The minerals industry is vital to national economies, energy sufficiency, and transformation worldwide. Exploiting a mineral deposit is a complex project, as it is related to technical, environmental, social, and economic aspects with significant impacts on the financial markets, societies, human life, and the global ecosystem. In this framework, sustainable exploitation and development are crucial in all mining sector activities. Considering the uncertainties related to factors that affect a mining project's viability and sustainability, the overall assessment of a mineral resource constitutes a complex and multidimensional decision-making problem [1]. In the decision analysis model, an integrated approach is required based on the spatial modelling of the mineral deposit in combination with exploitation planning and quality control [2]. In addition, evaluating alternatives in mine planning can incorporate sustainability criteria in the decision-making model [3].

In this work, a decision-making model regarding for the evaluation of a mineral deposit is developed, based on dynamic programming, and considering the whole life cycle of the extraction and processing of the mineral resource project. In this context, a quantification of sustainability and circular economy parameters is attempted through a system analysis model that combines the economic objective function, the constraints, and the cash flow analysis and optimization. 

The proposed framework can be applied as an effective tool for evaluating mineral resources planning exploitation strategies, managing mining activities, and validating research and operational objectives, by always taking into consideration sustainability and circular economy standards and viable development perspectives.

This presented work will introduce a new method for efficiently and selectively extracting pure RbCl_(s) from Na⁺ and K⁺ enriched brines emanating from the phosphoric acid production industry. Utilizing the ion exchange properties of self-synthesized PES coated Zn-Hexa-Cyanoferrate (PES-Zn-HCF) material, the approach enables effective Rb⁺ adsorption followed by stepwise, selective desorption. The process involves passing Rb⁺-containing brines through a column filled with PES-Zn-HCF beads, followed by chromatography-based separation between Rb⁺ and Na⁺/K⁺ using a second column pre-adsorbed with NH₄⁺. A 0.05M NH₄⁺-solution is initially used to extract Na⁺ and K⁺ from the first column, retaining a small Rb⁺ mass, partly re-adsorbed in the second column. After ensuring that the eluent solution flowing out of the column is devoid of Na⁺ and K⁺, the 0.05 M NH4Cl passage is ceased and a 1 M NH₄⁺-solution is now pumped in to extract the remaining Rb⁺. This solution undergoes water evaporation followed by NH₃/HCl sublimation/deposition, resulting in the production of a pure RbCl_(s) product and in the parallel recycling of the NH₄Cl salt that is used as eluent. The study employs theoretical simulations validated by empirical results to demonstrate the method's feasibility as well as a detailed cost assessment, showing the concept to be highly cost effective.

Laterites are valuable European sources to produce the critical battery metals cobalt, nickel, and manganese. In this study the wet-chemical leaching of pyrometallurgically treated laterites from the LARCO Ferronickel Plant in Greece was tested. It was shown that leaching with peroxydisulfate at 50°C allows to almost fully recover residual amounts of Co, Ni, and Mn from the rotary kiln dust and electric arc furnace (EAF) slag. The results of this study shows that EAF treatment followed by leaching the EAF slag is the most promising way. In sum, there were obtained ~ 65% overall yield of Co, ~95% overall yield Ni and ~100 % overall yield of Mn. In addition, up to 37% of chromium were mobilized and 98% of titanium, rendering this approach highly promising in terms of energy and resource efficiency and likewise overall process economy. As the successful development and application of this method in the field can increase the outcome of the plant by nearly ~50 million €/year.

Following a brief description of the background, a life timeline of industrial and scientific activity for 35 years will be presented. First, there will be presented the scientific work done, experiences gained and memories of working for 2 years as engineer in LARCO GMM SA Ferronickel Company. 

The scientific activity at National Technical University of Athens (NTUA) will follow along with the scientific achievements, the experience gained as visiting researcher in Columbia University, evaluator of the Research Excellence Center of MiMer, member of Scientific Bodies and Committees in the field of Mineral Processing, etc.

The establishment during thirty-five years as professor, researcher and Scientist of many collaborations with the best universities and professors in the world and lifetime lessons will be presented.

Currently, one of the main sources of electricity generation is coal-fired power generation. Coal-fired plants generate electricity by burning coal, resulting in a large amount of waste (ash and slag) being accumulated, which has a negative impact on the environment. Involving ash and slag processing will not only reduce the environmental burden, but also provide additional marketable products. Depending on the coal deposits, combustion conditions, and waste composition, ash and slags have different physical and chemical characteristics. Very often, ash and sludge contain elements such as Fe, Si, Ti, Al, Ni, Mo, V, and many others. Various enrichment methods are used to extract these valuable components: flotation, gravity separation, magnetic separation, and leaching.The choice of beneficiation process primarily depends on the size of the material to be processed, as well as the physical and chemical properties of the components that need to be separated.

Ash-and-slag waste (ASH) from thermal power plants (TPPs) was selected to investigate the possibility of extracting iron-containing components. To justify the processing method, studies on the granulometric and chemical compositions were carried out. The material mainly consists of fine particles with a fraction greater than 90 % in the -45 micron size class. At the same time, by electron microscopy, the presence of various microspheres, including aluminosilicates and iron-bearing ones, was established. Due to the small size of these particles, it is difficult to produce concentrates with marketable quality using conventional enrichment methods.

The conducted studies on magnetic fractionation allowed us to establish that the distribution of iron is quite uniform in all fractions, but microspheres, which include magnetite associated with intermetallides, are mainly concentrated in magnetic fractions obtained at current values equal to 2, 3 and 4 A. It was assumed that iron in the compounds is in different valence forms and has different magnetic properties. At the same time, microspheres containing hematite and aluminosilicates were not found in isolated magnetic fractions. It was proposed to use high-gradient magnetic separation to separate such microspheres from finely dispersed materials.

Studies on the influence of various parameters and settings of the magnetic separator, including matrix size, field strength, and pulsation frequency, on the characteristics of extraction and concentration of the target component, were carried out at a high-gradient magnetic separator while varying technological parameters and modes. As a result of these studies, it was found that the best results were achieved with the following operating parameters: magnetic induction of 1.1 T, diameter of matrix rods of 6 mm, and pulp pulsation of 300 rpm. In order to further increase iron extraction in the concentrate, a series of experiments using flocculants were conducted. As a result of the research, a technological mode was proposed that allows for the production of iron ore with a 50% iron content and a recovery of 94.5% in one stage using a magnetic induction of 1.1 Tesla, a matrix bar diameter of 6 mm, a pulse frequency of 300 cycles per minute, and the consumption of Flotifloc flocculant of 100 grams per ton. Scanning electron microscopy revealed that under these conditions, most microspheres containing hematite and aluminosilicate minerals with sizes ranging from 2 to 15 micrometers are extracted into the magnetic fraction.

Thus, for the extraction of microspheres with different compositions and sizes, a sequential magnetic enrichment scheme is recommended: magnetic separation in a weak magnetic field and high-gradient tailings separation. This proposed solution will not only allow us to obtain materials with unique technological properties, but will also reduce the environmental impact in areas where ash dumps are located.

This work was carried out within the grant of the Russian Science Foundation (Project № 23-47-00109).

To date, the main problem in the development of the mineral resource base has been the deterioration in the quality and technological properties of processed minerals. This has led to a significant decrease in the efficiency of traditional beneficiation techniques. These techniques are unable to meet industry standards in terms of the content of useful components, processing complexity, and environmental requirements.

The key factors determining the technological complexity of processing strategic raw minerals include: the dispersed connection between minerals of valuable components and waste rock, high complexity and variability in material composition, and the complexity of the morphology and separation of ore bodies involved in the processing. All these aspects significantly affect the efficiency of beneficiation processes and profitability of the final product.

The main directions for solving this problem are improving flotation beneficiation processes. The flexibility and versatility of flotation technologies allows increasing their efficiency through improving reagent regimes and intensification methods with the preceding grinding stage. Confirmation of the effectiveness of these solutions is possible through the use of complex numerical criteria based on experimental and theoretical studies of the physical and chemical properties of raw materials.

For numerical evaluation of the intensifying impacts during the grinding process, a semi-empirical criterion has been proposed, which characterizes the proportionality between the required specific energy for destruction and the relative reduction in the characteristic fineness of the product. This criterion is based on interpreting the Gibbs–Helmholtz equation in terms of the equivalence of energies expended on reducing the fineness and forming a new surface area. In grinding operations, the increase in the newly formed surface area is proportional to the energy spent breaking a certain amount of material, as described by Bond's law.

To establish the influence of variations in grinding and flotation technologies on beneficiation efficiency, a method for characterizing the distribution of materials by flotability has been proposed. This method allows for the numerical characterization of changes in the flotation ability of materials. The method is based on a probabilistic-kinetic approach to studying flotation, and it involves abstractly allocating flotability classes to materials according to their flotation properties. Each fraction of material is assigned a flotability value, which is proportional to the flotation constant rate of that fraction. The flotation index value represents the proportionality between the flotation recovery probability and the constant value of the fraction's flotation rate. Initial data for determining flotability functions are obtained from experimental studies of flotation kinetic enrichment using the γ model. The values of the flotation function characterize the distribution of materials into certain flotation classes and collectively represent a step function with an exponent b.

Thus, the criterion for intensifying the grinding process's efficiency will allow us to justify the most cost-effective ratio of particle size and energy consumption for the proposed ore preparation solutions. Parameters of floatability functions will allow estimating the effectiveness of new reagent regimens on the flotability of various ore components. Establishing correlations between these parameters will enable us to characterize the impact of intensified grinding on the efficiency of flotation processes.

This work was carried out within the grant of the Russian Science Foundation (Project № 23-47-00109).

The grinding method has been shown to significantly influence the shape characteristics of ground materials, including properties such as circularity, roundness and aspect ratio. Particle morphology plays a critical role in determining material properties, such as packing density, flow behavior, and surface reactivity, which are essential in various industrial and scientific applications.

This study investigates how different grinding techniques—specifically ball milling and vibrating pulverizer—affect the shape characteristics of ground particles. The material under study is natural volcanic glass, with a particle size distribution primarily within the 120–355 μm range. Shape descriptors, including circularity, aspect ratio, and roundness, were measured by image processing of SEM micrographs.

Ferrous ores play a remarkable role in the development of human activities, over the decades; iron is of the most common and crucial elements in construction field; from household appliance to automotive and aerospace equipment [1-2]. This statement is highly supported, by the fact that the iron content in ferrous ores has been diminished throughout the years. With that being said, it was considered of high importance to explore new physicochemical methods of separation and recovery of pure iron from hematite ores with significantly low percentages in iron [3].

In this scientific paper, the separation and recovery of fine iron particles from artificial mixtures of hematite and limestone is being studied, as the demand for iron has become more and more imperative. Limestone is met in great percentages in hematite ores as gangue mineral, which led to its usage in the artificial textures. Sodium oleate and dodecylamine are used as collector reagents in the testing procedure. 

The testing procedure includes preliminary tests in single minerals, in order to define the most effective operation points of the aforementioned mixture (pH, collector dosage, conditioning time). Afterwards, hematite and limestone are both subjected to flotation tests separately, in order to determine their behavior, in presence of sodium oleate and dodecylamine, as collector reagents. The results are really promising, as hematite’s recovery is particularly high; 84.5% and 93.5% using sodium oleate and dodecylamine, respectively. On the other hand, limestone in single-minerals tests has remarkable behavior, as the usage of sodium oleate leads to 93.5% recovery; while 98.5% recovery is achieved by using dodecylamine as collector reagent.

The lead complex of benzohydroxamic (Pb-BHA), as an effective collector, has realized the mixed flotation of wolframite and scheelite to a certain extent. The Pb-BHA complex can be adsorbed on the surface of wolframite and scheelite by bonding with the O on the surface of tungsten minerals through the lead ion in the structure. However, current research cannot explain the detailed difference between wolframite and scheelite in flotation behavior and kinetic, and it is of great significance for the design of corresponding reagents and the development of efficient flotation flowsheets in actual ores. In this paper, the flotation behavior and kinetics of two tungsten minerals under the Pb-BHA system are systematically studied. The flotation rate constant K for scheelite(0.20) is higher than wolframite(0.16), which is the reason why the tungsten minerals lost in the actual tailings are mainly wolframite. Subsequently, the internal reasons for the difference in their flotation behaviors are analyzed through adsorption experiments, solution chemical analysis, and quantum chemical calculation. The quantum chemical calculation showed that the ΔE(|EHOMO(mineral)-ELUMO(Pb-BHA)|) for wolframite is lower than scheelite but the adsorption capacity of Pb-BHA on scheelite surface is higher than wolframite. The contradiction is further explained by the different interaction characteristics between water molecules and mineral surfaces. The pre-hydration degree of two tungsten mineral surfaces affects the adsorption of Pb-BHA, further influencing the hydrophobicity of the two mineral surfaces.

Recently, the European Commission carried out an assessment of 83 raw materials and identified several elements including heavy rare earths, light rare earths, platinum group metals, non-metallic elements in supply risk, and other metals in supply risk within criticality zone of high economic importance (³ 2.8) and supply risk ((³ 1) [1], which place serious pressure related to sustainable supply chains and environmental issues. This ongoing technological evolution has resulted in a rapidly growing generation of electronic waste and toxic substances, leading to significant harmful effects on the environment and human health [2]. Therefore improving the efficiency of recovery of metal from either primary mining processing or from secondary waste, as well as sustainable urban mining /recycling, is of utmost importance to both the economy and environment. Contrary to traditional recovery techniques, which are chemically intensive and often require large pH or thermal swing [3], electrochemically mediated technologies offer modular approaches as alternatives of traditional chemical / thermal swing-based separations [4,5]. In this context we present here recent considerations on hydrometallurgical and electrochemical approaches that can benefit critical materials recycling, especially for rare earth elements and other valuable transition metals. More specifically, we provide insights into the mechanisms and applications for different electrochemical techniques [6,7], namely electrodeposition, electrosorption, electrodialysis and electrocoagulation, as well as recovery techniques at an interface electrode level, using porous capacitive electrodes, intercalation electrodes and redox active electrodes. In parallel,  judicious electrochemical engineering (e.g., the design of counter electrodes, types of electrical stimuli, optimizing electrochemical parameters) can significantly improve the separation and energy efficiency. In sum, the increasing demand and decreasing supply of global critical raw materials call for the development of the sustainable recovery and recycling of the valuable elements. Hydrometallurgical processes have been studied for various recycling applications, with increasing industrial-scale implementations in the last decades. There have been significant improvements but, at the same time, several issues with regard to chemical footprint, generation of wastes, slow leaching, and molecular selectivity still remain. In mitigating these challenges, electrochemical separations can be naturally coupled with existing hydrometallurgical processes, and we believe that this combination of electrochemical and hydrometallurgical separation steps, can pave a path toward sustainable materials recycling and critical element recovery.

Based on recent studies, the Greek Mining Industry has an important contribution to the Greek Gross Product, providing a competitive advantage for the Greek economy, and supplying raw materials that are key prerequisites for important economic-industrial activities as well as raw materials necessary to the EU economy and international market.

It possesses a remarkable share to the reduction of the dependence of EU economy from imported raw materials and an important role to the country’s exports. The contribution of the Greek Extractive Industry to the employment, especially in the province is a noteworthy fact. 

Some of the ores and minerals produced in Greece are highly ranked at international level. Just to mention some:

Magnesite: larger exporter in Europe

Perlite: 1^st world wide

Bauxite: largest producer in Europe, key for the remarkable national aluminum industry 

Bentonite: 1^st in Europe, 2^nd world wide

Marble: Global leader, famous for its quality 

Concerning the future:

Greek Extractive Industry has the potential to increase its share to the Greek GDP from 3% today to 7%, thanks to the variety of ores and minerals existing in the country and their significant reserves.

Additionally, the existing potential of Critical Raw Materials Act (CRMA) is expected to provide the country with a comparative advantage and economic benefits. As a proof:

• Four (4) CRMs (15% of the CRMA list) and one (1) strategic is in production now
• Four (4) are at the position to be extracted
• Five (5) are in the level of geological research to ensure the receivable deposits (Antimony, copper, gallium, germanium, graphite).

Finally, concerning the green transition, specific exploration research is on progress aiming at the discovery of suitable geological formations to ensure appropriate Carbon Capture Utilization System (CCUS) installation.

This study presents the primary results from field campaigns conducted in the Messara Basin, Crete, emphasizing the hydrogeological conditions and sustainability challenges in the region (Pictures 4-14). Geological maps at scales of 1:50,000 and 1:200,000 (Pictures 1-2) were foundational in understanding the basin’s geological framework and were used for hydrolithological classification, providing a detailed analysis of the hydrolithological characteristics linked to the region's geological features. Groundwater levels in the basin exhibit significant seasonal variations, largely due to over-exploitation for irrigation, raising critical sustainability concerns. Effective groundwater management requires systematic data collection and precise utilization of primary data (Picture 3). Despite the involvement of various authorities in localized groundwater management, the absence of a comprehensive, large-scale framework hinders the creation of a detailed master plan. Addressing this gap necessitates systematic fieldwork aimed at delineating the boundaries of groundwater systems.

The lack of a detailed hydrogeological map complicates the management of the region’s essential groundwater resources, which are crucial for irrigation. Changes in groundwater head were studied, identifying areas of generalized groundwater depressions, with maximum changes analyzed from May 2021 to October 2023 (Pictures 6-10). Additionally, data from the European Ground Motion Service (EGMS) were analyzed to detect induced land subsidence in the basin (Pictures 11-12). These findings were combined with areas of groundwater depressions for further investigation. The recent poor hydrological conditions over the past four years have exacerbated the sustainability crisis, posing significant economic and social challenges to the future of the Messara Basin.

The industrial metallurgical processing of spodumene, for the extraction of lithium hydroxide or lithium carbonate, comprises the calcination of a-spodumene to b-spodumene at 1100 ^oC followed by its leaching with sulfuric acid at 250 ^oC. Both steps are energy-intensive, while they present a high environment footprint [1]. Recent researches aim to the replacement of calcination/H₂SO₄ leaching steps by a single less energy-intensive process. Whitin this framework, among other techniques, the direct hydrothermal processing of a-spodumene, aiming to its conversion to lithium intermediate products, using sodium hydroxide at high temperature and pressure conditions, has been proposed. Despite the implemented experimental work [2-4], the literature is poor concerning the thermodynamic description of the process. Furthermore, contradictory results are presented in respect of the formed reaction products. The present study is focused on the thermodynamic study of the a-spodumene ore-NaOH system, by the using of HSC 10 software, in respect of various parameters including the: temperature, pressure, stoichiometry of the reagents and the addition of CaO as an additive. The equilibrium phase diagrams of lithium and non-lithium containing phases and, as well as, Pourbaix diagrams were conducted.

The electrical and electronic industry faces growing demands to address environmental degradation and social challenges arising from its linear production and consumption methods. To tackle these challenges, this paper proposes an innovative and inclusive framework that integrates the traditional Circular Economy Business Model (CEBM) Canvas with social considerations tailored for this industry. The framework aims to assist the electrical and electronic industry in adopting more sustainable and socially responsible practices while maintaining competitiveness and profitability. The development of the framework involves a multifaceted approach. Initially, an extensive review of existing literature identified crucial principles and successful practices in CEBM Canvas, as well as social responsibility within the sector. Additionally, research methods employed included case study analyses of companies in the sector, industry reports, and surveys that gathered insights from various industry stakeholders to shape the framework's design in order to provide a fundamental understanding of circular economy principles and relevant social issues within the electrical and electronic industry. The proposed framework consists of ten essential elements, including circular value proposition, circular revenue streams, key customer segments, circular customer relationships, circular channels, key circular resources, key circular activities, key circular partnerships, circular cost structure, and social considerations. Embracing this framework, the electrical and electronic industry can not only mitigate environmental risks but also contribute positively to foster societal benefits and promote social equity within the industry. It's evident that the forementioned approach embodies a comprehensive strategy for promoting circularity and ethical responsibility in the electrical and electronic industry, contributing to the transition towards a more equitable and regenerative economy.

Mr. President, Ladies and Gentlemen

I consider it a great honor that you invited me to your Symposium, and I regret that I cannot attend it. However, it remains for me a strong pleasure to write a few words about Professor Georgios Anastasakis, as he was one of my first students, whose development I followed closely during his career so far in the School of Mining and Metallurgy of the National Technical University of Athens, where we have now worked for a long period as colleagues. During this time, we became close friends, and now, 45 years later, after a rich scientific, teaching and research career, he is being honored in your distinguished Symposium that bears his name.

Mr. Anastasakis has worked tirelessly in teaching and research on a wide variety of topics, with a focus on mineral beneficiation and sustainable development. He dealt with issues of basic and applied research, producing an extremely large number of publications with high impact in the respective scientific field, thus opening new scientific perspectives. He also worked on numerous research projects together with other researchers to solve actual industrial problems.

Moreover, his scientific activity was not exhausted in publications, but it was coupled with his active participation as a member of international congress organizing and scientific committees, member of scientific boards, reviewer of scientific journals, and member of scientific and editorial boards, as well as other related activities on international level.

We must not yet overlook his exemplary engagement in the context of his teaching duties and in the multi-year direction of the Mineral Processing Laboratory, which produced excellently educated engineers and professionals in this field.

Thanks to the aforementioned overall achievements, he gained international recognition, for which he undoubtedly deserves an award.

Flotation tailings is waste material produced during the flotation process. Proper management and storage of these raw material is crucial to minimizing negative environmental impacts. The main elements contained in flotation tailings are copper (0.13 %) and iron (4.22 %). In addition, the tailings contain zinc, lead, aluminum, magnesium and calcium. The application of hydrometallurgical operations is possible for raw materials with a low metal content or a complex composition. The right choice of reagents is important for a successful process. Sulfuric acid is used as one of the most common reagents for the leaching copper from flotation tailings. [1] On the other hand, ionic liquids are recognized as green reagents due to their characteristics such as viscosity, thermal stability, negligible volatility, non-toxicity and high conductivity. [2] The leaching experiments were carried out in a sulfuric acid solution (H₂SO₄) and an ionic liquid solution 1-butyl-3-methyl-imidazolium hydrogen sulfate ([bmim]HSO₄) in the presence of hydrogen peroxide (H₂O₂). The diluted solution was analysed for copper and iron using a multiparameter photometer and ICP-OAS. Reagents concentrations of 0.01 mol/dm³ and 0.05 mol/dm³ without hydrogen peroxide were also tested. Leaching flotation tailings with sulfuric acid, the copper leaching degree reached 71.05% at lower solution concentrations and 76.59% at higher solution concentrations. When leaching flotation tailings with an ionic liquid solution of the same concentrations, the copper leaching degree was 72.57% and 77.10% for 0.01 mol/dm³ and 0.05 mol/dm³, respectively as shown in a previous study [3]. When leaching with sulfuric acid and in the presence of 0.1 mol/dm³ H₂O₂, the leaching degree of copper was 80.85% at the lower concentration of the solution and 82.24% at the higher concentration of the solution. In the leaching of flotation tailings with an ionic liquid solution of the same concentrations, and in the presence of 0.1 mol/dm³ H₂O₂, the leaching degree of copper was 72.56% (for 0.01 mol/dm³) and 83.14% (for 0.05 mol/dm³). The dissolution of iron was <5% under the tested conditions. These results indicate that hydrogen peroxide has a slight effect for the leaching process of flotation tailings. At the higher acid concentrations tested for both reagents, a greater influence of hydrogen peroxide can also be observed.  

The main purpose of this paper is to investigate the existence of super cycles, i.e. long waves, in global energy production and consumption between 1900 and 2016. The statistical data indicate the presence of long waves in global energy production and consumption between 1956 and 1999. According to the econometric estimates, the peak of the cycle is in 1975, immediately after the 1973 global oil price shock. If the paper's econometric estimates are statistically valid, one might expect another super cycle in global primary energy production and consumption between 2000 and 2043, with the peak of the cycle occurring around 2020. In addition, policy makers and other stakeholders in the energy sector could utilise the results of this paper in forecasting future global energy supply and demand. To generalize the findings of this article, potential avenues for further research include broadening the analyses for specific energy products, most notably coal, oil and natural gas. 

ESG criteria have increasingly been used by investors to measure sustainability levels for investment in a company or business. In the mining sector, most, if not all, of the available commercial software used for decision-making support, does not include sustainability indicators such as carbon footprint, water consumption, social license, and other factors commonly associated with ESG practices. In this context, the present work presents the current development state of an open-use, cloud-based computational tool called MAFMINE ESG, which aims to incorporate environmental, social, and governance (ESG) sustainability indices to the usual technical-economical parameters used into the preliminary evaluation of mining projects.

The MAFMINE ESG consists of the expansion version of “MAFMINE 3”, an already existing tool developed for the economic evaluation of mining projects (available at https://www.mafmine.com.br/v3/). The core of MAFMINE ESG consists of using parametric models supported by a relatively simple set of inputs (process targets and technical coefficients specified by the user), providing preliminary estimates of sustainability indicators as model outputs. These indicators are quantitative indices associated with one of the following ESG model parameters: emissions, water management, land use, social conflicts, automation and digitalization, and governance. For example, the following indicators are associated with the "water management" parameter: total water withdrawn, affected water sources, % of water reused/recycled, and quality and destination of effluents. The parameterization of indices is established through regression analysis, within specific validation ranges, using available databases for each parameter, such as the historical series report databases from the Intergovernmental Panel on Climate Change (IPCC) for emissions and the Global Reporting Initiative (GRI) for water management.

In addition to presenting the general structure of the software under development, this paper aims to discuss the challenges associated with selecting the indexing factors linked to each index to compare project scenarios considering the realities of different countries together with a preliminary simulation for the case of a base metals mining venture.

In the mining industry, one of the main concerns is estimating costs in order to carry out projects efficiently and profitably. MAFMINE is a tool that provides quick and effective results for decision-making. My research was carried out using two parametric equation modeling methodologies, mainly manuals were studied (Bureau of Mines Cost Estimating System Handbook and Costs and Cost Estimation of T. Alan O'Hara and Stanley C. Suboleski), this work focuses on the area of mineral processing, the estimates for operations in processing plant. The parametric equations proposed and added in the plant area make it possible to estimate the processing costs of various circuits, which are fundamental for future plant facility design. These equations also make it possible to estimate the cost of implementations within mineral processing, which in turn allows the most appropriate option to be selected based on the characteristics of each ore. Each methodology has its own advantages and disadvantages, so it was necessary to select appropriate standardization factors. Once the cost estimation tool had been updated with the new parametric equations obtained, it was applied to specific case studies. The results obtained demonstrate the tool's reliability. In conclusion, the study of parametric equation modeling methodologies has made it possible to update a cost estimation tool in the area of mineral processing plants. The inclusion of more parametric equations to estimate mineral processing costs will enable better decisions to be made.

Africa hosts many of the largest mineral deposits in the world, with vast reserves of critical minerals and metals. High-grade deposits of gold, diamonds, and any other metal position the continent as a prime destination for mining investments. Countries like South Africa, Ghana, and Tanzania are leading gold producers with the largest companies in the sector such as Barrick Gold and AngloGold acting there, while the Democratic Republic of Congo dominates in cobalt and copper production. Production costs are relatively low in comparison to western ones due to cheaper labor costs. 

This has led the mining sector to offering substantial economic growth potential in its countries alongside job creation and infrastructure development. Noravia Gold Mining has been acting in Tanzania since 2013. The country holds a major position in gold and metal extraction, everso growing the last ten years having unprecedented organization in an electronic database and license issuance based on NI 43-101 of Canadian law. At the same time the country is classed as one of the safest in Africa with a very little crime rate. Its products are transported to major markets, such as the UAE and Europe in renowned refineries such as Emirate Gold in Dubai, Umicore and Argentor in Antwerp Belgium and Balestri and Arezzo in Italy. 

In the current work, details are provided regarding the potential of the extractive sector in Africa and Tanzania, the opportunities and prospects, the sociopolitical framework and some concomitant hardships and risks regarding Africa.

Finally, details are presented regarding Noravia Ltd. Referred to its mining projects, processes and application of innovative technology to simultaneously recover three different metals through censoring, with the hardware expected to be presented in Canada’s biggest mining exhibition, PDAC in March of 2025.

The vanadium shale is a unique and valuable resource of vanadium, and its efficient development can significantly contribute to the expansion of the overall available vanadium resources. However, the distribution of vanadium shale resources is widespread, with varying ore properties and significantly regional extraction characteristics. Currently, the process mineralogy data of vanadium shale is intricate and indistinct, while gangue impurity elements also hinder the detection of vanadium traces within the lattice structure. In terms of technical reliability, replicating and popularizing advanced technology proves challenging due to the unclear mechanism behind vanadium extraction from shale. The crystal lattice characteristics and vanadium extraction rules of vanadium shales are investigated based on the analysis of vanadium shales in China, providing insights into the process of vanadium coordination transformation and migration within vanadium shale. With the aid of quantum chemistry and numerical simulation methods, significant advancements have been made in enhancing the mineral genetic information of vanadium shale, thereby unveiling the fundamental mechanisms underlying key strengthening technologies for efficient extraction of vanadium from shale. The primary objective of this study is to facilitate the sustainable development of highly effective and environmentally friendly extraction techniques for utilizing vanadium resources from shale.

Global competition for resources will become fierce in the coming decade. Dependence on mineral raw materials may soon replace today's dependence on oil.  The EU's ambition to become the first climate-neutral economy by 2050, and its ability to sustain the green and digital transition and achieve strategic autonomy, all rely heavily on reliable, secure, and resilient access to raw materials. The European Commission defined strategic and critical raw materials based on objective criteria including their economic importance and their supply risk (CRMs). In an important move to secure the supply of essential raw materials, the European Critical Raw Materials Act (CRMA) entered into force on 23 May 2024, introducing the concept of strategic raw materials (SRMs), which are key for some strategic technologies and vulnerable to shortages and setting specific ambitious benchmarks for extraction, processing, recycling, and supply diversification through strategic partnerships with mineral rich countries for 2030. Greece is a EU country with a significant mineral resources in terms of quality, quantity and variety of ores, minerals and aggregates. Also, there is satisfactory legislation framework, funding opportunities and a political support to start and implement investments in the sector. Greece’s mineral potential is largely contained in State-owned areas and includes resources with CRMs. Our strategic goal is to unlock the existing mineral potential and reform the Greek mining industry. The national steps for raw materials sector according to MOEE΄s action plan 2024 and EU CRMA are described in detail.

Introduction 

Games are increasingly recognized as bringing innovation in educational content. Educational games, as opposed to entertainment games, have the added imperative to infuse learning content along with game and engagement content. Games and gamification, the latter being different from the former, are often used as a tool to scale complexity of tough-to-teach topics. However, they can also be used to understand and appreciate the real-world complexity of processes, topics and actions albeit within the safety of a classroom/fictive setting. One such real-world topic, which is also of urgent concern these days, is sustainability & more specifically sustainability as an approach to counter some of the alarming trends of climate warming, biodiversity crisis, pollution of our ecosystems combined to the for raw materials and sources of energy.  

Significant interventions are underway to tackle climate change and bring more sustainability to the agenda and many science and technological innovations are being championed. However, one of the most important, but often invisible/underrated, forces that we see driving change is that of “Negotiations” or “Deal-making”. One might have the most innovative technology at hand but it is only through negotiations that one might be able to get it implemented. Often these skills are only developed through years of experience and hardly taught enough formally. We propose that a sustainable future can be fast-tracked not through technological innovations alone but the essential skill of negotiations.  

Educational intervention & Impact:  

Gamification is intended to exemplify the complex interdependencies between different land-use areas such as forest, lakes, mountains, coastal areas and even sea-beds and subsurface. In order to enhance the sustainability agenda, land modifications come at a significant cost and are made as such to mirror reality – such as European regulations around forest use and forest replantation tariffs). The paper proposes a game designed in such a way that one needs to grow their empire (of their own sector) to thrive and earn resources and money – both of which are needed to fuel further growth. Yet, growth will result in overlapping strategies and competition for resources as well as land. While one could be more unsustainable and expand at the cost of natural resources alone, the game stands out in its message that one can use the art of making deals to meet growth objectives with minimal or limited impact to the environment. The message being imparted is then along the lines of “savvy deal-making can influence and help you meet your sustainability objectives faster and cheaper”. The game is under development and the impact is yet to be measured – but from an engagement perspective we see very high engagement from the students as well as an acceptance of a transformed mindset- i.e. looking at the world from a different perspective than then one they started out with.   

 Contextualisation in conference theme:  The use of such a game to drive sustainability ambitions within the mining and mineral processing sector are axplored. It is one of the most pressing demands of society in their dialogue with the raw materials sector. The game will integrate the life cycle of a mining or quarrying activity, from mine area allocation, exploration drilling, acquisition of exploitation and environmental permits to full scale mine development, mineral & metal processing and waste management up to closure and land reclamation.  

Mining is often described as a low-accumulative activity, with high production costs and low prices for finished products, which puts it in an unequal position compared to other, less demanding industries. It is frequently noted that employees in the mining sector in our region (Western Balkans) typically focus more on production costs than on realized profits. This approach has persisted for a long time, while the full potential of available resources is not sufficiently utilized.

In Serbia, around 200 mines are engaged in the exploitation of non-metallic mineral raw materials. These raw materials are found throughout Serbia and play a significant role in its economic development, serving either as final products or as raw materials for processing in various industrial sectors. Given their quantity and diversity, these raw materials are among the most important domestic natural resources. Virtually all economic sectors utilize non-metallic mineral raw materials.

Serbia's territory boasts a substantial raw material base of non-metallic mineral raw materials (NMRM). To varying extents, 47 raw materials have been explored: 16 are in constant exploitation, 16 are occasionally exploited or not currently exploited, and 15 are insufficiently explored and not exploited. Among these NMRM, raw materials for construction materials hold the greatest economic significance. Additionally, other non-metallic raw materials of great economic importance include ceramic and refractory clays, quartz sand and sandstone, magnesite, quartz raw materials, kaolin, calcite, limestone (as industrial raw materials), gypsum and its anhydrite, pozzolanic tuff, dunite (olivine), rocks for ceramics and glass ("white granites"), and boron minerals.

Beyond the mentioned NMRM, there are ecological mineral raw materials, which belong to the group of natural mineral raw materials and have a wide range of applications, particularly in environmental protection. These materials are increasingly used to remove suspended particles or dissolved substances from industrial waters—pollutants of watercourses and soil—thanks to their outstanding adsorption, ion exchange, and catalytic properties.

This paper aims to highlight the possibilities and challenges of processing NMRM into new materials with added value, based on mineral powders. These materials are produced through the micronization process, which is currently the most widely applied method. Micronization involves very fine grinding, resulting in particles with an upper size limit of a few microns.

Over the last five decades, nearly 6 million tonnes of oil have contaminated our oceans solely from tanker spills, according to Ritchie et al., 2022, posing severe environmental and economic risks. Despite the development of various methods to contain oil spills, even advanced technologies have limitations associated with environmental and economic factors. Conventional cleanup methods face limitations, such as smoke production from in situ burning and dependency on calm seas for booms and skimmers. Oil absorption using industrial minerals, like perlite or bentonite, although cost-effective still poses challenges regarding collection and treatment of the remaining product and byproducts. The proposed innovative solution integrates perlite absorption with bioremediation methods, by utilizing an inorganic carrier acting as a “living sponge”, hosting oil-degrading microorganisms. Perlite’s lightweight and buoyant nature, enhanced by bioremediation functionalities, allows it to float on water and facilitate easy deployment, making it reliable for immediate oil spill response, resulting in non-toxic residues, while supporting global sustainability goals by preserving marine ecosystems and promoting economic competitiveness.

Copper is one of the most demanded minerals by the global industrial sector, with approximately 20 million tons mined worldwide each year. Silver, another important technical and precious metal, sees production around 26 kt/y. The general trend of declining average grades in these deposits has made mining low-grade ores a reality for many mines worldwide. The sensor-based sorting has emerged as a significant pre-concentration solution for these cases. This study investigates the applicability of this technique to copper ore samples from the Cerro do Andrade deposit, located in Caçapava do Sul, southern Brazil. The primary product of interest is copper (Cu), with silver (Ag) as a by-product. Pre-concentration tests are ongoing at the UFRGS Mineral Processing Laboratory (LAPROM) using a dual-energy X-ray transmission (DE-XRT) sensor sorter. Were analyzed 32 ore samples (64-16 mm size fraction). Relative density histograms and false-color images were generated. This data, along with Cu and Ag grades, was assessed in Excel to estimate recoveries (metallurgical and mass), concentration factors, and Cu and Ag grades in tailings fractions. Some scenarios of tailings generation and reuse were also explored. The analyzed samples had an average of 0.83% Cu and 7.31 g/t Ag. Pre-concentration simulations yielded Cu grades in the product ranging from 0.9% to 1.0% and Ag grades of 7.8 to 8.8 g/t in the Range A. Waste grades varied from 0.02-0.20% Cu and 0.7-2.2 g/t Ag. Range B exhibited more stable Cu and Ag grades in the product (around 0.9% Cu and 11 g/t Ag). Mass recoveries ranged from 92-77% in the Range A and reached 70% in the Range B. Metallurgical recoveries remained high: 99-95% Cu in the Range A and above 94% in the Range B. Silver recoveries were also promising (99-93% in Range A, 90% in Range B). Considering a feed of 1,000 kt/y, estimated ROM mass after pre-concentration ranged from 833-675 kt/y of product and 167-325 kt/y of coarse tailings. Currently, these preliminary results hold great promise, demonstrating the potential for achieving significant outcomes through the implementation of sensor-based sorting pre-concentration in the Andrade Project. 

This abstract deals with the physical separation processes of rare earth bearing placer heavy minerals. In general the Indian coast beach sand consists of the heavy minerals particularly ilmenite, rutile, garnet, sillimanite, zircon and monazite. Among these minerals monazite is considered as the primary mineral for recovery of rare earth elements. Due to high demand to the mankind on the use of mobile phones and motor vehicles etc, and the same time the requirement on the use of rare earth elements in day to day use of electronic and batter operated vehicles and mobiles, it is necessary to recover rare earth bearing minerals from primary secondary minerals. In recent it is found that rare earth elements are found not only in the primary mineral monazite, the other minerals such as garnet and sillimanite also contain rare earth elements in the placer deposits.    Hence this present paper deals with the recovery of rare earth bearing placer heavy minerals by gravity, magnetic and flotation processes. The experiments on the recovery processes and the economics of the process are also discussed. 

The continuous rapid growth in the use of lithium-ion batteries (LiBs) for electric vehicles (EVs) and portable electronic devices has resulted in even increasing demands for lithium and other metals related to their production. This, in turn, has led to the generation of continuously increasing and alarming number of spent LiBs. [1] Spent LiBs contain heavy metals like cobalt, nickel, and manganese, thereby posing a significant environmental hazard if not managed accordingly [2]. However, these metals along with lithium are considered valuable and their recovery is deemed beneficial. Recycling of spent LiBs helps minimize pollution from their toxic components, while simultaneously recovering the contained valuable metals. [3] This paper provides a comprehensive view on the current state of LiB recycling technologies for recovering valuable metals, highlighting the strengths and weaknesses of each approach in terms of efficiency and feasibility. Specifically, pyrometallurgical and hydrometallurgical processes, as well as direct recycling [4] are thoroughly discussed and evaluated, addressing problems and challenges. Moreover, the current and future market trends and regulatory landscape will be presented and examined. Additionally, recent advancements and prospects in the field are discussed.

In Poland, in 2023, renewable energy sources, such as wind turbines, solar photovoltaic panels, accounted for over 40%. installed capacity in the Polish energy mix and accounted for 27%. total energy production. Thus, Poland broke further European records in the increase in the share of renewable energy. The goals we set for ourselves are over 50%. green energy in 2030, and in 2050 we will have to reach 100%. the service life of installations of renewable energy sources: photovoltaics, wind turbines is estimated at 25-30 years[1,2]. After this time, the installation will be recycled. The article presents waste-free technologies for recycling photovoltaic panels and windmill blades developed by a consortium of universities (AGH University of Kraków) and 2LOOP TECH [3,4]. The developed technologies meet the assumptions of a closed-loop economy (circlar economy). The article presents a life cycle analysis (LCA) of PV panels and wind blades. The implementation of technology in industrial conditions implements the principle of “secondary first”. 


 

Vanadium shale is an important vanadium-bearing resource in China, with total vanadium reserves in vanadium shale accounting for more than 87 percent of domestic vanadium reserves.[1] Numerous studies have shown that the vanadium content of vanadium shale is low and that most of the vanadium is encapsulated in the crystal structure of the mica, which is difficult to destroy.[2] Therefore, excess sulfuric acid is usually used in the leaching process to increase the vanadium leaching rate.[3] Due to the complexity and variety of minerals in vanadium shale, often accompanied by pyrite, hematite and other iron-containing minerals, the vanadium leach solution obtained by acid leaching has a low pH and contains a large number of impurity iron ions.To meet the requirements for vanadium extraction by subsequent extraction methods, the pH of the vanadium-containing acid leach solution needs to be adjusted to above 1.8. Electrodialysis(ED) is considered to be an alternative to alkali neutralisation, which has the advantages of no vanadium loss, recoverable sulfuric acid, low waste residue and environmental friendliness.[4] 

Current studies have shown that Fe³⁺ in vanadium acid leach solution can form precipitate before the pH reaches 1.8, which adversely affects the ion exchange membrane.[5] However, the precipitation pH of Fe²⁺ is much higher, exceeding 1.8 or more. Therefore, before the recovery of sulfuric acid using ED, the Fe³⁺ in the vanadium-containing acid leach solution needs to be reduced to Fe²⁺ to ensure that the ED process is carried out smoothly.   

The effects of sodium sulfite, reduced iron powder and sodium hypophosphite on the reduction of Fe³⁺ and on the ED process were investigated in the present work. XRD, SEM-EDS and the pH tests were used to analyse the changes in the precipitates. UV spectrophotometry and the pH tests were used to analyse the changes in Fe²⁺ before and after reduction and during the ED process.Titration and ICP results were used to illustrate the migration of vanadium and impurity ions during the ED process.  

The results demonstrated that the acid leach solution with sodium hypophosphite as the reducing agent did not produce precipitation during the adjustment of pH to 1.8 by ED. Excess sodium hypophosphite could completely reduce Fe³⁺ to Fe²⁺ and prevent Fe²⁺ from being oxidised to Fe³⁺ by oxygen during ED. By monitoring the pH of the solution, precipitation formation and vanadium concentration in the acid leaching solution, it is shown that the acid recovery rate by electrodialysis can reach more than 80% and vanadium retention rate can reach more than 95%.

Determining Bond work index is part of the preparation plant design phase of a mining project, and can significantly affect the design costs associated with comminution.  According to the standard Bond procedure, the work index is determined by simulating dry grinding in a closed cycle in a Bond ball mill until a circulating load of 250 % was established.  This paper represents a continuation of research on the determination of the Bond work index for fine samples. The obtained results confirmed the validity and accuracy of the presented procedure. .

Mining, a pivotal societal contributor, furnishes crucial resources for diverse industries. However, mining operations exert significant environmental impact, necessitating subsequent environmental repair and rehabilitation. The importance of addressing both environmental and social implications in mine closure planning is escalating.

Under legal mandates, mining companies must formulate thorough closure plans, specifying the site's final condition, required measures, anticipated expenses, and financial assurances for effective closure execution. Accurately estimating closure costs, though challenging, is crucial to secure sufficient funding for rehabilitation.

In Brazil, mining site closures often diverge from initial plans, with closure efforts mistaken for rehabilitation. Responding to this, regulatory bodies are fortifying requirements for new projects, enhancing mine closure laws by mandating a comprehensive Mine Closure Plan (MCP) covering decommissioning, rehabilitation, and post-closure activities.

Recognizing, evaluating, and addressing mining site risks in a standardized manner is imperative. This includes ensuring the stability of the mining area in biological, physical, and chemical aspects, averting unintended emissions, and tackling issues like acid drainage. Groundwater geochemistry, particularly concerning mine acid drainage, assumes a vital role. Closure of underground mines involves flooding and continual water level monitoring, while open-pit mines necessitate efforts to repurpose the area for new economic or social activities.

Adhering to standardized criteria is essential to effectively manage the environmental and social impact of mining activities. By prioritizing comprehensive closure planning and adherence to environmental and social considerations, the mining industry can strive to minimize its environmental footprint and champion responsible post-mining practices for a sustainable future.

Dear Professor Anastassakis,

I am very sorry that I am not with you today, with your students, colleagues, family and friends. I am sure that the atmosphere that surrounds you is full of warmth, respect and deep loyalty to your ideas and knowledge, to your efforts to affirm our profession and give it real importance. You really succeeded in that.

I am one of your many colleagues who have essentially followed your work and largely adopted your attitude towards the preparation of mineral raw materials. You have very strongly influenced many generations to love this science and profession and to have the knowledge of complete fulfillment of life and joy that reveal the meaning of living in them.

Listening to your lectures at congresses and symposiums for many years, admiring your eloquence in private correspondence, the vast knowledge you selflessly shared, your interpretation of the concrete and the general, I realized more and more that our profession is a magical profession.

Forgive me if you perceive pathos in this letter, but it is there because of my admiration for an aristocracy of spirit such as yours.

Dear Professor Anastassakis, I wish you to still experience sparks of excitement and joy due to new thoughts, new feelings, new knowledge if this is at all possible in the space that your spirit and your thought permeate.

I greet you with the deepest respect,

Ljubiša Andrić

This study explores the combined effects of lignin nanoparticles and xanthate collectors on the recovery of pyrite and arsenopyrite concentrates. Lignin nanoparticles (LNp) were synthesized, characterized, and assessed as co-collectors with sodium isopropyl xanthate (SIPX) in batch flotation tests. Findings indicate that substituting SIPX with LNp by 25% and 50% yields enhanced pyrite and arsenopyrite concentrates, achieving higher gold grades and recovery, along with reduced lead content in the concentrates. However, higher LNp substitution ratios negatively impacted concentrate quality, reducing gold recovery and raising lead content. This study highlights LNp as a promising, eco-friendly alternative co-collector to improve flotation performance for pyrite and arsenopyrite ores.

The main part of chrome ore reserves in Albania is represented by chrome ores with a low Cr2O3 content, mainly below 12%. There are currently 16 chromium enrichment plants operating in Albania, which process raw chromium ores with content ranging from 5% to 12% and rarely up to 20% Cr2O3.

The very low content of Cr2O3 in the raw material of these plants has increased the production cost of chrome concentrates, doing necessary the testing efforts to improve the technological-economic indicators.

This paper aims to show the results of the tests and analyses that were done in some of the plants and the results that were achieved through the measures taken to increase the concentrate grade, to reduce losses and to reduce the production cost of chrome concentrates. The method followed has been that of taking samples in the industrial process and analyzing them, thus finding opportunities where to intervene in the process to improve the technical-economic indicators.

Based in the testing and analyses it has been implemented the removal of significant amounts of waste before the grinding process or before the enrichment processes, through pre-concentration processes, which has reduced the cost of processing per ton of raw material. Also, it was concluded that the separation and enrichment of very fine particles in the equipment with suitable parameters for the treatment of fine particles improves the recovery, reducing the losses of Cr2O3 in the tailings. 

The presence of mineral sulfides such as pyrite, chalcopyrite etc., can pose significant challenges in gold extraction processes, regardless of the extraction route used, including the use of cyanide and thiosulfate [1]. These sulfides consume the reagents used in the aforementioned extraction processes, leading to operational problems due to the increasing ionic strength during such processes, which impacts the solubility of the oxidizing agent, particularly dissolved oxygen, which is of utmost importance for extracting gold [2]. The presence of these sulfides in gold ores represents a major challenge in gold extraction [3], as they react with leaching agents with their consequent consumption, leading to a reduction in the efficacy of gold extraction processes causing operational problems. 

Therefore, this study aimed to carry out comparative tests to point to the effectiveness of the gold extraction process, from samples of gold ore subjected to three distinct forms of mineral processing: conventional crushing, in jaw crusher, crushing in high pressure grinding rolls (i.e., HPGR - High Pressure Grinding Rolls) and electrodynamic fragmentation (i.e., HVPF - High Voltage Pulse Fragmentation). 

In this study, different grinding operations were used, such as the use of a jaw crusher, high pressure grinding rolls, and high voltage pulse fragmentation, aiming to determine the influence of these unit operations on the bio-oxidative process (pre-treatment) of the aforementioned mineral sulfides, as preliminary steps to the extraction of gold particles trapped in the matrices of the aforementioned sulfides, substantially reducing the consumption of gold leaching agents, thus avoiding the grinding operation, which is the most expensive unit operation of extractive metallurgy.

In the bio-oxidation process, the tests were conducted in acrylic columns, filled with 3.5 kg of ore and subjected to different mineral processing for 30 days. The columns were fed from the top with a solution of salts from the MKM medium (i.e., Modified Kelly Medium - with the following composition: (NH₄)₂SO₄: 0.08 g.L^-1; MgSO₄.7H₂O: 0.08 g.L^-1; K₂HPO₄: 0.008 g.L^-1), at a flow rate of 10 L/h/m², and this solution was recirculated throughout the experiment. The mineral bed was aerated with an upward flow of humidified air at a flow rate of 0.5 L/min, 3 liters of leaching solution from the MKM culture medium were used, adjusted to pH 1.8 with 5M sulfuric acid when necessary, and maintained at 30°C. The culture medium included a mixed culture of Acidithiobacillus ferrooxidans(LR lineage), Acidithiobacillus thiooxidans (FG-01), and Leptospirillum ferrooxidans (ATCC 53992), each with a population density of 10⁷ cells/mL. For the gold extraction process, the material, after the bio-oxidation tests as bio-oxidative pre-treatment, duly exempted from acid solution residue, by successive aqueous washes, was placed in a glass column through which a descending flow of aerated cyanide solution passed, in distinct concentrations of free cyanide (usually varying from 3 to 10 g.L^-1), coming from a glass reactor, with a useful volume of 5 liters. Once the cyanidation was stopped, the leachate was analyzed by atomic absorption spectrometry to measure the extraction of gold. 

As initial results, the 30 day bio-oxidation experiments showed that high voltage pulse fragmentation (HVPF) was more effective in extracting copper and nickel from gold ore, compared to other crushing operations. HVPF generated microfissures that exposed the mineral sulfides to the microorganisms in the acid solution, increasing the concentrations of copper and nickel in the leachate. Crushing via HPGR showed less nickel solubilization and did not surpass the other operations at any time. These results underscore the need for continuous optimization of crushing operations for each type of ore. The cyanidation tests indicate that HVPF is the most effective operation, allowing a more efficient exposure of the gold particles to the joint action of the cyanide, complexing agent, with oxygen, oxidizing agent. The cyanidation tests revealed that processing via HVPF was the most efficient unit operation in the release of gold particles, followed by HPGR and, lastly, by the jaw crusher. 

It is concluded that the operation of high voltage pulse fragmentation (HVPF) stands out as the most efficient both in the bio-oxidation process and in the cyanidation of gold ore, providing a greater extraction of gold.

The generation of WEEE in Europe has been increasing steadily over the last decades and is expected to reach 14 million tonnes by 2021. Its composition, although highly dependent on the type of equipment treated, consists of a significant amount of plastics, ferrous and non-ferrous metals, and a small but relevant amount of precious metals and so-called rare earths. The recovery of valuable materials from WEEE is of particular interest due to the different legislation in place and the high concentration of WEEE, which is, in many cases, higher than that of primary ores. WEEE treatment and recovery lines start with manual sorting of easily identifiable equipment or components, followed by a shredding process to reduce the particle size and release the components. This is followed by physical concentration processes focused on the recovery of materials, the by-product is a plastic material with heterogeneous granulometry. The finest fraction of this plastic by-product contains relevant concentrations of different metals, whose concentration depends on the efficiency of the treatment plant. In the case of the treatment plan studied, these concentrations were approximately 33.0 g/kg of aluminium and 28.8 g/kg of copper.

The present study raised the possibility of generating a secondary treatment line, based on densimetric and gravimetric treatments to achieve the recovery of these valuable metals under the following perspectives: the generation of a dense product of metal concentrate and the obtaining of a light plastic waste that can be used as a by-product.

The first approach developed for this treatment was based on the direct use of a wet shaking table as a simple but precise gravimetric treatment. The results obtained after the setting of its operating parameters based on both technical manuals and the equipment operator's own experience showed a metallic concentrate product with aluminum and copper concentrations of 250 g/kg and 360 g/kg respectively and valuable yields of 15% for aluminum and 50% for copper. An intermediate-density product with potential for aluminum recovery (concentration of 100 g/kg and valuable yield of 50 %) was also observed. By the visual study of this treatment, it was observed that a large percentage of the wet shaking table classification surface was focused solely on the classification by density of the plastic fraction, which, in comparison with metals, has very low densities generally not exceeding 2.00 g/cm³. 

Based on this assumption, a preliminary material roughing treatment was proposed that would allow the precise recovery of plastics according to their density and, on the other hand, allow the vibrating table to work with a better quality material for separation. For this roughing process, the LARCODEMS dense media separator was used with two cutting densities, 1.00 g/cm3 (using water) for the precise recovery of light plastics suitable for energy recovery and 1.33 g/cm3 (using a calcium chloride brine) for the separation of the majority of plastics, minimizing the loss of valuable metals that could be encapsulated in the plastic material. After this pre-treatment, the pre-concentrated product would be placed on the vibrating table. The results obtained show that after the two roughing processes, the material to be treated was reduced to 26% of the raw material, obtaining a concentrated metallic product of 315 g/kg aluminum and 490 g/kg copper, with a valuable yield of 37% and 66% respectively. The intermediate density (aluminium-rich) product improved its properties with a concentration of approximately 230 g/kg and a recovery of 44%.

The results obtained show how the roughing process prior to concentration significantly improves the operation of the shaking table. The results obtained after this process show an improvement in the concentration of aluminum and copper of 25 and 35% respectively and their recovery of 145% and 32% respectively. Finally, the material recovered after first roughing, with a density of less than 1.00 g/cm3, can be used for further energy recovery.

The world is couming bulimically raw materials and the demand for metals skyrockets. Securing raw materials, processing industrial minerals, enabling higher recycling rates targeting zero residuals production, utilizing advanced manufacturing techniques together with established mass production and forming methods, tailoring materials and alloys to service conditions, mastering extreme environments set the prerequisites for the ongoing shift, both digital and green. Hence, raw materials, recycling, metals and alloys tailored to even the most extreme conditions underline today’s importance in the geopolitical chess board. At the same time, the 4^th industrial revolution affects also the minerals industry value chain. All these challenges bring the School of Mining & Metallurgical Engineering (SMME) again at the epicenter of academia and industry. Dedicated to actively addressing societal needs through the lens of sustainability, responsible resource management, and a profound respect for local communities, the SMME adapts to these challenges and prepares future leaders in the field.

The basis of this enrichment process is the difference in the densities of the minerals that make up the original raw material.

When such a mechanical mixture is immersed in a liquid with an intermediate density, the waste rock floats, while the metal-containing minerals, being heavier, sink.

Hence, the main emphasis in the development of such a high-precision enrichment process was placed on finding the optimal formulation of such a water-based working medium in close connection with the justification of a simple and energy-efficient procedure for its complete regeneration from the enrichment products and its return to the head of the process

Vanadium-bearing black shale, commonly known as stone coal, has been identified to have enrichments of vanadium. It is a strategic advantage vanadium resources in China, accounting for 87% of the global shale-hosted vanadium reserves [1]. It typically forms through shallow marine sediments at high temperature and pressure in certain reducing environment [1, 2]. There are vanadium enrichments in the black shale elsewhere in the world include United States, Australia, Argentina and Kazakhstan [4]. Compared to vanadium titanium magnetite resources, vanadium-bearing shale has emerged as a significant source of strategic vanadium products due to its low contents of iron, copper, chromium and manganese.

The world has entered a new era where the fourth industrial revolution and sixth scientific and technological revolution overlap for major countries and economies to strategically allocate mineral resources for emerging industries. Vanadium, a kind of rare metal, remains an important strategic reserve resource for developed nations. China currently holds the title of the world's largest vanadium producer and supplier with 255,500 tons produced in 2021 as reported by the Vanitec. Currently, V₂O₅ and other basic vanadium industrial products account for approximately 70% of the market share in China while high-end vanadium products make up over 20% [3]. With the implementation of the national strategic industrial layout, the acceleration of investment in key emerging sectors such as marine engineering, aerospace, new energy, and new materials will significantly propel the sustained growth in demand for high-end vanadium products. Efficient and environmentally-friendly extraction methods along with advanced manufacturing techniques have become crucial focal points for ensuring the healthy and sustainable development of vanadium resources in China, thereby enhancing international competitiveness.

Over the past two decades, the vanadium-bearing shale industry has undergone rapid development, transitioning from conventional and inefficient production to the integration of the entire industrial chain encompassing beneficiation, extraction, and material manufacturing. Vanadium products derived from black shale account for approximately 40% of China's total high-end vanadium product output. Significant advancements have been achieved in the efficient extraction of vanadium from shale sources, as well as in the effective separation of individual metals and the manufacturing of high-end adaptive components.

The following personnels will give a welcoming speech to Anastassakis International Symposium: 

1. Prof. Dr. Ioannis Chatjigeorgiou, Rector of National Technical University of Athens (NTUA), Greece
2. Dr. Peter Tzeferis, Mineral Raw Materials General Directorate, Greek Ministry of Environment and Energy, on behalf of: Ms ALEXANDRA SDOUKOU, Deputy Minister of Greek Ministry of Environment and Energy
3. Prof. Dr.-Ing. Spyridon Papaefthymiou, Deputy Dean, School of Mining and Metallurgical Engineering NTUA, Greece 
4. Mr. Ioannis Michalakis, M.Sc., Head of the Regional Branch of Crete, Hellenic Survey of Geology and Mineral Exploration H.S.G.M.E.
5. Mr. Christos Kavalopoulos, General Director of Greek Mining Enterprises Association