Loss Of Manganese Research Articles

Iron Separation from Iron-Rich Manganese Ore Leachate: Comprehensive Optimization of Operating Parameters and Economic Viability

In the current electrolytic manganese industry, iron separation and reuse from iron-rich manganese ore leachate (IRMOL) has become one of the most pressing challenges. This study aimed to investigate the optimal conditions for iron separation from IRMOL and to assess the economic and practical advantages of iron separation or removal in industrial manufacturing. To identify more cost-effective and technologically advanced production circumstances, we examined five key elements that weaken Fe(OH)3 colloidal production conditions in enterprises: reaction temperature, pH, crystal species, aging, and reaction time. The screening results showed that when the conditions were optimized, the efficiency of reducing manganese loss decreased from 6.15% to 4.69%. Additionally, the generation of iron-rich electrolytic manganese residue (IREMR) was decreased by 44.32%, and the filtration velocity of IREMR increased from 0.0030 to 0.0220 mL/(s·cm2) compared to the production conditions before optimization at the enterprise. Through multiphase equilibria modeling with Visual MINTEQ, we have determined that raising the temperature and pH levels increases the expenses associated with chemicals and energy usage and results in an elevation of Fe(OH)2+ concentration. This can lead to the creation of Fe(OH)3 colloidal, causing a high water content in IREMR, inefficient filtration, and significant loss of manganese. This strategy is highly significant for the production of electrolytic manganese and the reduction of electrolytic manganese residue.

Efficient recovery of lithium from shale gas wastewater: Fe, Ni, and Al doping of H1.33Mn1.67O4 for improved adsorption capacity and manganese loss reduction

To minimize manganese loss during acid leaching and to enhance the lithium adsorption capacity from shale gas wastewater of H1.33Mn1.67O4, this adsorbent material was doped with metallic elements in this study. Doping was achieved using solid-phase synthesis, resulting first in a Li1.33RXMn1.67−XO4 (R = Fe, Ni, Al) precursor powder through high-temperature calcination. Then, lithium was leached out under acidic environment to obtain the desired H1.33RXMn1.67−XO4 (HMO-R) adsorbents. The equilibrium adsorption capacities of HMO-R powders were measured as 20.7 mg/g, 20.7 mg/g, and 29.0 mg/g, for Fe, Ni, and Al dopants, respectively, surpassing that of the former H1.33Mn1.67O4 (13.7 mg/L). Moreover, an average reduction of manganese loss by 30% for HMO-R was observed during lithium recovery/extraction cycles by acid leaching compared to undoped Li1.33Mn1.67O4. Overall, the doped adsorbent exhibited a stable crystal structure and high adsorption capacity, enhanced stability, performance, and efficiency in cycling experiments with respect to the undoped material.

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.

Enhanced removal of iron from iron-rich manganese ore leaching solution: A promising strategy by seed-induced

Enhanced removal of iron from iron-rich manganese ore leaching solution has become a bottleneck limiting the development of the electrolytic manganese industry. Herein, iron-rich electrolytic manganese residue (IREMR) as a seeding to enhance iron removal. The results showed that the iron removal efficiency was 99.97 % with only manganese loss of 1.5 % whenadding 1 g/L IREMR. Compared with the traditional conditions of electrolytic metal manganese enterprise, it demonstrated several environmental advantages: lower manganese loss (from 16 % to 1.5 %), less IREMR produced (64.45 %), faster filtration speed (from 0.0013 to 0.1966 mL/s.cm2). Based on multiphase equilibria modelling and strengthening mechanism analysis, enhanced iron removal by seed-induced can reduce the formation of ammonium-alum complex salts and prevent the formation of Fe(OH)3 colloid. In addition, IREMR as seeding applied in the iron removal process can accelerate the formation of goethite and hematite to shorten the nucleation cycle. This strategy is important for source reduction and resource utilization of electrolytic manganese residue.

Investigation of manganese-iron oxide nanocomposite immobilized on powdered activated carbon as an efficient activator of peroxymonosulfate for antibiotics degradation: Conjunction of adsorption, radical and nonradical processes

Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have gained considerable attention for their efficient oxidation of persistent pollutants. A two-step chemical co-precipitation method was used to prepare a bimetallic nanocomposite (MnOx@Fe3O4) consisting of manganese oxides and ferroferric oxides, supported by powdered activated carbon (PAC). The synthesis of MnOx@Fe3O4-PAC (MFP) was aimed to enhance the degradation efficiency of oxytetracycline (OTC) via the simultaneous adsorption and oxidation processes on the solid-liquid interface. The OTC degradation process in the MFP/PMS system could be well described by pseudo-first-order kinetics. A wide pH range (3–6) was acceptable for MFP to degrade OTC via PMS activation with the highest removal efficiency reaching up to 85.6% (OTC0 = 150 mg/L), while a 60.8% removal efficiency of total organic carbon (TOC) was also attained simultaneously. SO4•− and 1O2, which were bound to the surface, played a crucial role as reactive oxygen species in the degradation of OTC. The combination of PAC, Fe3O4, and MnOx of MFP could enhance the degradation efficiency of OTC and fetch up their defects of separate application. The deduced OTC degradation pathway relied on the findings from UPLC-MS analysis and density functional theory (DFT) calculations. Noteworthy, MFP maintained efficient catalysis performance in the five cycles of stability experiment with neglectable loss of manganese and iron. These results provide valuable understanding of the conjunction of adsorption, radical, and nonradical processes driven by MFP for OTC degradation.

Manganese losses induced by severe soil acidification in the extensive Lei bamboo (Phyllostachys violascens) plantation stands in Eastern China

Manganese (Mn) is a critical element in soils, essential to plant growth. Long-term and intensively managed Lei bamboo (Phyllostachys violascens) stands are usually subjected to severe soil acidification and Mn activation. However, Mn migration from topsoil to deep soil induced by severe soil acidification was poorly recognized and studied. The distribution and changes of the total and the operationally defined Mn forms in soil profiles and its potential stress and environmental effect were investigated in a chronosequence of Lei bamboo stands (0, 2, 6, 11, and 16 years of stand age). The results showed that the Mn amount was significantly decreased in topsoil and accumulated in subsoil with the long-term and intensive fertilizer application. Soil exchangeable Mn and superphosphate extractable Mn demonstrated large different variation to total Mn, whereas their sum was largely higher than and highly correlated with 8-hydroxyquinoline (HQN) extractable Mn. Soil organic carbon, pH value, exchangeable bases, and soil redox simultaneously controlled soil Mn depletion. In conclusion, long-term and intensive fertilizer application leads to soil acidification and accelerated soil Mn depletion in bamboo stand soil, promoting Mn accumulation in bamboo shoots.

A fundamental investigation into the role of beam focal point, and beam divergence, on thermo-capillary stability and evolution in electron beam welding applications

In this work a novel mathematical framework, that fully describes fusion and vapourisation state transitions in multi-component substrates, has been applied to assist in understanding the fundamental mechanisms of thermo-capillary (keyhole) formation and stability during the electron beam welding process. Specifically the role of electron beam divergence, and the location of the beam focal-point within the substrate, is numerically investigated. It is shown that the location of the beam focal point directly influences the keyhole formation dynamics and leads to drastically different keyhole structures. It is further shown that a less divergent electron beam has a greater penetration rate and produces a more stable thermo-capillary. Finally the chemical heterogeneity induced due to preferential element evaporation during the process is explored and significant Manganese loss is predicted from the simulated SA508 steel substrate.

Preparation of PVC-LMZO membrane and its lithium adsorption performance from brine

The forming technology of lithium ion sieves is of great significance for their industrial production and application in brine. A PVC-LMZO lithium ion sieve precursor membrane was prepared by blending the zirconium-coated lithium ion sieve precursor LMZO with PVC, PMMA and PVPk30. The adsorption and cyclic performance of the PVC-LMZO membrane obtained after treatment with HCl were studied. The results showed that the optimal condition for membrane preparation is to add 10 wt% PVC, 20 wt% LMZO, 6 wt% PMMA and 2 wt% PVPk30. After treatment with 0.1 mol·L−1 HCl for 2 h, the lithium desorption reached equilibrium, and the manganese loss rate was approximately 0.332 %. After 15 cycles of adsorption and desorption in brine, the Li+ adsorption capacity was lost by only 5.8 % (from 18.33 mg/g to 17.27 mg/g). The PVC-LMZO membrane had high selectivity for Li+ in brine containing a variety of complex ions such as K+, Ca2+, Na+ and Mg2+. The PVC-LMZO membrane has a stable structure and excellent recycling performance, which is conducive to its industrial application. The PVC-LMZO membrane accords with the Langmuir adsorption isotherm model and pseudo-second-order kinetics model, indicating a monolayer chemisorption. The PVC-LMZO membrane has great development potential for extracting lithium from liquid lithium resources such as salt lake brine.

Simulated synthesis and atomic-level structural characterization of LiNi2O4

LiMn2O4 is a promising cathode material for advancing lithium-ion batteries due to its high-rate capabilities and high operating voltages. However, it suffers capacity fading due to the loss of manganese and lattice instabilities linked to Mn3+ during cycling. The simulated synthesis technique has been used to generate LiNi2O4 models rich in microstructural features that evolve during the crystal growth process. The microstructural features can be linked to the electrochemical performance and properties of LiNi2O4, which will guide the doping of LiMn2O4 spinel with Ni. Substitution of a small amount of manganese with nickel has been proposed as one of the solutions for reducing capacity loss. The LiNi2O4 spinel structure was synthesized successfully with the simulated amorphization and recrystallization technique. The RDF functions indicated the average Ni – O bond length of ~1.925 Å which is comparable to the Ni – O average bond length of ~1.923 Å synthesized by Thomas M.G.SR and co-workers.

Extruded monolith MnOx-CeO2-TiO2 catalyst for NH3-SCR of low temperature flue gas from an industry boiler: Deactivation and recovery

The selective catalytic reduction (SCR) of NOx with NH3 (NH3-SCR) technology has been widely applied for reducing NOx emissions from stationary and mobile sources. In this work, the extruded monolith MnOx-CeO2-TiO2 catalyst was installed in a cement kiln for NH3-SCR of NOx, where the flue gas temperature was 110–140 ℃. It is found that the monolith catalyst is severely deactivated after operating for about 200 h with almost no NOx conversion at 160 ℃ under GHSV of 50000 h−1, while the fresh monolith catalyst remains 60% NOx conversion. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), temperature-programmed desorption of SO2 (SO2-TPD) and thermogravimetric-differential thermal analysis (TG-DTG) experiments reveal that both MnOx and CeO2 oxides in monolith are severely sulfated to manganese sulfate and cerium sulfate, and the external monolith walls are covered by massive ceria sulfate and little ammonium nitrate. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis demonstrates that the formation of nitrates at low temperatures is inhibited due to the occupation of active sites in MnOx-CeO2-TiO2 by sulfates, resulting in the decrease of low temperature activity. After washing with water, the activity of deactivated monolith catalyst can be partially recovered, together with significant loss of manganese and cerium from monolith.

Primary Study on Medium and Low Carbon Ferromanganese Production by Blowing CO2-O2 Mixtures in Converter

The production of medium- and low-carbon ferromanganese (M-LCFeMn) using the converter method has not been industrialized to date in China due to the high manganese loss and serious erosion of the furnace lining. To solve the above problems and to improve the refining technology of M-LCFeMn, the introduction of CO2 gas into the traditional converter process is proposed. In this study, the oxidation behavior of C and Mn in various conditions was analyzed by blowing different proportions of CO2-O2 mixed gas into the high-carbon ferromanganese (HCFeMn) melt. The results showed that it is feasible to make M-CFeMn by blowing CO2-O2 mixtures, and the Mn loss can be effectively reduced during the decarburization process. It is considered that when the proportion of CO2 reaches 25%, the mixed gas has the best effect on the decarburization and manganese preservation under current experimental situation. Two hypotheses and corresponding rate formulas of decarburization kinetics by using pure oxygen are put forward, and the effect of CO2 on the kinetics of decarburization was studied according to different hypotheses.

Content and Balance of Trace Elements (Co, Mn, Zn) in Agroecosystems of the Central Chernozemic Region of Russia

This work is devoted to the study of the provision of arable soils with mobile forms of the most important trace elements (cobalt, manganese, and zinc). In modern Russian agriculture, the low provision of soils with trace elements is one of the reasons leading to lower yields and the deteriorating quality of most crops. The materials of the regional and local agroecological monitoring of soils in Belgorod region, which is part of the Central Black Earth region of Russia, were used in this work. The results of the local agroecological monitoring showed that the average gross contents of manganese, zinc, and cobalt in arable chernozems in the typical forest-steppe zone were respectively 345, 36.5, and 8.48 mg/kg, and in chernozems common in the steppe zone the contents were 397, 42.9, and 9.51 mg/kg. In the distribution of the gross contents of the studied trace elements in the profile of arable chernozems, a tendency of a gradual decrease in their concentrations with increasing depth was revealed. According to the results of the regional agroecological monitoring of arable soils in the Belgorod region for 2015–2018, it was found that the proportion of soils with a low content of mobile compounds of zinc (<2 mg/kg) was 90.3%; for cobalt (<0.2 mg/kg) and manganese (<10 mg/kg), the proportions were 99.3% and 38.6%, respectively. In these soils, it is advisable to introduce microfertilizers containing trace elements that are in deficit. The main sources of the manganese, zinc, and cobalt input to agroecosystems are organic fertilizers, which account for 79.3%, 86.3%, and 66.6% of the total amounts, respectively. Losses of manganese and cobalt from agroecosystems mainly occur as a result of the washing away of arable soils—82.8% and 96.8% of total losses, respectively—and 60.5% of zinc losses are due to alienation by the marketable part of the crop. A positive balance had been a feature of zinc, with an intensity of 106%, while manganese and cobalt had a negative balance, with intensities of 61.3% and 25.3%, respectively.

Solid-Phase Reduction and Separation of Iron and Phosphorus from Manganese Oxides in Ferromanganese Ore

The possibility of joint solid-phase reduction of iron and phosphorus from ferromanganese ore has been experimentally confirmed. Solid-phase reduction was performed at a temperature of 1000°C and exposure time of 2-5 hours, in a CO atmosphere, also produced the separation of the reduction products by melting. The distribution of iron and phosphorus was studied using an electron scanning microscope. The phase analysis of the samples was studied using a Rigaku Ultima IV X-ray diffractometer. The results were processed using the "Match" software. Reducing roasting in a CO atmosphere provides a transition from the oxide phase to the metallic phase of only iron and phosphorus without loss of manganese, thus increasing the concentration of MnO oxide in the residual oxide phase of the ore.

Metal ion fluxes controlling amphibian fertilization.

Mammalian oocytes undergo major changes in zinc content and localization in order to be fertilized, the most striking being the rapid exocytosis of over ten billion zinc ions, known as zinc sparks. Here we report that fertilization of amphibian Xenopus laevis eggs also initiates a zinc spark that progresses across the cell surface in coordination with dynamic calcium waves. This zinc exocytosis is accompanied by a newly recognized loss of intracellular manganese: synchrotron-based X-ray fluorescence and analytical electron microscopy reveal that zinc and manganese are sequestered in a system of cortical granules that are abundant at the animal pole. Through Electron-Nuclear Double-Resonance (ENDOR) studies, we rule out Mn2+ complexation with phosphate or nitrogenous ligands in intact eggs but the data are consistent with a carboxylate coordination environment. Our observations suggest that zinc and manganese fluxes are a conserved feature of fertilization in vertebrates and that they function as part of a physiological block to polyspermy.

Kinetics of Decarburization and Manganese Loss from Fe–15Mn–1C Alloy by Bubbling of Argon–Oxygen Gas Mixtures

Kinetics of Decarburization and Manganese Loss from Fe–15Mn–1C Alloy by Bubbling of Argon–Oxygen Gas Mixtures

Long-term performance of three mesophilic anaerobic digesters to convert animal and agro-industrial wastes into organic fertilizer

Few studies have investigated the performance of anaerobic digestion (AD) to convert animal and agro-industrial wastes to organic fertilizers over a long-term field conditions. This paper studied three large-scale mesophilic digesters (D1–D3) over two years for their effects on feedstocks, which were dairy manure for D1 and D2 and co-digestion mixed manure and agro-industrial wastes for D3. Hydraulic retention times (HRT) were 9 d for D1, 12 d for D2, and 34 d for D3. Digester influent and effluent samples were taken every two months from the digesters and analyzed for pH, and concentrations of total solids (TS), ammonium nitrogen (NH4-N), total Kjeldahl nitrogen (TKN), total phosphorus (TP), and eight metals. The study revealed high variability in converting feedstock in the three digesters. Compared with their respective influent, the mean digester effluent pH decreased from 7.9 by 0.6 in D1 (p < 0.01) and by 0.3 in D2 (p < 0.01), but it increased from 6.1 by 1.8 in D3 (p < 0.01). The mean digester effluent TS increased from 3.4% by 0.1% (p > 0.05) in D1, but it decreased from 4.9% by 1.3% in D2 (p < 0.05) and from 12.3% by 4.8% in D3 (p < 0.01). All three digesters significantly increased NH4-N concentrations by 21.4–81.8% (p < 0.05), but insignificantly changed TKN and TP concentrations (p > 0.05). Effects of AD on all metal concentrations were mixed and were insignificant (p > 0.05) because of large concentration variations. However, study of a ratio quotient (qMg) using magnesium (Mg) as the reference discovered accumulation of NH4-N, copper, potassium, and sodium, but loss of TKN, TP, iron, manganese, zinc, and calcium during AD for D2 and D3. The impact of AD conversion was closely related with types of feedstock (on pH) and HRT (on TS and NH4-N). The results of this study can assist in developing strategies for cleaner production using AD in an environmentally sustainable manner.

Study on the Growth Law of Manganese in Electrolysis Process of MnSO4 Solution Containing Magnesium

At present, there was no good industrial removal method for soluble impurity Mg2+ in electrolytic manganese industrial production, so MgSO4-MnSO4-(NH4)2 SO4 compound salt crystal with minimal solubility was formed by cyclic enrichment in solution. On the one hand, it caused the loss of manganese, ammonium and other main components, on the other hand, a large amount of storage caused environmental pollution. In order to find out the harmful effect of magnesium on the production of manganese in an all-round way, this paper studied the growth and deposition of manganese when the concentration of Mg2+ was 25g/L. The results showed that with the increase of electrolysis time, the grain size increases from 42.11μm for 2h to 185.71 μm for 10h, and the current efficiency gradually decreased from 73.3% for 2h to 67.26% for 10h. After 8 hours of electrolysis, the growth rate of grain size and the decrease rate of current efficiency were improved, and there were a certain relationship between them.

Improved High-Energy Na-NCM Cathode Prepared by Ion Exchange Route via Application of Various ALD Treatments

The application of layered oxide compounds as cathode materials for sodium-ion batteries is considered a promising direction for the development of high-energy Na-ion batteries. However, despite many efforts, practical implementation of such electrodes is still challenging, mainly due to structural and surface instabilities associated with the high operating voltage of these cathodes. One of the most effective ways to mitigate these undesirable phenomena is the use of atomic layer deposition (ALD) to form a Nano-sized protective layer on the electrode surface. Application of ALD treatment results in increased electrode stability by preventing irreversible interactions between the electrolyte and cathode material. In search of optimal coating formulations, the effect of various ALD coatings viz. sodium-aluminate, lithium-aluminate, and alumina on the electrochemical performance of Na-NCM cathode synthesized by ion-exchange method. While the initial capacity loss attributed to oxygen release was significantly suppressed in all coated samples, better stability was observed for NaxAlyOz coating. The stabilization mechanism of the NaxAlyOz coating further investigated by XPS, XRD, and TEM revealed improved surface properties that prevent irreversible oxygen loss and migration of manganese from the electrode bulk toward the surface.

Optimization of Production of Blast Furnace Ferromanganese in Conditions of Non-Integrated Iron Works

Production of high carbon blast furnace ferromanganese (HC FeMn) in conditions of Russian non-integrated iron works stipulates use of various combinations of permanently changed sorts of manganese ores with different mineralogy, manganese content and granulometric composition. Operation complexity is caused by challenge to satisfy with customers’ stringent requirements specific to percentage of manganese, silicon and maximum permissible content of tramp elements in produced alloy as well as by necessity to recycle fine fraction formed at the stage of crushing of solidified large-sized ferromanganese. Fluxless technological regime is defined as a most efficient mode to achieve high technical and economic indices. Special attention is given to methods of increase of manganese recovery in every stage of technological process. The largest losses of manganese are related to losses with slag and top gas, and developed techniques to minimize these losses are described with taking ecological aspects into consideration.

High-carbon ferromanganese smelting on high-base slags

The article presents the results of laboratory trials for the smelting of high-carbon ferromanganese on highly-basic slags. Laboratory trials have confirmed that an increase in the basicity of ferromanganese production slags has a positive effect on the reduction of manganese to the metal and a decrease in the concentration of silicon in it. However, the high basicity makes the slag high-melting and tough, leading to large losses of manganese with the slag. The use of on borate fluxes solves this problem by affecting the physical and chemical properties of the final slags, which allows the process to be carried out at high basicities with the achievement of optimal technological indicators. The obtained positive results of laboratory experiments served as the basis for approbation the developed technology on a semi-industrial scale with the smelting of high-carbon ferromanganese by the flux method from the manganese ore of the «Bogach» Deposit. As a result of studying the smelting of carbonaceous ferromanganese in large-scale laboratory conditions, the possibility of converting manganese ores on highly-basic slags with appropriate regulation of the transport properties of slag to a standard metal with high technical and economic indicators was established. The best results are achieved when the CaO/SiO2 ratio in the slag is 1.8 and the boron oxide content in the slag is 0.8%. It is established that under these conditions, the obtained boron-containing highly-basic slags of carbonaceous ferromanganese are not subject to slaking.