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N N Das - One of the best experts on this subject based on the ideXlab platform.
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silicoManganese production utilising low grade Manganese Nodules leaching residue
Mineral Processing and Extractive Metallurgy, 2013Co-Authors: N S Randhawa, R K Jana, N N DasAbstract:The use of washed leached Manganese Nodules residue (WMNR), generated by reductive roasting ammoniacal leaching of Manganese nodule, for production of standard grade silicoManganese (Si16Mn63), via carbothermic reduction smelting in electric arc furnace was described. The lower Mn/Fe ratio of WMNR was improved by its blending with Mn ore. Various parameters, such as Mn/Fe, Mn/Si, coke addition, CaF2 addition and holding time, were varied to optimise process to produce the desired grade of silicoManganese. Under optimised set of conditions, a charge mix with Mn/Fe≥3·5 and Mn/Si≥2·5 at basicity {(CaO+MgO)/SiO2} of 0·2 and R ratio {(CaO+MgO)/Al2O3} of 1·8 produced the standard grade silicoManganese in 15 min holding time with >77% Mn recovery. Excess coke (110% of stochiometric amount) in the smelting and CaF2 additions to the tune of 4 wt-% (WMNR–Mn ore blend) during the holding time, improved the metallic yield and Manganese recovery.
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adsorption of some bivalent heavy metal ions from aqueous solutions by Manganese nodule leached residues
Journal of Colloid and Interface Science, 2006Co-Authors: N N Das, R K JanaAbstract:Abstract The leached residue, generated after selective extraction of Cu, Ni, and Co in sulfur dioxide-ammonia leaching of Manganese Nodules, was characterized and batch isothermal adsorption experiments were conducted at ambient temperature to evaluate the effectiveness of the water-washed leached residue for removal of different bivalent metal ions from aqueous synthetic solutions. The effects of pH, initial metal ion concentrations, amount of adsorbent, interfering ions, and heat treatment were also investigated. The uptake of metal ions increased with increasing pH. Under identical conditions the adsorption capacity increased in the order Cd 2+ 2+ 2+ . The adsorption kinetics was found to follow a first-order rate expression and the experimental equilibrium adsorption data fitted reasonably well to both Langmuir and Freundlich isotherm models. Various metal ions present in the leached residue were found to be released during adsorption of heavy metals, which decreased with increased pH and were practically negligible at pH ∼ 6.0. Desorption of adsorbed metal ions from metal-loaded leached residue and its regeneration ability were also studied. The results obtained could be useful for considering the leached Manganese Nodules residue as adsorbent for removal of heavy metal ions from contaminated water bodies.
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catalytic ketonization of monocar ylic acids over indian ocean Manganese Nodules
Applied Catalysis A-general, 1998Co-Authors: K M Parida, Amarendra Samal, N N DasAbstract:Abstract The ketonization of monocar☐ylic acids was studied in the presence of seven different Indian Ocean Manganese Nodules. The reactions were performed in a continuous flow reactor with varying temperatures, flow rates of reactant and amounts of catalyst. The activity of Manganese Nodules increases with the increase in MnO2, alkali and alkaline earth metal/oxides content. Complete conversion with high selectivity was achieved at 375°C for acetic acid. A decrease in activity with increase in chain length of monocar☐ylic acid was also observed.
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studies on indian ocean Manganese Nodules iii adsorption of aqueous selenite on ferroManganese Nodules
Journal of Colloid and Interface Science, 1997Co-Authors: K M Parida, B Gorai, N N DasAbstract:Adsorption of aqueous selenite (SeO{sub 3}{sup 2{minus}}) on Indian Ocean Manganese Nodules was studied as a function of time, temperature, pH, and concentrations of adsorbate and adsorbent in acetic acid-sodium acetate buffer medium. Analysis of adsorption data supports a heterogeneous nature for the surface of Manganese Nodules. The adsorption capacity of various Manganese Nodules for selenite was correlated with their chemical composition and surface properties. Adsorption of selenite/selenate on hydrous oxides of iron, Manganese, and aluminum appears to be an efficient and inexpensive method for removing trace contaminants. Manganese Nodules, a naturally occurring complex material, with its high contents of oxides/oxyhydroxides of Mn, Fe, Si, and Al, high porosity, and high surface area may be a suitable substitute for conventional adsorbents.
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studies on indian ocean Manganese Nodules iv adsorption of some bivalent heavy metal ions onto ferroManganese Nodules
Journal of Colloid and Interface Science, 1996Co-Authors: K M Parida, Pramod K Satapathy, N N DasAbstract:Abstract The adsorption behavior of M 2+ ions ( M = Cu, Co, Ni, and Pb) onto Manganese Nodules has been investigated at 3.5 ≤ pH ≤ 5.6 (acetate–acetic acid buffer) and 30 ≤ T (°C) ≤ 50. Under identical conditions the adsorption capacity for different metal ions increased in the order Ni 2+ 2+ 2+ 2+ . In all cases the extent of adsorption increased with increasing pH and temperature. The behavior of various metal ions released from Manganese Nodules during adsorption has also been discussed.
R K Jana - One of the best experts on this subject based on the ideXlab platform.
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a brief overview on Manganese Nodules processing signifying the detail in the indian context highlighting the international scenario
Hydrometallurgy, 2016Co-Authors: N S Randhawa, Jhumki Hait, R K JanaAbstract:Abstract Manganese Nodules are the potential sources of base metals like copper, nickel, cobalt and Manganese. Considerable research and development effort have been made all over the world to extract the metals from the Manganese Nodules during the past four decades. The paper summarizes the processes developed by various research and development organizations and metallurgical consortia for the extraction of metal values from the Manganese Nodules. Since copper, nickel and cobalt in the Manganese Nodules are in oxide forms and they are present in the lattices of iron and Manganese minerals, these lattices are to be broken either by hydrometallurgical reduction or by reductive pyro-treatment for extraction of these metals. Based on this criterion, processing methods have been broadly divided into two categories: (i) pyrometallurgical treatment followed by hydrometallurgical processing and (ii) hydrometallurgical processing. Processes developed under these two categories have been discussed highlighting their merits and demerits. Pilot plant studies carried out by various metallurgical consortia like Kennecott Copper Corporation, Deep Sea Ventures, Metallurgical Hoboken Overpelt, and International Nickel Company are briefly described in this paper. The R&D efforts made in India in the processing of Manganese Nodules during last few decades are also discussed.
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application of Manganese Nodules leaching residue for adsorption of nickel ii ions from aqueous solution
International Journal of Environmental Science and Technology, 2015Co-Authors: N S Randhawa, D Dwivedi, S Prajapati, R K JanaAbstract:Deep ocean Manganese Nodules are significant futuristic resource of copper, nickel and cobalt. After recovery of these valuable metals, a huge quantity of residue (~70 % of ore body) is generated. In the present paper, investigations carried out for the application of washed Manganese nodule leaching residue (wMNR) for the removal of nickel (Ni) ions from aqueous solution by adsorption are described. Several parameters have been varied to study the feasibility of using wMNR as potential adsorbent for remediation of Ni(II)-contaminated water. The adsorption kinetics followed pseudo-first-order equation, and the rate of adsorption increased with solution temperature. Kinetics data of Ni(II) adsorption were also discussed using diffusion models of Webber–Morris and Dumwald–Wagner models. The equilibrium data were best fitted into Langmuir adsorption isotherm, and the maximum adsorption capacity was found to be 15.15 mg g−1 at pH 5.5 and temperature 303 K, which decreased to 10.64 mg g−1 upon raising the solution temperature to 323 K. The activation energy for Ni(II) adsorption onto wMNR was 9.56 kJ mol−1 indicated physical sorption. Desorption studies showed successful regeneration of adsorbent and recovery of Ni. This process can be utilized for removal and recovery of Ni from the industrial effluent.
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silicoManganese production utilising low grade Manganese Nodules leaching residue
Mineral Processing and Extractive Metallurgy, 2013Co-Authors: N S Randhawa, R K Jana, N N DasAbstract:The use of washed leached Manganese Nodules residue (WMNR), generated by reductive roasting ammoniacal leaching of Manganese nodule, for production of standard grade silicoManganese (Si16Mn63), via carbothermic reduction smelting in electric arc furnace was described. The lower Mn/Fe ratio of WMNR was improved by its blending with Mn ore. Various parameters, such as Mn/Fe, Mn/Si, coke addition, CaF2 addition and holding time, were varied to optimise process to produce the desired grade of silicoManganese. Under optimised set of conditions, a charge mix with Mn/Fe≥3·5 and Mn/Si≥2·5 at basicity {(CaO+MgO)/SiO2} of 0·2 and R ratio {(CaO+MgO)/Al2O3} of 1·8 produced the standard grade silicoManganese in 15 min holding time with >77% Mn recovery. Excess coke (110% of stochiometric amount) in the smelting and CaF2 additions to the tune of 4 wt-% (WMNR–Mn ore blend) during the holding time, improved the metallic yield and Manganese recovery.
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leaching of roast reduced Manganese Nodules in nh3 nh4 2co3 medium
Hydrometallurgy, 2011Co-Authors: Devabrata Mishra, R R Srivastava, K K Sahu, T B Singh, R K JanaAbstract:Abstract Reduction roast–ammonia leach process developed at NML for extraction of valuable metals from Manganese Nodules yielded low cobalt recovery (56%), although copper and nickel recoveries were > 90% (Jana et al., 1999b). With an aim to increase the cobalt recovery, a modified NH3–(NH4)2CO3 leaching flow-sheet have been developed for treatment of reduced Manganese Nodules. The major steps of this flow sheet are: (i) wet grinding cum preconditioning of reduced Nodules in concentrated ammoniacal liquor in presence of surfactant, (ii) precipitation of Fe and Mn from the preconditioned liquor by air purging, and (iii) leaching of the residue from the preconditioning stage. This paper describes the optimization studies of each of the above steps in bench scale for maximum metal recoveries. The role of surfactant (during preconditioning) and the need for S/L separation after the preconditioning stage for better Co recovery are highlighted. Bench scale trials under optimized conditions yield about 95% Cu, 94% Ni and 80% Co recovery. Based on the bench scale results, large scale leaching campaigns (10 kg/batch) under lock-cycle mode were also carried out, which gave quite encouraging results with average metal recoveries Cu 92.5%, Ni 91.5% and Co 71.3% in seven cycles.
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adsorption of some bivalent heavy metal ions from aqueous solutions by Manganese nodule leached residues
Journal of Colloid and Interface Science, 2006Co-Authors: N N Das, R K JanaAbstract:Abstract The leached residue, generated after selective extraction of Cu, Ni, and Co in sulfur dioxide-ammonia leaching of Manganese Nodules, was characterized and batch isothermal adsorption experiments were conducted at ambient temperature to evaluate the effectiveness of the water-washed leached residue for removal of different bivalent metal ions from aqueous synthetic solutions. The effects of pH, initial metal ion concentrations, amount of adsorbent, interfering ions, and heat treatment were also investigated. The uptake of metal ions increased with increasing pH. Under identical conditions the adsorption capacity increased in the order Cd 2+ 2+ 2+ . The adsorption kinetics was found to follow a first-order rate expression and the experimental equilibrium adsorption data fitted reasonably well to both Langmuir and Freundlich isotherm models. Various metal ions present in the leached residue were found to be released during adsorption of heavy metals, which decreased with increased pH and were practically negligible at pH ∼ 6.0. Desorption of adsorbed metal ions from metal-loaded leached residue and its regeneration ability were also studied. The results obtained could be useful for considering the leached Manganese Nodules residue as adsorbent for removal of heavy metal ions from contaminated water bodies.
K M Parida - One of the best experts on this subject based on the ideXlab platform.
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catalytic combustion of volatile organic compounds on indian ocean Manganese Nodules
Applied Catalysis A-general, 1999Co-Authors: K M Parida, Amarendra SamalAbstract:Abstract Catalytic combustion of acetone, methanol and 2-propanol as model volatile organic compounds (VOCs) has been measured over several Manganese Nodules of Indian Ocean origin in the temperature range 180–280°C. The catalytic activity of the Nodules for the decomposition of these species is correlated with their chemical composition/surface properties (e.g. surface oxygen). CO 2 and H 2 O are detected as the only combustion products of acetone and methanol at all reaction temperatures. In the case of 2-propanol, acetone and a small amount of propene are detected as byproducts. The formation of acetone and propene is correlated with the redox properties and silica content, respectively. These toxic effluents are further transformed to CO 2 and H 2 O by passing over another catalytic reactor containing Manganese Nodules at 230°C. The catalytic activity of this naturally occurring material is also compared with synthetic δ-MnO 2 and γ-FeOOH, which are the major components of Manganese Nodules. The iron-bearing phase, γ-FeOOH, has no contribution, while δ-MnO 2 plays the major role (at the operating experimental conditions). It is observed that Manganese Nodules are effective enough for the destruction of VOCs and can be considered as low temperature oxidation catalysts.
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studies on indian ocean Manganese Nodules viii adsorption of aqueous phosphate on ferroManganese Nodules
Journal of Colloid and Interface Science, 1998Co-Authors: K M Parida, Satyaranjan MohantyAbstract:Abstract Adsorption of aqueous phosphate on Indian Ocean Manganese Nodules was studied as a function of time, pH, and concentrations of adsorbate and adsorbent in acetic acid–sodium acetate buffer medium. The adsorption of phosphate follows the Langmuir adsorption isotherm. The adsorption capacities of various Manganese Nodules for phosphate were correlated with the chemical composition and surface properties.
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catalytic ketonization of monocar ylic acids over indian ocean Manganese Nodules
Applied Catalysis A-general, 1998Co-Authors: K M Parida, Amarendra Samal, N N DasAbstract:Abstract The ketonization of monocar☐ylic acids was studied in the presence of seven different Indian Ocean Manganese Nodules. The reactions were performed in a continuous flow reactor with varying temperatures, flow rates of reactant and amounts of catalyst. The activity of Manganese Nodules increases with the increase in MnO2, alkali and alkaline earth metal/oxides content. Complete conversion with high selectivity was achieved at 375°C for acetic acid. A decrease in activity with increase in chain length of monocar☐ylic acid was also observed.
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studies on indian ocean Manganese Nodules iii adsorption of aqueous selenite on ferroManganese Nodules
Journal of Colloid and Interface Science, 1997Co-Authors: K M Parida, B Gorai, N N DasAbstract:Adsorption of aqueous selenite (SeO{sub 3}{sup 2{minus}}) on Indian Ocean Manganese Nodules was studied as a function of time, temperature, pH, and concentrations of adsorbate and adsorbent in acetic acid-sodium acetate buffer medium. Analysis of adsorption data supports a heterogeneous nature for the surface of Manganese Nodules. The adsorption capacity of various Manganese Nodules for selenite was correlated with their chemical composition and surface properties. Adsorption of selenite/selenate on hydrous oxides of iron, Manganese, and aluminum appears to be an efficient and inexpensive method for removing trace contaminants. Manganese Nodules, a naturally occurring complex material, with its high contents of oxides/oxyhydroxides of Mn, Fe, Si, and Al, high porosity, and high surface area may be a suitable substitute for conventional adsorbents.
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studies on indian ocean Manganese Nodules iv adsorption of some bivalent heavy metal ions onto ferroManganese Nodules
Journal of Colloid and Interface Science, 1996Co-Authors: K M Parida, Pramod K Satapathy, N N DasAbstract:Abstract The adsorption behavior of M 2+ ions ( M = Cu, Co, Ni, and Pb) onto Manganese Nodules has been investigated at 3.5 ≤ pH ≤ 5.6 (acetate–acetic acid buffer) and 30 ≤ T (°C) ≤ 50. Under identical conditions the adsorption capacity for different metal ions increased in the order Ni 2+ 2+ 2+ 2+ . In all cases the extent of adsorption increased with increasing pH and temperature. The behavior of various metal ions released from Manganese Nodules during adsorption has also been discussed.
Wenfeng Tan - One of the best experts on this subject based on the ideXlab platform.
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arsenic detoxification by iron Manganese Nodules under electrochemically controlled redox mechanism and application
Journal of Hazardous Materials, 2021Co-Authors: Lihu Liu, Wenfeng Tan, Qi Qiao, Xuecheng Sun, Chengshuai Liu, Zhi Dang, Guohong QiuAbstract:Abstract Iron-Manganese binary oxides are characterized by high oxidation and adsorption capability and widely applied to arsenic (As) detoxification in contaminated waters. Despite of their lower preparation cost relative to synthesized iron-Manganese binary oxides, the low adsorption capacity of natural iron-Manganese oxides largely hinders their application. Here, electrochemically controlled redox was employed to improve the As(III,V) removal performance of iron-Manganese Nodules in a symmetric electrode system, and the removal mechanism and electrode reusability were also examined. Experimental results showed that both the electrochemical reduction and oxidation of birnessite in iron-Manganese Nodules contributed much to As(III,V) removal. Higher cell voltage facilitated a higher removal efficiency of total As within 0–1.2 V, which reached 94.7% at 1.2 V for actual As-containing wastewater (4068 μg L−1). The efficiency was obviously higher than that at open circuit (81.4%). Under electrode polarity reversal, the alternating reduction dissolution and oxidation recrystallization of birnessite in iron-Manganese Nodules promoted their contact with As, enhancing the total As removal efficiency from 75.6% to 91.8% after five times of repeated adsorption. This research clarifies the effect of electrochemical redox on As(III,V) detoxification by iron-Manganese oxides, and expands the application of natural iron-Manganese Nodules in the treatment of As-contaminated wastewaters.
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catalytic oxidation and adsorption of cr iii on iron Manganese Nodules under oxic conditions
Journal of Hazardous Materials, 2020Co-Authors: Ju Hai, Wenfeng Tan, Lihu Liu, Rong Hao, Guohong QiuAbstract:The speciation, toxicity and mobility of chromium (Cr) are significantly affected by natural iron-Manganese Nodules due to the adsorption and redox reactions in soils. However, the redox processes in oxic environments have received little attention. In this work, the interaction mechanism between Cr(III) and natural iron-Manganese Nodules was studied under oxic conditions, and the effects of chemical composition, dissolved oxygen concentration, pH, ionic strength and coexisting ions were further investigated. The results showed that iron-Manganese Nodules could effectively oxidize dissolved Cr(III), and most of the newly formed Cr(VI) was adsorbed on the surface of Nodules. In iron-Manganese Nodules, Manganese oxides mainly contributed to Cr(III) oxidation, and iron oxides facilitated the adsorption and immobilization of Cr(VI). In addition, Cr(III) could be catalytically oxidized to Cr(VI) on the surface of Manganese oxides through the generation of Mn(III) intermediate or Mn(IV) oxides from released Mn(II) under oxic conditions. The oxidation rate of Cr(III) by the Nodules decreased with increasing pH from 2.0 to 8.0, and increased with increasing ionic strength. This work reveals the adsorption and catalytic oxidation mechanism of Cr(III) by iron-Manganese Nodules in a simulated open system, and improves the understanding of the geochemical behavior of chromium in soils.
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microbial dna extraction and analyses of soil iron Manganese Nodules
Soil Biology & Biochemistry, 2008Co-Authors: Limei Zhang, Wenfeng Tan, Fan Liu, Xionghan Feng, Yongguan ZhuAbstract:iron-Manganese (Fe-Mn) Nodules and concretions are soil new growth, reflecting soil environmental conditions during their formation. Bacteria play a dominant role in the oxidation of dissolved Mn(II) in aqueous systems and the formation of marine and freshwater Fe-Mn Nodules. However, the role and significance of bacteria in soil Fe-Mn nodule formation have not been well recognized. In this paper, microbial DNA was directly extracted from two Fe-Mn nodule samples collected from Wuhan and Guiyang in central China. The extracted DNA was amplified by polymerase chain reaction (PCR) and cloned. The clones were then screened by amplified ribosomal DNA restriction analysis (ARDRA). Twenty patterns were obtained for Wuhan sample and Guiyang sample, respectively. DNA sequencing and phylogenetic analyses revealed that the bacterial compositions of the Fe-Mn Nodules were mainly belonged to Firmicutes, beta-protcobacteria, gamma-proteobacteria branches of the domain bacteria. These divisions had close relativeness with Mn(II)-oxidizing bacteria identified from marine Fe-Mn Nodules, implying the possible contributions of these bacteria to soil Fe-Mn nodule formation. (C) 2007 Elsevier Ltd. All rights reserved.
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elemental composition and geochemical characteristics of iron Manganese Nodules in main soils of china
Pedosphere, 2006Co-Authors: Wenfeng Tan, Fan Liu, L I Yonghua, H U Hongqing, Qiaoyun HuangAbstract:Elemental composition and geochemical characteristics of iron-Manganese Nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-Manganese Nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-Manganese Nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-Manganese Nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-Manganese Nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-Manganese Nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-Manganese Nodules.
B D Pandey - One of the best experts on this subject based on the ideXlab platform.
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leaching of copper nickel and cobalt from indian ocean Manganese Nodules by aspergillus niger
Hydrometallurgy, 2010Co-Authors: K D Mehta, Chitrangada Das, B D PandeyAbstract:Abstract The leaching of copper, nickel and cobalt from polymetallic Manganese Nodules from the Indian Ocean was investigated using a fungus — Aspergillus niger. Parameters such as initial pH, pulp density, particle size and duration of leaching were optimized for the bio-recovery of metals. At an initial pH of 4.5, 35 oC temperature and 5% (w/v) pulp density, about 97% Cu, 98% Ni, 86% Co, 91% Mn and 36% Fe were dissolved in 30 days time using adapted fungus — as against only 4.9% Cu, 8.2% Ni, 27% Co, 6.3% Mn and 7.1% Fe solubilized in control experiment. The results indicate that A. niger released organic acids such as oxalic and citric acids which in turn reduced the host metal oxides/hydroxides to their lower valence states, and thus dissolving the base metals following the indirect mechanism. A comparison of results obtained with chemical leaching of sea Nodules using citric and oxalic acids and bio-leaching using A. niger show that the leaching of metals was more effective in presence of the fungus. The appearance of some lower oxide phases of Manganese and iron in the leach residue identified by XRD phase analyses may account for unlocking of the host lattice leading to release and dissolution of metals during leaching.
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ammoniacal leaching of roast reduced deep sea Manganese Nodules
Hydrometallurgy, 1999Co-Authors: R K Jana, B D PandeyAbstract:The paper describes the reduction-roast ammonia leach process developed at NML for recovery of copper, nickel and cobalt from polymetallic sea Nodules. A brief account of the development of a two stage ammoniacal leaching scheme with a prior pre-conditioning step is given. The necessity of monitoring redox potential in the first stage leaching to control cobalt recovery has been emphasized. Based on the two stage leaching scheme, recycle leaching has been carried out to generate leach liquor having suitable composition for the subsequent solvent extraction–electrowinning operation. The average recovery of metals in 16 cycles of leaching has been found to be 92% Cu, 90% Ni and 56% Co.