Metallic Manganese Research Articles

Innovative integrated carbon paper supported Bi/rGO/MnO2 cathode with dual redox reactions for aqueous zinc-ion batteries

Developing cathode materials with dual redox reactions is an effective strategy to improve the electrochemical performance of aqueous zinc-ion batteries (AZIBs), and rational selection of the two electroactive components is the key to achieving this target. Herein, an integrated carbon paper supported Bi/rGO/MnO2 cathode is prepared via a two-step in situ growth process, in which metallic bismuth (Bi) and manganese dioxide (MnO2) are served as two types of electroactive components to realize dual redox reactions. The introduction of reduced graphene oxide (rGO) mitigates the interfacial mismatch of Bi and MnO2, meanwhile further increasing the electrochemical activity by reducing the size of Bi and preventing its self-aggregation. Featuring nanostructured Bi and MnO2, the integrated cathode enables dual redox reactions with enhanced reaction kinetics. This structural and compositional refinement of the Zn//Bi/rGO/MnO2 battery leads to superior electrochemical performance, evidenced by a significant specific capacity (388.3 mAh g−1 at 0.1 A g−1), high energy density (464.6 Wh kg−1) and great rate performance. This work underscores the potential of using MnO2 and Bi as dual electroactive components for AZIBs cathode, providing a pathway towards high performance energy storage systems.

Experimental Studies of Corrosion Resistance of Welded Seams of Steel Structures with a High Sulfur Content in Surface Layers Using Modern Methods of Modeling

Analysis of literature sources and empirical data indicate a variety and a large volume of experimental material, which often characterizes the uncertainty and contradiction of information regarding the effect of sulphur and manganese on the corrosion behaviour of steels obtained using traditional methods. This leads to the need to search for new, alternative methods for its effective analysis. The task of assessing and predicting the corrosion properties of structural steels is a key one in the general problem of managing the operational reliability of welded metal structures and equipment for the chemical, metallurgical, oil and gas, mining and other industries. The possibilities of its solution consist of using new information technologies, a component of which is intelligent means of information processing, such as artificial neural networks (ANN). The use of ANN makes it possible to create qualitatively new hardware and software that significantly expand the classes of emerging problems and increase the efficiency of analysis and forecasting. In the process of long-term operation of metal structures in many industrial industries, the metal is in direct contact with sulfur-containing agents at high temperatures. This leads to the saturation of the surface layer of the metal with sulfur with a concentration of up to 0.6%, which further makes it impossible to carry out repair and welding operations due to the formation of hot cracks. It was found that adding metallic manganese into the electrode coating in an amount of 20-25% significantly increases (4-5 times) the resistance against the formation of hot cracks. Sulfur content in the deposited metal has the opposite effect on the appearance of hot cracks. So, with a sulfur content of 0.042% and more, the resistance of the metal against the formation of hot cracks decreases sharply. It is shown that an increase in the content of metallic manganese in the electrode coating significantly reduces the content of dissolved sulfur in the deposited metal. Moreover, this tendency is typical for steels with different sulfur content in the surface layers and with different service life. For example, for steel with a service life of 20 years, the initial sulfur content in the surface layer of the metal (up to 1 mm) was about 0.52%. Adding metallic manganese in the coating of electrodes in an amount of 20-25% made it possible to reduce the sulfur content in the deposited metal to 0.03-0.045%, i.e. 12.6-17.3 times. In addition, the corrosion rate decreases with an increase in the content of metallic manganese in the electrode coating. The lowest corrosion rate for all steels involved in the research was established at 20-25% manganese content in the coating.

Band Engineering of Mn-P Alloy Enables HER-suppressed Aqueous Manganese Ion Batteries.

Aqueous manganese ion batteries hold potential for stationary storage applications owing to their merits in cost, energy density, and environmental sustainability. However, the formidable challenge is the instability of metallic manganese (Mn) anodes in aqueous electrolytes due to severe hydrogen evolution reaction (HER), which is more serious than the commonly studied Zn metal anodes. Moreover, the mechanism of HER side reactions has remained unclear. Herein, we design a series of Mn-P alloying anodes by precisely regulating their energy band structures to mitigate the HER issue. It is found that the serious HER primarily originates from the spontaneous Mn-H2O reaction driven by the excessively high HOMO energy level of Mn, rather than electrocatalytic water splitting. Owing to a reduced HOMO energy level and enhanced electron escape work function, the MnP anode achieves an evidently enhanced cycle durability (over 1000 hours at a high current density of 5 mA cm-2). The MnP||AgVO full cell with an N/P ratio of 4 exhibits better rate capability and extended cycle life (7000 cycles) with minimal capacity degradation than the cell using metallic Mn anode (less than 100 cycles). This study provides a practical approach for developing highly durable aqueous Mn ion batteries.

Band Engineering of Mn‐P Alloy Enables HER‐suppressed Aqueous Manganese Ion Batteries

Aqueous manganese ion batteries hold potential for stationary storage applications owing to their merits in cost, energy density, and environmental sustainability. However, the formidable challenge is the instability of metallic manganese (Mn) anodes in aqueous electrolytes due to severe hydrogen evolution reaction (HER), which is more serious than the commonly studied Zn metal anodes. Moreover, the mechanism of HER side reactions has remained unclear. Herein, we design a series of Mn‐P alloying anodes by precisely regulating their energy band structures to mitigate the HER issue. It is found that the serious HER primarily originates from the spontaneous Mn‐H2O reaction driven by the excessively high HOMO energy level of Mn, rather than electrocatalytic water splitting. Owing to a reduced HOMO energy level and enhanced electron escape work function, the MnP anode achieves an evidently enhanced cycle durability (over 1000 hours at a high current density of 5 mA cm‐2). The MnP||AgVO full cell with an N/P ratio of 4 exhibits better rate capability and extended cycle life (7000 cycles) with minimal capacity degradation than the cell using metallic Mn anode (less than 100 cycles). This study provides a practical approach for developing highly durable aqueous Mn ion batteries

Electrolytic manganese residue and red mud co-treatment: Synthesizing zeolite X and adsorbing leaching solution from electrolytic manganese residue

Electrolytic manganese residue (EMR) and red mud (RM) are solid wastes from electrolytic metallic manganese and alumina production. These wastes continue to accumulate, causing significant environmental damage and resource waste. To solve these problems, porous zeolite X (ERZ) was synthesized with EMR and RM as the main raw materials. ERZ was then employed to adsorb the leaching solution generated during EMR purification. Also, an investigation was carried out to ascertain the most favorable parameters for the synthesis of zeolite, and the resulting ERZ was characterized. The results indicated that the synthesized ERZ exhibits excellent crystallinity, high thermal stability, and a large specific surface area. Next, solid-state NMR (SSNMR), XRD, and Raman spectroscopy were used to characterize the ERZ synthesis process: the structural units of X zeolite are β cages and 4Rs. Additionally, the study examined the adsorption impact of ERZ on impurity ions in the leaching solution, revealing that the adsorption mechanism is chemisorption. Furthermore, the effective regeneration of ERZ demonstrated its significant practical utility. To summarize, this study presents a new feasible way for effectively utilizing EMR and BA.

Process and kinetics of ammonium sulfide removal of zinc, nickel and cobalt from manganous sulfate electrolyte

In producing electrolytic manganese and manganese-based lithium batteries, Manganous sulfate solution serves as a crucial intermediate material. During the preparation of manganese sulfate solution by acid leaching, the removal of impurities such as zinc, nickel, and cobalt ions by sulfide precipitation is essential for obtaining high-quality metallic manganese and high-purity manganese sulfate. The results show that when the temperature is 45 °C, the pH is 5.60, the ammonium sulfide dosage is 40 %, the time is 5 min, and the rotation speed is 650 rpm, the sulfidation rates of zinc, nickel and cobalt are 99.07 %, 89.30 %, and 87.70 % respectively. At this time, the loss rate of manganese in the solution after sulfide impurity removal is 11.45 %, and the manganese-impurity ratio is 80.00. Response surface methodology analysis revealed that temperature, pH, and ammonium sulfide concentration significantly affected the manganese loss rate. After process optimization, at a temperature of 32.70 °C, a pH of 5.20, and an ammonium sulfide concentration of 32.73 %, the manganese loss rate decreased to 6.05 %, while the removal rates of Ni, Co, and Zn were 75.35 %, 60.80 %, and 99.51 %, respectively. In the Manganous sulfate electrolyte with or without ammonium sulfate, the sulfide precipitation processes of zinc, nickel and cobalt ion are all first-order reactions, and the reaction order is zinc > nickel > cobalt. More importantly, the density functional theory (DFT) calculation results also confirmed the formation sequence of zinc sulfide > nickel sulfide > cobaltous sulfide, which supported the experimental results well. This study will lay the foundation for process optimization and mechanism elucidation of impurity ions in ammonium sulfate electrolyte precipitated by ammonium sulfate.

A Novel Titanium-Based Dimensionally Stable Anode toward Energy-Efficient and Clean Electrowinning of Metallic Manganese

A Novel Titanium-Based Dimensionally Stable Anode toward Energy-Efficient and Clean Electrowinning of Metallic Manganese

Energy-efficient and advanced electrowinning of metallic manganese within a novel H+ exchange membrane cell using a Ti/IrO2−RuO2−SiO2 anode

Coated Titanium Anodes (CTAs) exhibit significant potential in addressing the high energy consumption challenge inherent in current manganese electrowinning processes. However, the electrodeposition of manganese dioxide (MnO2) at the anode limits the utilization of CTAs in conventional manganese electrolytic cells. Herein, a novel H+ exchange membrane (HEM) electrolytic cell was proposed and applied to manganese electrowinning employing Ti/IrO2 − RuO2 − SiO2 anode. The HEM electrolytic cell is a three-chamber electrolytic reactor consisting of cathode chamber, acidification chamber and anode chamber separated by woven terylene diaphragm and HEM. The results indicated that after 24 h of electrowinning, the cathodic current efficiency (CE) of 85.1 % was achieved, along with a specific energy consumption (EC) of 4189 kW·h/t. Compared to conventional industrial electrowinning technology, this represents an increase in CE by more than 15 % and a reduction in EC by over 1400 kW·h/t. The unique structure of the HEM electrolytic cell effectively prevents MnO2 deposition, ensuring the functionality of the CTAs and eliminating the generation of anode mud. Additionally, the H+ from the oxygen evolution reaction at the anode is collected and concentrated in the acidification chamber. This resulted in a spent electrolyte with 15.2 g/L H2SO4, enabling its reuse in extracting manganese ores. Employing the HEM electrolytic cell with a Ti/IrO2 − RuO2 − SiO2 anode for manganese electrowinning is therefore considered an energy-efficient and clean approach. It is highly recommended for saving energy and reducing carbon emissions in industrial processes.

ПРОГНОЗУВАННЯ ВЛАСТИВОСТЕЙ ЛЕГУЮЧИХ ДОБАВОК – ВАЖЛИВА СКЛАДОВА ОДЕРЖАННЯ ЯКІСНОГО МЕТАЛУ

The main goal of the work is to predict the complex of physicochemical and thermophysical properties of additives from the standpoint of their contribution to the directed formation of the quality of steels. As a scientific basis for the development of analytical dependencies, the work uses the original concept of directional chemical bonding, the core of which is the consideration of metal melts as chemically unified systems, and not a mechanical mixture of constituent elements, and taking into account the contribution of all components, even in small concentrations, as well as the accumulated experience of creating information and analytical systems for forecasting and management of iron and steel smelting processes at the Iron and Steel Institute of Z.I. Nekrasov National Academy of Sciences of Ukraine. The information component is a database on the properties of metallurgical melts, namely the "Ferroalloys" database chosen as the starting point for modeling, which is continuously updated with modern data. A successful combination of information and scientific resources ensured the development of stable models with high forecast accuracy (R2 ≥ 0.95) for domestic brands of ferroalloys (ferromanganese, ferrosilicomanganese, metallic manganese). The findings presented in this work are recommended for integration into the automated technological process management systems of steelmaking with the aim of further forming a competitive final product.

Facile manganese ion-coordination assembly of nanogels for synergistic cancer chemo–chemodynamic-immunotherapy

Metal-ion therapy is an emerging technique for cancer treatment, where anticancer metals trigger an immune response against tumor cells due to immunogenic cell death while enabling chemokinetic therapy, and the integration of these activities holds considerable anticancer potential for achieving high specificity and efficiency. Herein, we designed acid-responsive manganese-based nanogels with high drug-loading capacity for combined chemotherapy, chemodynamic therapy, and metal-immune therapy. The chemotherapeutic drug mitoxantrone, metallic manganese ions, and polymeric polyacrylic acid self-assembled into stable nanogels that could be efficiently internalized by cancer cells efficiently, releasing Mn2+ to catalyze highly toxic of hydroxyl generation from endogenous H2O2 and induce tumor cell apoptosis. Furthermore, the Mn2+-mediated activation of cyclic guanosine monophosphate adenosine synthetase activated the stimulator of interferon genes (STING) pathway, thereby inducing dendritic cell maturation. Following intravenous injection into immunocompetent tumor-bearing mice, the nanogels effectively exerted a tumor-killing effect and enhanced the antitumor immune response in combination with an aCTLA-4 antibody. Manganese ions also enhanced T1-weighted magnetic resonance imaging for integrated diagnosis and treatment. Overall, the manganese-based nanogel demonstrates significant synergistic efficacy through combined chemotherapy, chemodynamic therapy and metal-immune therapy, providing a versatile therapeutic strategy for cancer treatment.

Synergistic Corrosion Engineering on Metallic Manganese Toward High‐Performance Electrochemical Energy Storage

AbstractMnO/rGO with enhanced electrochemical kinetic properties is widely investigated as electrode for high‐performance electrochemical energy storage (EES) devices. However, the synthesis of MnO/rGO via traditional methods suffers from low atomic utilization and complex techniques that are undesirable for practical implementation. Different from existing fabrication strategies, here using metallic manganese as Mn source, a novel, eco‐friendly, and corrosion engineering‐based approach to address the above issues is demonstrated. It is thermodynamically feasible as supported by the E‐pH analysis and for the first time, a significant synergetic effect is observed between NH4+ and GO in strengthening the metallic Mn corrosion reaction. Particularly, in the “ammonia circulation” process, the NH3 molecule, derived from NH4+, acts as a “carrier” for Mn2+ to facilitate its transfer by forming [Mn(NH3)2]2+, which effectively prevents “in situ corrosion”. The phase and structure evolution during the reaction are clarified, and the synergistic corrosion mechanism is also proposed. Benefiting from the efficient lithium‐ion evolution kinetics, Mn─O─C bond formed between MnO and rGO and outstanding structural integrity, the resultant MnO/rGO demonstrates exceptional EES performances in both lithium‐ion batteries and lithium‐ion capacitors. This finding will offer potential for mild, cost‐effective, and environmentally friendly fabrication of other graphene‐based metal oxide electrodes using corrosion engineering.

Pyrometallurgical reduction of manganese-rich black mass from discarded batteries using charcoal

The recycling of heavy metals contained in alkaline batteries allows minimizing the environmental impact and gives an alternative use to this waste, which can be used in the pyrometallurgical industry. In the present research work, we evaluated the possibility of reducing the manganese oxide black mass from discarded alkaline batteries to produce metallic manganese, using charcoal as a reducing agent. The procedure begins with the characterization of the raw materials, the stoichiometric calculations and the preparation of a practical method to produce self-reducing pellets, composed of manganiferous material, charcoal and bentonite as agglomerant. Computer simulations were performed, to establish the appropriate thermodynamic conditions for reduction. The tests were carried out in a tubular-type furnace, and the results obtained were evaluated using optical microscopy, scanning electron microscopy coupled with microchemical analyses and X-ray diffraction techniques. It was verified that the agglomerates showed a self-reducing behavior, so an increase of the %Mn in the samples due to increasing the temperature of the reduction treatment was found, as well as the presence of a metallic manganese phase that was identified by X-ray diffraction analysis.Graphical Flow sheet for the production of self-reducing pellets containing eucalyptus charcoal for the recycling of manganese contained in spent alkaline batteries

Prenatal exposure to selenium, mercury, and manganese during pregnancy and allergic diseases in early childhood: The Japan Environment and Children's study

BackgroundPrenatal exposure to metallic elements may adversely affect early childhood health. However, more evidence is needed as population-based cohort studies are currently limited. ObjectivesWe aimed to examine the associations between prenatal metallic (mercury, selenium, and manganese) exposure and the risk of allergic diseases in early childhood until three years of age. MethodsThe data from 94,794 mother-infant pairs, who participated in the Japan Environment and Children’s study, were used in this study. Prenatal metallic element exposure was measured in maternal blood collected during mid-pregnancy. The incidence of atopic dermatitis, food allergies, asthma, and allergic rhinitis during the first three years of life was prospectively investigated using self-reports of physician-diagnosed allergies. A multivariable modified Poisson regression model was used to estimate the cumulative incidence ratio and their 95% confidence intervals of allergic diseases associated with prenatal exposure to mercury, selenium, and manganese. We further evaluated the interaction between mercury and selenium exposures in this association. ResultsWe confirmed 26,238 cases of childhood allergic diseases: atopic dermatitis, food allergies, asthma, and allergic rhinitis in 9,715 (10.3%), 10,897 (11.5%), and 9,857 (10.4%), 4,630 (4.9%), respectively. No association was found between prenatal mercury or manganese exposure and the risk of allergic diseases. Prenatal selenium exposure was inversely associated with atopic dermatitis, food allergies, allergic rhinitis, and any allergic diseases, but not with asthma. These inverse associations were more pronounced for lower mercury exposures than for higher exposures. ConclusionsOur findings suggest that prenatal exposure to selenium may be beneficial for reducing the risk of atopic dermatitis, food allergies, allergic rhinitis, and any allergic diseases in early childhood, especially with lower prenatal mercury exposure.

Manganese(II)‐Guided Separation in the Sub‐Nanometer Regime for Precise Identification of In Vivo Size Dependence

AbstractA precise understanding of nano‐bio interactions in the sub‐nanometer regime is necessary for advancements in nanomedicine. However, this is currently hindered by the control of the nanoparticle size in the sub‐nanometer regime. Herein, we report a facile in situ Mn2+‐guided centrifugation strategy for the synthesis of large‐scale ultrasmall gold nanoparticles (AuNPs) with a precisely controlled size gradient at the sub‐nanometer regime. With the discovery that [Mn(OH)]+, especially metallic manganese (Mn0@[Mn(OH)]+) nanoparticles, could selectively interact with larger AuNPs through synergistic coordination and hydrogen bonding to form aggregates, we also realized the fast (<1 h) synthesis of water‐soluble atomically precise Au25 with high yields (>56 %). We further demonstrated that sub‐nanometer size differences (approximately 0.5 nm) significantly alter non‐specific phagocytosis of AuNPs in the reticuloendothelial system macrophages, elimination rate, and nanotoxicology.

Manganese(II)-Guided Separation in the Sub-Nanometer Regime for Precise Identification of In Vivo Size Dependence.

A precise understanding of nano-bio interactions in the sub-nanometer regime is necessary for advancements in nanomedicine. However, this is currently hindered by the control of the nanoparticle size in the sub-nanometer regime. Herein, we report a facile in situ Mn2+-guided centrifugation strategy for the synthesis of large-scale ultrasmall gold nanoparticles (AuNPs) with a precisely controlled size gradient at the sub-nanometer regime. With the discovery that [Mn(OH)]+, especially metallic manganese (Mn(0)@[Mn(OH)]+) nanoparticles, could selectively interact with larger AuNPs through synergistic coordination and hydrogen bonding to form aggregates, we also realized the fast (<1 h) synthesis of water-soluble atomically precise Au25 with high yields (>56%). We further demonstrated that sub-nanometer size differences (approximately 0.5 nm) significantly alter non-specific phagocytosis of AuNPs in the reticuloendothelial system macrophages, elimination rate, and nanotoxicology.

A novel lead-based pseudo dimensional stable anode toward efficient and clean extraction of metallic manganese

Although the application of the dimensionally stable anode (DSA) is of great value to meet the environmental demands for sustainable development of electrometallurgy, the unsatisfactory stability and high-costs hinder its industrialization in Mn metallurgy. Hereby, a novel lead-based pseudo dimensional stable anode (LBP-DSA) was proposed firstly to overcome the intrinsic defects of the lead-based anodes and inherit the advanced characteristics of the DSA. The unique advantage for the hierarchical skeleton of LBP-DSA (lead-based/TiB2/γ-MnO2) was discussed in detail. To begin with, a sufficiently robust lead-based/TiB2 substrate was constructed to eliminate the lead pollution in electrolysis system. The key role of TiB2 interlayer was devoted to solidify the lead substrate and provide suitable anchors for subsequent layer adhesion. Subsequently, the as-synthesized γ-MnO2 on different substrates were comparatively analyzed to highlight that the tantalizing oxygen evolution selectivity relied on screening the lead pollution in γ-MnO2 lattice. Beneficial from the synergistic effects of TiB2 with γ-MnO2, our LBP-DSA exhibited a great potential in energy-saving and hazardous anode slime reduction. The satisfactory long-term stability and corrosion resistance made the LBP-DSA as a promising candidate for cleaner production of metallic manganese.

Therapeutic Strategies and Metal-Induced Oxidative Stress: Application of Synchrotron Radiation Microbeam to Amyotrophic Lateral Sclerosis in the Kii Peninsula of Japan.

A series of extensive gene-environment studies on amyotrophic lateral sclerosis (ALS) and Parkinsonism–dementia complex (PDC) in Guam Island, USA, and the Kii Peninsula of Japan, including Auyu Jakai, West New Guinea, have led us to hypothesize that a prolonged low calcium (Ca) and magnesium (Mg) intake, especially over generation, may cause oxidative stress to motor and nigral neurons by an increased uptake of environment metallic elements, i.e., aluminum (Al), manganese (Mn), and iron (Fe). Otherwise, 5–10% of total ALS cases are familial ALS (fALS), of which 20% of the fALS cases linked to a point mutation of Cu/Zn superoxide dismutase (SOD1). In the vicinity of the Kii Peninsula, about 7% of the ALS cases are also linked to the SOD1 mutation. Using synchrotron radiation (SR) microbeam, conglomerate inclusion (SOD1 aggregates) within a spinal motor neuron of the fALS case in the vicinity revealed a loss of copper (Cu) in contrast to extremely high contents of Zinc (Zn) and Ca. That means an exceptionally low Cu/Zn ratio with an increased Ca content, indicating the abnormalities of the active site of SOD1 protein of the fALS. Furthermore, sALS in the southernmost high incidence areas of the Kii Peninsula showed a low Cu/Zn ratio within a motor neuron, suggesting a fragility of SOD1 proteins. From the perspective of gene–environment interactions, the above two research trends may show a common oxidative stress underlying the neuronal degenerative process of ALS/PDC in the Kii Peninsula of Japan. Therefore, it is a crucial point for the prospect of therapeutic strategy to clarify a role of transition metals in the oxidative process in both ALS/PDC, including ALS elsewhere in the world. This paper reviews a history of the genetic epidemiological studies, especially from the aspect of gene–environment interaction, on ALS/PDC in the Kii and Guam high incidence foci and the results of a series of analytical research on trace metallic elements within neurons of both sALS and fALS cases, especially using a synchrotron radiation (SR) microbeam of Spring-8 and Photon Factory of Japan. The SR microbeam is an ideal X-ray source, which supplies an extremely high brilliance (high-intensity photon) and tunability (energy variability) to investigate trace metallic elements contained in biological specimens at the cellular level, even more without any damages. This research will provide a valuable information about the mechanism of oxidative stress involved in neuronal cell death in ALS and related neurodegenerative disorders. To elucidate the physicochemical mechanism of the oxidative process in neuronal degeneration, it will shed a new light on the therapeutic strategies for ALS/PDC in near future.

A cost-effective method for enhancing manganese leaching from rhodochrosite caused by surfactant-regulated crystal growth of CaSO4·2H2O

The cost-effective leaching of manganese (Mn2+) from rhodochrosite is critical for achieving energy saving, curtailing pollutants, and cleaner production of electrolytic metallic manganese (EMM). In this work, different surfactants were used to enhance Mn2+ leaching from rhodochrosite. The effects of the surfactants: trisodium citrate (TC), sodium oleate (SOL), ethylenediaminetetraacetic acid (EDTA), sodium dodecyl sulfate (SDS), and tetradecyltrimethyl ammonium bromide (TTAB) on the Mn2+ leaching efficiency were evaluated. The enhanced mechanism of Mn2+ leaching is discussed, and an economic evaluation is presented. The leaching efficiency of Mn2+ reached 91.8% in the presence of 5 mg/L TC, which is 13.8% higher than that in the absence of TC using a temperature of 50 °C, a solid-liquid ratio of 1:5, an acid-to-ore ratio of 0.58:1, and reaction time of 3.5 h. In the leaching mechanism, TC inhibited the growth of the 020, 040, and 041 crystal planes of CaSO4·2H2O; thus, CaSO4·2H2O crystals with a shortened columnar morphology and smaller sheet shapes were obtained. The grain refinement of CaSO4·2H2O did not readily wrap on the surface of rhodochrosite, consequently increasing the probability for rhodochrosite to react with H+, and improving the leaching efficiency of Mn2+. Moreover, TC did not remain in the leachate to impact the subsequent electrolytic deposition. This study provides a cost-effective method for leaching Mn2+ from rhodochrosite.

MnMOF-based microwave-glutathione dual-responsive nano-missile for enhanced microwave Thermo-dynamic chemotherapy of drug-resistant tumors

Metal-organic frameworks (MOFs) have been developed for tumor therapy in recent years, but so far there have been very few reports about the use of single metallic manganese (Mn) MOF in tumor therapy due to limited types of organic ligands. Expending on advantages of Mn-based nanoplatform, a novel magnetic resonance imaging (MRI)-monitored, microwave (MW) thermo-dynamic sensitized, and glutathione (GSH)-responsive Mn-based MOF is nano-engineered by combining imidazole containing sulfhydryl bond with Mn2+ for cisplatin (CDDP) loading, the phase-changing material (PCM) and tumor cell membrane (TCM) with homologous targeting are modified to finally generate MnMOF-CDDP@PCM-TCM nano-missile (TMCP Nm). Through active and passive targeting, MW-GSH dual-response, and site-directed release, the nano-missile can effectively reverse CDDP resistance, amplify the efficacy of MW thermo-dynamic chemotherapy, and finally achieve excellent therapeutic effect on drug-resistant tumor models both in vivo and in vitro. This strategy differs from traditional chemotherapy and MW thermotherapy (MWT), which triggers a series of changes in the tumor microenvironment that make subsequent chemotherapy more effective. In this study, a novel Mn-based MOF is designed and synthesized, which opens a new way to solve the problem of drug-resistance caused by chemotherapeutic drugs represented by CDDP in tumor therapy, and will greatly expand the application of MOFs and chemotherapeutic drugs.

The dynamics of ferroalloys commodity flows within Russia

The paper deals with the commodity flows (production, import, export, consumption, prices) of manganese, chromium, silicon, vanadium, niobium, molybdenum, tungsten, titanium and nickel ferroalloys in dynamics from 2000 to 2019 throughout Russia. The paper also specifies groups of ferroalloys: import-dependent (silicomanganese, metallic manganese, ferroniobium), export-oriented (ferrosilicon, ferrochrome, ferrovanadium, ferromolybdenum) and counter import-export (ferromanganese) flows. The paper notes that there has been a liquidation of import dependence on ferromanganese and ferromolybdenum. Trends in shares of Russian ferroalloys in their world production and consumption, as well as in the world trade are determined. The share of Russia in the world production of ferromolybdenum increased (up to 5&ndash;8 %), while ferrovanadium and ferrosilicon decreased. The shares of Russian consumption (in world demand volume) of ferrovanadium (up to 11&ndash;7 %) and ferroniobium (up to 5&ndash;7 %) increased, and the shares of national demand for ferrosilicon and silicomanganese in the volume of world supply decreased. The shares of Russian import in the world trade volume of metallic manganese (up to 11&ndash;16 %) and ferroniobium (up to 5 %) are increased, and the share of national imports of silicomanganese and ferromanganese decreased. The shares of Russian export in the world trade volume of ferrosilicon (up to 17&ndash;21 %) and ferromolybdenum (up to 5&ndash;8 %) are increased, while the share of national exports of ferrovanadium decreased. As a result, the authors give proposals to mitigate the import dependence on certain types of ferroalloys (metallic manganese, silicomanganese and ferroniobium. This research was supported by TPU development program.