An overview on potential hydrometallurgical processes for separation and recovery of manganese (original) (raw)
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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.
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.
Hydrometallurgical Processing of Manganese Ores: A Review
Journal of Minerals and Materials Characterization and Engineering, 2014
Hydrometallurgy is the most suitable extractive technique for the extraction and purification of manganese as compared to all other techniques including biometallurgy and pyrometallurgical processes. In the hydrometallurgical processing of manganese from its ore, the leach liquors often contain divalent ions such as iron, manganese, copper, nickel, cobalt and zinc along with other impurities which make manganese very difficult to separate. The processes employed for solution concentration and purification in the hydrometallurgical processing of manganese include precipitation, cementation, solvent extraction and ion exchange. Solvent extraction also proves more efficient and it plays vital roles in the purification and separation of the manganese as compared to all other techniques. A detailed review of the various steps involved in the hydrometallurgical manganese processing, concentration and purification processes and newer processes of extraction of manganese from ores and waste materials were discussed.
Hydrometallurgy, 2016
To minimize the environmental impacts of electrolyte manganese residue (EMR) and to recover the valuable manganese element, precipitation of the soluble manganese from EMR using ammonia bubbled with CO 2 was investigated. Precipitation behaviours in the presence of ammonia with or without CO 2 are discussed by comparison. It was found that the process using a combination of ammonia and CO 2 results in better precipitation of manganese, yielding MnCO 3 as observed by XRD analysis. The molar ratio of ammonia to manganese and the strength of bubbling and agitation with CO 2 were studied as parameters affecting the recovery of manganese. The optimal experimental conditions for the recovery of manganese were found to be an ammonia-to-manganese molar ratio of 3:1, CO 2 bubbling at a rate of 2 L/min for 2 min, and agitation at 190 rpm at 298 K for 12 min. Under these conditions, a manganese recovery of 94.2% was obtained. Kinetic analysis indicated that the order of the reaction and the energy of activation for the precipitation of manganese are approximately 2.2 and −56.7 kJ/mol, respectively.
Journal of Hazardous Materials, 2011
During the hydrometallurgical extraction of zinc by electrowinning process, a hazardous solid waste called anode mud is generated. It contains large quantity of manganese oxides (55-80%) and lead dioxide (6-16%). Due to the presence of a large quantity of lead, the anode mud waste is considered hazardous and has to be disposed of in secure landfills, which is costly, wastes available manganese and valuable land resources. For recovery of manganese content of anode mud, a process comprising of carbothermal treatment using low density oil (LDO) followed by sulphuric acid leaching is developed.
Hydrometallurgical Production of Electrolytic Manganese Dioxide (EMD) from Furnace Fines
Minerals
The ferromanganese (FeMn) alloy is produced through the smelting-reduction of manganese ores in submerged arc furnaces. This process generates large amounts of furnace dust that is environmentally problematic for storage. Due to its fineness and high volatile content, this furnace dust cannot be recirculated through the process, either. Conventional MnO2 production requires the pre-reduction of low-grade ores at around 900 °C to convert the manganese oxides present in the ore into their respective acid-soluble forms; however, the furnace dust is a partly reduced by-product. In this study, a hydrometallurgical route is proposed to valorize the waste dust for the production of battery-grade MnO2. By using dextrin, a cheap organic reductant, the direct and complete dissolution of the manganese in the furnace dust is possible without any need for high-temperature pre-reduction. The leachate is then purified through pH adjustment followed by direct electrowinning for electrolytic mangane...
Acid leaching and electrochemical recovery of manganese from spent alkaline batteries
This paper discusses a procedure for manganese recovery as manganese dioxide by anodic oxidation of acid solutions obtained by leaching of spent alkaline batteries with sulfuric acid. Spent size D alkaline batteries were dismantled, separating case, contacts and separator from the reactive paste. A series of laboratory tests were conducted to define the best conditions for manganese and zinc extraction with sulfuric acid. ICP analysis of the leaching solutions showed high levels of Zn and Mn, low concentrations of Fe and Cu and only traces of Hg, Cd, Pb and Ni. Concentrations were found to be between 0.17 and 0.73 mol L -1 for zinc and between 0.03 and 0.74 mol L -1 for manganese. The recovery of Mn in form of electrolytic manganese dioxide (EMD) was carried out under potentiostatic control using carbon fiber cloth anodes. The samples were submitted to scanning electron microscopy and EDAX analysis for characterization and X-ray diffraction method for qualitative analysis. MnO 2 and MnOOH were detected as main components. Impurities coming from other components of leaching solutions were not detected. The deposits exhibited uniform thickness and the carbon fibers were encapsulated by a cylindrical growth possibly caused by the uniform current distribution. MnO 2 deposition essays in acid media and reduction in acid and alkaline media were carried out on small electrodes to obtain information on the different steps of MnO 2 reduction. The efficiency of discharge of the potentiostatically obtained EMDs was in the order of 50% or less, probably due to the compact structure of the oxide. Results indicate that the presence of other metallic cations in the leaching solution has not any appreciably influence on the electrolytic Mn +2 oxidation reaction neither on the electrochemical properties of the obtained electrolytic manganese oxide.
Anodic Lodes and Scrapings as a Source of Electrolytic Manganese
Metals, 2018
Manganese is an element of interest in metallurgy, especially in ironmaking and steel making, but also in copper and aluminum industries. The depletion of manganese high grade sources and the environmental awareness have led to search for new manganese sources, such as wastes/by-products of other metallurgies. In this way, we propose the recovery of manganese from anodic lodes and scrapings of the zinc electrolysis process because of their high Mn content (>30%). The proposed process is based on a mixed leaching: a lixiviation-neutralization at low temperature (50 • C, reached due to the exothermic reactions involved in the process) and a lixiviation with sulfuric acid at high temperature (150-200 • C, in heated reactor). The obtained solution after the combined process is mainly composed by manganese sulphate. This solution is then neutralized with CaO (or manganese carbonate) as a first purification stage, removing H 2 SO 4 and those impurities that are easily removable by controlling pH. Then, the purification of nobler elements than manganese is performed by their precipitation as sulphides. The purified solution is sent to electrolysis where electrolytic manganese is obtained (99.9% Mn). The versatility of the proposed process allows for obtaining electrolytic manganese, oxide of manganese (IV), oxide of manganese (II), or manganese sulphate.
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.
Electrolytic manganese metal production from manganese carbonate precipitate
Hydrometallurgy, 2016
The recovery of manganese metal from manganese carbonate precipitate by leaching-purification-electrowinning was studied. The manganese carbonate precipitate from Baja Mining Corp.'s El Boleo project was readily leached into acidic ammonium sulfate solution. The manganese extraction reached 99.7%. The manganese leachate was purified using ammonium sulfide to remove harmful impurities (Ni, Co, Cd, Cu and etc.). Manganese electrowinning was conducted in a diaphragm cell designed to eliminate edge effects and improve manganese deposition. The addition of polyacrylamide polymer had a significant leveling effect on manganese electrodeposition. However it increased the deposit internal stress and even resulted in cracking of manganese deposits at a high dosage. With increasing polyacrylamide polymer concentration, current density, and pH, the manganese current efficiency first increased, reached a maximum value and finally decreased. The manganese current efficiency decreased with increasing deposition time as the deposit became rougher and the real current density deviated from its ideal value. A reasonable catholyte circulation rate is important to maintain the optimum manganese electrodeposition. The presence of chloride in solution has a little effect on manganese deposition in its concentration range from 0 to 2 g/L. The diaphragm selection as an important part of the cell design was analyzed.