REWAS 2016

Within the last years it has become a mutual business to look at different residues, either dumped or continuously produced, trying to utilize them as secondary resources. Especially those from Zinc-, Lead- and Copper production are well known for carrying different valuable metals in parallel but also highly disturbing impurities. Therefore, as a matter of environmental considerations as well as economic issues, process development has to be carefully done to allow feasible treatment concepts. The paper gives an overview on characteristics, available amounts and possible routes for the treatment of such poly-metallic materials. Beside this it describes how present minor metals can contribute to an economic processing. Furthermore, the option for a “zero-waste” solution and with this a complete remediation of potential dumps is discussed. Finally, the paper draws an outlook on how a successful recycling of these residues could contribute to the base metals production in future.

Phosphorus compounds have been used in a wide variety of industrial and agricultural applications. However, they have also been shown to cause eutrophication in water systems. It is important that the phosphorus is removed from water systems and potentially reclaimed for reuse. One potential phosphorus capture material is bauxite residue. Bauxite residue is a waste product from the Bayer process of aluminum production. The residue is kept in large, alkaline holding pools where it remains unused. Through processing, bauxite residue has been shown to remove phosphorus compounds from waste water. Here, bauxite residue is modified and processed, and the structure-properties relationships are investigated. The effects of microstructure and chemical composition on the removal of phosphorus from water are examined and methods for bauxite valorization are discussed.

The kerf waste from the sawing of PV silicon wafers is pelletized and then remelted in an induction furnace. The furnace has a square cross-section quartz crucible, surrounded by graphite susceptors and heated by an induction coil that enables directional solidification of the new ingot. Top and bottom ‘pancake’ coils provide additional temperature control. Once melted, silicon becomes electrically conductive and subject to stirring by induction. To recycle the silicon, particulate impurities (due to the sawing, condensed silicon oxides or carbides) need to be removed. Flow control and the electromagnetic Leenov-Kolin force are used to expel particulates, through a novel dual frequency induction scheme. Three-dimensional numerical modeling captures the electromagnetic, fluid-flow and heat-transfer effects in this problem, in a multi-physics finite volume computational framework. Results are presented for typical electromagnetic, velocity and force fields and conclusions are drawn about the expected effectiveness of the electromagnetic separation system which is still under construction.

The focus of recycling processes for industrial residues from lead, zinc and copper industry in the past was mainly on the recovery of the base metals. Silver, gold or also PGMs are well-known valuable side elements in the corresponding ores and with this significant contents can be found in some of the residues but were not recovered in the past. Therefore, the recovery of for instance silver is highly interesting, beside the above described base metals to contribute to the overall economy of a potential recycling process, although they occur in much smaller quantities in materials like tailings, sludge, slags or dusts. As an example, the annually produced and mainly dumped amount of zinc leach residues contains roughly 500 tons of silver beside lead, zinc and others. Therefore, the present paper tries to answer how recycling of such industrial residues can contribute for example to the supply of silver or also other precious metals.

Electric arc furnace dust is a listed hazardous solid waste and is thus subjected to a high treatment cost. Development of cost-effective technologies to recycle the dust is always a challenge. There are two critical problems in existing recycling practices of electric arc furnace dust: (1) iron in the dust is not recovered and is lost in slags or residues; (2) recovery of zinc from zinc-lean electric arc furnace dust is more costly. Strategy of in-process separation of zinc from electric arc furnace dust, being aimed at producing two recyclable electric arc furnace offgas byproduct streams, zinc-rich one and iron-rich one, has been recently proposed to attack these two problems. However, suitability of facilitating this strategy in electric arc furnace offgas cleaning systems has been questioned. In this study, thermodynamic analysis on zinc status in the upstream electric arc furnace offgas cleaning systems was carried out to examine possibilities of applying in-process separation strategy in producing cleaner byproducts of both zinc-rich dust and iron-rich dust for complete recycling of the electric arc furnace dust.

In this work the evaluation of a filter press type Reactor (REOV-01) with Ti electrode was realized, applied in the silver recovery from industrial wastes. Macroelectrólisis studies were performed at different flow velocities with empirical and dimensionless correlations and parameters. The results of the variation of the concentration of Ag at different flow linear velocities allowed the determination of the mass transfer coefficients of silver (order of 10exp-5) for Ti electrode, which are consistent with the literature. Chronopotentiometric studies showed that the Ti electrode performed better for the recovery of silver because to a current of -150 mA during 210 minutes was achieved 99.8% of silver recovery. The current efficiency values above 100% indicated that the electrochemical process is coupled to an electroless process. The results showed low energy consumption and high space-time yield values indicating that the REOV-01 presents an excellent performance in the recovery of silver.

High amounts of Steel Mill Dust is produced worldwide each year. Although the Waelz kiln is the preferred route for processing these wastes, significant amounts of this residue stays untreated. Very often, the unprocessed dust gets landfilled and therefore, it is lost for the recovery of zinc and further heavy metals accompanied in the waste. An alternative way with respect to treating Electric Arc Furnace Dust would be the so called 2sDR (Two step Dust Recycling) process, which allows the simultaneous recovery of high purity zinc oxide as well as iron and other heavy metals. This leads to a zero waste process, because the remaining slag is free of heavy metals which allows a utilization for e.g. construction purposes. The present publication should give an overview on the process set-up itself; moreover, achieved data from extended lab scale trials underlines the sustainability of this process.

Energy storage and recycling are among the most important strategies identified by governments and non-governmental organizations to confront the challenges of developing a more “circular” economy. The need for more efficient batteries to help the energy storage industry meet the changing needs of a growing world population is presenting new opportunities for metals used to make batteries. For the use of these metals to be compatible with the needs of a circular economy, recycling is key to the efficient utilization and conservation of natural resources. Some materials used in the battery industry have been adapted to the needs of a circular economy more successfully than others. Lead is the most recycled of all metals, with a battery recycling rate of 99%. The lessons learned from the utilization of a highly-recycled metal such as lead must be considered a model for the development of batteries made with other metals.

Waste from alkaline and carbon batteries is processed in this research and combined with white ordinary Portland cement. In Colombia, battery waste is not used or recycled at all, and those that are collected are put in a landfill facility. After removing the metal, plastic and paper from the battery, the waste is mostly composed of zinc, manganese and iron oxides. This research presents results for the use of these materials, and characterization of the by-products. Scanning electron microscopy (SEM), X-Ray Fluorescence, and compression tests were conducted in this investigation. It was found that samples have good compressive strength, this is over 20MPa for 50wt% of battery waste for a process suitable to improve and increase this value. As expected, results showed that compressive strength decreased as waste content increased.

Lithium-ion Batteries (LiBs) are today used in significant quantities in the automotive industry. As these batteries are expected to last the lifetime of the vehicle, they will not be ending their useful lives in large numbers for another 10-15 years. An opportunity does therefore exist to prepare for some of the roadblocks that might arise during the development of technologies for environmentally sound recycling of LiBs. In view of this, there is a need for reliable thermodynamic and kinetic data so that a secondary product of high enough metal value, as well as quality, can be produced making it possible to find a market for its purpose.In the present study the equilibrium conditions for obtaining the best conditions possible for recovering the metal content through the aluminum recycling process were studied. All thermodynamic calculations were performed using the FactSage™ software, and the chosen chemical compositions represent the two main families of LiBs, i.e. LiNiCOAlO₂ and LiFePO₄. The possible production of PH₃ and P₄ (white phosphor) during the recycling process is also briefly discussed.

Some have raised concerns regarding the contribution of lithium-ion battery pack production to the total electric vehicle energy and emissions profile versus internal combustion vehicles, and about potential battery end-of-life issues. This detailed life cycle analysis (LCA) examines these issues and identifies potential hot-spots within the battery pack life cycle for five cathode materials and a proposed lithium metal anode. The battery assembly stage, identified by some as an energy concern, is determined to be problematic only for “pioneer” plants (i.e. low-throughput facilities), but not for at-capacity plants, and battery electric vehicles with batteries from either facility type outperform conventional vehicles in terms of lowering GHG emissions. For at-capacity plants, the battery materials dominate energy impacts, with cathode materials representing 10–50% of that energy, depending on cathode type. Recycling can further mitigate battery life-cycle impacts, while also being economically attractive for all cathode materials, even those with low elemental values.

The environmental life cycle impacts of conceptual rare earth production processes were assessed. An average greenhouse gas emission of 65.4 kg CO₂e/kg was estimated for the 15 rare earths produced from monazite, ranging from 21.3 kg CO₂e/kg for europium to 197.9 kg CO₂e/kg for yttrium. The average water consumption of rare earth production was 11,170 kg/kg ranging from 3,803 kg/kg for samarium and gadolinium to 29,902 kg/kg for yttrium. The average gross energy requirement for production was 917 MJ/kg, ranging from 311 MJ/kg for samarium and gadolinium to 3,401 MJ/kg for yttrium. Given the low concentration of HREE in monazite, the high impacts across all categories for yttrium and other HREE are not necessarily representative of HREE sourced from all rare earth resources. Further studies into other rare earth mineral resources (e.g. bastnasite and xenotime) are recommended to improve the overall understanding of environmental impacts from rare earth production.

Rare Earth Elements (REEs) have unique properties that have led to a rapid increase of consumption in modern technological products. This has in turn led to a greater awareness of the limited and highly localized nature of mineral reserves, and the dilute nature of the undeveloped resources including those from secondary sources.Recycling of REEs is seen as one possible way to increase the supply of these elements with less impact on the environment than extraction from ores. In the present recycling processes for electronic waste these elements are, however, largely oxidized and diluted into discarded streams making recycling a challenging task.Selected industrial ferrous streams of electronic waste that contain significant amounts of NdFeB magnets were investigated in the present work. Highly reducing conditions and high temperature were applied to obtain a slag containing only the most stable oxides, which also proved to include very high concentrations of REEs.

This study aims to investigate phase relations of the CaO-SiO₂-Nd₂O₃ ternary system for high temperature recycling of Neodymium. The slag samples were equilibrated at 1500°C and 1600°C for 24h in Ar, and quenched in water. From the phase analysis of the samples, the isothermal sections were partially constructed and the liquid stability regions were assessed. Based on the identified phase relations, a solidification process with different cooling paths was studied in-situ using a confocal scanning laser microscope within the interesting slag phase regions for recycling. The phases needed for optimizing recycling can be produced accordingly.

Critical materials are minerals with potential supply chain risks that cannot be easily substituted in many of their applications, including, but not limited to, clean energy technologies, LEDs, smartphones, lasers, and microwave circuits. With increasing demand for these products, supply chain disruptions pose an ever-growing risk to the economic wellbeing of many nations, including the United States. One under-examined potential source of risk arises from sociopolitical instabilities and direct or indirect market manipulations, referred to generally as trade risks. To illustrate the potential challenges posed by some of these trade risks, US tariff policies for nine critical materials were examined for potential to inform future material-related trade policies. Two of these case study materials, gallium and tantalum, were examined in depth to estimate relevant economic impacts. Findings from these case studies suggest that a reduction or abolishment of tariffs in general may foster trade, economic growth, and a lowering of supply risk. Further work will be required to cement a cause and effect link between trade barriers and criticality risk.

Rare earth elements (REEs) are among the strategic materials that have revolutionized modern industry. These materials have unique properties, so they are essential to the production of many technologically advanced products that are dominating the world; thus the REEs demand is continuously rising. To address this challenge, finding new sources for them is highly of interest. Here, we identified a waste stream from phosphoric acid production plants, called phosphogypsum, which contains some amounts of REEs. We developed a novel hydrometallurgical process to recover REEs from phosphogypsum. We investigated several leaching agents at various conditions and identified the optimum leaching parameters. Not only can the developed process decrease the size and associated environmental risks with the existing phosphogypsum stacks, but also can slow down the need for additional stacks. In addition to waste valorization, this novel process provides a new source for REEs production, addressing the sustainability challenges associated with them.

Recently Rare Earth Elements (REEs) have received increased attention due to their importance in many high-tech and clean energy applications. Although production of REEs is known to be heavy polluting, very limited environmental Life Cycle Assessment (LCA) studies have been conducted. This is particularly true for the solvent extraction of REEs from aqueous solutions, a key step in the REE production pathway. In this study, an LCA is carried out on a typical REE solvent extraction process using P204/kerosene. The material and energy flow data were based on production information collected from several solvent extraction facilities in Inner Mongolia, China. The life cycle inventory was developed using Simapro 7.1 and Ecoinvent 3, in combination with mass/energy balance and stoichiometry. Eco-indicator 99H was used for impact assessment and LCA results were used to evaluate and identify environmental hotspots of solvent extraction process. Moreover, challenges and opportunities for improved environmental performance of solvent extraction process were discussed.

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 metals are one of the alternative resources for this critical rare metals crisis. Various mineral waste sources such as mine residues and coal ash are rich sources of rare earth elements. This study sought to identify the information needed to determine whether there might be a potential for commercial extraction of the rare earth elements (Nd, Dy) from coal power plants ash. The aim of this study was to recovery and characterize the light rare earth metals from Korean coal power plants ash and simultaneous utilization of CO₂. Accelerated carbonation was a more suitable process for CO₂ capture and simultaneous utilization of this CO₂ for the manufacturing of “green cement” (Calcium Sulfo Aluminate) from coal power plants ash.

In this study, metallurgical and gasification slags mixed at a specific composition were heated to a slag discharge temperature range (i.e., tap out temperatures in iron & steelmaking) in the presence of CO₂, resulting in a reaction generating energy — enough to convert CO₂ to CO which can be used in other processes such as ore reduction, gas turbine power generation, and synthetic liquid/gaseous fuel production. Computational simulations suggested that the generation of H₂ from H₂O would also be possible using the same mixed slag approach at no additional heat supply. Energy generated from the reaction remains largely in excess after conversion (CO₂ to CO), which can be utilized independently for or support other processes. Furthermore, a final slag volume is expected to decrease to about 30%, dramatically decreasing landfill burden.

Lightweight aggregate and ceramic balls were produced from a mixture of gold tailings, red mud and limestone by using a high temperature process. Raw materials were quantitatively analyzed and hazardous materials content was checked by chemical analysis. Oxide systems for the lightweight aggregate and ceramic balls were chosen based on the CaO-FeO_t-Al₂O₃-SiO₂ quaternary system. Sintering, softening and melting behavior of the samples were investigated to optimize the sintering conditions. Phase change during sintering was observed by X-ray diffraction. Microscopic analysis by SEM / EDS was carried out to check the morphological changes of the samples.

Variation in life cycle inventories (LCI) for a materials industry are significant but rarely reported, in spite of the fact that inventories are often created by aggregating data from several locations. In this study, two approaches for aggregating LCI data, inventory-level (horizontal) and plant-level (vertical), were compared in the context of a specific materials industry: portland cement production in North America. We present a derivation of the methodologies to highlight the similarities and differences. Finally, we show results from a life cycle impact assessment of cradle-to-gate portland cement production using a Monte Carlo simulation approach to explore the quantitative differences. For the case study, we observe that the mean values of GWP using both approaches are similar, but the standard deviations can be significantly different. The reasons for this difference — the handling of correlation across exchange magnitudes within a facility and zero-inflated data — are discussed.

It is well-known that the recycling of steelmaking slag in iron and steel industry would bring out a problem of phosphorus enrichment in hot metal, which will do harm to steelmaking process. In the present paper, dephosphorization from steelmaking slag by leaching with solution composed of citric acid, sodium hydroxide and hydrochloric acid was studied. Kinetic parameters including temperature, slag particle size and solution pH were optimized. The results showed that temperature has no obvious effect on dissolution of phosphorus. The dephosphorization rate increase with the decrease of slag particle size and pH value of solution. 90.0% of phosphorus can be dissolved in the solution while the corresponding leaching ratio of iron was only 30.0% in the optimal condition. Leaching kinetics of dephosphorization follows the unreacted shrinking core model with a rate controlling step by the solid diffusion layer and the corresponding apparent activation energy is 1.233 kJ mol-1.

Steel slag can be an alternative in cement mineral admixture, partially as a substitute for blast furnace slag. A pyrometallugical process has been investigated to promote the chemical composition modification of molten steelmaking slag in a metallurgical reactor. Experiments were conducted by remelting 300 kg of steel slag followed by chemical modification of liquid slag. The modified slags were naturally cooled in the metallurgical reactor or cooled by steel balls. XRD and SEM analysis of slag samples revealed the relationship among chemical composition, cooling conditions and amorphous and crystalline phases. Cement samples were produced by mixing 25% of treated steelmaking slag with 75% of Portland cement, resulting in more than 280 J/g of accumulated hydration heat in 72 h, expansion lower than 0,1% in the autoclave tests and compressive strength higher than 42 MPa after 28 days. The process indicates potential to be applied as a steelmaking slag treatment.

This work has as its objective to evaluate the use of sewage sludge from wastewater treatment plant into heavy clay ceramic body. Compositions were prepared with amounts of 0, 2.5, 10 and 15 wt.% of sludge incorporated into the clay body. Rectangular specimens were obtained by 20 MPa pressure molding and then fired at 850°C in a laboratory furnace. Characterization of the waste was done by X-ray-fluorescence, differential scanning calorimetry and thermogravimetric analysis. Ceramic properties related to the water absorption and compression strength were determined. The results indicated that the incorporation of the sludge into clay bricks must be done in low amounts. In higher amounts the sludge increases the water absorption and reduces the mechanical strength of the ceramic. This is a consequence of the changes caused in the porosity by the relatively elevated weight loss of the waste during the firing stage.

Developing countries like India, characterized by large working populations and significantly lower cost of capital, have become hotbeds for manufacturing activities. A distinctive feature in regions of India is that majority of the industrial material flows are through unorganized micro, small and medium scale enterprises (MSMEs). These highly constrained MSMEs have limited resources to comply with environmental regulations because of significant investments required in pollution control measures. An important way to improve the environmental performance of these industrial clusters is to quantify, treat, and reduce industrial byproducts. This objective could be achieved through industrial symbiosis or byproduct synergy, terms used for beneficial reuse of materials or energy streams from one facility by another. In the present study an attempt has been made to identify and understand existing and potential industrial symbiosis connections in Muzaffarnagar, an industrial town in north India home to several dozen paper mills, another dozen sugar mills, and a large range of other MSME manufacturing entities. In addition to the presence of small and medium enterprises there is also a strong bond between industry owners in the region.

Simulation combined with Life Cycle Assessment (LCA) can be used to quantify the environmental impact of metals production processes. The results for different processing options, as well as the effect of having the same plant at different locations can be evaluated and compared. HSC SIM 8, which is linked with GaBi, or other LCA software can be used to carry out this work. The material flows are calculated using HSC SIM, and they are then converted to environmental indicators. The refining of silver using the High Current Density (HCD) electrorefining process is used as an example in this paper in order to show the link between simulation software and LCA.

This paper studies total-corrosion effects of Anthocleista djalonensis (green natural-plant) and Na₂Cr₂O₇ (well-known inhibitor, but environmentally-hazardous chemical) on steel-reinforcement in concrete immersed in 0.5 M H₂SO₄, simulating microbial/industrial environment. Equal-mass models of the plant leaf-extract and of Na₂Cr₂O₇ were employed as admixtures in steel-reinforced concrete samples immersed in the test-system, from which macrocell corrosion measurements were obtained and analysed as per ASTM G109–99a. Results showed that only the 3.33 g/L Anthocleista djalonensis, among the equal-mass models of leaf-extract and the chemical admixtures, was outperformed by the 3.33 g/L Na₂Cr₂O₇ in total corrosion reduction effects. In the study, 5.00 g/L Anthocleista djalonensis exhibited optimal effectiveness, η = 93.77%, on the total-corrosion effect of concrete steel-reinforcement. The many Anthocleista djalonensis admixtures that exhibited better inhibition than Na₂Cr₂O₇ admixtures indicates positive prospects of the plant as an eco-friendly and sustainable corrosion-protection alternative for the toxic chemical in microbial/industrial environment.

Each year, the TMS Annual Meeting brings together materials experts from across the field and across the globe, creating unique opportunities for multidisciplinary discussions of grand challenges. Enabling a clean energy transition without creating new chronic energy material shortages is one such challenge. The present work aims to inspire materials researchers from across the disciplinary spectrum to consider their skills in the context of need for risk mitigation research; particularly for the vulnerable subclass of critical materials mined as byproducts. Key leverage points are identified and assessed using existing case study data for tellurium. Results show that rapid demand growth, driven by solar PV, rendered supply-side mitigation strategies (byproduct yield improvement and recycling) much less effective than demand-side solutions, like dematerialization and substitution. Overall, the results serve as a reminder that there is no universal mitigation strategy; instead, optimal results can be obtained by targeted and temporally-relevant strategic development.

The durability of heterogeneous nuclear waste forms depends on the individual constituent properties as well as their internal morphology and boundary conditions. The end of life is defined by mechanical and chemical failure modes. Chemical failure occurs when increasing porosity reaches a threshold value, creating continuous pathways for the internal material to come in contact with the outside environment. Mechanical failure occurs when the waste form loses its structural strength due to porosity. In this work we employ conformal finite element analysis of heterogeneous waste forms set on the actual microstructure determined by tomography. The model calculates species flux in the constituents and the composite waste form subjected to various storage environments to estimate the development of porosity with time and the subsequent life. The analytical approach with preliminary results is discussed. The method is postulated to be a foundation for design of heterogeneous waste form materials.

The use of “life-cycle costing” makes it more likely that durable and maintenance-free corrosion resistant alloys will be chosen. The cost of corrosion failure is examined and compared with raw material costs, and the excess cost of using lower initial cost, but inadequate material is explored. The desirability of using suitable corrosion-resistant alloys is highlighted. The use of life-cycle costing (LCC) to justify the use of materials with higher initial cost is illustrated.

Dynamics of general economic growth is to a considerable extent determined by results of research, technical and innovation policies in the Arctic zone of Russia. According to scholars’ evaluations contribution of innovation-technological development of the economy in growth of the country’s GDP accounts for 70–80%. Mineral formations, accumulated during the industrial epoch, affect significantly economic and ecological situation in the Arctic region. On the one hand, production wastes destroy the region’s environment. On the other hand, man-made mineral formations contain a lot of valuable scarce components. Volumes of solid wastes increase annually. Transition to innovation economy provides re-comprehension of mining in the society. Measures should be directed to radical renovation of production technologies. It will ensure rapid growth of competitiveness, increased demand and stronger position at the international market. Development of innovation technologies can be provided at the expense of active state and private innovation activities.

Electrodynamic Sorting (EDX™), or variable-frequency eddy-current sorting, is an evolution of sorting technology aimed primarily at light-metal and aluminum alloy recycling. EDX™ is being developed by the Department of Metallurgical Engineering, University of Utah, under an ARPA-E (Advanced Research Projects Agency — Energy) contract. From a purely physical perspective, the EDX system operates by generating an alternating magnetic field in the gap of a toroidal ferrite core. As metallic particles pass through the gap, eddy currents are induced by the presence of the alternating field, which repel the particle from the gap. The velocity at which they exist then varies with distinct physical properties like electrical conductivity, mass density, excitation frequency, and geometry. In this presentation, we describe the fundamental physics of the phenomenon, including simulation data with CST software and results in pilot scale (100 kg/h) systems. Finally, the results on auto shredder scrap mix is presented.

Managing the secondary production process for aluminum auto-shred scrap is of prime importance considering the projected demand increase for aluminum alloys in the transportation, electronic and packaging industries. Aluminum auto-shred scrap is a major end-of-life, mixed metallic stream that must be recovered and recycled effectively and efficiently to ensure infinite lifetime involving a broad distribution of re-use applications determined by specific alloy chemistry [1, 2]. Currently, secondary recyclers that dilute the melt chemistry using primary aluminum minimally only produce A380.1 as this alloy has broad alloy chemistry specifications [3]. Downgrading mixed auto-shred scrap streams is a significant waste of intrinsic value and re-use applicability. Downgrading here is defined as not utilizing all sortable chemistries within this mixed auto-shred. This, paired with scrap export, are the two major present day options for mixed aluminum scrap.

Recycling low-quality scrap and dross is of great interest in the aluminum industry due to its economic and environmental benefits. However, using these raw materials in alloy production requires reprocessing prior to the re-melting stage, leading to two-stage blending operations. In addition, there are energy saving opportunities through 1) immediately processing hot dross collected from alloy production and 2) delivering reprocessed scrap and dross as liquid to produce final alloys. This presentation will describe developing integrated production planning models that determine batch plans for reprocessing and re-melting stages simultaneously. Also, key drivers that maximize the benefits of integrated production planning will be presented. The results suggest that this approach enables aluminum producers to maximize incorporation of reprocessed low-quality raw materials.

South Africa currently is experiencing an electricity constraint due to economic growth and lack of investment in generation capacity, resulting in power blackouts in 2008. With increased electricity prices, the economic sustainability of energy intensive industries is threatened. The aluminum smelting industry is a significant consumer of electricity.The consumption of electricity and the amount of emissions in the process of aluminum recycling can be reduced by the application of solar thermal technologies. A process concept for the solar thermal recycling of aluminum waste material was developed. The process takes place in a rotary kiln heated by concentrated solar radiation.A directly absorbing rotary kiln receiver-reactor was tested on a lab-scale in the DLR high flux solar furnace. In this paper the design of the rotary kiln in the solar furnace is presented. A concept for a pilot-scale rotary kiln operated on a solar tower is shown.

There are many areas in the aluminum cast house and smelter operations that can benefit from efficient recycling and recovery of materials thru low cost, simple rotary processing operations. DIDION has the most widely developed uses and applications for rotary crushing and separation systems for the recycling and recovery of dissimilar materials that are often mechanically bonded together. The development of this technology was started in the foundry industry in the early 1970’s. The first step was the separating of metal castings from the foundry sand mold pieces in which they were created. These hot, heavy castings required the development of a very durable machine. The equipment was next used for sand reclamation to keep these foundry materials in use and out of landfills.

At present, recycled aluminium is “diluted” by primary metal to keep the impurity concentrations at acceptable levels. Future increase in recycling will require a new process for efficient removal of all impurities, including noble elements, from secondary aluminium. In the current preliminary laboratory study, an electrochemical method based on the well-known three-layer refining cell was explored. Metal with purity comparable to primary metal could be obtained from highly alloyed scrap feeds containing elements more noble than aluminium, such as iron, copper, manganese, and zinc. The energy consumption was as low as 8.5 kWh/kg Al, indicating that the process can be expected to be less expensive than for production of primary metal, but with higher costs than re-melting.

An experimental proof of concept was demonstrated for a patent1 and trademark2-pending RE-12™ process for extracting a desired amount of Mg from recycled scrap secondary Al melts. Mg was extracted by electrorefining producing Mg product suitable as Mg alloying hardener additive to primary grade Al alloys. This efficient electrorefining process operates at high current efficiency, high Mg recovery and low energy consumption. Mg electrorefining product can meet all the impurity specifications with subsequent melt treatment for removing alkali contaminants. This economical and environmentally friendly chlorine-free RE-12™ process could be disruptive and transformational for the Mg production industry by enabling the recycling of 30,000 tonnes of primary-quality Mg annually.

The extraction of metals from a primary or a secondary resource is achieved by pyrometallurgy and hydrometallurgy. Currently, most of metal production plants consist of both pyrometallurgical and hydrometallurgical processes. Dust generation during the processes is one of the disadvantages of pyrometallurgical plants. Therefore, dust collection systems are installed in metal production plants to capture the emission of air pollutants from their off-gases. Due to environmental problems associated with the dust and high cost of disposal, proper treatments are required to minimize these problems. Recycling some metals from the dust during waste treatment could be a good way to utilize metal resources. In this research, alkaline leaching on the aluminum smelter baghouse dust has been studied with different reagents, bath temperature and pulp densities. Based on the alkaline leaching tests, the recovery of aluminum is high with sodium hydroxide at high temperature and low pulp density. HSC chemistry analysis shows that the product of NaOH leaching on the aluminum smelter baghouse dust is the sodium aluminate.

EIT Raw Materials is a major European initiative supported by more than 120 core and associate partners from industry, research and academia. Among the core missions of this network is the establishment of a Raw Materials RM Academy to educate T-shaped professionals that will contribute to the development of a sustainable and resource efficient Europe.Every T-shaped professional should combine an in depth knowledge of his own discipline with a sound understanding of the challenges of the full raw materials value chain and with a mindset for innovation and entrepreneurship. The main objective of the RM Academy is to connect all T-shaped professionals to help create the circular economy steering wheel. Therefore, the RM Academy has the following missions: Label and support educational programs.Promote a permanent offer of cross-disciplinary programmes, workshops and courses.Train T-shaped professionals into T-shaped entrepreneurs.Promote lifelong learning initiatives.Stimulate wider society learning initiatives aiming at raising social and political awareness.Closely collaborate with industryEnable a high degree of mobility of students and professionals

The scale of the metallurgical industry of China is very huge. The energy consumption, resources supplying and environmental impaction of China are also causing severe challenges. The education programs and activities in universities towards undergraduate students and graduates concerning about the sustainability of metallurgical industry in China are introduced in this paper. Since the beginning of the 21centry, the courses related with environmental protection, energy saving, ecology, eco-materials were opened. Even the school of metallurgical engineering was changed to the school of metallurgical and ecological engineering and undergraduate students majoring in ecological engineering were cultivated. On the other hand, key laboratories related with metallurgical engineering and resources utilization which affiliated with Minister of Education were established in different universities. These laboratories provide platforms for educating and researching activities concerning sustainability of the metallurgical industry. The content of those courses, activities and achievements of education programs and research including international exchange will be reported in detail.

The theoretical and methodological foundations of the sciences and technologies are essential to the removal of barriers to achieving sustainable systems. The teachings of these concepts still lie in traditional academic disciplines such as engineering, science, and mathematics. This structure can often manifest significant barriers to progress in tackling challenging sustainability issues due to an absence of a multi-faceted, interdisciplinary, systems approach. This work will explore approaches for using current sustainability issues and problems to introduce both systems thinking and traditional discipline specific learning objectives to the classroom. Specific examples will be illustrated for a diverse set of courses and curriculum. Assessment shows an improved rate of achieving teaching outcomes compared to traditional curricular techniques.

Three 3D printed plastic materials, ABS, ABS plus, and CFRP, have been studied for their potential applications in engineering education. Using tensile test, the stress strain curves of the materials have been measured. The Young’s modulus, ultimate strength, and fracture toughness of the materials are calculated from the stress strain curve. The results show that CFRP has the highest stiffness or Young’s modulus. ABS plus has strongest mechanical properties, with highest ultimate strength and fracture toughness. With the measured properties, the 3D printed samples are a viable solution for engineering students to learn mechanical properties of materials.

Due to economic and societal reasons, informal activities including open burning, backyard recycling, and landfill are still the prevailing methods used for electronic waste treatment in developing countries. Great efforts have been made, especially in China, to promote formal approaches. A formal recycling process can, however, engender environmental impact and resource consumption, although information is currently limited. To quantitatively assess the environmental impact of a formal printed wiring board (PWB) recycling chain, life cycle assessment (LCA) was applied to the steps from waste liberation through materials refining [1]. Scenario modeling was conducted, and results were compared to conventional primary metals production processes.

Waste electrical and electronic equipment (WEEE) provides complex challenges and unique opportunities for maximizing resource efficiency in the European Union (EU). This is due in part to the increasing volume, complexity, and value, and decreasing life cycles of such items. Current EU regulations, specifically the WEEE Directive and Battery Directive, focus on the end-of-life management of electronics and the impact of device design and material composition on environmental and human health. While these Directives are robust, the mass-based metrics on which they are focused can lead to a loss of materials that are impactful from an economic, resource availability, and environmental perspective. There is a need for increased research on the impact of these Directives on the availability of secondary raw materials and for an alignment of the WEEE Directive with the European Commission’s Circular Economy Strategy. This can facilitate the development of more holistic policies based on the complete life cycle of devices and all stakeholders involved in its design, manufacturing, use, reuse, repair, and recycling.

The elemental composition of selected e-waste materials has been determined through fusion in a metal and slag bath. During this process the elemental components of the inhomogeneous pulverized material distributed to the copper, slag and fume process streams. Through the analysis and mass of these streams the composition of the original e-waste was calculated.This characterization information was used as the basis of a techno-economic study of the collection and processing of e-wastes in the Melbourne (Australia) metropolitan area. Four consumer electronic items were considered in the study and included: mobile phones, DVD players, televisions and personal computers. In this, the first part of the study, the value contained in these representative items of e-waste was calculated based on the composition, the e-waste disposal rate, the population of the Melbourne region, and the proportion of PCB’s to the total mass of the consumer item.The results showed that the total contained value of elements in the e-waste disposed in the Melbourne region was $19.8 million/year. The consumer item which had the largest contribution was to the total was personal computers at about $9.8 million/year. Most of the value contained in the e-waste is associated with precious metals ($9.0 million/year) and with transition elements ($8.8 million/year).

Thermal management is an ongoing concern in electronics largely because of the challenging specifications of the substrate materials. Substrates must be electrically insulating so as to not interfere with devices or circuits, and so historically have had very poor thermal conductivity. These low thermal conductivity substrates cause heat to build up around devices, raising the local operating temperature and decreasing energy efficiency and device lifetime.This work focuses on creating thermally conductive, electrically insulating epoxy/boron nitride composites. Past work has been limited by the necessity of very high loading levels of BN required to achieve acceptable thermal conductivities (>5W/mK).

Electronic waste (e-waste) contains a wide variety of heavy metals that are detrimental to human and environmental health if they are not disposed of properly. Cathode ray tube (CRT) funnel glass is an important component of the growing volume of end-of-life CRT television and computer monitor waste. CRT glass contains 14–23% of lead (Pb) by weight, which is necessary for protecting monitor users from the cathode ray radiation and for connecting various glass pieces together. However, the large amount of lead contained in the CRT funnel glass creates a serious problem when the CRT glass products reach their end-of-life because lead can escape into the environment and cause severe damage to humans and the environment. Small amounts of lead exposure can result in adverse central nervous system damage that leads to headaches, behavior problems, reproductive issues, and cognitive deficits in children. Despite these wellknown health effects, CRT funnel glass still faces improper disposal fates. In recent years, various researchers have investigated the environmental or economic impacts related to CRT glass recycling. These investigations have focused on the collection, dismantling, and materials recovery of various CRT glass recycling processes. Despite these previous investigations, a systematic evaluation of the economic and environmental attributes of various waste management options for CRT funnel glass specifically, especially at the detailed process level, does not exist. In this paper, environmental impacts and economic feasibility of four currently available and one novel CRT funnel glass waste management options are compared and discussed [1].

The present work aims to recover carbon fiber from industrial polymeric composite waste so as to determine the optimum process parameters of pyrolysis. It is also part of the scope of this study to evaluate the influence of the resin impregnation methods (Prepreg) on the recovered carbon fiber morphological properties. Thermal degradation behavior of the composites and of the virgin carbon fiber was investigated by thermogravimetric analysis (TGA) and pyrolysis was held under an inert atmosphere. The samples were heated up to isotherms of 300, 450 and 550 for 1 hour. To assess the morphological properties and chemical composition of the recovered carbon fiber surface, visual inspection was performed with scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS), respectively, before and after the recovering process. Virgin carbon fiber was used as means of comparison to indicate that the recovered reinforcement material had its structural integrity maintained.

The production of residues in pulp and paper industry is continuously increasing, which generates storing expenses and greater environmental impacts. The grits is an inorganic solid waste generated during the Kraft process by the pulp and paper industry, which presents in its composition the main ingredients of Portland cement. Therefore this paper aims to evaluate the feasibility of incorporating grids to the manufacture of soil-cement compressed bricks. To set the ideal amount of waste to be used, various samples with varying contents of cement, soil and grits were carried. The materials were characterized by mechanicals, physical and environmental tests and the results are consistent with the prescriptive requirements. Regarding the compressive strength at 28 days, all samples had their mean values higher than the normalization, which is 2.0 MPa. The bricks produced with higher amount of grits showed better performance in compressive strength.The global manufacture of pulp, paper and paperboard have been increasing at constant rates since 1960. In 2012 a production of 204 million tons of pulp and 507 million tons of paper and paperboard were registered. Brazil, for instance, produced 14 million tons of pulp and 10 million tons of paper and paperboard generating 240 thousand tons of grits in 2012. Hence, Brazil is positioned as the fourth worldwide producer of pulp and the eleventh producer of paper and paperboard [1]. Grits are yellowish solid and granulated residues from calcined green liquor, composed of sintered and vitrified lime.In this context, the pulp and paper industries are faced with the challenge of increasing the production and, simultaneously, solving the problems related to the final disposal of residues. In the search for a solution to the final destination of these residues, innumerous researches are being developed in order to minimize the economic and environmental impacts of its final disposal. An interesting alternative is the utilization of these residues as a construction material to produce new technologies to the civil construction [2, 3, 4, and 5]. The incorporation of grits residue to the manufacture of soil-cement compressed bricks is a feasible solution from the technical and economic perspectives. This is due to the facts that grits have similar granulometry of a soil considered adequate to the production of soil-cement bricks and it presents two of the most abundant components in cement (lime and silica) in great quantity.Therefore, the aim of this paper is to evaluate the feasibility of incorporating grits residue to the manufacture of soil-cement compressed bricks, obtaining the maximum consumption of residue and respecting the regulatory requirements.

Unique technical means of electric pulse method of disintegration of material and the prospects assessment of the practical realization of new technology are submitted. Analysis of development experience physical bases, unique technical means and prospects assessment the practical realization of electric pulse (EP) method disintegration ores are submitted. The ways which could significantly improve the specific characteristics of high voltage pulse generators are determined and analysed. The experiments have proved the possibility to adapt these technological solutions for EP devices, and a further strategy of the EP technologies development and application has been suggested on this base.

In recent years, alternative treatment processes of nickel low-grade ores have been studied for nickel mining. The present work intends to study the precipitation of metals such as nickel, aluminum, cobalt, iron, zinc and copper from liquor obtained in the atmospheric leaching of a limonite nickel waste. Initially, synthetic solutions were prepared to simulate the sulfuric leach liquor. The iron in the first solution was found in the form of ferrous ions (Fe+2), while in the second solution was found as ferric ions (Fe+3). Precipitation tests were carried at 25ºC and pH was varied with KOH additions. Metal concentration in aqueous and solid samples were analyzed by energy-dispersive X-ray (EDX) and a scanning by electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. Around 100% of iron, 60% of cobalt and 10% of copper were precipitated at pH 3,0 from the solution with ferric ions, while in the solution with ferrous ions, the highest metal precipitation were achieved at pH 5,5.

Raw clay waste is generated in the products conformation stage in the structural ceramic industry. Incorporation of raw clay waste is an alternative to make the structural ceramic sector more environmentally sustainable while reducing the consumption of clayey raw material. The Brazilian structural ceramic industry consumes 10.3 million tons of clay per month. This work aims to study the technical feasibility of raw clay waste addition in clayey mass used in the structural ceramic production. Samples of raw clay waste and clay were tested for chemical, physical and mineralogical characterization. Specimens containing waste contents, varying from 10% to 90% (wt.), were produced and burned in an industrial tunnel at 850°C. The technological properties evaluated were: water absorption, apparent porosity, apparent density, loss on ignition, firing shrinkage and mechanical strength. The results show that the addition of waste improves the evaluated properties significantly. With this, the reuse of raw clay waste in the clayey mass for production of ceramic roof tiles and blocks can contribute to the sustainability of ceramics sectors, reducing raw materials consumption and avoiding waste disposal in landfills. It becomes a feasible alternative to aim the ceramic industry comes to be a “green structural ceramic”.