly in mixtures with silicates and vanadates, were also observed. These minerals are formed by a combination of different processes, including rock-fluid interactions, gas-water interactions, and alteration/oxidation of primary fumarolic minerals. Temperatures for the depositions of the vanadates-bearing assemblages are interpreted to be in the range of 100 to 400 °C.

Effect of zeolite-containing mineral complex on substrate microbiological characteristics during protected cultivation of <i>Rubus fruticosus</i> L. planting material

Effect of zeolite-containing mineral complex on substrate microbiological characteristics during protected cultivation of <i>Rubus fruticosus</i> L. planting material

Low Resistivity Pay Zone Detection in Hydrocarbon Formation: The Feasibility of the Spectral Induced Polarization Method

Summary Identifying and characterizing low resistivity pay (LRP) zones within hydrocarbon-rich formations has long been challenging in the petroleum industry due to their complex mineral composition, microporosity, and diminished resistivity contrasts. Traditional methods, such as resistivity measurements, struggle to effectively pinpoint LRP zones, prompting the need for innovative approaches in reservoir evaluation. This paper explores the feasibility of using the spectral induced polarization (SIP) method for detecting LRP zones. The SIP method measures complex conductivity across a frequency range from 1 mHz to 10 kHz. While this technique has been widely used in mining and environmental studies, its potential for petrophysics applications in the oil and gas sector remains largely unexplored. This study acts as a proof of concept, demonstrating the capability of SIP for detecting LRP zones. Laboratory experiments utilized dual-porosity silica gel samples with controlled micro- and macroporosity fractions and added pyrite content. Despite a high crude oil saturation of approximately 60%, the presence of brine in continuous micropores resulted in low resistivity readings (0.7 Ω·m) at low frequencies, as conventionally measured by direct current resistivity tools. However, at higher frequencies (>100 Hz), the study observed high average resistivity values (82 Ω·m), indicating a frequency-dependent behavior in electrical measurements. This behavior is attributed to polarization mechanisms, including the electrical double layer (EDL). This study’s findings propose the SIP method’s potential effectiveness for detecting LRP zones, paving the way for future research to delve deeper into the application of SIP in petrophysics.

Gold concentration during polyphase deformation: Insights from Boulanger Project, French Guiana

The Boulanger gold deposit is hosted within the Rhyacian greenstone belts from the Guiana shield located within the North Guiana Through, French Guiana. The Boulanger deposit is characterized by a complex polyphase deformation and mineralization history involving a coaxial shortening phase, D1, followed by a transcurrent deformation event, D2. The main ore bodies consist of a series of quartz-tourmaline-pyrite-carbonate extension and shear veins in response to NNE-SSW shortening event (D1), and adjacent altered host-rocks. The proximal alteration bordering the vein system is characterized by pyrite-tourmaline (main ore assemblage). This shortening event is followed by transcurrent deformation, D2. Locally, D2 is expressed by the formation of N020-030 narrow zones (F2 axial trace) along which D1 structures are reoriented. The structural analysis performed on both S1/0 foliation and on geophysical data interpretation highlights the presence of Type-1 interference patterns. These zones are associated with significant gold enrichment and the presence of a new ore assemblage dominated by pyrrhotite-pyrite. Quantitative structural analysis approach, based on measured foliations (S1/0) and gold grade demonstrates that D2-related folding is associated with important gold endowment. These findings suggest that the characterization of the exact fold interference pattern is fundamental for the targeting of favorable enriched zones at the deposit scale.

Efficient extraction of Li and Rb from zinnwaldite via thermal activation and acid leaching

Lithium and its associated rubidium are regarded as the strategic metal resource, which have a wide use in many commercial products. Nowadays, the continuing growth in demand for Li resources, propelling the object of industrial exploitation will focus on low-grade, complex minerals composition and unwieldy ores. Zinnwaldite has received increasing attention as a potential lithium-containing resource in recent years. However, there are a lack of effective extraction processes for zinnwaldite. Hence, this paper proposes an effective method to extract metal cleanly and efficiently from zinnwaldite by using CaO and B2O3 as thermal activation additives and H2SO4 as the leaching agent. The results showed that the destruction of Fe-O and Si-O-Si bonds led to increased extraction efficiency. The breathing vibrations of oxygen atoms symmetric in 4- and 3-membered rings and Si-O symmetric stretch could influence the Li separation from silica skeleton. Ultimately, the 91.32 % Li, 93.09 % Rb, 81.14 % Fe, 95.00 % Al and 71.12 % K were recovered under the optimal conditions. Meanwhile, about 10 % F escaped into the air during thermal activation and the concentration of F in the leaching solution was lower than 2 mg/L. The use of B2O3 provides a valuable reference for the efficient and clean treatment of lepidolite using the salt roasting method.

Effect of fertilizers and meliorants on the value of soil acidity of sod-podzolic light loamy soil, yield and chemical composition of the green mass of spring rapeseed (according to laboratory and vegetation experience)

Under controlled conditions of laboratory vegetation experience based on very strongly acidic sod-podzolic sandy loam soil, a comparative study of the fertilizing value and reclamation properties of complex mineral fertilizers (azofoska andAPAVIVA) and meliorants of a carbonate nature was carried out: conversion chalk (CC), gravel screening (GS), dolomite (DM) and dolomitized (DIM) limestone flour, as well as silicate nature–blast furnace slag (BFS) and hydroxide nature–Mg(OH)2.Culture–spring rape of theLexus variety.It was shown that the reclamation effect obtained as a result of the use ofBFSand meliorants of a carbonate nature differed little from each other and after 45 days of plant cultivation were insignificant.Magnesium hydroxide did not have a reclamation effect.The yield data of the vegetative mass of rapeseed after harvesting are given.It is shown that the chemical composition of meliorants had a significant effect on the formation of the elemental composition of plants.