Grade Manganese Research Articles

EVALUATION OF COMPATIBLE PROCESSING ROUTES USING THERMAL TREATMENT FOR UPGRADING OF MOPA MURO AND OBAN MASSIF MANGANESE DEPOSITS

The present study deals with evaluation and compatibility of processing routes using thermal treatment for upgrade of mopa muro and oban Massif manganese ore deposits. The study samples are characterized by XRD, XRF and SEM analysis. The results of SEM analysis show the micro-cracks in the thermally treated manganese sample, Mineralogical investigation shows that in the Mopa Muro manganese ore, most of the Manganese occurs in the silicate managenese mineral as in Almandine (Fe2+)3Al2(SiO4)3, Spessartine(Mn2+)3Al2(SiO4)3, Clinochlore (Al-Fe-SiO2-OH), Geothite FeO(OH),while the Oban Massif is rich in, Pyrolusite MnO2, Clinochlore (Al-Fe-SiO2-OH ), and Spessartine(Mn2+)3Al2(SiO4)3. The mineralogy of the two deposits also revealed that there is a Free Silica (Quartz) in abundant. The low content of sulphur and phosphorus is however within the requirement of the metallurgical grade manganese ore, while 44.08% and 42.07% of manganese (Mn) obtained for Mopa Muro and Oban Massif manganese ores respectively after all analysis indicate apparent inability of the ores meet the requirement of metallurgical grade manganese with values less than 66% recommended specification using thermal treatment.

Study on condition prediction and influencing factors of manganese carbonate recovery by high gradient pulse magnetic separation

Manganese carbonate ore belongs to weakly magnetic minerals, and its co-associated minerals are mainly non-magnetic minerals, which can be separated from gangue minerals at high magnetic field intensity. However, manganese grade and recovery of magnetic separation concentrate of manganese carbonate ore are low in actual production. Therefore, the influences of manganese carbonate particle size, magnetic field intensity, volume susceptibility, pulse stroke, pH, and other factors were studied. The optimal test conditions for manganese carbonate ore recovery by high-gradient magnetic separation were predicted through the calculation results. The results show that the particle radius of manganese carbonate is 0.020 mm, the pulse impulse time is 200 r/min, and the magnetic field intensity is 0.9 T. The optimum condition test was carried out with Qianbei manganese carbonate ore as the material. The test results show that the optimum conditions are the particle radius of 0.074-0.019 mm, pulse impulse time of 200 r/min, and magnetic field intensity of 1.2 T. The reason for the deviation is that the actual ore has a fine distribution particle size, many associative bodies, complex composition, and serious agglomeration, resulting in variable particle volume susceptibility. The capture yield increases with the increase of magnetic field intensity and volume susceptibility but decreases with the increase of pulse. The lower the surface potential of manganese carbonate, the higher the recovery of manganese carbonate. The grade of manganese concentrate was 19.06% and the recovery was 76.85%. Mixed manganese concentrate with a grade of 18.04% and recovery of 87.14% was obtained by adding drugs and changing the grinding method.

Mineralogy and geochemistry of Kliripan manganese ore deposit, Hargorejo Village, Kokap District, Kulonprogo Regency

This study discusses the mineralogy and geochemistry of manganese deposits in the Kliripan area, where manganese had been mined since the Dutch occupancy until the 1970s. Although mining has been discontinued since then, the demand for manganese has increased in various industries, prompting exploration to continue to meet this demand. We performed petrographic, XRD, and XRF analysis of the ore and wall rock samples. Jasper and grainstone from the Sentolo Formation are the two lithologies where manganese mineralization occurs. Manganese-bearing minerals include pyrolusite, manganite, rhodochrosite, and lithiophorite, while the gangue minerals consist of quartz, calcite, hematite, and clay minerals. We interpret that Jasper is a product of alteration and has MnO content as high as 5.02 wt.%. Meanwhile, the economic grade manganese ore in grainstone has an MnO content up to 48.51 wt.%. The elements Ce, Zr, Co+Ni+Cu, are important discriminants to determine the type of manganese deposit. The results showed that the diagenetic process in reductive water formed the manganese ores. Oxidation of divalent manganese ion formed pyrolusite and manganite. Rhodochrosite crystallized when dilute manganese solution reacts with CO2 from limestone diagenesis. We concluded that the Kliripan manganese ore deposit has both hydrothermal and diagenetic deposits.

Processing of low grade manganese ore in submerged arc furnace

ABSTRACT This paper presents an innovative technology that has been developed for the smelting of Egyptian low-grade manganese ore to produce low-manganese pig iron and high-manganese slag. This produced slag has a high Mn/Fe ratio, which, therefore, can be used in a second smelting process in the production of manganese alloys. In this developed technology, selective reduction of iron oxides from a ferruginous manganese ore (with Mn/Fe ratio equals 0.68) has been carried out via carbo-thermic reduction, in a 5 kg bench scale submerged arc furnace. The highest metallic yield, iron recovery in the pig iron, and MnO recovery in the manganese-rich slag, equal to 98%, 95.82%, and 94.59% respectively, were achieved at the optimum conditions of 4.5 kVA for pre-reduction power, 15 kVA for smelting power, 0.8 for coke ratio and 0.26 for CaO/SiO2 ratio. The reduction process was applied successfully on a 100 kVA pilot scale submerged arc furnace

Development of Low-cost Smelting Reduction Process Using Cupola Furnace for Efficient Use of Inferior Grade Manganese Ores and Rejects

Development of Low-cost Smelting Reduction Process Using Cupola Furnace for Efficient Use of Inferior Grade Manganese Ores and Rejects

An efficient and green method to separate iron and manganese from ferromanganese ore by suspension magnetization roasting and magnetic separation

Despite the rich reserves of ferromanganese ore, it can only be discarded as waste rock due to the difficulty of its development and the unavailability of conventional methods. In this study, suspension magnetization roasting (SMR) and low-intensity magnetic separation (LIMS) were used to process ferromanganese ore. Under the optimum conditions, magnetic products with an iron grade of 69.66% at an iron recovery of 98.17% and nonmagnetic products with a manganese grade of 51.60% at a manganese recovery of 88.48% were obtained. X-ray diffraction (XRD), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy and energy-dispersive spectrometry (SEM–EDS) were used to analyze the process mechanism. The data show that the newly generated products had greatly enhanced magnetic properties and that the surface became rougher and more porous after SMR-LIMS. Finally, hematite was transformed into magnetite in the magnetic product, and other minerals were transformed into the nonmagnetic product, realizing no tailing recycling or utilization.

Anaerobic reductive bioleaching of manganese ores

The increasing demand of manganese in the industries and various hindrances in its production from low grade ores by conventional method has made it imperative for researchers around the world to develop a method of manganese extraction from low grade ores that is both environment-friendly and economical. Bioleaching has shown significant potential in manganese extraction and efficiencies of extraction have been found to be 70–98% with the help of various bacteria and fungi.This study focuses on extraction of manganese with the help of mixed bacterial strains that have been collected from their natural anaerobic environment where manganese reducing activity was evident. The extraction of manganese from reagent grade manganese dioxide and high grade manganese ore has been studied over 180 days in an anaerobic environment at room temperature and pH around 5, without the addition of any mineral acids. Highest concentrations of dissolved manganese have been found to be 928.58 mg Mn/L for reagent grade manganese dioxide and 864.54 mg Mn/L for ore grade manganese, corresponding to 650 mg and 400 mg of cumulative manganese, respectively.

Synthesis and characterization of manganese ferrite from low grade manganese ore through solid state reaction route

Manganese ferrite spinel has been synthesized by using low grade manganese ore and ferric oxide as sources of manganese oxide and iron oxide through solid state reaction route by taking manganese and iron mole ratio of 1:2 respectively. The impact of sintering temperature on phase composition and particle size is investigated. Similarly, the impact of frequency on dielectric constant, dielectric loss, AC (alternating current) conductivity and tangent losses is also investigated. The results shows the presence of spinel structure manganese ferrite (MnFe2O4) as the major phase for the sample sintered at 1200 °C. It has been established that the crystallite size increase with rise in sintering temperature. The surface morphology of the sample sintered at 1200 °C show pyramidal and triangular shape grains. The dielectric constant (εʹ) and dielectric losses (εʹʹ) were observed to decrease with increasing the sintering temperature and frequency. Furthermore, the AC (alternating current) conductivity was found to rise with rise in applied frequency. On the other hand, the tangent losses falls considerably with rise in applied frequency.

Hyper spectral and Geochemical Signatures Study on Late Archeaen of Indian High Grade Manganese Deposits in Halekal Band of Bhahaddurghatta-Hosahatty Village, Chitradurga Schist Belt (Csb), Karnataka, India

Manganese is one of the most widely distributed elements in the earth’s crust and mapping of these deposit are of high economic interest. Manganese occurs as diverse genetic types that is vital for iron and steel production. It occurs usually in the form of oxide, hydroxide, carbonate and silicate which is an important raw material for iron, steel industry, chief manufacturer of chemicals and dry cells in the form of manganese dioxides. Advanced analysis of hyperspectral signatures and GPS applications have opened a newest approach in exploration and systematic mapping of economic ore deposits. The present study aims to integrate the hyperspectral signatures with major elements of manganese ore deposits of Halekal band in Bhahaddurghatta-Hosahatty village of Chitradurga Schist Belt. The samples collected from field are studied in the laboratory using thin and polished sections under microscope and X-Ray Diffraction (XRD) analysis. Efforts are created to assess the spectral signatures of four representative random ore samples collected and analyzed through ASD Spectro-radiometer instrument operative in Visible and InfraRed (325 to 2500 nm) region with concentration of major elements. This study clearly demonstrated and documented the spectral absorption features of the selected rock samples in the study area mainly depend on the optical and physico-chemical characters of the rock and major elemental composition as well as mineral constituents of the samples.

Geochemical approach to the genesis of the Oligocene-stratiform manganese-oxide deposit, Chiatura (Georgia)

The Chiatura deposit is considered to be among the largest deposits of metallurgical grade manganese ore in the world, yet its geochemistry is poorly known, which is the focus of this paper. The Oligocene sedimentary Mn deposit is located in the Chiatura region of central Georgia and formed in a restricted arm of the Paratethys on stable crystalline basement during a regressive-transgressive cycle. An Oligocene basal conglomerate is overlain by sandstone that is in turn overlain by the ore deposits. The Chiatura sedimentary deposits form horizontal beds, 1.5 to 4 m thick, average 2 m, of which 1 to 1.5 m is high-grade ore, covering an area of some 150 km2. The Chiatura deposit contains three types of ore, primary oxide ores, carbonate ores, and oxidized carbonate ores and this paper focuses on the oxide ores. The common manganese minerals in the oxide ore are manganite, pyrolusite, braunite, and psilomelane, and less commonly bixbyite, rhodochrosite, and vernadite. Eighteen manganese-oxide and four wall-rock (low manganese content) samples were analyzed for geochemistry and found on average 36.6 wt% MnO, 2.45 wt% Fe2O3, 23.5 wt% SiO2, 5.88 wt% Al2O3, 3.84 wt% CaO for major oxide concentrations. The mean main trace element concentrations of the samples are 3944 ppm Ba, 946 ppm Sr, 511 ppm Ni, 150 ppm Zn, 94 ppm V, 84 ppm Cu, and 55 ppm Co. These element concentrations are generally low and indicate an enrichment assemblage of V, Ni, Co, Cu, Zr, As, Ba, Cd, Pb, and Zn. The total rare earth element (REE) concentrations of the deposits vary from 83 ppm to 521 ppm (mean 199 ppm). The Post-Archean Australian Shale (PAAS)-normalized REE concentrations have similar trends and show heavy REE (HREE) enrichments. All manganese-oxide samples show negative Ce (mean 0.58) and generally positive Eu (mean 1.20) anomalies, except for four samples. These geochemical data indicate that the Chiatura deposit precipitated rapidly in oxic seawater with a characteristic negative Ce anomaly. The carbonate and mixed ores compared to the oxide-hydroxide ores formed in a deeper-water environment of the shallow sea. Further, both Pb isotopic data and chemical discrimination diagrams show that the Chiatura deposit was affected by both hydrothermal activity located in deeper water, and by terrestrial input. The manganese metals in the oxide ores were syngenetically transported to the area of mineralization from deeper waters than the region where the carbonate ores formed.

Individual enrichment of manganese and iron from complex refractory ferromanganese ore by suspension magnetization roasting and magnetic separation

Owing to its complex characteristics, the large-scale utilization of ferromanganese ore is limited by the traditional processes. In this study, suspension magnetization roasting and magnetic separation technology was proposed, and the thermodynamics, phase and magnetic transformation, and microstructure evolution of the main minerals were systematically investigated during roasting. Results show that iron concentrate with iron grade of 68.31% at a recovery of 96.34% can be obtained in the magnetic separation concentrate, and manganese concentrate with manganese grade of 33.70% at a recovery of 86.83% can be obtained in magnetic separation tailings under optimum conditions. Pyrolusite and braunite were reduced to weak magnetic manganosite, and weak magnetic hematite was selectively transformed into strong magnetic magnetite. Many cracks appeared in the ores owing to the multiple reduction and dehydration reactions of ferromanganese ore, which was favorable for grinding and separation of manganese and iron.

Studies on Beneficiation of Manganese Ore through High Intensity Magnetic Separator

Upgradation techniques like wet sieving and magnetic separation were used to evaluate the beneficiation potential of manganese ore. During wet sieving, manganese content in raw ore was upgraded from 27% to a maximum value of 38% in the concentrate with a recovery of 30%. Size classification was found to have no measurable effect on manganese grade in magnetic separation. In the unsieved ground ore, manganese content of 45% was achieved with a recovery of 23% and Mn/Fe ratio of 19% at a magnetic intensity of 8500 Gauss. At the same operating conditions, SiO2 was reduced from 56% in the raw ore to 30% in the magnetic fraction. So, wet sieving technique leads to a comparatively lower manganese grade but better recovery. Conversely, a magnetic separation technique produced higher manganese grade but relatively lower recovery. Blending of the upgraded manganese ore with high grade iron ore can be done to achieve the required Mn/Fe ratio.

An innovative technology for full component recovery of iron and manganese from low grade iron-bearing manganese ore

Low grade iron-bearing manganese ore is a potential solid waste resource. In this study, an innovative technology of suspension reductive roasting and magnetic separation (SRMS) was used to treat the iron-bearing manganese ore for comprehensive recovery of iron and manganese. The phase transformation of minerals in roasting process was systematically investigated by X-ray diffraction analyzer (XRD) and high-resolution transmission electronic microscope (HRTEM). The results show under the optimum conditions of reduction temperature 680 °C, reduction time 30 min, CO concentration 20% and particle size −0.9 mm, iron concentrate with iron grade 67.38% and iron recovery 87.14% and manganese concentrate with manganese grade 30.51% and manganese recovery 87.02% were obtained respectively. Magnetite converted from hematite was enriched in the concentrate of magnetic separation, while manganosite transformed from pyrolusite and braunite was enriched in the tailings of magnetic separation. SRMS can achieve full component utilization of iron-bearing manganese without residues.

Modeling and kinetics study of microwave heat drying of low grade manganese ore

During the industrial-scale smelting process of manganese ore, blast may occur due to the high moisture content of the ore, and drying pretreatment of the manganese ore is needed in the aspects of safety. In the present paper, microwave drying experiments were conducted under different particle size distributions and different microwave power conditions to explore the basic theory of microwave drying characteristics and kinetics of manganese ore, and the experimental data were fitted and analyzed by using thin-layer drying dynamics model. Results indicated that with the increase of the particle size and the microwave power of the manganese ore, the microwave drying rate increased, and accompanied with a promoting on the drying efficiency. For describing the microwave drying process of manganese ore, diffusion approach model was adopted among the commonly used thin-layer drying kinetic models. Based on Fick's second law, it can be seen that the surface diffusion coefficient increased from 4.27 × 10−13 m2/s to 8.24 × 10−8 m2/s with the increase of particle size from a particle size range of 0.012–0.095 mm to a particle size range of 4.2–5.0 mm. Clearly, the particle size has a significant influence on microwave drying efficiency.

Separation of manganese and iron for low-grade ferromanganese ore via fluidization magnetization roasting and magnetic separation technology

As a potential solid waste resource, low-grade ferromanganese ore has not been fully utilized or recycled. In this study, fluidization magnetization roasting and magnetic separation technology were used to recycle low-grade ferromanganese ore. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), sample vibrating magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM) were used to systematically detect the process mechanism. The results show under the optimized conditions, high-quality products of iron concentrate with iron grade of 69.05% at iron recovery of 95.94%, and a manganese concentrate with manganese grade of 53.30% at manganese recovery of 90.41% were obtained. The fluidization magnetization roasting technology can make the weak magnetic hematite in raw ore transform to the strong magnetic magnetite, while it makes the pyrolusite and braunite transform to manganosite. The newly formed mineral lattice had clear stripes and remarkable magnetization properties. After magnetic separation, magnetite and manganosite were individually separated at individual concentrates, which efficiently transforms and utilises this low-grade ferromanganese ore without any residue using this process.

Effect of Particle Size and Shaking Speed on Enhancing Concentration of Manganese using Shaking Table

Increased levels of elements or minerals from ore are usually always done in the metallurgical industry. In the present investigation, low grade manganese ores from Kulonprogo, Yogyakarta has investigated by gravity methods using shaking table. In this context, the effect of different process variables such as particle size (-60 + 100 mesh; -100 + 200 mesh and -200 + 270 mesh) and shaking speed (80 rpm, 100 rpm and 120 rpm) was analysed. The table slope and wash water flow rate are a constant variable, which are at 11° and 13 dm3/minute. The interactional effects between different process variables were analysed using contour plot. It was founded that enhancement of the concentration of Mn is more than 5% with the shaking speed condition of 100-120 rpm and the particle size of 0.17 mm. Second order quadratic equations have developed to predict enhancement of Mn concentration using shaking table.

Efficient enrichment of low-grade refractory rhodochrosite by preconcentration-neutral suspension roasting-magnetic separation process

Low-grade refractory rhodochrosite ores are difficult to be utilized by traditional beneficiation process owing to their complex characteristics. In this study, preconcentration-neutral suspension roasting-magnetic separation process was firstly proposed, and the thermodynamics, kinetics, phase and microstructure evolution of mineral reaction during rhodochrosite roasting were systematically studied. The results show the raw ore was preconcentrated by high intensity magnetic separation. The suspension roasting was carried out under optimum conditions. After magnetic separation, the magnetic separation concentrate with 24.30% manganese grade and 59.61% manganese recovery was obtained. Manganese ore was transformed from MnCO3 to MnO during roasting. The thermal decomposition reaction of manganese ore conformed to random nucleation and subsequent growth model. The original minerals was destroyed due to the cracks caused by the decomposition of carbonate in rhodochrosite ore, which was conducive to the full dissociation of useful minerals and gangue mineral, and further improve the separation and enrichment effect.

Recovery of bi-metallic oxalates from low grade Mn ore for energy storage application

The depletion of primary resources has led to exploitation of secondaries which are a promising source for the future if explored wisely. The authors report a novel approach of leaching low grade manganese ore and evaluation of the energy storage properties of the precipitated oxalates. The reaction rates were around 3.57 and 2.05 approximately in presence of oxalic acid and 1.92 and 0.43 respectively in presence of acid mix. The energy storage capacity of the precipitated metal oxalates has been thoroughly investigated. Oxalate sample with Fe:Mn ratio of 0.67 showed the highest energy storage behaviour with 86.9 Fg−1 specific capacitance values with 94.3% retention after 1000 cycles. Energy density of 15.4 WhKg−1 and power density of 80 WKg−1 was obtained at 0.1 Ag−1 current density.

Reduction behavior of medium grade manganese ore from Karangnunggal during a sintering process in methane gas

In this investigation, manganese has been produced from medium grade manganese ore from Karangnunggal mine (West Java, Indonesia). The effects of keeping it at a temperature of 1200°C in methane gas on the structural properties have been studied. The material’s properties have been characterized on the basis of the experimental data obtained using X-ray fluorescence (XRF), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared (FTIR) spectroscopy. It has been found that MnO2 is reduced to hausmannite (Mn3O4), manganosite (MnO) and manganese carbide (Mn7C3). An increase of the keeping time up to 45 minutes during the sintering process leads to an increase of the MnO concentration, while at 90 minutes, the concentration decreases. The analysis based on the interpretation of both XRD patterns and FTIR spectrum allows one to explain the blockage in the particle surface of the ore by an increase of the carbon deposition.

Crystal and microstructure of MnFe2O4 synthesized by ceramic method using manganese ore and iron sand as raw materials

We have succeeded to synthesize the octahedral micro shape of MnFe2O4 through the co-precipation process followed by a ceramic processing method. At the beginning, the Mn3O4 and Fe2O3 nanoparticles were separately synthesized by the co-precipitation method from the low grade manganese ore and iron sand, respectively. Here, effect of the weight ratio of Fe2O3 and Mn3O4 to the crystal and microstructure of MnFe2O4 were investigated. Four cases of weight ratio i.e. 60:40, 70:30, 80:20, and 90:10 were considered. After mixing and compaction process in the cylindrical mould shape, the samples were sintered at 1000 °C and for 6 hours. XRD data showed that a high quality crystal phase of MnFe2O4 can be obtained for both mass ratio of 60:40 and 70:30, while in the case of 80:20 and 90:10 the MnFe2O4 appear together with impurity of α-Fe2O3. The particle shapes are almost octahedral in the micrometer size in the range of 1.2 to 1.5 m. The magnetic property shows a soft-magnetic type with a 27.5 emu/g of saturated magnetization. This will be potential for applications as the electrode materials and the magnetic core.