Geobiotechnical Recovery of Metals from Manganese Nodules: First Experiments

2015 ◽  
Vol 1130 ◽  
pp. 201-204 ◽  
Author(s):  
Christina Heller ◽  
Axel Schippers
Keyword(s):  
Size Fraction ◽  
Acid Leaching ◽  
Basal Medium ◽  
Sulfur Oxidation ◽  
Chemical Kinetic ◽  
Acidithiobacillus Thiooxidans ◽  
Manganese Nodules ◽  
Biological Reduction ◽  
Sulfuric Acid Production ◽  
The Pacific

Marine polymetallic nodules represent an important resource of the metals Ni, Co, Cu, Mn, Zn, Li, Mo, V and Zr. Nodules consist mainly of Mn-Fe oxy-hydroxide precipitations with valuable metals mostly present within the structure of these host minerals. To recover the favoured metals via hydrometallurgy it is necessary to dissolve the Mn-Fe oxy-hydroxides. To test nodules processing via bioleaching, nodules were sampled during a ship cruise to the German license area located in the Pacific Ocean in 2013. They were ground in a mortar, washed to remove seawater chloride, and afterwards sieved to obtain the particle size fraction of 63 to 315 µm. Bioleaching experiments were conducted under aerobic conditions in shake flasks at 2 % pulp density at 30°C in a basal medium. A mixed culture of acidophilic chemolithotrophic iron- and sulfur-oxidizing bacteria (Acidithiobacillus thiooxidans, At. ferrooxidans, Leptospirillum ferrooxidans, L. ferriphilum) and Acidiphilum cryptum was inoculated. Elemental sulfur was used as substrate for acid leaching via sulfuric acid production. At pH values between 1.5 and 2.2 during the experiment, 40 % Ni, 25 % Cu, 1.2 % Mn, 0.3 % Co, 1 % Fe, 70 % Zn and 70 % Zr were leached from the Mn-nodules after 56 days. In preparation for future reductive bioleaching under anaerobic conditions, chemical kinetic reaction experiments were conducted. Different amounts of Fe(II) were added to a certain amount of the Mn nodules. These experiments showed that Fe(II) chemically reduced Mn(IV) to Mn(II) at a stoichiometry of 2 to 1. This reaction is prerequisite for anaerobic leaching based on biological reduction of Fe(III) to Fe(II) coupled to sulfur oxidation (Ferredox process). Up to 82 % Ni, 98 % Co, 68 % Cu, and 97 % Mn were leached in these chemical experiments indicating that anaerobic reductive bioleaching of manganese nodules should be possible.

scholarly journals Spent sulfuric acid plant catalyst: valuable resource of vanadium or risky residue? Process comparison for environmental implications

2020 ◽  
Author(s):  
Bartosz Mikoda ◽  
Anna Potysz ◽  
Agnieszka Gruszecka-Kosowska ◽  
Ewa Kmiecik ◽  
Anna Tomczyk
Keyword(s):  
Sulfuric Acid ◽  
Acid Leaching ◽  
Single Step ◽  
Metal Mobility ◽  
Metal Extraction ◽  
Production Plant ◽  
Acidithiobacillus Thiooxidans ◽  
Potential Candidate ◽  
Environmental Implications ◽  
Sulfuric Acid Production

Abstract The enormous amount of spent catalysts generated worldwide may pose a risk to the environment because of their high load of metals, including vanadium. The latter may be mobilized and released to the environment if managed improperly. Moreover, the catalysts could be considered as secondary resources rather than waste. This study aimed at the efficient extraction of vanadium from spent desulfurization catalyst (SDC) from a sulfuric acid production plant. The raw SDC and the post-extraction residues were characterized in terms of their chemical and phase composition. The metal mobility from the materials was examined with both single-step and multi-step extractions. The environmental risk assessment was performed using sequential extraction. The study revealed that both tested methods (citric acid leaching and bioleaching with Acidithiobacillus thiooxidans) enable the extraction of nearly 96% of V from SDC with a simultaneous reduction of metal mobility. However, the bacterial treatment was found more suitable. The leached residue was mostly (> 90%) composed of SiO2, which makes it a potential candidate for application in construction (e.g., concrete mixtures) after additional examinations. The study highlights the need to develop a metal extraction process for SDC in a way that metal-free residue could be a final product.

scholarly journals 1. Note on the Manganese Nodules found on the bed of the Ocean

1878 ◽  
Vol 9 ◽  
pp. 287-289
Author(s):  
J. Y. Buchanan
Keyword(s):  
Manganese Nodules ◽  
The Pacific

The manganese nodules occur in greater or less quantity all over the ocean-bed, and most abundantly in the Pacific. They occur of all sizes, from minute grains to masses of a pound weight, and even greater, and form nodular concretions of concentric shells, round a nucleus, which is very frequently a piece of pumice or a shark's tooth. Their outside has a peculiar and very characteristic mammillated surface, which enables them to be identified at a glance. When freshly brought up they are very soft, being easily scraped to powder with a knife. They gradually get harder on exposure to the air.

scholarly journals 14C Dating of Carbonate Mortars from Polish and Israeli Sites

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 857-866 ◽  
Author(s):  
Danuta Nawrocka ◽  
Justyna Czernik ◽  
Tomasz Goslar
Keyword(s):  
Radiocarbon Dating ◽  
Size Fraction ◽  
Acid Leaching ◽  
Building Construction ◽  
14C Dating ◽  
Preliminary Processing ◽  
Small Scales ◽  
Quartz Aggregates ◽  
Leaching Reaction ◽  
Good Agreement

The presented research involves the analysis and radiocarbon dating of 2 different groups of carbonate mortars, from Kraków, Poland and Hippos, Israel. Differences in composition of the mortars are reflected in different rates of their acid leaching. The Israeli mortars contain carbonate-basaltic aggregates, which may cause overestimation of 14C age. Preliminary processing of these samples (choice of selected grain-size fraction and collection of CO2 released during the first phase of the acid-leaching reaction), enabled us to obtain good agreement between the 14C dates and the age derived from historical contexts. A similar method of preliminary processing was applied to the carbonate mortars of the Medieval building in Kraków. The Polish samples represent carbonate mortars with some admixture of quartz aggregates, suggesting that they would be an ideal material for 14C dating. However, these samples contained white lumps of carbonates, the structure of which differed from that of the binder. These admixtures, possibly related to the hydrological conditions at the site and to the character of the ingredients, appeared modern, and if not removed prior to acid leaching, they could cause underestimation of the age of samples. The 14C dates of the mortars from the walls of the Small Scales building in Kraków are the first obtained for this object, and their sequence does not contradict archaeological indications on several phases of the building construction.

X-ray diffraction line profile analysis of acid-resistant goethite in Western Australian nickel laterite ore

2015 ◽  
Vol 48 (3) ◽  
pp. 814-826
Author(s):  
Xiaodong Wang ◽  
Jian Li ◽  
Robbie G. McDonald ◽  
Arie van Riessen ◽  
Robert D. Hart
Keyword(s):  
Size Distribution ◽  
Size Fraction ◽  
Acid Leaching ◽  
Domain Size ◽  
Line Profile Analysis ◽  
Nickel Laterite ◽  
X Ray ◽  
Peak Broadening ◽  
Nickel Laterite Ore ◽  
Laterite Ore

The goethite peaks in synchrotron and laboratory X-ray powder diffraction (XRPD) patterns of an acid-resistant nickel laterite ore sample from a site in Western Australia exhibit a `super-Lorentzian' shape. The method for extracting the coherently scattering domain size distribution published by Leoni & Scardi [J. Appl. Cryst.(2004),37, 629–634] is adapted to fit the asymmetric goethite peak profiles, allowing the refinement of lattice parameters for multiple goethite structural models while maintaining their relationships. The anisotropic peak broadening due to the acicular shape of the goethite crystals is addressed using spherical harmonics predefined from an XRPD pattern of a synthetic goethite sample. A bimodal coherently scattering domain size distribution of goethite crystals is predicted from the goethite profile fitting and agrees with previous transmission electron microscopy findings that two goethite populations with different domain sizes and metal substitutions exist in the ore sample. The small goethite size fraction dissolved slowly during atmospheric acid leaching, while the large goethite fraction barely dissolved. Caustic pre-treatment by KOH digestion significantly enhanced the acid-leaching performance of the small goethite fraction, but had no effect on the large goethite fraction. This study demonstrates that quantitative phase analysis on designated goethite size fractions can successfully fit the super-Lorentzian shaped line profiles of natural goethite crystals with a confirmed bimodal domain size distribution.

scholarly journals XXXII.—On the Manganese Oxides and Manganese Nodules in Marine Deposits

1895 ◽  
Vol 37 (4) ◽  
pp. 721-742 ◽  
Author(s):  
John Murray ◽  
Robert Irvine
Keyword(s):  
Manganese Dioxide ◽  
Deep Sea ◽  
Manganese Oxides ◽  
Manganese Nodules ◽  
Red Clay ◽  
Marine Deposits ◽  
The Pacific ◽  
Manganese Deposits ◽  
Volcanic Debris ◽  
Challenger Deep

During the “Challenger” Deep-Sea Exploring Expedition a great many peculiar-looking manganese nodules or concretions were dredged from the floor of the ocean at great depths, chiefly in the Red Clay areas of the Pacific, but also in less abundance in the Red Clays of the Atlantic. In the other varieties of Deep-Sea deposits these nodules were much less abundant than in the Red Clays.In still more recent soundings, both American and British ships have discovered in many regions of the Pacific and Indian Oceans a dark-brown coloured deposit containing a large amount of manganese dioxide, similar in character to the Red Clays from which the “Challenger” procured the largest hauls of manganese nodules. There is then every reason for supposing that manganese deposits and nodules are very widely distributed over the ocean's bed, especially in deep water at great distances from land. It was only occasionally that manganese nodules were present in any abundance in a Globigerina Ooze, and in these exceptional instances there was always much volcanic debris associated with the deposit. In the Blue Muds surrounding continental shores manganese nodules were rarely observed; still, on some rocks and boulders dredged from terrigenous deposits, a coating of manganese dioxide was observed on that portion of the stone which had projected above the surface of the mud.

scholarly journals The Reduction Behavior of Ocean Manganese Nodules by Pyrolysis Technology Using Sawdust as the Reductant

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Xiang-yi Deng ◽  
Dong-sheng He ◽  
Ru-an Chi ◽  
Chun-qiao Xiao ◽  
Jin-gang Hu
Keyword(s):  
Activation Energy ◽  
High Efficiency ◽  
Acid Leaching ◽  
Reduction Process ◽  
Reduction Reaction ◽  
Pyrolysis Process ◽  
Manganese Nodules ◽  
Valuable Metals ◽  
Shrinking Core ◽  
Isothermal Kinetic

Ocean manganese nodules, which contain abundant Cu, Co, Ni and Mn resources, were reduced using biomass (sawdust) pyrolysis technology. Valuable metals were further extracted by acid leaching after the reduction process with high efficiency. The effects of sawdust dosage, reduction temperature, and time were investigated to obtain optimal operating parameters. The extraction rates of Mn, Cu, Co, and Ni reached as high as 96.1%, 91.7%, 92.5%, and 94.4%, respectively. Results from TGA show that the main pyrolysis process of sawdust occurs at temperature range of 250–375 °C with a mass loss of 59%, releasing a large amount of volatile substances to reduce the ocean manganese nodules. The pyrolysis activation energy of sawdust was calculated to be 52.68 kJ∙mol−1 by the non-isothermal kinetic model. Additionally, the main reduction reaction behind the main sawdust pyrolysis process was identified by the comparison of the assumed and actual TG curve. The thermodynamic analysis showed that the high valence manganese minerals were gradually reduced to Mn2O3, Mn3O4, and MnO by CO generated from sawdust pyrolysis. The shrinking core model showed that the reduction process is controlled by the surface chemical reaction with activation energy of 45.5 kJ∙mol−1. The surface of reduced ore and acid leached residue exhibited a structure composed of relatively finer pores and rougher morphology than the raw ore.

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