Preparation of Industrial Manganese Compound from a Low-Grade Spessartine Ore by Hydrometallurgical Process (original) (raw)
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International Journal of Environmental Analytical Chemistry
This study highlights a hydrometallurgical method for the purification, extraction, and beneficiation of a multi-elemental leach liquor obtained via reductive leaching of spessartine ore, for the production of high-grade manganese compound. During these treatments, the effect of Cyanex®272 concentrations, pH, aqueous: organic (A/O) was quantified. At optimal conditions (Temperature = 27 ± 2°C, 0.2 mol/L Cyanex®272, pH = 4.5, A/O = 1:1), manganese extraction efficiency was >90%. The stripping of the loaded organic phase by 0.1 mol/L sulphuric acids yielded 95.7% in a single stripping stage. The resulting aqueous solution was appreciably beneficiated to produce manganese sulphate monohydrate (MnSO 4 .H 2 O: 49-315-9500, melting point = 702.8°C) via precipitation and crystallisation methods. Finally, a flow sheet summarising the analytical treatment steps was provided.
Preparation of manganese sulfate from low-grade manganese carbonate ores by sulfuric acid leaching
International Journal of Minerals, Metallurgy, and Materials, 2016
In this study, a method for preparing pure manganese sulfate from low-grade ores with a granule mean size of 0.47 mm by direct acid leaching was developed. The effects of the types of leaching agents, sulfuric acid concentration, reaction temperature, and agitation rate on the leaching efficiency of manganese were investigated. We observed that sulfuric acid used as a leaching agent provides a similar leaching efficiency of manganese and superior selectivity against calcium compared to hydrochloric acid. The optimal leaching conditions in sulfuric acid media were determined; under the optimal conditions, the leaching efficiencies of Mn and Ca were 92.42% and 9.61%, respectively. Moreover, the kinetics of manganese leaching indicated that the leaching follows the diffusion-controlled model with an apparent activation energy of 12.28 kJ•mol −1. The purification conditions of the leaching solution were also discussed. The results show that manganese dioxide is a suitable oxidant of ferrous ions and sodium dimethyldithiocarbamate is an effective precipitant of heavy metals. Finally, through chemical analysis and X-ray diffraction analysis, the obtained product was determined to contain 98% of MnSO 4 •H 2 O.
Processing of ferromanganese fumes into high-purity manganese sulphate monohydrate
Journal of the Air & Waste Management Association, 2020
A novel process for recovering Mn values from two types of FeMn fumes (wastes from smelters) was developed incorporating several stages of leaching, roasting and precipitation. Fumes containing high K (as K 2 O) were first leached in water at ambient conditions to recover K, purified to remove metal impurities and precipitated as 99.9% pure K 2 SO 4. The residues containing Mn and remaining impurities were then leached in sulphuric acid at 80 ºC using oxalic acid as reductant yielding Mn sulphate liquors. The leach liquors were then purified to remove Fe at 95 ºC as jarosite at pH 2.8 and Fe(III) hydroxides at pH 5.5. Base and transition metal impurities were removed as sulphides. K, Na, Ca and Mg were separated from Mn in a novel step based on precipitation of Mn hydroxide from the Mn sulphate liquors. Subsequent redissolution of Mn hydroxide in sulphuric acid under reducing conditions using oxalic acid produced a high purity Mn sulphate liquors containing < 5 ppm of these impurities. After evaporation by boiling manganese sulphate monohydrate (MSM) was crystallised, achieving purity >99.5%. Another fume containing oil contaminants having low K was subjected to sulphation roasting to produce Mn sulphate. The calcine was water leached to produce Mn sulphate liquors and treated in a similar process to make high purity MSM. Novelty aspects of the proposed process include the recovery of K as a by-product and separation of Mn 2+ from other impurities by its selective precipitation to produce a high R I P T
Journal of Physics: Conference Series
Manganese oxide (Mn3O4) was successfully synthesized from manganese sulphate using co-precipitation method. The manganese sulphate recovered from Sumbawa manganese ore. In order to predict the manganese oxide product, the Gibbs free energy calculation was performed for the possible reaction between MnSO4 and NaOH. The experimental results showed that the manganese oxide product was Mn3O4, which is consistent as the calculated Gibbs free energy is the lowest among other products. No secondary phase such as MnO, MnO2 or Mn2O3 were found in the X-ray diffraction analysis. However, Mn3O4 had coarse particle size, i.e., 1669 ± 431 nm, which is not the type of co-precipitation's results. Therefore, further study is needed to obtain fine particle size of Mn3O4.
Characterization of Sumbawa manganese ore and recovery of manganese sulfate as leaching products
The aims of this research were to study the leaching process of manganese ore which originated from Sumbawa, Indonesia and its characterization. A high grade Indonesian manganese ore from Sumbawa, West of Nusa Tenggara was characterized by X-Ray Fluorescence (XRF). The result showed composition of 78.8 % Mn, 17.77% Fe and the rest were trace elements such as Si, Co, Ti, Zn, V and Zr contents. X-Ray Diffraction analysis showed that the manganese ore was consisted of pyrolusite (MnO 2), rhodonite (MnSiO 3), rhodochrosite (MnCO 3) and hematite (Fe 2 O 3). Manganese ore was also analyzed by thermal analysis to observe their thermal decomposition character. In this study, sulphuric acid (H 2 SO 4 , 6 M) was deployed as leaching agent. The leaching process was performed at 90 ᵒC for two hours with the addition of NH 4 OH to control pH. Recovery percentage of leaching process yielded of 87 % Mn extracted. The crystallization process result at heating temperature of 200 °C was confirmed by XRD as manganese sulfate.
Manganese metallurgy review. Part II: Manganese separation and recovery from solution
Hydrometallurgy, 2007
Various methods for manganese separation and recovery from solution are reviewed, which are potentially applicable to leach solutions of secondary manganese sources, particularly nickel laterite waste effluents. The main methods include solvent extraction, sulfide precipitation, ion exchange, hydroxide precipitation and oxidative precipitation. These methods are briefly compared and assessed for both purification of manganese solutions and recovery of manganese from the solutions in terms of their selectivity, efficiency, reagent costs and product quality. The strategies for co-recovery of valuable metals including nickel and cobalt are discussed.
Hydrometallurgy, 2007
The world rapidly growing demand for manganese has made it increasingly important to develop processes for economical recovery of manganese from low grade manganese ores and other secondary sources. Part I of this review outlines metallurgical processes for manganese production from various resources, particularly focusing on recent developments in direct hydrometallurgical leaching and recovery processes to identify potential sources of manganese and products which can be economically produced.
Hydrometallurgy, 2001
Leaching studies of low-grade Joda manganese ore containing 24.7% Mn and 28.4% Fe were carried out at high temperature and atmospheric pressure using oxalic acid as reductant in sulphuric acid medium. The experiments were designed according to 2 4 full factorial design, and regression equations for extraction of manganese, iron and aluminum were determined from the data. All the significant main and interaction effects on extraction of Mn, Fe and Al have positive effect, except oxalic acid concentration and time interaction for extraction of Al. Oxalic acid concentration has strongest effect on extraction of Mn, whereas temperature and time have strongest effect on extraction of Fe and Al, respectively. 98.4% Mn and 8.7% Fe were extracted from À 150 + 105 mm ore with 30.6 g/l oxalic acid, 0.543 M sulphuric acid concentration at 85°C in 105 min. D 2001 Published by Elsevier Science B.V.
Recovery of manganese from iron containing sulfate solutions by precipitation
Minerals Engineering, 2011
Worldwide consumption of manganese is increasing, nevertheless huge amounts of manganese from hydrometallurgical processes still end up as waste since the recovery of manganese from multi-metal solutions at low concentrations is not considered feasible. Poor iron control typically prevents the production of high purity manganese. This work studies a number of precipitants in manganese recovery and iron separation from sulfate solutions. The precipitation reagents were compared from the point of view of selectivity and economy. Carbonate precipitation is a fast and effective method for the recovery of manganese from bulk solutions. Subsequent leaching of metal carbonate is also easier and consumes less acid than, for example, hydroxide or sulfide precipitates. In order to avoid gypsum formation, soda ash should be used instead of limestone. It was found that efficient selective iron removal from MnSO 4 solutions is achieved with combined O 2 or air oxidation and CaCO 3 precipitation at pH >5.8 and at a redox potential of >200 mV. Effective mixing and sufficient retention time are essential to make the method technically efficient and economically feasible.
European Journal of Engineering and Technology Research
The leaching of manganese (Mn) ore in sulphuric acid (H2SO4) under reductive conditions has been studied. The effects of leaching parameters such as ore/reductant mass ratio, acid concentration, ore particle size, solid/liquid ratio, leaching time and different reductant potential on the maximum recovery of manganese have been investigated. The optimal leaching conditions were ore/reductant mass ratio of 1:3.4, acid concentration of 10% v/v H2SO4, ore particle size of 63-200 µm, particle size of iron powder of –150 µm, solid/liquid ratio of 1:20, and leaching time of 1.5 hours at room temperature. A comparative analysis on the recovery of manganese ore was also investigated under the optimal leaching conditions for two different reductants, iron sulphate (FeSO4) and iron powder. The maximum manganese recoveries at the optimal leaching conditions in the presence of FeSO4 and iron powder are 80.6% and 95%, respectively. The results indicate that manganese can readily be leached during...