Leaching Of Manganese Research Articles

Extraction of manganese and ammonia nitrogen from electrolytic manganese residue by enhanced leaching with ammonium persulfate

Electrolytic manganese residue (EMR) represents a solid waste generated during the production of electrolytic manganese. Under the leaching and dissolution by rainwater, manganese, ammonia nitrogen, and heavy metal ions in EMR can infiltrate into the surrounding environment, thereby disrupting ecological balance and posing threats to human health. This study optimized the leaching conditions for manganese from EMR using ammonium persulfate(APS) through single-factor and orthogonal experiments. It was found that temperature, APS concentration, and reaction time significantly influenced the manganese leaching efficiency. Under leaching temperature of 80°C, leaching time of 3hours, APS concentration of 30g/L, and a liquid-to-solid mass ratio of 6mL/g, a high manganese leaching rate of 88.91% was achieved in a single process, and significant removal of ammonia nitrogen was observed. After enhanced leaching, the content of organic matter and the total amount of water-soluble salt were 4.10wt.% and 3.11wt.%, respectively. And it meets the requirements of the standard GB 18599-2020 for solid waste entering the class II site in China. Kinetic analysis revealed that the manganese leaching process was controlled by intraparticle diffusion within the solid phase. Mineralogical phase analysis indicated that the primary mineral structures were oxidatively decoupled and disrupted, leading to the dissociation of aggregates, which facilitated the leaching of manganese and ammonia nitrogen. This study provides a practical, green, and economical technological route for the harmless treatment of EMR.

Hydrometallurgical Leaching of Manganese Using Hydrochloric Acid in The Presence of Thiourea from Um Bogma Area, Sinai, Egypt

Hydrometallurgical Leaching of Manganese Using Hydrochloric Acid in The Presence of Thiourea from Um Bogma Area, Sinai, Egypt

A single-atom manganese nanozyme mediated membrane reactor for water decontamination

Single-atom nanozymes possess high catalytic activity and selectivity, and are emerging as advanced heterogeneous catalysts for environmental applications. Herein, we present the innovative synthesis and characterization of a single-atom manganese-doped carbon nitride (SA-Mn-CN) nanozyme, integrated into a polyvinylidene fluoride (PVDF) membrane for advanced water treatment applications. The SA-Mn-CN nanozyme demonstrates high peroxidase-like activity, efficiently catalyzing the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) and generating reactive oxygen species (ROS) for effective antibacterial action. Notably, the SA-Mn-CN/PVDF membrane showcases enhanced water permeability, superior antifouling properties, and ultra-fast degradation kinetics of organic pollutants. Mechanistic studies reveal that the nanozyme selectively generates Mn(IV)-oxo species via peroxymonosulfate (PMS) activation, crucial for the efficient oxidation processes. Our integrated membrane system effectively removes (within 1 min, > 92 % removal) a variety of organic micropollutants in continuous-flow operations, demonstrating excellent stability and minimal manganese leaching. Compared to conventional advanced oxidation process (AOPs)/membrane system, the SA-Mn-CN/PVDF/PMS system holds the advantages of high catalytic activity and selectivity for generation of reactive species, wide working pH range (pH3–11) and excellent stability and reusability under the backwashing conditions. The developed device-scale AOPs/membrane system was proven to be effective in bacterial inactivation and pollutants degradation, verifying the vast application potential of the SA-Mn-CN/PVDF membrane for practical water decontamination. This work pioneers the development of enzyme-mimicking nanozyme membranes, offering a sustainable and high-performance solution for wastewater treatment, and sets a new benchmark for the design of nanozyme-based catalytic membranes in environmental applications.

Selective Lithium Recovery from Spent Lithium Manganate Batteries Using Oxidative Stabilization Technique.

Using oxidizing compounds to handle the recycling of discarded lithium batteries has advanced significantly in recent years. One of the most prominent methods is the sintered electrode powder treatment using pre-used additives, with an aqueous solution of the oxidizing agent fueling highly selective lithium extraction and transition metals retention in the refractory material. Herein, phosphoric acid (H3PO4) was used as the exchanger and hydrogen ions provider, the oxidant (K2S2O8) activity was driven by heating, the raw material structure was deformed and adjusted by the oxidizing drive, and lithium was exhausted, while manganese was converted into manganese(III) phosphate hydrate and manganese dioxide insoluble material. The optimized conditions resulted in a lithium leaching rate of 94.16 % and a separation factor of 95.74 %, while the corresponding manganese leaching rate was limited to less than 5 %. The X-ray diffraction, X-ray spectroscopy, scanning electron microscopy, and inductively coupled plasma mass spectrometry measurements were used to investigate the influence of oxidation driving force and lithium leaching. Finally, the lithium leach solution was continuously stirred with sodium carbonate in boiling water to obtain the precipitate, which was separated and washed several times to obtain high-purity lithium carbonate.

Optimization and Kinetic Study of Manganese Leaching from Pyrolusite Ore in Hydrochloric Acid Solutions with Oxalic Acid

The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol.Graphical

Hydrogen peroxide enhancing the process of MnO2-modified ceramic membrane catalyzing micro-nano bubble

In this study, MnO2-modified ceramic membranes (MnO2@CMs) with different morphologies were prepared via hydrothermal method. The concentration of K+ and H+ in the solution determined the morphological evolution of the MnO2 on the CM. We then structured a H2O2/MNB/MnO2@CM system through adding H2O2 to the system of MnO2@CM coupling MNB. The performance analysis of the MnO2 catalyst, including loading, pH zero point charge, crystalline phase, and Mn(Ⅲ) content, determined that the sheet-like MnO2@CM was the most effective for removing pollutants in the H2O2/MNB/MnO2@CM system, achieving 99.45% decolorization and 73.07% TOC removal of methylene blue (model pollutant). The durability of the system was also confirmed through tests on membrane water flux, reuse, and manganese leaching. Mechanism analysis revealed that H2O2 could induce MNBs to generate reactive oxygen species (ROS) in the solution through reaction or hydrolyzing H+, which acted as a pretreatment for MnO2@CM catalytic filtration. In addition, a Fenton-like reaction was also formed on the surface of the MnO2@CM. These reactions greatly enhanced the process of MnO2@CM catalyzing MNB and its efficiency for removing pollutants. This work provides important insights for designing more efficient catalytic CMs and developing novel processes for wastewater treatment.

A low-carbon cement based on silicomanganese slag and granulated blast furnace slag: Hydration process, microstructure, mechanical properties and leaching risks

The calcium content of silicomanganese slag is only about 50 % of that in granulated blast furnace slag but the manganese content is high (>10 wt%), which limits the wide application of silicomanganese slag in cementitious materials. The present study provides a low-carbon cementitious material with an above-average silicomanganese slag content, which provides a new method for the recycling of silicomanganese slag and other solid wastes. The mechanical properties, hydration mechanisms, and pore structures of low-carbon cementitious materials with different silicomanganese slag and granulated blast furnace slag ratios were investigated using carbide slag as alkali-activator and flue gas desulfurization gypsum as sulfate-activator. The feasibility of silicomanganese slag as a significant replacement for granulated blast furnace slag in cementitious materials was explored, and the risk of manganese leaching was assessed. Silicomanganese slag has slower hydration rate in the early stage, but the reaction accelerates in a later stage and the gap with granulated blast furnace slag decreases. The 3, 7, and 28-d compressive strengths of mortars consisting of 40 % silicomanganese slag, 40 % granulated blast furnace slag, 12 % flue gas desulfurization gypsum, and 8 % carbide slag reached 28.7, 41.2, and 49.9 MPa, respectively. When the silicomanganese slag content is 80 %, the leaching toxicity test results showed ≤0.1 mg/L, and jouravskite was present in the hydration products, which indicated a low risk of manganese leaching in normal service environments.

Simultaneously leaching of copper and manganese from low-grade ore from Boleo Mine by bacterial sulfur oxidation

Simultaneously leaching of copper and manganese from low-grade ore from Boleo Mine by bacterial sulfur oxidation

Ammonia removal and simultaneous immobilization of manganese and magnesium from electrolytic manganese residue by a low-temperature CaO roasting process.

A large amount of open-dumped electrolytic manganese residue (EMR) has posed a severe threat to the ecosystem and public health due to the leaching of ammonia (NH4+) and manganese (Mn). In this study, CaO addition coupled with low-temperature roasting was applied for the treatment of EMR. The effects of roasting temperature, roasting time, CaO-EMR mass ratio and solid-liquid ratio were investigated. The most cost-effective and practically viable condition was explored through response surface methodology. At a CaO: EMR ratio of 1:16.7, after roasting at 187°C for 60 min, the leaching concentrations of NH4+ and Mn dropped to 10.18 mg/L and 1.05 mg/L, respectively, below their discharge standards. In addition, the magnesium hazard (MH) of EMR, which was often neglected, was studied. After treatment, the MH of the EMR leachate was reduced from 60 to 37. Mechanism analysis reveals that roasting can promote NH4+ to escape as NH3 and convert dihydrate gypsum to hemihydrate gypsum. Mn2+ and Mg2+ were mainly solidified as MnO2 and Mg(OH)2, respectively. This study proposes an efficient and low-cost approach for the treatment of EMR and provides valuable information for its practical application.

Selective recycling of lithium from spent LiNixCoyMn1-x-yO2 cathode via constructing a synergistic leaching environment

The global response to lithium scarcity is overstretched, and it is imperative to explore a green process to sustainably and selectively recover lithium from spent lithium-ion battery (LIB) cathodes. This work investigates the distinct leaching behaviors between lithium and transition metals in pure formic acid and the auxiliary effect of acetic acid as a solvent in the leaching reaction. A formic acid-acetic acid (FA-AA) synergistic system was constructed to selectively recycle 96.81% of lithium from spent LIB cathodes by regulating the conditions of the reaction environment to inhibit the leaching of non-target metals. Meanwhile, the transition metals generate carboxylate precipitates enriched in the leaching residue. The inhibition mechanism of manganese leaching by acetic acid and the leaching behavior of nickel or cobalt being precipitated after release was revealed by characterizations such as XPS, SEM, and FTIR. After the reaction, 90.50% of the acid can be recycled by distillation, and small amounts of the residual Li-containing concentrated solution are converted to battery-grade lithium carbonate by roasting and washing (91.62% recovery rate). This recycling process possesses four significant advantages: i) no additional chemicals are required, ii) the lithium sinking step is eliminated, iii) no waste liquid is discharged, and iv) there is the potential for profitability. Overall, this study provides a novel approach to the waste management technology of lithium batteries and sustainable recycling of lithium resources.

An immobilized Schiff base-Mn complex as a hybrid magnetic nanocatalyst for green synthesis of biologically active [4,3-d]pyrido[1,2-a]pyrimidin-6-ones.

The immobilization of metal ions on inorganic supports has garnered significant attention due to its wide range of applications. These immobilized metal ions serve as catalysts for chemical reactions and as probes for studying biological processes. In this study, we successfully prepared Fe3O4@SiO2@Mn-complex by immobilizing manganese onto the surface of magnetic Fe3O4@SiO2 nanoparticles through a layer-by-layer assembly technique. The structure of these hybrid nanoparticles was characterized by various analytical techniques, including Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), and inductively coupled plasma-optical emission spectrometry (ICP-OES). Fe3O4@SiO2@Mn-complex was successfully utilized in the synthesis of biologically active 7-aryl[4,3-d]pyrido[1,2-a]pyrimidin-6(7H)-one derivatives in an aqueous medium, providing environmentally friendly conditions. The desired products were manufactured in high yields (81-95%) without the formation of side products. The heterogeneity of the solid nanocatalyst was assessed using a hot filtration test that confirmed minimal manganese leaching during the reaction. This procedure offers numerous advantages, including short reaction times, the use of a green solvent, the ability to reuse the catalyst without a significant decrease in catalytic activity, and easy separation of the catalyst using an external magnet. Furthermore, this approach aligns with environmental compatibility and sustainability standards.

Sequential separation of critical metals from lithium-ion batteries based on deep eutectic solvent and electrodeposition

The rise and development of electric vehicles have brought much attention to the recycling of lithium-ion batteries (LIBs). However, the recovery of critical metals from LiNixCoyMn1−x−yO2 (NCM) is a challenge, especially for the nickel and cobalt, which have similar chemical properties. Here, a novel ternary deep eutectic solvent (DES) composed of choline chloride, ethylene glycol, and tartaric acid was proposed. Our protocol of DES synthesis, nickel separation, and leaching of cobalt and manganese were integrated into one step, which significantly simplified the recovery process. The crystallization occurring during DES leaching was subjected to detailed investigation. The lithium, nickel, and cobalt were sequentially separated as Li2CO3, NiO, and Co(OH)2 by anterior formic acid leaching and posterior electrodeposition. After electrodeposition, DES was reused. This work provides new ideas for the sequential separation of critical metals from NCM and has great application prospects.

Efficient leaching of manganese from electrolytic manganese residue and recovery of the leaching solution: Reuse and purification

Electrolytic manganese residue (EMR) is a hazardous solid waste, while it also contains resources of Mn over 7 %. In this study, sulfuric acid with high concentration was used to leach Mn from EMR, and the leaching solution was reused and purified to produce battery-grade manganese sulfate. The optimal leaching conditions for EMR were determined through single-factor experiments and response surface methodology. Under the conditions of H2SO4 concentration at 5.4 mol/L, liquid–solid ratio at 4.8 mL/g, and temperature at 80 °C, the highest Mn leaching efficiency of 99.12 % was achieved. The kinetics of leaching Mn from EMR follows the Avrami model. The leaching characteristics were described according to the basic hypothesis made by the Avrami equation and the fitted Avrami index. The kinetic process is macroscopically regarded as the inverse process of non-equilibrium crystallization. According to the Arrhenius equation, the leaching of Mn is controlled by the mixture of diffusion and reaction with an apparent activation energy of 19.8 kJ/mol. The EMR leaching solution was then reused for the leaching step of rhodochrosite ore to simulate actual production. The secondary leaching solution was purified using neutralization, sulfide precipitation, and fluoride precipitation, and manganese sulfate with high purity was produced from it by evaporative crystallization. This study provides a low-cost and high-efficiency process for leaching and recovering Mn from EMR, which can also reduce the environmental risk.

Influence of citric acid on the extraction level of manganese in green and black tea infusions

Manganese concentration in green and black tea (10 samples of each type) was determined by means of graphite-furnace atomic absorption spectrometry. Both the dry leaves and the infusions were analysed. The concentration of manganese in dry leaves was in the range of 502–1277 mg · kg−1 for black tea and 798–1906 mg · kg−1 for green one. Since lemon juice is commonly added for tea to enrich its taste, citric acid was used to simulate lemon juice influence on manganese concentration in the infusions. The infusions prepared with and without citric acid addition were analysed and the results showed significant influence of citric acid on manganese leaching. The average extraction levels of manganese from black tea equal 16% (for non-acidified infusions) and 34% (for acidified ones) while these values for green tea equal 13% and 38%, respectively. Statistical evaluation of the results showed that the differences between acidified and non-acidified infusions were statistically significant. High manganese content makes the tea an important source of manganese in human diet.

A Green Cyclic Leaching Process for Low-Grade Pyrolusite via a Recyclable Fe(II) Reductant

The low-cost Fe(II) reductants used in the leaching of pyrolusite usually cause high concentrations of iron ions in the leaching solution, which are difficult to treat and recover. Herein, a green cyclic leaching process for pyrolusite with recycling and reusing of Fe(II) reductants was developed. Sodium sulfide was introduced to reduce and precipitate iron ions in the leaching solution. Ep-H diagrams show that Fe3+ can be reduced to Fe2+ by S2− and form a precipitate with the high efficiency of 93.09%. Since the main component of the precipitate was ferrous disulfide with reducibility, it was used as a reducing agent for low-grade manganese oxide ores. A total of 97.96% of the manganese was highly reductively leached by the obtained precipitate of 0.28 g·g−1 ore. Furthermore, the leaching efficiency was almost unchanged after five iterations of cyclic experiments. The cyclic leaching process enables the efficient leaching of manganese and the recycling of iron, which provides a green and economic method for the efficient utilization of low-grade pyrolusite resources.

Leaching of base and metal cations from litter and soils vary in two forest stands with different tree species

Understanding the distribution of cations in forest soils is important for forest management. Here, we evaluated the leaching of cations, potassium (K+), sodium (Na+), calcium (Ca2+), magnesium (Mg2+), iron (Fe3+), aluminium (Al3+), and manganese (Mn2+), from litter through soils in two forest stands with different tree species. We incubated Castanopsis carlesii leaf litter in a Castanopsis carlesii stand and Cunninghamia lanceolata needle litter in a Cunninghamia lanceolata stand using a microcosm method with monthly collections of litter and soil leachates, and the concentrations of cations and fluxes of these cations were assessed separately. We found more Ca2+ but less Na+, Mg2+, and Fe3+ fluxes in litter leaching solutions in Cunninghamia lanceolata than in Castanopsis carlesii stand because of their different initial concentrations in fresh litter. Although cations leached from leaf litter differed among tree species, the leaching fluxes did not vary between stands. Moreover, annual fluxes of cations leached from soils were significantly higher than those from leaf litter, leading to a net loss of soil nutrients to downstream environment. Therefore, the results suggest that reforestation with mixed stands by introducing broadleaved trees in Chinese fir monoculture plantations might reduce soil nutrient loss through the leaching pathway.

Highly Active Manganese Oxide from Electrolytic Manganese Anode Slime for Efficient Removal of Antibiotics Induced by Dissociation of Peroxymonosulfate.

In this paper, high-activity manganese oxide was prepared from electrolytic manganese anode slime to realize the efficient removal of antibiotics. The effects of sulfuric acid concentration, ethanol dosage, liquid-solid ratio, leaching temperature and leaching time on the leaching of manganese from electrolytic manganese anode slime were systematically studied. Under the optimal conditions, the leaching rate of manganese reached 88.74%. In addition, a Mn3O4 catalyst was synthesized and used to activate hydrogen persulfate (PMS) to degrade tetracycline hydrochloride (TCH). The synthesized Mn3O4 was characterized by XRD, XPS, Raman, SEM and HRTEM. As a result, the prepared Mn3O4 is spherical, with high purity and crystallinity. The catalytic activity of Mn3O4 for PMS to degrade TCH was increased to 82.11%. In addition, after four cycles, the performance remained at 78.5%, showing excellent stability and recyclability. In addition, O2- and 1O2 are the main active species in the degradation reaction. The activity of Mn3O4 is attributed to it containing Mn(II) and Mn(III) at the same time, which can quickly realize the transformation of high-valence and low-valence manganese, promote the transfer of electrons and realize the degradation of organic pollutants.

Removal and Resource Utilization of High Concentration Flue Gas Sulfur Dioxide Using Manganese Carbonate Ore

The removal of high concentration flue gas sulfur dioxide (SO2) using manganese carbonate ore desulfurization (MCO-FGD) is a promising route that combines economic benefits and pollution control. However, the problems of intermediate oxidation and by-product control have plagued the industrial application of the MCO-FGD technique for a long time. Based on the fact that there is symbiosis of manganese and iron in natural manganese ore, in this study, small amounts of Fe(III) and MnO2 were introduced into the MCO-FGD reaction system to enhance the oxidation of SO2 to SO4− and suppress the manganous dithionate (MnS2O6) by-product generation. The results suggested that the addition of Fe(III) led to the generation of potent oxidant Mn(III) in the reaction system, which accelerated the generation of SO3−• radicals and, thus, enhanced the oxidation of SO2. Under the optimum reaction conditions, the 2.0% of inlet SO2 could be removed to 62 ppm, obtaining 90.1% manganese leaching efficiency, and the concentration of MnS2O6 in the desulfurized liquid was kept below 2.5 g/L after a six-stage desulfurization. The results are of great importance for the sustainable development of the manganese metallurgical industry, which provides theoretical and technical support for the recycling of sulfur and manganese. The influences of different operational conditions on SO2 removal, the catalytic mechanism, and manganese leaching were studied to provide theoretical and technical support for resourceful MCO-FGD technology.

Microwave efficient extraction of manganese from low-grade pyrolusite by pyrite reduction acid leaching process

With the continuous economic and social development of China, the demand for pyrolusite has increased tremendously, accompanied by a decrease in high-grade pyrolusite (HGP). Thus, it is urgent to find viable alternatives, such as low-grade pyrolusite (LGP). Currently, a relatively mature process technology is a one-step acid leaching of manganese (Mn) from pyrolusite using pyrite (PY) as a reducing agent. While the method can achieve a relatively high leaching efficiency of Mn at atmospheric pressure, it requires a significant amount of time. To pursue maximum effectiveness and efficiency, here we applied microwave leaching technology to the one-step acid leaching process to the extraction of Mn from LGP, and PY as a reducing agent. The results showed that the leaching efficiency of Mn reached 96.2% at time = 150 min, agitation speed = 400 rpm, temperature = 363 K, acid concentration = 1.5 M, liquid-solid ratio = 10: 1 (mL: g), and SLGP-SPY mass ratio = 10: 2. Furthermore, the kinetic analysis showed that the chemical reaction control model (1-(1-X)1/3 = kt) can be used to explain the mechanism of the microwave leaching process. Finally, according to the Arrhenius equation, the apparent activation energy (Ea) for the microwave leaching process was calculated as 44.8 kJ/mol. This work provides the preliminary theoretical and technical basis for recovering Mn from LGP. In summary, these results imply that LGP could be effectively utilized and developed by microwave heating technology in the future.

Options to recover high-purity MnO2 from leach liquors of manganese dust containing Mn3O4 and iron and zinc oxide as minor impurities

Manganese dust, predominantly made up of manganese oxides is produced during the manufacturing of ferromanganese alloys at high temperatures. Pure Mn compounds can be recovered from manganese dust. In this study, a hydrometallurgical process was developed to recover pure MnO2 from manganese dust containing iron and zinc oxides. The oxide species Mn3O4 in manganese dust was first completely dissolved using a mixture of sulfuric and oxalic acids at room temperature. Small amounts of iron and zinc oxides were also dissolved during manganese leaching. Iron(III) in the clarified leach liquor was then completely separated by solvent extraction using D2EHPA. Zinc(II) in the Fe(III) free raffinate was separated by either solvent extraction with Cyanex 272 or by ZnS precipitation through the addition of Na2S. Addition of Mn powder to the leach liquor separated Zn(II) by cementation and increased the solution pH and hence Fe(III) was separated by precipitation. The MnO2 powder with a purity of 99.995% was recovered from real leach liquor of manganese dust after consecutive solvent extractions of Fe(III) and Zn(II) by D2EHPA and Cyanex 272, respectively and oxidative precipitation of MnO2 from the purified solution (raffinate) using NaClO at room temperature.