This paper consists of an experimental investigation of multifunctional bulk nanocomposites based on Titanium, Nickel, Aluminum and Boron. The crystalline Ti, Ni, Al coarse elementary pure (at list 99%) powders and amorphous Boron were used as an precursors. The blend with different Ti, Ni, Al, B powders were prepared. The high energetic planetary ball mill is used for blend processing, mechanical alloying, amorphization and nanopowder production. Phase composition and particle sizes of the blend components were controlled by X-ray diffraction system. The optimal technological regimes for nanopowder preparation were determined experimentally. Ball milled nano blend compacted by explosive consolidation technology and nanostructured bulk composite materials are fabricated. The technological parameters of the nanocomposites fabrication and the structure-properties relationship are discussed in the paper.

A landfill in Grand Cayman Island has accumulated up to two million tires over many years. There have been a series of landfill fires, including the most recent fire on March 1, 2015. There were four failed attempts to sell scrapped tires piled at the landfill. It has been proposed to use over one million tires in the construction of golf courses. Scrap tires can be used in various forms in the golf course. The objective of this study was to determine creative methods of scrap tire application for sustainable golf course design and construction.
It has been found that scrap tires can remove nitrate and phosphate in fertilizers and pesticides used in golf courses. This property of scrap tires can be applied in golf course construction to make the golf course sustainable. First, ground rubber (0.425~12 mm) can be used as the substitute for 15-cm thick gravel layer for drainage specified in the revised United States Golf Association (USGA) green construction method. Second, tire shreds (50~305 mm) and/or tire chips (12~50 mm) can be used in the revetment as a filter layer for removal of pesticides and fertilizers. Third, tire chips can be used as backfill materials for drainage pipes in greens, bunkers, and fairways. Fourth, tire chips can be used as a runoff treatment zone before entering into a pond that is used to withdraw water for irrigating the golf course. These four applications will make a golf course sustainable by minimizing the impact of pesticides and fertilizers on the surrounding environment. The other applications include island green backfill materials, cart path pavement, elevated tee boxes and other mounds. From the detailed calculations of scrap tires required for the specific golf course to be built in Grand Cayman Island, it was possible to use over one million tires in various forms while saving the construction and maintenance costs.
Key words: golf course, fertilizers, ground rubber, pesticides, scrap tires, tire chips

In the last years, the growth in hydrogen's demand has created considerable interest in the development of more efficient processes for its production. The production of hydrogen with membrane reactors is considered one of the most promising areas. The key concept of membrane reactors is to separate the hydrogen meanwhile it is produced, thus shifting the chemical equilibrium towards reaction products in order to obtain higher conversions of the hydrocarbon feedstock, at lower temperatures, thereby increasing the energy efficiency of the conversion process.
The fundamental element of this new technology is the presence of a membrane semipermeable to hydrogen. For the most interesting membranes, from an industrial point of view, however their cost still prohibitive (up to 10,000 a‚¬/m2), it evidences that a potential recovery and recycling of the main elements constituting the membrane can potentially contribute to a significant reduction in the unit production cost.
The purpose of this work is to identify an optimized process for the recovery of membranes based on palladium and silver, prepared from substrates of stainless steel, since this particular configuration seems to be the most promising in terms of hydrogen recovery, purity and for a potential scale-up.
Hydrometallurgical processes were identified as the best solution for the dissolution of Pd and Ag.
The leaching process was carried out at different times, temperatures and acid solutions concentration. The reaction products were analysed by atomic absorption spectrophotometry and scanning electron microscopy.
The optimal leaching solution allowed to completely remove the selective layer of Pd and Ag, while leaving the support undamaged. The results obtained enabled the development of an optimized process scheme and the design of a reactor to this aim.
A preliminary economic evaluation confirms that such type of process could help at least to reduce in 50% the cost of the membrane per m2.

The environmental cost of chromate based surface treatments over metal, due to the toxicity of Cr+6 ions, stimulates the search for equally efficient and environmentally friendly alternatives. In this context, silane-based coatings are a promising possibility, once their efficiency as primer to painting treatment has already been proved. The most common technique used in order to obtain such coatings is currently the dip-coating on silane hydroalcoholic solution, which may result in non-homogeneous films, weakening their capacity of barrier protection against corrosion. Such difficulty can be overcome with the use of silane electrodeposition. In this study, TEOS coatings were produced by electrodeposition technique over low-carbon steel surface using different potentials, with the samples eventually receiving organic coating of acrylic resin. These electrodeposition coatings were compared to dip-coating obtained ones. Both coatings were tested comparatively by electrochemical impedance spectroscopy and polarization, accelerated corrosion and adherence tests. The coatings were also compared to conventional chromate-based and phosphate-based conventional coatings. The results show a promising technology to the achievement of efficient and environmentally friendly coatings.

Photolife project aims at the realization of a prototype for automatic treatment of different kinds of photovoltaic panels (Si-based, Cd-Te and innovative types) according to a common process route. A demonstration activity is foreseen including the retrieval and treatment in the prototype of the collected photovoltaic devices.
Laboratory data were used to formulate energy and mass balances for PV panel treatment according to two process schemes (thermal treatment vs. solvent treatment for EVA disruption and panel opening). Solvent treatment gives final recovery yields of glass similar to thermal treatment with lower energy consumption and higher glass quality. Demonstration activities will allow the characterization of EVA residues after solvent treatment and the evaluation of their reuse.
Historical data of PV installation in EU were employed to estimate the fluxes of wastes resulting from the disposal of end-life photovoltaic panels during the period 2025-2045. In 2011 in Italy a dramatic increase was registered due to government incentives, but such peak was not maintained during successive years. Accordingly a big amount of wastes should be expected since 2030. More specifically the amount of wastes to be treated in Italy will remain around 400.000 ton/year even in the period 2030-2055.
Preliminary economic analysis of the Photolife process evidenced that feasibility can be reached starting from 75.000 ton/y for Si-based panels, while larger potentiality (>200.000 ton/y) is necessary if only CdTe are fed in the plant. These results encouraged the choice of a unique process route for the treatment of different kinds of PV panels as proposed in the Photolife project, which reaches economic feasibility for potentiality in agreement with future national waste fluxes.
Preliminary LCA evidenced that the Photolife approach is very favourable for the environment, giving net credits for the most relevant impact categories considered.

Flux skimming is generated as a by-product in hot dip galvanizing process, which contains about 45% of Zn. For significant quantity of zinc, flux skimming becomes a very remarkable source of it. With the purpose of recovering zinc, the flux skimming was studied. The presented paper deals with characterization and hydrometallurgical treatment of flux skimming obtained from 2 companies. Various zinc phases were identified by XRD analyses. The most presented phase in the first sample of flux skimming (VZ1) is ZnOHCl (96%). Different zinc phases were found in sample 2 (VZ2). The highest percentage of zinc phases analysed in sample VZ2 were 70.8% of Zn5OH8Cl2.H2O and 24% of (NH4)2(ZnCl4). Divergence in morphology and chemical composition of 2 studied samples of flux skimming caused different results after hydrometallurgical treatment of various samples. Both samples of flux skimming were leached in distilled water and hydrochloric acid (0.25M) at 20°C and 40°C, during 90 minutes. Using solution of HCl as leaching medium for flux skimming has shown better results than distilled water. During leaching treatment of VZ1, maximum extraction of zinc was 93% in the first minute at 40°C. At sample VZ2, the highest percentage of extraction was 62% at 40°C within 5 minutes

Rare earth elements (REE) have been identified as one from 20 critical raw materials for European Union. One of the rare earth elements is also neodymium, which is primarily used for Nd-Fe-B magnets production. These magnets are irreplaceable commodity for reliable working of hard discs in personal computers. Deficiency of neodymium in primary raw materials caused high interests of many companies to deal with possibilities of Nd recycling from spent Nd-Fe-B waste magnets. This study is focused on treating Nd-Fe-B magnets obtained from spent personal computers hard discs. Demagnetization of magnets was realized by thermal treatment (at Curie temperature of 340 °C). In further treatment steps, magnets were crushed and milled, followed by leaching in diluted acid solutions of H2SO4 and HCl, in order to compare the leach ability of neodymium and iron from magnets. In 2M H2SO4 at 20 °C, without stirring the extraction of 99.96 % after 10 minutes of leaching was achieved. In 0.1 M HCl at 80 °C, with stirring (250 rpm) the extraction of 89.96 % at 2 minutes of leaching was achieved.

Galvanic processes are based on metal plating baths and rinsewater. They generate effluents with a metal concentration varying with the installed process. These solutions are usually treated using conventional physicochemical processes that generate the galvanic sludge that needs to be discharged in landfill sites. In the last decades, the economic conditions and the increasingly stringent environmental legislation worldwide have led the electroplating industry to adopt new technologies for the treatment of the waste generated. In fact, what is needed is an economical method for the removal of heavy metals from wastewater, but also for the recovery of these metals. Electrodialysis (ED) has already been used to treat many different water and wastewater streams to produce potable and industrial process water. In addition, ED is one of the most recent technologies that is applied to the recovery of plating chemicals from rinsewater. This process is based on the selective migration of aqueous ions through ion-exchange membranes resulting in an electrical driving force. In ED, low concentrations of heavy metals can be concentrated, and the other part of effluent water can be diluted for reuse. <br />Nickel plating effluent was treated by electrodialysis in bench scale and the quality of solutions produced was evaluated by chemical analysis. From the results obtained in these tests, an industrial-scale electrodialysis was evaluated in a continuous treatment process connected on a rinsewater line of nickel plating. It was determined the concentration of metals and other ions recovered for reuse as bath reinforcement. The diluted solution was again reused as rinsewater, reducing by 90% the volume of effluent sent to the wastewater treatment plant. The amount of chemicals used for the treatment of nickel electroplating rinsewater and the volume of nickel sludge were almost eliminated. ED provided a closed loop galvanic process, reducing environmental and economic costs.

Production of steel is associated with generation of waste containing non-ferrous metals. The aim of this contribution is hydrometallurgical recycling electric arc furnace dust containing about 30 % Fe, 20 % Zn, 1, 5 % Pb and other metals in minority content. The work was focused on the kinetic study of EAF steelmaking dust by leaching in aqueous HCl solution at concentration 0,1; 0,5 and 1M and ratio L:S=20. The temperature range 20°C – 95°C was used for experiments. The highest extraction of zinc (66%) and iron (49%) was achieved in 1M HCl at 95°C. The concentration has expressive influence to extraction of lead into the solution. By increasing concentration of HCl, extraction of lead to solution raises and temperature did not have influence to lead extraction into the solution. The highest lead extraction (80%) was achieved using 1M HCl at all selected temperatures. The extraction of zinc, iron and lead into solution can be increased by using more concentrated HCl, respectively by using an intensification leaching method.

In this study, the hydrometallurgical processing of EAF steelmaking dust (Ironworks Podbrezova) was investigated in laboratory scale. The behavior of calcium under the influence of sulphuric acid as the leaching agent is discussed. The main aim is the transfer of zinc into the solution while iron ought to remain as a solid residue. Calcium, too, is transferred to the solution, but due to its low solubility, it is precipitated from solution into solid residue. Acid is continuously consumed, spending gradually calcium phase from EAF dust and also other zinc and iron containing phases. In such a way, it is possible to set up the conditions for the leaching of EAF dust, namely sufficient sulphuric acid concentration in order to achieve an optimum zinc yield to the solution without iron dissolution. However, the problem is that the calcium content of each steelmaking dust is individual. Therefore, it is necessary to study the processing conditions for each one of them.

Non-ferrous metals, whether primary production from primary sources or industrial waste recycling, bring with them a burden on the environment. One very important load is the excessive production of carbon dioxide and waste water containing heavy metals. These two environmental problems are closely linked. This article briefly describes the method of using carbon dioxide arising from industrial processes for the preparation of biomass needed for subsequent removal of heavy metals from wastewater. In this particular case, we use special nanotechnology based material to improve the process and the quality of recovered biomass. The results are very promising. During the first step of the process, we increase biomass production by 30% and also reduced the cost of the whole biomass preparation process. These results are very useful for future application in the next steps. With this technology improvement, we can now produce more biosorbent based materials and after that we use it as a source to bioreactor for heavy metals removal procedure.

One of the main pollutants of water are active pharmaceuticals compounds (PhACs) produced by pharmaceutical companies. These PhACs, reach the water bodies through incomplete removal in conventional effluent treatment plants. Therefore, processes that are more effective should be investigated. The objective of this study was to apply the photoelectrocatalysis process in the treatment of the effluent of the pharmaceuticals industry containing PhACs aiming process water reuse. The initial effluent was prepared by dilution of the norfloxacin in distilled and deionized water to a final concentration of 200 Aµg/L. A concentration of 2 g/L Na2SO4 was added as a support electrolyte. The reactor used was a jacket borosilicate glass reactor with a capacity of 3 L, connected to an ultra-thermostatic bath. The anode was dimensionally stable (DSAA®) and composed of (70-30%) TiO2RuO2-Ti, while the cathode was composed of TiO2-Ti. The electrodes remained under UV radiation by a 250 W high-pressure commercial mercury vapor lamps, without the glass bulb and inside a quartz tube. 5 L of the initial effluent was placed in the reservoir that feeds the reactor at an average flow rate of 1 L/min with the aid of a peristaltic pump. The experiments were conducted 6 times. The effluent samples were collected before and after the photoelectrocatalytic (PEC) treatment and characterized by different analytical methods: UV/Vis spectroscopy, pH and TOC. The preliminary results of UV/Vis showed that the norfloxacin absorb UV radiation in the wavelength of 273 nm (UV-C) and can be degraded by direct photolysis. The UV radiation source used in this experiment exhibited a single absorbance peak at 365 nm, i.e. the photocatalysis will be favored. The TOC results exhibit a TOC reduction after the PEC process.

The Slovak University of Technology in Bratislava is currently involved in the project "Research of progressive technologies for the recovery of waste from scrap automobiles", 1 , in harmony with the priorities of the Slovak Ministry of Environment (SME). The basic requirements for the new barrier were: produced from recycled materials, self-anchoring but not permanently anchored to the ground, could be used on firm and soft ground, allow for convex and concave configurations, can copy rough terrain, can be easily deployed and removed, and can adjust the barriers height. The investigators filed a utility model application no. SK 5847 Y12 entitled "Modular flood barrier structure", 2.

In the past, industrial residues were partly recycled in general focusing on the recovery of base metals like zinc, copper, lead or others. Indium, gold, silver and PGMs are accompaniments of lead, zinc or copper ores leading to significant and interesting contents also in the residues arising from the corresponding primary industry, but were not recovered in many cases in the last decades. Because of political unrest, strikes, economic reasons, or decreasing primary resources leading to supply risks also the minor metals, like the mentioned above, moved into the focus of the recycling industry. Therefore, beside the base metals, first of all the recovery of those minor metals would be of high interest contributing to the economic viability of recycling processes, although they occur in much smaller quantities in materials. Examples for such residues can be tailings, sludge, slags and in some cases dusts. The paper shows selected residues, their characteristics, possible treatment to recover next to base metals also selected minor ones and with this especially tries to answer the question on how recycling of such industrial residues can contribute in future to the overall production of for instance precious metals.

Global demand for zirconium dioxide is actively growing. It is connected with the increase of its consumption not only in ceramic industry but also in high-tech fields. This factor imposes additional requirements on purity in the process of zirconum dioxide cleaning from impurities of phosphorus, silicon, iron and aluminum. This article focuses on the problems of baddeleyite cleaning, which is natural zirconium dioxide. It comprises in kamaforite complex apatite-magnetite ores in alkaline ultrabasic massifs of the Kola Peninsula. This study offers a technological solution to the intensification of baddeleyite concentrate and various tailings deep cleaning. With the help of mathematical modeling, it was managed to confirm that the mechanical activation is effective for intensifying the process of baddeleyite sulfation in order to clean it of impurities. The use of calculated optimum modes allows to reduce such process parameters as temperature, duration of the process, sulfuric acid consumption and also to determine conditions of the outrunning extraction into the solution of scandium and the main impurities in comparison with zirconium dioxide.

Hydraulic fracturing is a well-developed technology that has been used for production of natural gas from the shale for at least 60 years. The type and composition of fluid applied for fracturing depend on the specific geologic formation, its structure and target for a wellbore. Usually, fluid contains some chemicals (hydrochloric acid, friction reducers, biocides, guar gum, emulsifiers and emulsion breakers) and proppants, e.g. suspended sand or ceramic grains, in order to keep an induced hydraulic fracture open. In back flow fluid, the components of the host rock, like heavy metals, leached during penetration of the pores by fluid are present.
If water is used as the pressurized fluid, as much as 20 % can return to the surface via the well as backflow fluid. This fluid can be treated and reused for subsequent hydraulic fracture procedures what significantly reduces the volume of fresh water consumed and the amount of wastewater generated by hydraulic fracturing. The injected fluid is managed by various methods and can be recovered to some extent; the rest is left for temporary storage. The new technologies are continually being developed to better handle wastewater and improve to reusability of backflow fluids.
In the present work, the method of treating the backflow fluids with simultaneous recovery of the valuable metals is proposed. The elaborated scheme for treatment of the fluid after hydraulic fracturing involves several stages of processing that includes oxidation of organic components, reduction of salinity and removal of dissolved matter by membrane methods, and separation of specified elements by ion exchange chromatography. Trace elements, e.g. uranium, chromium, thorium, scandium, arsenic, nickel and lanthanides are present in the fluids in various concentrations. Some of them, like uranium, are worthy to be recovered.
The treatment of the backflow fluids is necessary before reusing in the next fracturing actions or safe discharge to the environment; the separation of metals leached from the rocks during shale gas extraction not only reduces the environmental impact, but also may have an economic dimension.

Since the mid-2000s, the European Union has realized how dependent we have become on foreign imports to access non-energetic raw materials. This dependence has been interpreted as a threat to Europe's industry and global competitiveness. A list of "Critical Raw Materials" was established in 2010 and revised in 2014. None of the 20 listed raw materials are significantly mined or produced in Europe. It has also been recognized that Europe holds valuable mineral resources in both primary and secondary mines. Concerning the primary mines, Europe has been actively mined over many centuries and many easy-to-access mineral deposits are mostly depleted. The major opportunities to access raw materials within the EU are in populated areas, in low grade or small complex deposits that may vary in composition over time and contain different size of particles from coarse to very fine grains. The challenge in the processing of these raw materials lays on the evolution of the existing processing to the European constraints. For the secondary mines, the challenges are various and the task even more complex. Processes must be adapted or even specifically designed for the material or the waste to be treated. Before being industrially developed, these processes need not only to be efficient but also to take into account the economic, environmental and societal aspects in Europe and abroad.
Therefore, it is necessary for European industry (mining and metals industry, technology providers, recyclers) to have access to a network of knowledge that can work cross-sectorially and innovatively by combining the expertise of all members. Flexibility and speed will be enhanced and solutions will come into industrial use faster and more efficiently. Future needs and challenges are not known, but the flexibility and versatility of the network and the cooperation between research partners and stakeholders enable industry to respond to these challenges more efficiently.
Established in 2014 following an EIP-RM commitment, PROMETIA is an International Non Profit Association gathering academia, R&D centres, pilot platforms and industries. It promotes innovation in mineral processing and extractive metallurgy for mining and recycling of raw materials. It is has been designed as a research and integration network to (i) develop innovative technological solutions to optimize raw materials & waste treatment, (ii) enhance EU skills in mineral processing and extractive metallurgy of ores and industrial residues, and (iii) in the longer term, boost the innovation capacity of the EU raw materials related sectors.
PROMETIA aims to strengthen technical skills and industrial know-how in Europe in raw materials processing for supporting the industrial and economic development by promoting an easier access of industrial partners to the most relevant and competent European R&D teams as well as to services & facilities for up-scaling metallurgical and mineral processes in Europe, promoting the most innovative cutting-edge scientific results from the European research teams towards the industrial partners, facilitating the visibility and the access of all the partners to different funding opportunities.
This paper will present the activities of the association and its first achievements.

Material re-processing is commonly applied in material separation systems with the aim of increasing the output purity and amount of recovered materials. In spite of its importance, there is no model in the literature for quantitative evaluation of material re-processing. In this paper a methodology that is called linearization is introduced for quantitative analysis of material re-processing. In this method material re-circulation is modeled by substituting the actual machine with a linear system of inter-connected machines. Different experiments are performed for method validation and investigating the effect of material re-processing on separation process performance. The results verify the precision of the linearization method and its applicability in real separation processes. <br /><br />Keywords: Re-process, Linearization, Material separation, Process optimization

The optimized particle-size-dependent separation methodology of pulverized electric arc furnace (EAF) slag to lower Fe contents has been sought via consideration on the microstructure and physical properties of each solid phases. Vickers hardness and fracture toughness were measured on the spinel and amorphous phases within the solidified slag by the indentation method after isothermal cooling processes which were intended for spinel growth. The differences in the hardness between each phase were enlarged when the slag was isothermally cooled. The variation in the hardness of the spinel was observed in the slags at different FetO/Al2O3 mass ratios and isothermal cooling temperatures, showing reduced hardness of the amorphous phase with isothermal cooling time. Structural studies using X-ray diffraction (XRD) and Raman spectroscopy suggested that the formation of the triclinic unit cell which expands with the increased FetO/Al2O3 ratio results in decrease of hardness for the primary spinel crystals and structural transformation into silicate-dominant with increased isothermal cooling period leads to densification for the amorphous phase and consequent lower hardness. Fracture toughness could be calculated by using the crack information obtained from the Vickers hardness test and Young's modulus could be calculated based on the force-displacement curves from nano-indentation test. The controlled milling process produced particles of different size for each phase due to the distinguished fracture toughness allowing separation of Fe content within the EAF slag powder based on the particle size.

In the year 2014, the European Union classified indium as one of the twenty critical raw materials. Indium, due to its unique properties, is widely used mainly in electrical, metallurgical and chemical industries. Nowadays, the industrial development, high quality and new technology requirements, leads to increasing of demand for this metal. The knowledge of the technological processes to produce indium from primary raw materials and waste is required for better utilization of limited indium sources. This work deals with general characteristics of indium and its applications in modern technologies. The aim of this contribution is to describe and characterize the primary raw materials and waste containing indium followed by summarization of technological processes of indium recycling.

The aim of the recycling processes developed in our laboratory is to recover rare earth elements and platinum group metals.
Following are some of the projects carried out. The rare earth elements are included in fluorescent lump, LED, magnet, and special lens, abrasives and so on. In the material recycling of fluorescent lump, the powders obtained after the size reduction of waste lump is recovered after removing the mercury. Three kinds of powders, containing rare earths elements, are then separated by the oil and water phase separation. The benefit of rare earth recovery from LED is also discussed.
The disintegration of magnet in rotor is carried out by underwater crushing method. The collected magnet powders are then leached, and the rare earth elements are recovered by crystallization and solvent extraction.
The rare earth elements in lens are dissolved in water by alkali fusion and separated by solvent extraction.
The platinum group metals are used in catalysts, dental polished powders, batteries and slags. The catalysts containing platinum group metals are selectively crushed and collected by physical separation as pretreatment. The precious metals in the dental polished powders are leached and separated by sedimentation.
The small amounts of platinum group metals in the smelting slags are discussed for the concentration by the heat treatments.

Waste electrical and electronic equipment (WEEE) contains significant amounts of metals such as Au, Cu, Ni, etc .. These metals are largely concentrated in WEEE, which determines the type of waste for possible future secondary raw material. WEEE is highly heterogeneous and therefore before the actual treatment it is important to know the exact characterization. The aim of this paper is to propose a possible sampling procedure of waste electrical and electronic equipment in order to obtain a representative sample.

The growing demand for energy combined with the scarcity of non-renewable energy sources has led to the research of alternative energy sources capable of replacing the traditional ones with the least environmental impact. Among these alternatives, solar energy is very important, since it is a virtually inexhaustible source and generates relatively small environmental impact compared to other traditional generation sources. The collection of solar energy and its conversion into thermal or electrical energy is only possible with photovoltaic panels. These panels have a limited lifespan of 20 -25 in average and will eventually be replaced by new ones and thrown away. Thus, in the near future, large amounts of solar modules will become electronic waste. In order to retrieve important raw materials, reducing production costs of new panels and environmental impacts, recycling such materials is important. <br />In this paper, photovoltaic module components were characterized through visual inspection, x-ray fluorescence, energy dispersion spectroscopy and atomic absorption spectroscopy. The glass was identified as ordinary glass (soda-lime glass), which can be reused without any previous treatment. The metallic filaments were identified as tin-lead coated copper, which can be recycled through known pyrometallurgical processes. The modules' cells were made of silicon and had silver filaments attached to it. The silicon and silver were separated and recovered through chemical processes. The modules' frames were identified as aluminium and can be recycled without any previous treatment. <br />Moreover, different segregation methods have been studied in order to separate the different components with the smallest environmental impact. Chemical, pyrometallurgical and mechanical methods have been tested. Pyrometallurgical methods have shown the most promising results so far. A detailed description of the separations methods and the experiments' layouts will be given.

Sensor-based technologies, such as sorting, have become state of the art in many branches of solid waste treatment. As solid waste has been recognized as an important deposit of secondary resources economically and politically, sensor-based technologies help to increase the width and depth of solid waste treatment. For example, massive throughputs as well as recovery of residual materials are made possible and feasible. Nevertheless, there are opportunities for innovation to ultimately expand our useable resource basis even further.
This paper highlights the experimental development of a spectral inductive analyzer to be incorporated into a testing method. The goal of the method is to detect residual metals of low concentration at three levels of increasing complexity: indicative, qualitative and quantitative. A conductive coil at close proximity to a moving material stream is electrically charged with a sinusoidal waveform between 0 and 100 kHz. By crossing this frequency spectrum, different responses are created from different materials and recorded to be analysed. This paper presents initial results that allow for positive conclusions regarding the above mentioned levels of detection. An outlook is given on further developments and goals.

Nowadays, one of the significant secondary sources of the rare earth elements (REE) in Europe are spent permanent magnets. The main application of Nd-Fe-B permanent magnets is in hard disc drives, but they also become an important part in green technologies, e.g. electric/hybrid vehicles, wind turbines or in other various electric and electronic devices. The European Union raw materials initiative (RMI; Communication on raw materials, COM 2011/25) labelled REE as one of the most critical elements for EU. Nevertheless, today the recycling of REE is counted only to around 1-10%, globally. The absence of REE wastes recycling at individual countries had caused accumulation of wastes, as a result of missing proper technologies. The aim of this work is to introduce the possible methods for recycling and recovery of Nd from spent Nd-Fe-B magnets from waste electric and electronic equipment (WEEE). Moreover, the description and identification of composition of waste Nd-Fe-B magnets from various sources after demagnetisation at Curie temperature are presented. For characterisation of the individual samples, the chemical elemental analysis, X-ray diffraction phase analysis and scanning electron microscopy have been applied. The results indicated different phase and elemental composition of individual spent Nd-Fe-B magnets.<br />Keywords: spent Nd-Fe-B magnets, characterisation, rare earth elements, Nd

Steel mill dust recycling nowadays is dominated by the waelz process, having a market share of roughly 90 %. However, such waelz kilns must be seen as centralized units, where approximately 100 000 t/a are necessary to enable an economical operation. From the view of steel mills, the strong dependency is seen as negative and intensive research has been carried out to find recycling concepts which can be installed directly at the steel mill, treating solely the generated dust from one site. These so called mini mill solutions are generally available as hydrometallurgical and pyrometallurgical concepts. The paper describes typical concepts and especially the question why they have not been successful. Furthermore, actual developments of small scale processes for the treatment of steel mill dusts are discussed, presenting some new solutions. In this context, the available amount of dusts in future as well as possible new sources are evaluated. Especially the economic and environmental aspects, being able to influence the utilization of mini mill solutions positively, are investigated. Another focus is to put on future role of lower zinc containing dusts, and their potential for mini mill concepts.

The paper describes selected rare earth elements (REE) which the European Union included in the list of critical raw materials in 2010. These elements have a wide range of potential uses, for example as phosphors in display and lighting technology, in ceramics, metallurgy and automobile industry. Due to increasing demand for REE waste treatment containing these metals is very important nowadays. The most appropriate method appears to be hydrometallurgical processing and leaching in acid solution. The work deals with the general characteristics of REE and studying the possibility of processing selected species of WEEE containing REE especially the fluorescent lamps. Moreover, the work presents some experimental results from leaching of demercurized powder from spent fluorescent lamps in sulfuric and hydrochloric acid medium.

We reported the possibilities of controlling the critical rare metals crisis existed for several years. Currently, critical rare metals are highly demanded and growing fast in green technologies. Recycling of mineral waste sources for the recovery of critical rare earth elements are other alternative source of this critical rare metals crisis. Various mineral waste sources such as mine residues, coal waste (fly ash and bottom ash) and bauxite residue waste (red mud) are expected to be potential recovery sources for critical metals (gallium, yttrium and other rare earth elements) in the future. Sustainable recycling technologies are necessary for the utilization of CO2 for the recovery of rare earth elements and other value added materials. Carbonation or CO2 sequestrations of waste residues are pioneered to reduce alkalinity. The carbonation of alkaline materials is an inexpensive and safe process that leads to the formation of thermodynamically stable products. This paper mainly concerns the possibility studies of controlling the critical rare metals crisis in various fields and managing the supply chain risks of rare earth elements (REEs) by recycling the mineral waste sources.

The steel industry slags including Blast Furnace (BF) slag and Ferro nickel alloy (SNNC) slag were used to produce the glass-ceramics based on SiO2-(CaO+MgO)-Al2O3 system, which can be used for high strength and anti-wear materials. Six samples of different composition were prepared by mixing starting resources with prescribed ratio, casting and heat treatment. To investigate the effect of composition on the properties and crystallization mechanism of material, the characterization was made with XRD, DSC, measurement of compressive strength and micro hardness. XRD results showed that three different phases, anorthite, diopside and gehlenite, were the main phases of the material. Diopside was formed in every sample, but anorthite was formed in SiO2 rich material, and gehlenite in CaO rich material, respectively. DSC analyses indicated that the glass material has glass transition point around 973~993K, undergoes crystallization around 1073~1173K, and melts around 1447K. The crystallization temperature has increased as the content of Fe oxide decreased. By changing the heat treatment pattern with multiple steps, anorthite phase has formed more, and various phases were generated in the present experimental condition. It is expected that Fe oxide works as a nucleating agent. By changing heat treatment pattern, more various phases could be formed, and anorthite phase was formed more. Also, thermodynamic simulation was made with FactSage to simulate stable phases in glass-ceramics material. Additionally, viscosity and latent heat of liquid glass-ceramics materials will be discussed.

Nowadays, tinplates belong among the most important food packing material used e.g. for production of cans. Tin cans are used widely to store and keep safely juices, drinks and liquid products of different taste. Especially in food industry, one has to consider the effects of pH, acid content, presence of corrosion accelerators, oxygen etc. inside can. Thus, some of the liquids can be very aggressive to the metals and their surface treatment. The consequence is failures of cans due to the dissolution of high level of tin and iron. This paper deals with investigation of "run-off" effect of Sn into solution via monitoring of the impedance data retrieved by EIS. We have observed that release of Sn is not only time but also temperature dependent. The equivalent circuit models for tin under various pH, conductivity and TDS conditions were built. Here, minimizing corrosion process is sufficient, so "run-off" effect of Sn from cans into drink during short-term storage were calculated and compared to WHO legislative.
On the other hand, maximizing corrosion process during tin recycling from waste is of interest. Only little research is focused on tin as waste material coming from food industry and from electrical parts. Our group has measured maximum corrosion rate of Sn under special pH/conductivity/TDS conditions supported by coulometric stripping technique which could serve as process for effective recycling. The rapid increase in prizes of Sn on stock market builds up conditions for development of new effective recycling processes for this metal. By electrochemical approach, we can optimize the recycling process with minimal current and maximum efficiency.

This paper presents preliminary results as the incorporation of waste iron ore and BOF slag, already stabilized, with free CaO contents of less than 3% in ceramic artifacts. The clay was chosen based on local availability and the wastes by their chemical and physical characteristics.
The bodies prepared for analysis contained the following contents: fine tailings (10, 20 and 25%) and slag (5, 10 and 25%), both in volume of clay. Materials in this order, the results for moisture were 2.15, 35 and 35.3%; real density 3.05, 2.85 and 2.55 g/cm3 and particle sizes less than 0.600 mm. The specimens were homogenized and formed in manual mechanical press with uniaxial pressure of 20MPa. Subsequently, they were weighed and dried at 110°C during 24 hours. Therefore, weighed and sintering in a muffle furnace at 950°C for 1 hour. After all, a visual and structural analysis in the Scanning Electron Microscope (SEM) was made. The results provided by SEM showed that the pressure of 20 MPa was not enough for the complete compression of the material, which in general, had an excess of voids between the grains. From the visual analysis, it was noticed that the burned time was not sufficient for complete sintering of the samples that comprised 25 to 50% of waste. Which can be explained by the silica content (8.44%) and iron oxide (32, 71 and 86.6%) respectively present in the slag and the fine tailings. Thus, in the function of the chemical and physical characteristics of each component used in this work, the data indicate that should be used compaction pressures greater than 20MPa and larger sintering time, for use of higher levels wastes in red ceramics.

Thin-walled cement-based elements reinforced with alkali-resistant glass fibres combine a range of very advantageous qualities, esp. high flexural and impact strength. They have a lot of benefits, among others they minimize production, transport and assembly costs and save the environment as well. Due to utilization of various kinds of waste materials from different sources of industry, e.g. fly ash, furnace slag or furnace clinker, it is possible to reduce also raw materials costs and save natural resources of raw materials, which are used for concrete production nowadays. Considering initiative analyses, there was a set of various waste materials selected for utilization in fibre-cement composites with technological, ecological and economical aspects. These waste materials were added to dry mixtures in several amounts as a substitution of cement, aggregates and fine admixtures. A set of tests was carried out, including durability within accelerated ageing.

The paper describes research on utilization of solid wastes, which are produced during the manufacture of mineral wool. The aim of the four-year research is to verify the best way of processing of these waste materials and determine the maximum value of their addition into the construction materials, which will not have undesirable effect on requested physical-mechanical and ecological properties of the final construction product. The verified applications are vibro-pressed thin-walled concrete blocks, thin-walled glass fiber elements, self-leveling flooring mixtures and thermal insulation panels. The requirements for the construction materials are based on appropriate EU standard requirements and requirements for commercially available construction products.

Efficient leaching of chalcopyrite concentrates at ambient pressure still remains a challenge because of the low extracting yields and slow dissolution kinetics due to the passivation of the solid surface. In this work, we investigated the generation process of surface species during the leaching of chalcopyrite. Leaching was carried out for up to 24 hours by using 1 mol/L H2SO4 plus Fe3+ as oxidizing agent. The influence of temperature (25, 50, 70A°C) and solution potential (600mV, 700mV) on leaching rate and composition of surface species was investigated by ICP/AES and XPS. Results showed that leaching of chalcopyrite takes place by a first quick dissolution of Fe-O-OH and CuSO4 from the solid surface and then by a slower dissolution of CuS2, which then gradually leaves the surface to CuFeS2. As the leaching proceeds, the formed CuFeS2 undergoes passivation, resulting into the surface product Cu0.34Fe0.20S2, which acts though as an obstacle to the further dissolution of copper, i.e. passivation, thus arresting the leaching. The leaching rate of Cu increased by increasing the temperature but it decreased by increasing solution potential whilst no differences were observed as composition of surface species.

Zeolite was synthesized from Naantali power plant coal flyash (CFA) using two step fusion and thermal process. Effect of fusion temperature, thermal treatment time, washing effects etc were investigated and analysed. The zeolite so formed were characterized by SEM, EDX, XRD. The XRD analysis revealed the type as Zeolite HS with sodalite framework. The unique feature of this framework is that it has smallest pore size and is commonly used in sieving operation to purify wastewater from heavy metals and organic effluents. A corresponding reaction mechanism has also been proposed. The zeolite had very high crystallinity of 85-100%. The best specimen were found at 500°C; fusion and 8 hour thermal treatment along with 16 hours thermal treatment. The reproductive tests carried out revealed identical results which prove the process can be repeated. This is the first time ever that zeolites from coal flyash were made in Finland. This is an initiative towards circular economy where wastes are not thought as wastes but raw materials for other processes and valuable materials and is in clear line with EU Horizon 2020 industrial and innovation objectives.

Natural zeolites are abundant and low cost resources, which are crystalline hydrated aluminosilicates with a framework structure containing pores occupied by water, alkali and alkaline earth cations. Due to the nature of cation exchange, natural zeolites exhibit high performance in adsorption of cations in aqueous solution. Surface modification using various chemicals can change the surface charge of natural zeolite, making them more efficient for cations removal from solution. In this study, powdered Slovakian clinoptilolite has been tested as sorbent for zinc removal efficiency. The aim of this work was to study the adsorption process of zinc from synthetic solution. The effects of various operating parameters, modification effect, adsorbent dosage, initial concentration of metal ions and contact time were investigated in a batch adsorption technique.

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