Black Shale Ore Research Articles

The Prospect of Recovering Vanadium, Nickel, and Molybdenum from Stone Coal by Using Combined Beneficiation and Metallurgy Technology Based on Mineralogy Features

Black shale ore contains rich strategic metal resources such as vanadium, nickel, and molybdenum, but due to its complex composition, it is currently only used in the vanadium extraction industry. Metals such as nickel and molybdenum have not been effectively recovered, resulting in environmental pollution and resource waste. Using mineralogical features and a combination of beneficiation and metallurgy-based tests, the present work carried out feasibility studies of the combined beneficiation and metallurgy processes. The mineralogical features of the stone coal sample were studied using chemical analysis, an automatic mineral analyzer (BPMA), etc., and we identified the main phase composition, embedded characteristics, and particle size distribution of the associated strategic metals, vanadium, nickel, and molybdenum. The results showed that the grade of V2O5 in the stone coal was 1.29%, which was mainly present in carbonaceous clay and mica minerals. The nickel grade was 0.53%, mainly in the form of nickel–magnesium spinel and a small amount of nickel-containing magnesite. The stone coal contained 0.11% molybdenum; the mineral particles were fine, mostly in the form of molybdenite, and some were associated with carbonaceous matter and carbonaceous clay minerals. Based on the mineralogical feature, we proposed using the scrubbing–desliming and flotation process to enrich vanadium, nickel, and molybdenum. Our preliminary experiments obtained two products: vanadium–molybdenum-rich sludge and nickel-containing tailings. The V2O5 and molybdenum grades in the sludge were 4.10% and 0.44%, respectively, and the recovery was 41.31% and 51.40%, respectively. The nickel grade in the tailings was 1.49%. These products were roasted and leached. The vanadium, nickel, and molybdenum in the stone coal were effectively recovered through the beneficiation–metallurgy combination process, and the comprehensive utilization rate of the stone coal was improved.

Black shale ore of Big Karatau is a raw material source of rare and rare earth elements

The ores of Big Karatau are a valuable, currently unused source of rare and rare earth elements (REEs). To develop an integrated technology for processing black shale ore, it was studied using chemical, X-ray phase, infrared, mineralogical, X-ray spectral, and electron microscopic analyses.Rare and particularly REEs in the ore are found in various minerals in the form of inclusions in the siliceouscarbonaceous matrix. This explains the failures of the previously proposed processing methods, which either resulted in the incomplete extraction of the valuable components or were not profitable. For more complete extraction, novel ore processing approaches are required.A method for the early development of the original black shale ore using sintering with (NH4)2SO4 in the presence of concentrated H2SO4, followed by leaching of the cake with a diluted H2SO4 solution, is proposed. The optimal conditions for each stage are determined.The kinetic dependencies of the extraction of rare and REEs from sulfated cake under the most suitable conditions yielded maximum extractions of 98% for U, 92% for V, 89% for Mo, and 78% for the REEs. The rate constant and effective activation energy of V leaching, as the most representative of the rare and rare earth metals, were calculated. The process was limited by diffusion.After the leaching of the valuable components, the cake may be used in froth flotation enrichment to recover the carbonaceous material, and then it may be used as part of the charge to obtain ferrosilicon. The solution obtained from the leaching of the initial cake may be used to recover U, Mo, V, and the REEs using sorption.

Extraction of vanadium and associated elements from black shale ores by hydrodynamic activation technology of sulfuric acid solutions

The purpose of the work was to justify the possibility of converting vanadium in ore mainly into a readily soluble form in the form of hydrated oxides — vanadyls of the general formula VO2+ X (X is an anion) due to the hydrodynamic activation of sulfuric acid solution. Leaching tests were carried out in several stages and by various methods, the duration of which depended on the final indicators of vanadium extraction into the productive solution and its residual content in ore, as well as side components (Mo, W, rare earth metals). The article for the first time is examined the extraction of vanadium and associated elements from black shale ores (Kurumsak deposits, Kyzylorda oblast, the Republic of Kazakhstan) by the hydrodynamic activation of sulfuric acid. The activation of sulfuric acid solutions is carried out in the cavitation mode in a circulating type hydrodynamic apparatus at a pressure of 5 atm supplying a fluid flow to the cavitation nozzle by means of a centrifugal pump. It was found that the hydrodynamic activation of sulfuric acid leads to a significant increase in the degree of extraction of vanadium from 6 to 87% and related components depending on the decreasing in granule size. The technological parameters of leaching, such as pH, redox potential, salinity, acid intensity and filtration, are significantly improved. The results of chemical analysis of productive leaching solutions of the ore for the total contents of V2O5, uranium and rare earth concentrates were equal to 0.62 and 0.95 g/l, 47.26 and 41.43 mg/l and 62.44 and 37.26 mg/l irrespectively, that indicate the technological possibility of carrying out the heap leaching process.

The Geological Occurrence, Mineralogy, and Processing by Flotation of Platinum Group Minerals (PGMs) in South Africa and Russia

Russia and South Africa are the world’s leading producers of platinum group elements (PGEs). This places them in a unique position regarding the supply of these two key industrial commodities. The purpose of this paper is to provide a comparative high-level overview of aspects of the geological occurrence, mineralogy, and processing by flotation of the platinum group minerals (PGMs) found in each country. A summary of some of the major challenges faced in each country in terms of the concentration of the ores by flotation is presented alongside the opportunities that exist to increase the production of the respective metals. These include the more efficient recovery of minerals such as arsenides and tellurides, the management of siliceous gangue and chromite in the processing of these ores, and, especially in Russia, the development of novel processing routes to recover PGEs from relatively low grade ores occurring in dunites, black shale ores and in vanadium-iron-titanium-sulphide oxide formations.

Study of leaching processes of sintered black shale ore

This paper presents the results of physical and chemical investigation of black shale ore, as well as the investigation of combination of hydro- and pyrometallurgical methods in the sintering process of black shale ore with ammonium hydrosulfate to convert metals into water-soluble form. The homogeneous composite of black shale ore taken for the study consists of 67 % SiO2, 18 % C and 3 % H2O, 0.683 % V, 0.0415 Mo, 0.0148 % U3O8 and other components. Thermogravimetric analysis of sintering of carbon-silica ore with ammonium hydrosulfate in the presence of sulfuric acid was performed in the temperature range 20-1000 °C. It is established that at low-temperature sintering of ore with hydrosulfate ammonium after further leaching with sulfuric acid solution the extraction of uranium, vanadium, molybdenum and rare earth metals is 98.2 %, 91.3 %, 82.2% and 78.3 % respectively. The optimal leaching temperature is 90 °C, the ratio S: L = 1:3, and the leaching time is 2 hours.

Extraction of vanadium and uranium from refractory black shale ores

Extraction of vanadium and uranium from refractory black shale ores

Investigation of the leaching process of rare-earth metals from the black shale ores of greater Karatau

The purpose of this investigation was studying the process of an acid leaching of vanadium and other valuable components from black shales of Big Karatau of the Republic of Kazakhstan. The maintenance of principal components in ore of 0,8% V2O5, 67,7% of SiO2, 3,1% of Al2O3, 0,3% of Mo, 0,2% of U3O8 and 0,05% of rare-earth metals. To provide this process was used low-temperature sintering and leaching of this type of raw material for the subsequent extraction of vanadium, uranium, molybdenum and rare earth metal concentrates. Moreover, it was established that with increasing concentration of sulfuric acid to 40 g/l, the degree of leaching of uranium, vanadium, molybdenum and rare earth metals (REM) increases noticeably. The degree of extraction of vanadium includes 81.7 %; uranium – 93,3%; molybdenum – 82.2 % and REM – 78.3%. Besides, it was determined the optimal leaching time, which takes 2 hours long, and the chemical composition of the cakes after leaching.

Mineralogical distribution of base metal sulfides in processing products of black shale-hosted Kupferschiefer-type ore

The extraction of copper from black shales associated with fine-grained and complex base metal ore mineralization traditionally using pyrometallurgy becomes increasingly uneconomic, because one of the most significant cost factors is the high energy consumption. Thus, energy-saving alternative mineral processing methods are to be considered to improve the metal recovery route economically and environmentally. In this study, a milled, organic carbon-rich black shale ore from the Sangerhausen mining district in central Germany has been pre-treated by ethanol prior to the froth flotation tests to gain a copper concentrate marked by an increased copper content and more efficient copper recovery. The flotation product (15.3% Cu) was used for biohydrometallurgically batch tests to extract copper and associated trace metals. SEM-based automated particle analyses on the comminuted black shale ore, flotation product as well as tailings, bioleaching residues and abiotic leaching residues were used to trace the recovery performance particularly of copper sulfides. The black shale ore is characterized by high contents of bornite (2.8 wt%) and chalcopyrite (1.3 wt%) associated with a high grade of pyrite (5.8 wt%). Considerable enrichments were achieved in the flotation product for bornite (20.7 wt%) and chalcopyrite (10.3 wt%) as well as for galena and sphalerite, while pyrite was successfully depressed in the tailings. Compared to abiotic chemical leaching, the bioleaching test of the bornite- and chalcopyrite-rich copper concentrate was particular efficient in the recovery of bornite and chalcocite. However, chalcopyrite was leached insufficiently in both, abiotic and microbial leaching tests, and presents a common component in the residues.

Comparative Bioleaching and Mineralogical Characterization of Black Shale-Hosted Ores and Corresponding Flotation Concentrates

In this study, two black shale copper ores from different Mid-European Kupferschiefer-type deposits and their flotation concentrates were used for bioleaching tests. All samples were subjected to stirred tank bioleaching using an acidophilic, moderately thermophilic microbial consortium. The distribution of sulfides and gangue minerals in the ores, copper concentrates and residues of both, bioleaching and sterile chemical control tests were investigated using EDX-based particle analysis. The black shale ores and the extracted copper concentrates varied in their mineralogical composition with respect to the distribution of sulfides and gangue. While the copper-bearing sulfides in the Sangerhausen black shale and concentrate were dominated by bornite and chalcopyrite, the Rudna black shale and its flotation concentrate were rich in chalcocite and bornite. Differences in the portion of gangue minerals were detected in particular for carbonates that represented the dominant mineral group in the Rudna black shale and its copper concentrate. Distinct Cu dissolution kinetics and recovery rates of Co and other associated metals were observed for the various materials processed by bioleaching. Copper sulfides were completely dissolved also in both black shale ores. However, the sulfide distribution in the bioleaching residues of the Sangerhausen concentrate revealed that a significant portion of chalcopyrite was not leached. Even higher recovery rates for copper and other metals were determined for the bioleaching tests on the Rudna concentrate, in which copper sulfides were nearly completely dissolved. Alteration of copper sulfides and the formation of calcium sulfate were in particular observed in the sterile control residue of the Rudna concentrate, due to excessively use of sulfuric acid for pH stabilization. Lead sulfate precipitates increasingly occurred in the bioleaching residues, but represented also a common secondary phase in the sterile leaching residues.

Approaches for Eliminating Bacteria Introduced during <i>In Situ</i> Bioleaching of Fractured Sulfidic Ores in Deep Subsurface

The major objective of the EU Horizon 2020 project “BioMOre” is the technical realization of indirect in situ leaching of Kupferschiefer sandstone and black shale ore by a ferric iron lixiviant generated by a mixed culture of autotrophic, acidophilic, iron-oxidizing bacteria and archaea in a ferric iron-generating bioreactor (FIGB). These organisms could colonize the deeply buried geological formations even under anaerobic conditions as most are able to grow by coupling the reduction of ferric iron to the oxidation of reduced sulfur compounds in the absence of oxygen. Development of an inhibition protocol to eliminate these allochthonous microbial bioreactor populations subsequent to the completion of in situ bioleaching was therefore investigated. Column bioleaching experiments using a laboratory-scale FIGB confirmed not only that metals were solubilised from both the sandstone and shale ores, but also that significant numbers of bacteria were released from the FIGB. The efficacy of 13 different chemical compounds in inhibiting microbial iron oxidation has been tested at different concentrations in shake flask and FIGB-coupled columns. Iron-oxidation activity, microcalorimetrically-determined activity and ATP measurements, in combination with microscopic cell counts and biomolecular analysis (T-RFLP, qPCR), plate counts and most-probable-number (MPN), were used to monitor the inhibiting effects on the acidophiles. Complete inhibition of metabolic activity of iron-oxidizing acidophiles was achieved in the presence of 0.4 mM formate, 300 mM chloride, 100 mM nitrate, 10 mM of primary C6 to C8 alcohols, 100 mM 1-butanol, 100 mM 1-pentanol, 0.1 mM SDS or 0.35 mM benzoic acid. No inhibition was found for 0.6 mM acetic acid and 200 mM methanol. Based on these results a recipe for the chemical composition of the “decommissioning solution” is proposed.

Electrochemical Process Engineering in Biohydrometallurgical Metal Recovery from Mineral Sulfides

Primary copper sulfides are recalcitrant to bioleaching, probably due to semi-conductivity or passivation effects which result in slow dissolution kinetics. The mineral dissolution strongly depends on redox reactions and, consequently, electrochemical techniques are recommendable for analyzing and processing of redox-active minerals. For this reason we installed a three electrode system into a conventional bioreactor. Electrolytic bioleaching was applied to a copper concentrate from black shale ore. First results verified the operational capability of ferric iron reduction during electrochemical leaching and that bioleaching is not hindered by the physical presence of the electrochemical setup. Although the working electrode was able to reduce ferric iron and to regenerate it as electron supply for ferrous iron oxidizing microorganisms, the electron input into the bioleaching process has to be further increased to keep up with fast biocatalytical iron oxidation.

Effect of Temperature Ramping on Stirred Tank Bioleaching of a Copper Concentrate

Kupferschiefer-type ore represents an important source for base metals and several studies concerning the bioleaching of black shale ores and Cu concentrates have been carried out with focus on various microbial communities and processing parameters. However, the incomplete dissolution of chalcopyrite remains a key issue for copper ore bioleaching improvement and requires further investigations in order to ensure an optimal control of the process for upscaling. Our study clearly showed that bioleaching tests are characterized by two separate phases with a distinct optimal temperature. A distinct effect of the temperature on the copper recovery and the advantage of temperature ramp in order to enhance copper bioleaching and chalcopyrite dissolution were demonstrated.

Autoclave Leaching of Vanadium from Black Shale

Autoclave breakdown of black shale ore without adding oxidizing agent is considered. It is demonstrated by experiment that for total breakdown of ore and vanadium oxidation in an autoclave prior ore treatment is required under atmospheric conditions. IR-spectroscopic analysis shows that under atmospheric conditions CH-groups present in the ore break down and in an autoclave there is breakdown of vanadium minerals. Optimum parameters are established for autoclave leaching of black shale ore of the Balasauskandyk deposit: temperature 140°C, sulfuric acid concentration 150 g/liter, time 2 h. The degree of vanadium leaching is 90%.

Synergistic extraction of uranium from Korean black shale ore leach liquors using amine with phosphorous based extractant systems

Synergistic extraction of uranium using amine combined with phosphorous based extractant systems was described. The present study focused on the continuous extraction processing of uranium to form precipitation under higher pH conditions and higher aqueous phase ratios. To address this, synergistic extraction studies were carried out with P-based extractants as synergists and investigations were done with better pairs with an amine-based extractant system. Finally, all of the developed synergistic extraction methodologies were compared with each other. This showed that Alamine 336 and D2EHPA was the best pair for uranium extraction, offering as much separation as possible from other associated metals.

Hydrodynamic Study Of Column Bioleaching Processes

Abstract The modelling of flow leaching solution through the porous media has been considered. The heap bioleaching process can be tested using the column experimental equipment. This equipment was employed to the hydrodynamic studies of copper ore bioleaching. The copper ore (black shale ore) with the support, inertial materials (glass small balls and polyethylene beads) was used to the bioleaching tests. The packed beds were various composition, the ore/support ratio was changed. The correlation between the bed porosity and bioleaching kinetics, and copper recovery was investigated.

Mineralogy of Early Cambrian Ni‐Mo Polymetallic Black Shale at the Sancha Deposit, South China: Implications for Ore Genesis

AbstractThe mineralogy of the Early Cambrian Ni–Mo polymetallic black shale ores at the Sancha deposit, South China, was investigated to better the understanding of the complex ore genesis by optical microscope, electron microprobe, and scanning electron microscope. Analytical results show that the sulfides in the ore bed mainly comprise C/MoS2 mixed‐layer phase (MoSC), millerite, and pyrite. Of these, MoSC and millerite are the main ore minerals of Mo and Ni, respectively. Pyrite is subdivided into six types based on its morphology, occurrence, relationship to Ni‐ and Mo‐bearing minerals, and chemical composition. Many millerite crystals cut early‐formed MoSC, implying that these two minerals formed at different stages. The concentrations of biogenic elements (e.g., Sb) in the MoSC are high compared with those in millerite, implying a close relationship between MoSC and organic matter. These data provide a new and improved understanding of the complex ore genesis at the Sancha deposit, and can be applied to other black‐shale‐hosted mineral deposits worldwide.

Mobility and generation of mosaic non-autonomous transposons by Tn3-derived inverted-repeat miniature elements (TIMEs).

Functional transposable elements (TEs) of several Pseudomonas spp. strains isolated from black shale ore of Lubin mine and from post-flotation tailings of Zelazny Most in Poland, were identified using a positive selection trap plasmid strategy. This approach led to the capture and characterization of (i) 13 insertion sequences from 5 IS families (IS3, IS5, ISL3, IS30 and IS1380), (ii) isoforms of two Tn3-family transposons – Tn5563a and Tn4662a (the latter contains a toxin-antitoxin system), as well as (iii) non-autonomous TEs of diverse structure, ranging in size from 262 to 3892 bp. The non-autonomous elements transposed into AT-rich DNA regions and generated 5- or 6-bp sequence duplications at the target site of transposition. Although these TEs lack a transposase gene, they contain homologous 38-bp-long terminal inverted repeat sequences (IRs), highly conserved in Tn5563a and many other Tn3-family transposons. The simplest elements of this type, designated TIMEs (Tn3 family-derived Inverted-repeat Miniature Elements) (262 bp), were identified within two natural plasmids (pZM1P1 and pLM8P2) of Pseudomonas spp. It was demonstrated that TIMEs are able to mobilize segments of plasmid DNA for transposition, which results in the generation of more complex non-autonomous elements, resembling IS-driven composite transposons in structure. Such transposon-like elements may contain different functional genetic modules in their core regions, including plasmid replication systems. Another non-autonomous element “captured” with a trap plasmid was a TIME derivative containing a predicted resolvase gene and a res site typical for many Tn3-family transposons. The identification of a portable site-specific recombination system is another intriguing example confirming the important role of non-autonomous TEs of the TIME family in shuffling genetic information in bacterial genomes. Transposition of such mosaic elements may have a significant impact on diversity and evolution, not only of transposons and plasmids, but also of other types of mobile genetic elements.

Leaching behavior of uranium and vanadium using strong sulfuric acid from Korean black shale ore

The present scientific study focused on leaching behavior of uranium and vanadium from Korean domestic ore. The leaching process experimental conditions optimized for uranium and vanadium metals recovery from Korean domestic ore and developed the basic experimental procedures such as time, particle size, acid influence, temperature effect and pulp density (PD) behavior. Acid influence on leaching process was tested and noted that 2.0 M sulfuric acid concentration is the optimized conditions for present study. The time influence on leaching process was observed and its optimized 2 h for complete leaching process. The temperature influence tested and optimized the 80 °C for complete leaching process and PD is 50 % (wt%). The bench scale experiments developed in a laboratory and tested in pilot level each batch 100 kg of ore sample.

Process development for uranium and vanadium recovery from Korean Okcheon black shale ore leach liquor

The main goal of the proposed chemical methodology is to extract uranium and vanadium without other associated metals such as iron and aluminum. It also deals with the development of recovery processes for uranium and vanadium by preparation of yellow cake and vanadium pentoxide. Korean Okcheon black shale ore leach liquor contains 570 mg/dm3 uranium and 890 mg/dm3 vanadium with high iron (12,560 mg/dm3) and aluminum (13,460 mg/dm3) metal concentrations, at lower pH conditions were developed for uranium recovery and then modify the extraction of raffinate pH for vanadium recovery studies. By invoking a scrubbing process, unwanted impurities were separated from loaded organic phases, and the regenerated extractant was utilized for further cycles. The metal contents in aqueous solution were determined by using the advanced analytical technique inductively coupled plasma optical emission spectrometry. Finally in the present developed methodology, ~95 % of uranium was recovered in the form of yellow cake and ~50 % of vanadium was recovered as vanadium pentoxide.

국내(國內) 흑색(黑色) 점판암으로부터 우라늄 및 바나듐 회수(回收)의 연구개발(硏究開發)

본 발표는 국내 흑색 점판암으로부터 우라늄 및 바나듐 회수의 일반적인 현황 및 연구개발에 관한 내용이다. 우라늄 화합물(yellow cake)의 세계적인 수급 및 향후 전망뿐만 아니라, 국내 우라늄광의 매장량, 품위 및 특성에 대해 설명하였다. 그리고 국내 우라늄광의 기술개발에 관한 기 연구 실적 및 수행중인 연구과제의 개략적인 내용에 대해 기술하였다. 또한, 우라늄 및 바나듐 성분이 함유된 국내 흑색 점판암을 대상으로 하여 침출, 분리정제 및 회수에 관한 기술을 하였다. This general paper covers three parts of the uranium research and development. Part one covers scope of research and development of uranium ore and future prospect, supply and demand of uranium in the world market, deposit, grade and properties of Korean uranium ore and the second part covers status of previous study and supply target for yellow cake, technology of leaching, separation and preparation, procedure of the recovery of U / V from Korean black shale ore. Final part concludes the summary of the present discussion.