Anastassakis International Symposium (10th Intl. Symp. on Sustainable Mineral Processing)

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.

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).

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.

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 sector 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 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 and social responsibility within the sector. Additionally, research methods employed included case studies analysis of companies in the sector, interviews 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. Each component integrates circular economy principles alongside social factors. Embracing this framework, 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.

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 analysis in [2] searches for the presence of long waves, i.e., cycles lasting 45-60 years through to through, in the prices of six metals traded on the London Metal Exchange in the past 150 years. In addition, the analysis in [3] tests for long waves in the prices of three additional metals: steel, iron, and molybdenum. Following these studies, the primary purpose of this paper is to examine the presence of long waves in global energy production and consumption in the last two centuries by applying the band-pass filter from [1] that selects for the number of leads and lags via spectral frequency representation. Some preliminary statistical results identify long waves in global energy production and consumption waves between 1956 and 2000. These initial results are robust to different stationarity assumptions regarding global energy production and consumption behavior. Potential avenues for further research include broadening the analyses for specific energy products to generalize the preliminary findings of this research. 

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.

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.   

Contextualization in conference theme: The use of such a game to drive sustainability ambitions within the mining and mineral processing sector are explored. 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.  

Оften repeat phrases that mining is a low-accumulative activity, that production costs are high and prices of finished products are low, put mining in an unequal position with other, much less demanding activities. What is often pointed out is that employees in the field of mining in our region (Western Balkans) very usually pay much more attention to the production costs than to the realized profit. This approach lasts a very long time. At the same time, the possibilities are not used to a sufficient extent.

About 200 mines operate in Serbia in the exploitation of non-metallic mineral raw materials. Non-metallic mineral raw materials are represented in all parts of Serbia and occupy a significant place in its economic development, whether they serve as final products or as raw materials in production in processing and other industrial branches. According to the available quantities, as well as diversity, these raw materials are one of the most important domestic natural resources. There are almost no economic branches that do not use non-metallic mineral raw materials.

The territory of Serbia has a large raw material base of non-metallic mineral raw materials (NMRM). To a greater or lesser extent, 47 raw materials have been explored,  of which 16 are in constant exploitation, 16 are in occasional exploitation or out of exploitation, and 15 raw materials are insufficiently explored and are not exploited. Of all the listed NMRM, raw materials for construction materials have the greatest economic importance. In addition to them, the following non-metallic raw materials are also of great economic importance: ceramic and refractory clays, quartz sand and sandstone, magnesite, quartz raw materials, kaolin, calcite, limestones (as industrial raw materials), gypsum and its anhydrite  , pozzolanic tuff, as well as dunite (olivine ), rocks for ceramics and glass ("white granites"), as well as boron minerals.

In addition to the mentioned NMRM, the so-called ecological mineral raw materials that belong to the group of natural mineral raw materials and which have a wide range of applications and are very important from the point of view of environmental protection have enormous value. These mineral raw materials are used more and more to remove suspended particles or dissolved substances from industrial waters – pollutants of watercourses and soil, thanks primarily to their outstanding adsorption, ion exchange, and catalytic properties.

In this paper, we would like to point out the possibilities and problems of NMRM processing, which obtains new materials, with added value, based on mineral powders. These materials are obtained by the currently most applicable known process - the micronization procedure. Micronization is a process of very fine grinding, in which particles with an upper size limit of a couple of microns are obtained.

In the field of mineral processing, and all the problems that arose in the period of globalization, the possibilities of their direct and indirect use, for environmental protection as well as for other purposes, are still being studied [1-9].

Xanthates is a family of highly efficient collectors, widely used in the industry of sulphide minerals flotation, which, however is considered toxic and hazardous to the environment, and can pose significant risks to aquatic life and human health. The need for its replacement by other more environmental friendly reagents is of vital importance towards a more sustainable extractive industry.

Organosolv lignin  is natural, biodegradable material that possesses a low carbon footprint compared to the conventional reagents. The study investigates the potentiality of the use of organosolv lignin as collector in the flotation of metalic sulphide minerals (sphalerite, pyrite/arsenopyrite) from greek mixed sulphides. Critical parameters under investigation was the collector dosage and composition, while the efficiency of the collector formula was evaluated according to the achieved selectivity, grade and recovery. To simulate and evaluate the performance of the optimum formula under realistic operating conditions, locked cycle flotation tests were carried out and the results are discussed.

Copper is one of the most demanded minerals by the global industrial sector, with approximately 20 million tons mined worldwide each year [1]. To address declining deposit grades, sensor-based sorting technology has been studied and employed for pre-concentration [2, 3]. The subject of this study is the copper deposit known as Cerro do Andrade, located in Caçapava do Sul, in southern Brazil. This study aims to present preliminary results of ongoing research analyzing the applicability of sensor-based sorting techniques for this ore pre-concentration. Initial analyses indicate Cu grades around 0.5% and Ag grades between 3 and 4 g/t in the mineral deposit under study. The distribution of Cu and Ag grades in each granulometric range has a proportional variation trend, the P80 of the material exceeded 150# in the initial grinding test and reached 325# in subsequent tests, with a liberation degree of approximately 90%. Preliminary tests indicated a potential ore sorting ability by the DE-XRT sensor; however, further studies are required. Possible scenarios for tailings reuse, have been studied the possiblity production of soil remineralizers, accord the Brazilian regulations [4] and the production of aggregates for civil construction. At the end of this study, it is expected that the sensor-based sorting technique can bring significant benefits to the project, such as the reduction of estimated electricity consumption, the effective possibility of using waste minerals as by-products for agriculture or construction, reduction of cut-off grade at the mine, and greater regularity and increased feed grade to the plant. Furthermore, indirect benefits such as an increase in the lifespan of the deposit, better utilization of mineral resources, generating gains through reduced consumption of inputs and the reduction of negative outputs. However, some potential bottlenecks, such as possible ore losses due to false negatives, need to be considered. These will be explained futher after the performance analysis [5], along with their impact on the overall plant recovery.

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.

In the past fifty years, tanker spills alone have resulted in nearly 6 million tonnes of oil polluting the ocean, posing severe environmental and economic risks. Even though advanced technologies for entrapping oil spills are available they have environmental and economic limitations. Traditional 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, although cost-effective, still poses challenges regarding collection and treatment [1]. 

In the current study a new, adaptable and simplified technology is proposed, wherein perlite, an industrial mineral, acts as a “living sponge” hosting oil degrading microorganisms. The primary components of this method are perlite, which is an inorganic mineral, and a consortium of naturally occurring hydrocarbon-degrading bacteria, both of which are environmentally benign throughout the application. Notably, the residue remaining after the bioremediation process is non-toxic to marine ecosystems, supporting contemporary goals of global environmental sustainability while also promoting economic competitiveness in the realm of sustainability. 

This bio-based approach is sustainable, utilizing natural ingredients, while the production is non-toxic and overall energy efficient. The perlite-based carrier can be deployed quickly and effectively, regardless of sea state, making it a reliable option for immediate oil spill response. A wide portfolio of indigenous bacteria can be applied, capable of efficiently degrading oil in the local environmental conditions. 

The life cycle of our product starts with the extraction of raw perlite ore from the quarry. The extracted perlite is then conveyed to a processing plant for further refinement, which can also be executed on site, in order to minimize the transportation cost. Initially, the raw perlite ore is crushed, and once a uniform size is achieved, the pulverized ore passes through a temperature-regulated rotary kiln dryer to eliminate surplus moisture. It is crucial to control the temperature during the drying process in order to avoid overheating the perlite particles and thus preserve the ore’s properties for expansion. After the drying process is complete, mechanical screening is performed to group dehydrated perlite particles into different sizes. The final stage of perlite processing is its expansion, involving chemical treatment to increase its surface area and porosity, unlocking the mineral’s full potential. 

Then, using a screw mixer, the nutrient solution is integrated into the carrier, adsorbed onto the processed perlite’s high surface area. This allows immobilization of the microorganisms on the nutrient layer, enabling them to colonize the perlite's pores. The perlite, inoculated with a hydrocarbonoclastic bacterial consortium is then freeze-dried to preserve the bacterial cells and extend the product's shelf life. At this point the production is complete, and the product is applied to the area of the oil spill area, followed by the eventual biodegradation of the absorbed oil. The degradation process typically takes 14 days to achieve an excellent 93% degradation degree [2]. The bacteria are then bioconversed into environmentally friendly biomass, thereby reducing disruption of the marine ecosystem’s food chain and protecting marine biodiversity. Meanwhile, the perlite particles float harmlessly, posing no threats, allowing its potential collection and reuse, thus promoting circular economy.

In conclusion, our innovative “bio sponge oil-consumer” represents a significant advancement in addressing one of the most pressing environmental challenges of our time.

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.

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.