In seeking to improve efficiency in the mine to mill process, mining companies are incorporating ore processing variables during ore planning and scheduling stages to improve decision making. Therefore, the accurate modelling of these ore processing variables has become more critical.

This case study presents a D-vine copula modelling process applied to predict recovery (Rec) from three geometallurgical variables, that is, Bond Work index test (BWi), resistance to abrasion and breakage index (A*b), and semi-autogenous grinding (SAG) power index test (Spi), using a dataset consisting of 775 diamond drill core samples of the four geometallurgical variables from the Tarkwa Mine in Ghana. The distributions of the four variables were used to create a geometallurgical model to predict values of Rec based on SPI, BWi, and A*b using a 10-D version of copula-based quantile functions, which can be integrated in the mine planning and scheduling process. The module produced an average predicted recovery of 89.26% compared to an observed average recovery of 88.64%. A mean absolute error of 4.41 was obtained indicating an acceptable module performance considering the observed recovery values, which suggests that the model's predictions closely align with the observed values.

This modelling framework enables the creation of a geometallurgical block model that not only improves the prediction of metallurgical variables but also significantly improves the integration of geological and metallurgical information, thereby optimizing processing outputs, project revenue, and cash flows for mining companies.

Located 30 km southeast of the Tagragra d’Akka inlier, Jbel Addana forms part of the Ordovician Jbel Bani chain within the Paleozoic cover of the Moroccan Anti-Atlas. The area is composed of weakly metamorphosed Upper Ordovician detrital units, mainly quartzites, shales, and sandstones. Metallogenically, it corresponds to a mining district comprising several mineralized zones, among which the Central Plateau represents the largest deposit. Lithostratigraphically, the sequence includes interbedded sandstones, shales, and quartzites of the Rouid-Aïssa Formation, overlain by the Upper Ktaoua shales and capped by Second Bani quartzites. Geological mapping focused on lithostratigraphic architecture and structural features controlling mineralization. Petrographic, metallographic, and Scanning Electron Microscopy (SEM) analyses were conducted to identify mineral assemblages and alteration stages. Electron-microprobe analyses were performed to determine the chemical composition of ore bodies. Structural data were processed using Win-Tensor software to reconstruct the paleostress responsible for fracture formation and ore emplacement.

Mapping revealed that competent units of the Rouid-Aïssa Formation preferentially host mineralization. Ore bodies occur as N110°E–N130°E vertical subparallel veins with regular spacing, carrying lead and copper mineralization. Metallographic and Scanning Electron Microscopy (SEM) observations indicate two main paragenetic stages: (1) a hydrothermal stage marked by quartz, galena, chalcocite, stromeyerite calcite, and siderite; and (2) a supergene stage characterized by anglesite, cerussite, covellite, malachite, smithsonite, and iron oxides. Microprobe analyses show that galena contains minor gold and bismuth (88.77 wt.% Pb, 12.48 wt.% S, 0.76 wt.% Bi, 0.72 wt.% Au) with a structural formula of Pb1.04Bi0.01Au0.01S0.94.

Structural analysis indicates that mineralization is hosted by a dense network of regularly spaced joints. Win-Tensor results show that these fractures were opened under a sub-vertical σ1 stress controlled by the Hercynian uplift of Precambrian basement blocks. This stress regime promoted fracture opening along the anticline hinge, enabling hydrothermal fluid circulation and ore deposition.

This work is a mineralogical study of fluorite samples (colourless, yellow and purple) from the mining districts of Villabona-Arlós and Caravia-Berbes (Asturias, Spain). It integrates data from UV fluorescence microscopy, SEM-EDS, fs-LA-ICP-TOFMS and fluid inclusions. Different growth stages were identified, some with abundant fluid and solid inclusions, and, in yellow fluorites, yellow bands alternated with colourless bands. UV fluorescence microscopy revealed growth bands with emissions of varying intensity and colour. SEM-EDS identified growth bands with inclusions of barite and celestine crystals, rich in aqueous fluid inclusions containing the same trapped minerals. In one fluorite crystal, an innermost colourless zone contained primary H₂O–NaCl–CaCl₂ fluid inclusions with trapped barite/celestite. Surrounding this zone was a yellow band full of tiny barite/celestite inclusions and an external colourless band hosting H₂O–NaCl fluid inclusions and sulphides. This growth zoning supports a fluid‑mixing process previously proposed by other authors. Such mixing induced a local transition from oxidizing to reducing conditions, facilitating the shift from sulphate to sulphide precipitation. Trace and ultra-trace element analyses by fs-LA-ICP-TOFMS were performed in the fluorite growth bands. The designed analytical conditions (15 μm spot size, 3-3.5 J/cm² fluence, 5 s of background and 5 s measurement, Ca as internal standard, NIST610 and 612 as external standards) show the REE distribution at a single crystal level. The REE patterns have an enrichment in the MREE, a positive yttrium (Y) anomaly and a LREE impoverishment. Yellow growth bands have higher REE and yttrium concentrations compared to colourless bands and violet fluorites. The bands with higher UV fluorescence intensity are those with higher concentrations of REE and Y. The results confirm that fluorites from the Villabona-Arlós district contain more ΣREE than those from the Berbes District. These results are consistent with bulk-sample chemical analyses reported by other authors (Sanchez et al., 2010).

Between 2020 and 2050, global tailing generation is projected to reach 300 Gt. When poorly managed, mine tailings pose significant environmental and safety risks, contributing to more than 2,650 recorded deaths since 1915. Despite this, the mining industry continues to rely heavily on reactive waste strategies—repurposing and reuse—rather than preventing tailings at the source. Ore-sand, a by-product derived from mineral processing, offers a preventative pathway. This opportunity stems from the realisation that most mineral waste originates from discarding dominant minerals—particularly silicates—that could instead be mined as fit-for-purpose by-products. Ore-sand has demonstrated strong technical feasibility as a substitute for natural sand, the world’s second-most consumed resource. An estimated 50 billion tonnes of natural sand are extracted annually from rivers and coasts, with environmental and social consequences particularly severe for communities in coastal regions. Successful implementations already exist. Vale’s Brucutu iron ore mine produces around 2 Mt of ore-sand per year, while Newmont’s Cadia copper–gold mine has demonstrated the viability of coarser ore-sand production using HydroFloat technology. However, despite these promising examples, no comprehensive method currently exists to estimate ore-sand resources, reserves, and recoverable quantities as a by-product, nor to align these estimates with application-specific and market-driven requirements such as particle size distribution, shape, elemental and mineralogical composition. In this study, we present the first framework for estimating ore-sand resources, reserves, and recoveries across different sand applications. We evaluate key factors influencing ore-sand generation, including primary commodity production, mineral processing circuits and technologies, market-based performance criteria, and market absorption. This framework provides a crucial foundation for understanding the true valorisation potential of ore-sand, including the volume of tailings that can be avoided, the degree to which natural sand extraction can be offset, and the extent to which ore-sand can meet the technical requirements of various sand applications.

Emerging frontiers in mineral science emphasize the need for sustainable, low-impact materials that leverage waste resources while delivering functional performance for advanced applications. In this study, agro-industrial waste—specifically rice husk ash combined with excess aluminum sulfate—was transformed into synthetic alkali feldspar particles through a rapid sol–gel process. The resulting powder exhibited an optimal chemical composition of 59.33% SiO₂, 16.42% Al₂O₃, and 7.12% alkali oxides, confirming its successful conversion into a synthetic feldspathic mineral. The product also displayed a high lightness value (L* ≈ 100), indicating a bright white chroma suitable for reflective and thermal management coatings. X-ray diffraction patterns further verified the presence of albite, orthoclase, quartz, and thenardite phases, demonstrating the formation of mixed alkali feldspar and associated phases.

To assess its application potential, the synthesized alkali feldspar was incorporated into a paint matrix and applied to a glass substrate. At a low particle concentration of 1.59%, the coating reduced thermal conductivity to 1.03 W/m·K, whereas a higher particle concentration of 7.90% increased conductivity to 1.68 W/m·K relative to the control substrate of 1.07 W/m·K. Optical microscopy confirmed well-dispersed particles within the coating layer, suggesting favorable compatibility and dispersion behavior.

Overall, the findings highlight waste-derived alkali feldspar as a tunable, sustainable mineral resource with promising applications in energy-efficient coatings, reflective surfaces, and thermally adaptive construction materials—aligning with innovative future opportunities in material resource development.

Advancements in materials development continue to drive innovations in sustainable and resource-efficient construction materials. Coconut shell ash (CSA), a byproduct of using coconut shells as fuel in industries, is a good resource to utilize because of its abundance. This study explores the potential of waste-derived coconut shell ash (CSA) as a material resource-based micro-filler for concrete, aligning with emerging frontiers in waste resource utilization. CSA was incorporated at 10% by volume as a partial sand replacement to evaluate its influence on the physical, mechanical, and thermal performance of the composite. Comprehensive chemical, mineralogical, and morphological analyses were conducted on both CSA and CSA-modified concrete.

Results show that CSA addition slightly reduced concrete density from 1.813 to 1.760 g/cm³ and increased apparent porosity and water absorption to 1.77% and 7.68%, respectively. Mechanical performance decreased moderately, with flexural strength declining from 4.60 MPa to 4.02 MPa and compressive strength from 6.76 MPa to 6.04 MPa. Thermal conductivity, on the other hand, increased from 0.451 to 0.490 W/mK, attributed to the intrinsic porous microstructure of CSA, as shown in Figure 1.

Overall, CSA incorporation significantly influences the physical and thermomechanical behavior of concrete. While the mechanical properties slightly decrease, the findings highlight the potential of CSA as a viable waste-derived resource for developing greener, low-impact construction materials, contributing to breakthrough directions in sustainable material/mineral engineering.

Our opportunity to directly sample the deeper mantle is limited to the investigation of rocks and minerals delivered to the surface by magmas, such as kimberlites. Kimberlites bring to the surface mantle xenoliths formed at depths of up to 250 km, while the Earth's deepest sublithospheric minerals are found as inclusions in diamonds. During crystallisation, a small proportion (<5%) of diamonds captures tiny inclusions of other minerals. These minerals record information about the composition and processes occurring at depths in the range of 150–700 km and possibly even deeper. Less than 10% of all uncovered inclusions in diamonds belong to the sublithospheric mantle (Stachel & Harris, 2008), and, among these, majoritic garnet and ferropericlase are the dominant phases. Other minerals include broken-down davemaoite (former Ca–Si perovskite), bridgmanite (former Mg-perovskite), CF, NAL, and more rare inclusions. Recently unusual high-pressure phases including breyite, davemaoite, ice-VII, and ringwoodite have been discovered in inclusions in diamonds, making a breakthrough in our understanding of deep mantle petrology and composition.

Such discoveries would be impossible without new methods and analytical techniques, which have brought the possible size of investigated material from hundreds and tens of microns to just a few microns.

In this talk I am going to concentrate on new analytical advances and their applicability to diamond research. I will show examples of how the improvement of optical microscopy and Raman spectroscopy allows us to identify inclusions even a few hundred microns under the surface, how cutting-edge computer tomography allows us to identify multi-phase inclusions, and how synchrotron X-ray diffraction permits us to solve the structure of a 10-micron lamella within a complex multi-phase inclusion. I will conclude with how these new opportunities are helping to drive mantle research forward.

Stachel, T. & Harris, J. W. (2008). Ore Geology Reviews 34, 5-32.

The Jingzhushan Formation, a typical post-collisional continental molasse within the Bangong–Nujiang Suture Zone (BNSZ) of the Tibetan Plateau, preserves important evidence related to the closure of the Tethys Ocean and the collision between the Lhasa and Qiangtang terranes. However, key aspects such as its depositional age, sediment sources, and burial history remain poorly constrained, limiting our understanding of the tectonic evolution of this region. In this study, we conducted an integrated analysis of the Puga Jingzhushan section in Nyima County, combining field stratigraphy, detrital zircon U–Pb geochronology, cathodoluminescence (CL) imaging, stable isotope analysis, and clumped isotope (Δ47) thermometry, supplemented by solid-state reordering modeling. Detrital zircon U–Pb results indicate that the Jingzhushan Formation began depositing at approximately 94 Ma, with sediments mainly derived from Early Cretaceous magmatic rocks in the North Lhasa Terrane and limestone of the Langshan Formation. Clumped isotope temperatures (ranging from 51.9 to 79.2°C) are higher than expected primary depositional temperatures, indicating significant post-depositional thermal alteration. Solid-state reordering modeling constrains a maximum burial temperature of ~172°C, attributed to the combined effects of sedimentary burial and magmatic activity around 88 Ma. Furthermore, different fossil types (Auroradiolites, Eoradiolites, Sauvagesia) exhibit distinct diagenetic pathways, influenced by variations in shell microstructure, leading to either C–O bond reordering or closed-system recrystallization. We conclude that the Jingzhushan Formation was deposited in a continental setting following the Lhasa–Qiangtang collision. Its burial and exhumation history reflects Late Cretaceous tectono-magmatic interactions, offering new thermochronological insights into early uplift and tectonic transition in central Tibet.

The main conditions for fast ionic transport are related to the disorder in the positions occupied by the mobile ion and the presence of conduction channels running inside the structure*.

A few examples which confirm the aforementioned statements are reported below. Synthetic analogs of tetragonal Na₂TiSiO₅ natisite, namely Na₂TiGeO₅ and Li₂TiGeO_5, can serve as an illustration of the structural condition of ionic conductivity. Their structures contain the layers (001) formed by tightly connected GeO₄ tetrahedra and TiO₅ semioctahedra. As a result, the alkaline cations can easily move between the layers and the conductivity along a axis is 10³–10⁴ times higher compared with one parallel to c-axis. Another example is the Na₅YSi₄O₁₂ crystal. Its characteristic features are 12-membered rings of silicon-oxygen tetrahedra. According to the symmetry of the cell, it should contain 90 Na atoms, but only 48 atoms were localized. This discrepancy should be associated with the possible movement of Na atoms within the structure. The results obtained using X-ray diffraction methods are extremely important for understanding the structural requirements of ionic conductivity in crystals. The structural refinement of K₃NdSi₆O₁₅ with the silicate layer [Si₆O₁₅], similarly to those found in rare mineral dalyite K₂ZrSi₆O₁₅, allowed us to establish that one of three unequivalent K atoms has the highest thermal displacement U₃₃. Accordingly, these cations are most mobile along the c-axis, and it is confirmed by the values of the principal elements of the specific electrical conductivity tensor. Among the materials exhibiting high ionic conductivity with relatively low transition temperatures to the superionic state, Li-ionic conductors with the general formula Li₃M₂(PO₄)₃ (M = Fe, Sc, Cr, In) and with mixed framework structures are considered in this presentation.

*Pushcharovsky, D.; Ivanov-Schitz, A. Minerals, 2024, 14, 770.

The Norilsk region, the largest metallogenic province in the world, is located in the northern part of Eastern Siberia. This area contains many basic–ultrabasic intrusive bodies related to the Siberian Traps, some of which contain very rich platinum-group element (PGE)–copper–nickel ore deposits, such as Talnakh, Oktyabr'sky, and Norilsk 1. To discover new massifs with sulfide mineralization, the composition of rock-forming minerals, such as olivine and pyroxene, was studied using EPMA, LA ICP-MS, and SIMS methods in ten intrusive bodies with different volumes of sulfide mineralization. It was found that all the massifs exhibit strong variations in mineral composition across vertical cross-sections: olivine varies from Fo₈₂ to Fo₄₃ and pyroxene changes from Mg# 87 to Mg# 52. Additionally, for the first time, it was shown that the composition of minerals within each horizon (picritic, tacxitic, and olivine-bearing gabbro-dolerite) varies in trace elements, particularly in Ti for pyroxene and Ni and Y (HREEs) for olivine. Similar horizons from different intrusions, especially picritic ones, are characterized by different trends in the Fo (Mg#)-trace element coordinates on diagrams. This feature allows us to separate ore-bearing intrusions from all studied massifs. The specific features of intrusions with high sulfur content were demonstrated using statistical methods, as their olivine is enriched in Ni, Ca, Ti, and HREE as compared to barren intrusions. The composition of the parental melts of ore-bearing intrusions was determined by studying melt inclusions in olivine and pyroxene, which corresponds to typical intraplate magmas with normal volatile component contents (H₂O, CO₂, Cl, B). Thus, mineral compositions, rather than rock compositions, aid in recognizing mineralized intrusions. This seems to be based on the difference in f_O2 of barren and sulfide-containing magmas during crystallization.

This study was supported by state assignment of the Ministry of Science and High Education of Russian Federation for GEOKHI RAS.