The European Green Deal targets a carbon-neutral, resource-efficient economy by 2050. Rare earth elements (REE) are essential to this transition, especially for green energy technologies. However, rising demand and supply concerns have prompted research into REE mining and processing. This study focuses on flotation behavior of rare earth minerals (REM), particularly parisite, monazite and bastnasite, synchysite from a Norwegian carbonatite deposit. REM (parisite, bastnasite, monazite, synchysite) were tracked throughout the beneficiation process using ICPMS and SEM-based automated mineralogy. Results showed 72 % recovery of total rare earth oxides (REO) with a 48 wt% REO grade in the final concentrate. The second cleaner step yielded a concentrate with 39 wt% parisite (72 % recovery), 14 wt% bastnasite (75 % recovery), 8 wt% monazite (70 % recovery), and 4 wt% synchysite (69 % recovery). In this study, mineral association patterns of major REM subtypes (parisite-Ce, parisite-Ce-La, monazite-Ce, bastnasite-Ce-La, and synchysite-Ce) were analyzed across all beneficiation products and the feed. The mineral association analysis revealed that parisite-Ce and bastnasite-Ce-La had similar trends, while monazite-Ce was associated with apatite and barite, reflecting its geochemical origin. Synchysite-Ce had the highest intergrowth with other REM and the lowest liberation. Nevertheless, all target minerals exhibited a sufficient surface exposure to be successfully recovered in the final concentrate, meeting the requirements for a marketable REM concentrate. The study offers critical mineralogical insights into REM flotation, particularly the underexplored parisite, supporting future beneficiation strategies for carbonatite-hosted REE deposits.

The global demand for rare earth elements continues to rise, while newly discovered deposits typically exhibit lower ore grades as most high-grade resources have already been exploited. Their extraction is often constrained by complex mineralogy. Economically important rare earth minerals such as bastn & auml;site and monazite typically occur in fine-grained, heterogeneous assemblages with carbonates and silicates as gangue minerals. Linking mineralogical variability to beneficiation performance enables the identification of suitable concentration techniques, including gravity, magnetic, electrostatic, and froth flotation methods. This study employs a process mineralogical approach to characterize low-, medium-, and high-grade intervals of a rare earth carbonatite drill core containing monazite, parisite, bastn & auml;site, and synchysite, and to evaluate their implications for mineral processing. Elemental and mineralogical data are investigated to evaluate beneficiation potential and guide flowsheet development. At the current grind size, each sample grade has the potential to achieve acceptable recovery, each exhibiting distinctive characteristics. Low-grade sample may require specific conditions due to the phosphate nature of the main target mineral (monazite). Medium-grade sample may exhibit limited efficiency in magnetic separation due to higher association degree between magnetite and the target minerals and reduced selectivity during flotation due to its higher apatite content. High-grade sample, containing the highest Fe-bearing carbonates, may require the use of tailored reagents to maintain satisfactory separation. The findings emphasize that grade-specific process design, informed by elemental and mineralogical characterization, is essential to maximize rare earth recovery. This integrated approach provides a framework for optimizing beneficiation strategies in complex REE-bearing carbonatite deposits.

Mine tailings represent a valuable secondary resource with strong potential for material recovery. This study presents a detailed mineralogical and chemical characterization of mineral materials from three Norwegian deposits - mine tailings from Rana iron formation (R tailings), and lab-scale tailings from mineral processing of the Fen carbonatite complex (C tailings) and Nussir copper deposit (N tailings) to evaluate their potential as valuable materials in soils, including soil reconstruction, technosol developments, mine-site reclamation, and nutrient source in agronomic plant production. Mineralogy was analyzed using scanning electron microscope-based automated mineralogy (SEM-AM), and bulk elemental composition was determined via X-ray fluorescence (XRF). SEM-AM results show that the Fen sample is dominated by soluble carbonates (>90%), being a source of Ca, Mg, Fe, with limited contribution of P from apatite (1.4%). Rana tailings are dominated by quartz and silicates (>60%), with similar to 10% carbonates and similar to 10% Fe-oxides. Nussir sample, containing 37% carbonates and 7.3% biotite, offers valuable sources of Ca and Mg. XRF analysis detected trace elements of potential concern for soil ecosystems, including Mn, Ba, Sr, La, Ce, Nd in Fen sample, and Mn in Rana and Nussir samples that require further speciation and bioavailability analyses. All three materials exhibit fine particle size (C tailings <150 mu m, R tailings <400 mu m, N tailings <140 mu m), high alkalinity (pH 9-10), and an absence of sulfide minerals, reducing the risk of acid mine drainage. Based on well-established analytical methods for mineral characterization, the findings suggest that mine tailings can potentially be recycled within the soil ecosystems as a soil amendment and nutrient source, although further studies are needed to assess element bioavailability and long-term environmental impacts.

This study investigates thermomagnetic analysis (TMA) as a rapid screening and quantification tool for detecting pyrrhotite polytypes in concrete aggregates with concentrations as low as 0.1% by weight. Pyrrhotite, particularly in its hexagonal (NC-type) and monoclinic (4C-type) forms, can cause expansive deterioration reactions in concrete when oxidized. Current quality assurance methods, such as differential thermal analysis, optical microscopy, and total sulfur measurement, lack the specificity and resolution to distinguish between pyrrhotite polytypes and concentrations, leading to either underestimation of the risk of not detecting potentially internal sulfate attack reactive aggregates and, on the contrary, to inflate the disposal rates of viable aggregate raw materials. Here, thermomagnetic analysis measures magnetic susceptibility changes across heating cycles to identify and quantify pyrrhotite polytypes based on their magnetic transitions. Pure NC-and 4C-type pyrrhotite reference samples were analyzed and used to develop a TMA quantification correlating magnetic susceptibility peaks with pyrrhotite concentration. Thermomagnetic analyses of crushed aggregates from Norway and North America were tested and compared with results from electron microprobe analysis and automated mineralogy. The proposed quantitative model for the estimation of the pyrrhotite concentration, using single-grain NC-and 4C-type pyrrhotite, describes a novel approach to calculate the pyrrhotite content by weight % in bulk samples. The findings demonstrate that thermomagnetic analysis effectively differentiates between pyrrhotite polytypes reliably and estimates their relative content within acceptable margins compared to automated mineralogy. Thermomagnetic analysis offers a fast, low-cost complement to current testing protocols. Therefore, adopting thermomagnetic analysis as a standard method could help to significantly improve material assessment accuracy, reduce unnecessary aggregate disposal, and mitigate ISA risks in concrete infrastructure.

Despite extensive research on municipal solid waste incineration (MSWI) fly ash (FA) and air pollution control ash (APCA), comprehensive studies employing multiple characterization techniques remain limited. This study evaluates an extensive suite of analytical methods to characterize MSWI FA and APCA before and after water washing. Washing effectively removed soluble salts (e.g., NaCl, KCl), increasing stable phases like CaCO3 and silicates, with variations dependent on ash origin and phase solubility. Washing also reduced particle size variability, yielding more uniform distributions. Chemical analyses demonstrated portable X-ray fluorescence (PXRF) as a reliable, cost-effective alternative to ICP-MS for elements including Al, Ca, Cu, Fe, P, and Zn, though weaker correlations for Pb, Si, and S suggest the need for more precise methods. Automated mineralogy showed sample-specific phase distributions: rotary kiln (RK) ash contained abundant ultrafine, unclassified matrix that increased post-washing, while grate furnace (GF) samples were dominated by lime, gypsum, and Ca-Si-Al phases, with washing reducing Cl-bearing and gypsum phases and slightly increasing reacted silicates. The circular fluidized bed (CFB) sample predominantly contained lime, and Ca-Cl-O and related reacted phases, showing minimal changes after washing. Minor metals such as Zn and Cu appeared heterogeneously distributed, bound within discrete or embedded phases, whereas bulk elements (Al, Ca, Mg, Si, Na) were uniformly integrated into the matrix. The findings emphasize the importance of combining multiple analytical techniques to achieve comprehensive characterization of MSWI ashes, bridging rapid screening with detailed analysis.

This study demonstrates how the response of ultramafic lithologies to infiltrating H20-CO2 fluids depends on the primary mineralogy. This has major implications on fluid flow through the lower crust and upper mantle as mineral reactions control the permeability and rheology. The studied samples are from the hanging wall of a 2 kilometer-long transtensional shear zone within ultramafic-mafic rocks in the Reinfjord Ultramafic Complex (RUC), part of the Seiland Igneous Province (SIP) in Northern Norway.Fluid-rock interaction surrounding shear zones with abundant pseudotachlylites is highly variable and depends on bulk rock compositions. Thermodynamic modelling demonstrates that mineral reactions involving hydration and carbonation differ between dunitic rocks and the pyroxenitic dykes which intersect them. Alteration of dunitic rocks results in the formation of dominantly magnesite-anthophyllite-talc and talc-magnesite assemblages causing approximately 12% volume expansion. This results in a sharp reaction front contacts with the host rock. When the alteration zones cross the dunite-pyroxenite boundary the associated alteration has a more gradual boundary towards the unaltered rock and the alteration zone widens by approximately 40%. In contrast to the simpler dunite alteration assemblage, the pyroxenetic dykes are altered to a complex mixture of cummingtonite-anthophyllite, magnetite and chlorite. Additionally, orthopyroxene is completely pseudomorphed by a mixture of cummingtonite and magnetite, whereas olivine xenocrysts are partly preserved and surrounded by a magnesite-anthophyllite assemblage. Other, open cavity-like areas are filled by chlorite, amphibole, and Mg-MgCa carbonates, indicating volume reduction during alteration of the pyroxene.Accordingly, dunite alteration effectuates a significant volume expansion, and are therefore only altered locally during seismic creep events. The pyroxenites are near volume neutral throughout interaction with the same fluids, and are thus more homogeneously altered. The formation of chlorite in hybrid compositions, such as the dykes in the lower crust, may create weak permeable zones that are consequently exploited as pathways for fertile mantle fluids and will hence also be the locus of ore bearing fluids moving to the upper crust. Increased understanding of fluid mediated metamorphism increases our current knowledge on fluid flow and strain localization in the lower crust. We further suggest that the hydrothermal assemblages are closely related to deformation leading to the formation of grain size sensitive creep in olivine facilitated carbonation of olivine and clinopyroxene to form orthopyroxene and dolomite and associated pseudoctacylites in the peridotites (Sørensen et al., 2019) , commonly associated with volatile rich mafic dykes (Ryan et al., 2022). Either the ductile magnesite-chlorite-talc assemblages formed at the same time in a shear-related heat gradient or they formed during cooling and continued CO2 infiltration from depth through the shearzones. Ryan E J, et al. 2022 Infiltration of volatile-rich mafic melt in lower crustal peridotites provokes deep earthquakes. J. Struct. Geol. (https://doi.org/10.1016/j.jsg.2022.104708)Sørensen, B.E., et al., 2019 In situ evidence of earthquakes near the crust mantle boundary initiated by mantle CO2 fluxing and reaction-driven strain softening. Earth and Planetary Science Letters (https://doi.org/10.1016/j.epsl.2019.115713 )

The reprocessing of historical mine tailings is gaining increasing attention as a more responsible approach to resource management and environmental remediation. However, comprehensive mineralogical and geochemical characterizations of submerged tailings remain scarce. This study provides the first detailed investigation of sulfide-rich tailings stored underwater in Hudningsvatnet Lake from the former Joma mine, which exploited one of Norway's largest volcanogenic massive sulfide (VMS) deposits. The study assesses both the environmental stability of these tailings and their potential for revalorization, contributing to the broader understanding of submerged mine waste and secondary resource recovery. To achieve this, a multi-method characterization using scanning electron microscope-based automated mineralogy (SEM-AM), electron probe microanalysis (EPMA), and geochemical analysis is conducted to determine mineralogy, metal deportment, and assess reprocessability of the Joma mine tailings. The results show that the tailings contain significant concentrations of copper (7080 ppm), zinc (5140 ppm), cobalt (255 ppm), and silver (11 ppm), with critical raw materials such as cobalt (Co) and silver (Ag) hosted within pyrite and pyrrhotite, rather than discrete mineral phases as previously assumed. Furthermore, subaqueous storage has effectively prevented sulfide oxidation, with pyrite (54.7 wt%) and pyrrhotite (13.5 wt%) remaining largely unweathered. Chalcopyrite (2.1 wt%) and sphalerite (0.9 wt%) are the main ore minerals with a considerable fraction occurring in potentially recoverable liberation state. Their distribution varies with particle size, with sphalerite enriched in the -38 mu m size fraction, while chalcopyrite is more evenly distributed as a consequence of the employed flotation circuit and the original ore textures. Electron Microprobe analyses on sulfide phases indicate Co, Ag and Au distribution within pyrite, pyrrhotite and chalcopyrite with up to 0.3 wt% Co, 362 ppm Ag and 494 ppm Au, which has important implications for their revalorization. The results of this study show that the historical Joma mine tailings contain potentially recoverable amounts of copper, zinc, cobalt and silver making them a viable secondary resource. Additionally, their high content of unweathered sulfides indicates a substantial potential for environmental impact, reinforcing the need for further assessment and management. The results can be used to design a more comprehensive sampling campaign of the Joma tailings and evaluate reprocessing strategies.

This study investigates the effect of calcined clays (metakaolin, metasilt, metaclay) on the chemical composition, distribution, and structure of alkali–silica reaction (ASR) gels. Using 10 wt% of calcined clays reduced concrete expansion and minimized cracking but did not inhibit ASR gel formation. Micro X-ray fluorescence mapping revealed an average ASR gel content of 3 wt% in concrete, incorporating up to two-thirds of K2O and nearly all Na2O from the binder. Raman spectroscopy indicated structural similarities among gels in different concrete mixes, with an increased degree of polymerization in the metakaolin-containing concrete. Automated mineralogy identified four gel phases: Si gel, Ca-Si gel, Al-Ca-Si gel, and Al-Si gel. Ca-Si gels are formed at binder interfaces, while non-swellable Al-bearing gels are mainly formed in metakaolin-containing concrete located within aggregates. This study shows that aluminum can be incorporated into gels in calcined clay concretes, altering their structure and potentially affecting their expansion behavior in concrete.

Deciphering the history of active continental margins is of key importance for paleogeographic reconstructions, but the low preservation potential of such margins commonly hampers such attempts and may introduce unrecognized biases. Here, we present new sedimentological observations and detrital zircon U-Pb and Hf isotopic data from the Ediacaran-Cambrian Vestertana Group in Finnmark, Arctic Norway. The data are consistent with derivation from the Fennoscandian Shield and the appearance of an Ediacaran source at the Ediacaran-Cambrian transition. However, the new paleocurrent observations dispute that this influx is related to a change in paleocurrent direction from northerly to southerly. Instead, we argue for the possibility of an alternative source represented by the Kalak Nappe Complex, which we suggest may be a remnant of a Neoproterozoic accretionary margin outboard of western Baltica that was thrust onto Baltica during the Ediacaran rather than during the Silurian Caledonian Orogeny. Further work focusing on detrital minerals other than zircon may provide a more comprehensive understanding of the character of these potential sources. Comparisons with detrital zircon data from Ediacaran-Cambrian sedimentary rocks around the North Atlantic show that both Baltica and Siberia are characterized by large Neoproterozoic populations, while such ages are all but absent from Laurentia. The apparent link between Baltica and Siberia during the Ediacaran-Cambrian is consistent with fossil data and suggests that the two continents were separated from Laurentia by this time.

Polymetallic black shale from the Buckton deposit in Alberta, Canada, is an undeveloped resource for V, rare earth elements (REEs), Ni, Li, and a few other metals. In this work, the valuable elements are extracted from the shale using a low-temperature sulfation roasting-water leaching method. Sulfation roasting enables the destruction of mineral phases releasing V ions as well as REEs, Li and Ni. We compare microwave and conventional roasting under varying temperature, sulfuric acid dosage, and time, followed by water leaching, to determine the optimum leaching efficiencies of metals. Microwave roasting consumes less energy than conventional roasting for similar release

Sediment provenance studies were conducted to constrain the establishment of the eastern Laurentian or Humber passive margin in Newfoundland, Canada, and examine models for the opening of the Iapetus Ocean and Humber Seaway. Ediacaran to Cambrian Series 2 strata of the lower Labrador and Curling groups contain garnet, muscovite, and feldspar, and yield 1000–1500 Ma detrital zircon grains that reflect local derivation from Grenville Province basement rocks during regional extensional deformation. Cambrian Series 2 to early Miaolingian units of the upper Labrador and Curling groups are quartz-rich and characterized by 556–586 Ma and 1000–2700 Ma detrital zircon grains that instead reflect continental-scale drainage and transition to passive margin deposition along eastern Laurentia. The geological relationships along the Humber margin are compared with modern analogues in the Newfoundland-west Iberia rift system to propose a magma-poor rift model that includes two breakup sequences which formed in response to isostatic adjustment after the rupture of crust and mantle, respectively. Crustal breakup resulted in an Ediacaran to Cambrian Series 2 breakup sequence that was connected to hyperextension, mantle exhumation, and bimodal magmatism. Mantle breakup likely occurred >20 Myr after first mantle exhumation and resulted in a breakup sequence that is best characterized by Cambrian Series 2 to early Miaolingian strata. The mantle breakup sequence consists of regressive-transgressive cycles that record the transition from breakup to thermal subsidence and was probably driven by the separation of the Dashwoods microcontinent from eastern Laurentia and outboard opening of west Iapetus. The Humber Seaway opened between the Humber margin and Dashwoods and was at least partially underlain by exhumed continental mantle. Our scenarios support hypotheses for equivalent magma-poor rift elements elsewhere in the Caledonian-Appalachian orogen, and we predict that crustal and mantle breakup sequences are exposed in the Scotland-Ireland and Quebec-New England segments of the eastern Laurentian margin.

Collectors play a critical role in the flotation process as they help bubbles to selectively adsorb onto the surface of target mineral particles. The selection of proper collectors and/or their blends is crucial in optimizing the flotation process for specific ores. The existing literature suggests that the use of a combination of different collector types generally results in an improved flotation performance compared to the use of a single collector type. Thus, this paper, for the first time, investigates the influence of commercial thiol collectors NAX (Minova-Ksante Sp. z o.o), AEROPHINE® 3422 (Solvay S.A.), and Aero® MX-5149 (Solvay S.A.), in varying dosages and combinations (blends), on the flotation performance of Kupferschiefer copper ore in the REFLUX Flotation Cell (RFC). This study aims to explore the impact of collectors on copper and silver flotation using new RFC technology and to replace xanthate with an eco-friendly alternative. A scanning electron microscope (SEM)-based automated mineralogy (AM) was applied for selected flotation tests to track minerals affected by collectors and their blends. The findings show that the increase in the type of collector within the blend improves the flotation performance (i.e., recovery, kinetics, and selectivity). Comparing collector mixtures, AEROPHINE® 3422, a blend of isopropyl ethyl thionocarbamate (IPETC) and dithiophosphinate (DTPi), outperformed the NAX (a blend of sodium isobutyl xanthate (SIBX) and sodium ethyl xanthate (SEX) mixture) in both copper and silver flotation.

Alkali-silica gels formed during alkali-silica reaction (ASR) can vary in composition and structure. This variation depends on the concrete composition, environmental conditions, gel maturation and the location of gel formation within the concrete matrix. An effective and well-known method to mitigate ASR is the use of aluminum-rich supplementary cementitious materials (SCMs). To investigate the effect of aluminum on ASR gel properties, concrete prisms with quartz sand, borosilicate glass, 90 wt.

&lt;p&gt;Planar deformation features are a common feature in shock-deformed olivine, both experimentally in conditions corresponding to crustal shear zones [1] and impact structures e.g., [2] and in deep crustal shear zones [3, 4]. &amp;#160;Hence, the identification of different planes associated with the shock deformation is essential to access the stress levels during deformation, important feature during studies of earthquake deformation. &amp;#160;A combination of optical and EBSD data combined to infer which of the possible crystallographic planes and EPMA to study trace elements to investigate planar deformation features and grain size reduction in olivine. Samples originate from the Reinfjord Ultramafic Complex, exposing lower crustal earthquakes induced by with CO&lt;sub&gt;2&lt;/sub&gt; bearing magmatic volatiles causing reaction facilitated grainsize reduction and weakening [3, 4]. &amp;#160;First, calculated plane traces are compared with the observed plane traces in the free open source Matlab &amp;#174; toolbox MTEX&amp;#160; [5], then the dip and dip direction of the observations of planes in the optical microscope. &amp;#160;Our results demonstrate: 1) That several planes are active during high stress deformation of lower crustal olivine rich rocks. 2) Some planes develop recrystallization features, whereas others develop later and do not develop recrystallization features. 3) Our results shows that these new olivine grains are a mix of grains with an orientation relationship with the host grains and grains that are far of the orientation of the host grain. 3) Further investigation using trace element mapping shows that P (Phosphorous) is a marker of fluid involvement in the recrystallization. P is mobilized preferably along grain boundaries and sub-grain boundaries involving twist, shown by zones of local P enrichment.&lt;/p&gt;&lt;p&gt;By looking at several grains we found that the developed fractures highly depend on the orientation of the host grain with respect to the external stress field.&amp;#160; Using the demonstrated methodology, it should be possible to map out the relative abundance of planar deformation features along different crystallographic planes in high stress deformed olivine and other transparent silicates.&amp;#160; The method can be refined by calculation of the exact thickness of the sample using interference colours calculated using the code published by [6] now available in MTEX.&amp;#160; This will enable the calculation of exact plane inclinations extracted from multifocal optical images that can be compared with crystallographic planes calculated in MTEX from the EBSD data. Further combination of trace elements reveals that fluid mobilisation is involved in the recrystallization process.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;[1]&amp;#160;&amp;#160; Druiventak A, Trepmann C A, Renner J and Hanke K&amp;#160; 2011&amp;#160; &lt;em&gt;Earth Planet. Sci. Lett.&lt;/em&gt; &lt;strong&gt;311&lt;/strong&gt; 199&amp;#8209;211&lt;/p&gt;&lt;p&gt;&amp;#160;[2]&amp;#160; St&amp;#246;ffler D, Keil K and Edward R D S &amp;#160;1991&amp;#160; &lt;em&gt;Geochim. &lt;/em&gt;&lt;em&gt;Cosmochim. Acta&lt;/em&gt; &lt;strong&gt;55&lt;/strong&gt; 3845-3867&lt;/p&gt;&lt;p&gt;&amp;#160;[3]&amp;#160; Ryan E J, &lt;em&gt;et al.&lt;/em&gt;&amp;#160; 2021&amp;#160; Infiltration of volatile-rich mafic melt in lower crustal peridotites provokes deep earthquakes. &amp;#160;&lt;em&gt;J. Struct. Geol.&lt;/em&gt; 2022&lt;/p&gt;&lt;p&gt;[4]&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160;&amp;#160; S&amp;#248;rensen, B.E., et al., In situ evidence of earthquakes near the crust mantle boundary initiated by mantle CO2 fluxing and reaction-driven strain softening. Earth and Planetary Science Letters, 2019.&lt;/p&gt;&lt;p&gt;[5] Bachmann F, Hielscher R and Schaeben H&amp;#160; 2010&amp;#160; &lt;em&gt;Solid State Phenomena&lt;/em&gt; &lt;strong&gt;160&lt;/strong&gt; 63-68&lt;/p&gt;&lt;p&gt;[6] S&amp;#248;rensen B E&amp;#160; 2013&amp;#160; &lt;em&gt;Eur. J. Mineral.&lt;/em&gt; &lt;strong&gt;25&lt;/strong&gt; 5-10&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

The Fen carbonatite complex, situated in Vestfold and Telemark County, South Norway, is one of the largest known rare earth elements (REE) deposits in Europe with ongoing exploration drilling. Literature regarding the complex processing of the Fen ore is lacking, and thus, the present work investigates for the first time its beneficiation potential and applies process mineralogy studies to understand in a sound manner the performance variations during the processing of REE ore. Flotation kinetics studies revealed that (i) high concentration of total REE-oxide (TREO) can be achieved during rougher flotation; (ii) the high concentration of sulphur (in form of pyrite as main sulphide) can be achieved at the beginning of flotation; (iii) the highest concentration of TREO can be reached after flotation of S. Further processing (i.e., by the addition of cleaning stages and grinding) has a potential to improve the overall recovery of TREO and S. However, the decision of further processing will depend, among other factors, on the definition of following hydrometallurgical routes (e.g., leaching, solvent extraction) and the economic aspects of the overall process. So far, the reported results show that a rather flexible process can be achieved for the material from the Fen deposit.

Obtaining detailed and precise information from a classified refractory gold ore has been a long-standing challenge in mineral processing and process mineralogy. Although the concept of diagnostic leaching has been extensively addressed in the literature, very little information is available linking this approach with current advanced characterization techniques such as automated mineralogy. The present research study aims to characterize the flotation concentrate of refractory gold ore by combining diagnostic leaching and automated mineralogy to examine its processability. The diagnostic leaching process was applied stepwise at five stages, and the automated mineralogy was performed on different size fractions of the flotation concentrate. The chemical (X-ray fluorescence (XRF), atomic absorption spectroscopy (AAS), and inductively coupled plasma-optical emission spectroscopy (ICP-OES)) and mineralogical (X-ray diffraction (XRD)) analyses of the feed sample confirmed that the ore is a low-grade gold ore with 0.7 g/t Au. Initially, bottle roll tests were carried out to investigate leaching behavior, and the ore’s refractory nature, and gold recoveries of bottle roll tests in different sizes were below 40 wt%; it is classified as a high refractory gold ore as a result of direct cyanide leaching. Bulk sulfide flotation was applied to increase the gold content of the material. Automated mineralogy results demonstrated that most of the gold in the concentrate is present as an invisible gold form, and 63.7 wt% of gold was distributed in pyrite. Diagnostic leaching results showed 39.7 wt% of total gold was leachable using direct cyanide leaching, and around 33 wt% of undissolved gold was located in pyrite and arsenopyrite.

Interdiffusion of transition metals across the cathode-electrolyte interface is identified as a key challenge for the practical realization of solid-state batteries. This is related to the formation of highly resistive interphases impeding the charge transport across the materials thus limiting the battery performance. Herein, we investigate the hypothesis that formation of interphases is associated with the incorporation of Co into the LLZO lattice representing the starting point of a cascade of degradation processes. It is shown that Co incorporates into the garnet structure preferably four-fold coordinated as Co2+ or Co3+ depending on oxygen fugacity. The solubility limit of Co is determined to be around 0.16 pfu, whereby concentrations beyond this limit causes a cubic-to-tetragonal phase transition. Moreover, the temperature-dependent Co diffusion coefficient is determined, e.g., D700 °C = 9.46 × 10-14 cm2/s and an activation energy Ea = 1.65 eV, suggesting that detrimental cross diffusion will take place at any relevant process condition. Additionally, the optimal protective Al2O3 coating thickness for relevant temperatures is studied, which allows to create a process diagram to mitigate any degradation with a minimum compromise on electrochemical performance. This study provides a tool to optimize processing conditions toward developing high energy density solid-state batteries.

The Deep Adda-1 well in the Danish Central Graben, North Sea, provides a record of mid-Cretaceous sedimentation on the eastern flank of the intrabasinal Adda–Tyra inversion high. An upper Hauterivian – lower Barremian core in the Tuxen Formation spans the lower boundary of the laminated organic-rich Munk Marl Bed (MMB), a key marker bed in North Sea Cretaceous stratigraphy. Multidisciplinary sedimentological–biostratigraphic–palaeoecological data document the abrupt environmental shift at this boundary. The upper Hauterivian – lowermost Barremian lower Tuxen Formation (nannozones BC10 – lowermost BC14), beneath the MMB, represents a well-ventilated, current-swept setting supporting a diverse benthic fauna and characterized by a condensed succession with hardgrounds, at one level defining a biostratigraphic hiatus, and stacked, thin shallowing-upward parasequences. The succeeding lower Barremian MMB (nannozone BC14) attests to poorly oxygenated bottom waters and a total lack of epi- and infauna; the calm, inhospitable sea floor was intermittently disturbed by muddy turbidity currents and debris flows. The base-MMB surface is a complex fractured hardground indicative of relative sea-level fall and protracted winnowing of the cemented sea floor. The Deep Adda-1 core thus records a sea-level excursion that accompanied the onset of early Barremian oxygen depletion in concert with additional potential forcing factors such as coeval volcanism and watermass warming.