Effect of basicity on ferromanganese production from beneficiated low-grade manganese ore (original) (raw)
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Ferromanganese production from the mixture of medium-grade and low-grade Indonesian manganese ore
Advances in Materials and Processing Technologies
In this present work, the ferromanganese was produced by mixing two different grades of Indonesian manganese ore. The possibility of mixing medium-grade manganese ore (27.77 Mn-4.44 Fe-14.7 Si) and low-grade manganese ore (16.39 Mn-19.22 Fe-20.23 Si) to produce ferromanganese was investigated clearly. The 30 Kg of manganese ore mixture was smelting by using submerged arc furnace (SAF). The composition of manganese ore mixture in percent weight to produce ferromanganese was 100-0, 75-25, 50-50, 25-75, and 0-100 for medium-grade and low-grade manganese ore, respectively. These ores were smelted together with stoichiometry cokes. Limestone was added in this smelting process to obtain 0.75 of basicity in this smelting process. The chemical composition of ferromanganese was analyzed with X-Ray Fluorescence (XRF). From the smelting process, the ferromanganese with 31.13 Mn-59.84 Fe-7.84 Si and 75.19 Mn-20.17 Fe-3.27 Si were resulted from 100% of low-grade and medium-grade manganese ore, respectively. The Mn-content in ferromanganese and the yield of ferromanganese production were decreased with the increasing of low-grade manganese ore in the mixture of low-grade and medium-grade manganese ore smelting process.
Beneficiation of two different low-grade Indonesian manganese ores to improve the Mn/Fe ratio
2017
The beneficiation of two different low-grade manganese ores had been done by gravity separation and reduction-roasting process followed by the magnetic separation to improve their Mn/Fe ratio. The effect of particle size and temperature of reduction-roasting in this beneficiation process had been investigated clearly. XRF and XRD analyzer were used to characterize the as-received and beneficiated of these low-grade manganese ores. From the result, the manganese oxide in the form of pyrolusite (MnO 2) was easier to beneficiate for enhancing the Mn/Fe ratio than in the form of pyroxmangite (MnSiO 3) and grossular manganoan (Ca 1.3 Mg 0.1 Mn 0.8 Fe 0.8 Al 2 (SiO 4) 3. The optimum beneficiation resulted from the reduction-roasting process of low-grade manganese ore in-40+60 mesh at temperature 700ºC followed by the magnetic separation process. It had improved the Mn/Fe ratio of this low-grade manganese ore from 1.39 into 4.0.
Characterization of Egyptian Manganese Ores for Production of High Carbon Ferromanganese
Journal of Minerals and Materials Characterization and Engineering, 2013
This work aims at studying the reactivity of Egyptian manganese ores to be used in the production of ferromanganese alloys in submerged electric arc furnace. Ores with different manganese content (high-medium and low) were selected and characterized by X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). The main mineralogical compositions in the three ores are pyrolusite (MnO 2) and hematite (Fe 2 O 3). Porosity of selected Mn ores was determined. The reactivity of the different ores was carried out through pre-reduction of the selected ores using thermobalance at 900˚C and 1100˚C and mixture of CO and CO 2 gases. The reduction process was done until steady weight. The reduced ores were examined using XRD and SEM. The results showed that pyrolusite in high and medium ores are converted completely to MnO at 1100˚C. However, the ore with low manganese content was converted to MnO and Mn 3 O 4. Consequently, it is clear from the results that Mn ores with high and medium MnO 2 content are more reactive than those with low MnO 2. Therefore, high MnO 2 content Mn ores are preferable to get good economic impact during the production of high carbon ferromanganese.
Production of High Carbon Ferromanganese from a Manganese Ore Located in Erzi̇ncan
2010
Ferromanganese is an important additive used in the production of steel. Turkey produces more than 25 million tons of steel a year and the quantity produced is steadily increasing. Ferromanganese is not produced in Turkey, therefore, the country's entire supply is imported. Studies related to ferromanganese production would be benificial for future investments in ferromanganese production facilities. The production of high carbon ferromanganese from a manganese ore deposit located in Erzincan was examined in this study. The ore was smelted using carbon as the reducing agent. Time, weight ratio of graphite to ore, fluorspar addition, and charge basicity were used as the experimental variables and the resulting alloy and slag phases were subjected to chemical analysis. The objective of this study was to investigate the possibility of high carbon ferromanganese production from manganese ore in Erzincan.
A Review of Ore Smelting in High Carbon Ferromanganese Production
Mineral Processing and Extractive Metallurgy Review, 2019
Manganese ore smelting is reviewed in terms of processing parameters such as feed material particle sizes, energy input methods, heat transfer modes, smelting mechanisms, experimental findings on specific smelting aspects, and rates of MnO reduction and carbon dissolution into ferrous alloys. This paper provides a comprehensive current review of our fundamental understanding of manganese ore smelting. Process parameters and resultant cost effects are discussed in terms of existing industrial smelting processes, the Submerged Arc Furnace (SAF) and the Blast Furnace (BF), and the AlloyStream process demonstration plant. Bench-scale experimental results for AlloyStream induction furnace smelting are discussed with reference to rate measurements reported in literature. The experimental results clearly illustrate the importance of higher alloy bath temperatures in induction smelting to improve alloy production rates, whilst the effect of alloy bath chemistry was of less importance. AlloyStream process benefits and issues are discussed with reference to the SAF and BF processes.
MnO reduction in high carbon ferromanganese production: practice and theory
Mineral Processing and Extractive Metallurgy Review, 2018
The SAF (Submerged Arc Furnace) process is most widely used for industrial production of high carbon ferromanganese. Most plants use ore feed in the form of lump ore (-75mm +6mm), but long term supply is limited, and large quantities of ore fines are generated in ore mineral processing. Therefore development of alternative processes using ore fines (-10mm) is important. The AlloyStream process is one such process developed to use a feed material mixture of fine ore, coal and flux. This process development provided a unique opportunity to correlate MnO reduction process theory to pilot plant production practice represented in minerlogical observations furnace heap samples.
Pre-reduction of manganese ores for ferromanganese industry
Ironmaking & Steelmaking, 2011
Pre-reduction of manganese ores by solid carbon was investigated to try to increase the efficiency and cost effectiveness of the ferromanganese industry. The pre-reduction reactions of manganese ore containing 57?2%MnO 2 has been conducted by solid carbon in a rotary kiln furnace at 800-1100uC. The reaction was stopped intentionally at the formation of MnO in order to investigate the pre-reduction behaviour of manganese ore and the factors affecting the process. The ore and reduced samples were characterised by X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectroscopy analysis. The isothermal prereduction behaviour was followed using a thermogravimeteric technique and a quadrupole mass spectrometer in order to determine the reduction kinetics and mechanisms of the process. Relatively, the rate of reduction of manganese ore increased with increasing reaction temperature. The highest reduction of MnO 2 to MnO was achieved at 1000uC which was confirmed by bench scale rotary experiments where 45?3%MnO and 1?72%MnO 2 were detected. Application of the optimum reduction condition on a semipilot scale resulted in 44?6%MnO and 2?55%MnO 2. The pre-reduction reactions proceeded in stepwise manner. The calculated values of activation energy (129 kJ mol 21) revealed that a solid state diffusion mechanism plays a significant role in the carbothermic pre-reduction process of manganese ore.
Characterization and Reduction Roasting Studies of an Iron Rich Manganese Ore
Transactions of the Indian Institute of Metals, 2017
The article presents the reduction roasting followed by low intensity magnetic separation studies of a low grade Mn ore assaying 27.7% Mn and 26.1% Fe in order to obtain a Mn rich non-magnetic concentrate. The reflected light microscopic studies followed by the liberation studies of the as-received sample using quantitative mineralogical evaluation by scanning electron microscope suggested a poor liberation pattern of the constituent Mn and Fe minerals owing to a complex association of the different phases present. The reduction roasting studies carried out while varying different process parameters such as ore particle size, temperature, reductant content and residence time ended up with products containing 45-48% Mn with a Mn/Fe ratio of 5-6 at a yield of * 60% with the optimum level of conditions such as temperature: 800-850°C, time: 90-120 min and charcoal: 10-12%. The scanning electron microscopy-energy dispersive X-ray spectroscopy studies of the roasted product reported manganite as the major Mn bearing phase while magnetite was found to be the major iron bearing phase.
Parameters Affecting the Production of High Carbon Ferromanganese in Closed Submerged Arc Furnace
This study has been performed to investigate the different parameters affecting on the production of high carbon ferromanganese in closed submerged arc furnace. The analysis of industrial data revealed that using manganese ores with low Mn/Fe ratio necessitates higher amount of Mn-sinter in the charge. Using Mn-blend with higher Mn/Fe ratio reduces the coke consumption and this leads to reducing the electrodes consumption. The recovery of Mn ranges between 70 and 80 %. Much higher basic slag has slight effect on Mn-recovery. However, as slag basicity increases, the MnO-content of slag decreases. The manganese content of produced HCFeMn depends mainly on Mn/Fe ratio of Mn-blend. For obtaining HCFeMn alloy containing minimum 75%Mn, it is necessary to use Mn-blend with Mn/Fe ratio of higher than 6. A model for determination of the amount and composition of off-gases has been derived based on the chemical composition and material balance of the input raw materials and the produced alloy and slag. By using this model, the amount of off-gases was found to increase by increasing both Mn-blend and coke consumption.
Revue De Metallurgie-cahiers D Informations Techniques, 2020
During the production of high carbon ferromanganese, the feed undergoes different stages of reduction. Three main zones were assumed instead of traditional four. The influence of phases formed during pre-reduction have a gigantic impact on the kinetics of the quality of the final products. In the current investigation, basic South African manganese ores were used. Two different fluxes were tested namely alumina and silica. For the experiments the ore, flux and coke were mixed and milled to 75 µm for 15 minutes for better homogenization. Using a graphite crucible placed into a silica crucible, the crucible was placed in the hot zone of the alumina tube furnace which was programmed at different temperatures. To avoid the reaction between the graphite crucible and the manganese ore. Argon was blown into the furnace from room temperature to 600 °C then switched off to allow carbon only to react with the oxide ore. The furnace was kept for two hours and switched off until the furnace reached 600 °C then argon was blown into the furnace down to room temperature. XRD, XRF and SEM were used for characterization. With the use of alumina as fluxing agent the temperatures used were 1200, 1250 and 1300 °C whereas with silica used as fluxing the temperatures tested were 1200 and 1350 °C. The influence of the A/S (alumina/silica) ratio on the kinetics was assessed.