The effect of machine and material parameters on rare earth roller separation

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009."June 2009." Cataloged from PDF version of thesis.Includes bibliographical references (p. 40-41).This study addresses the affect of machine and material factors on the separation of PET plastic and aluminum on the Rare Earth Roller magnetic separator. The purposes of this study are to gain a better understanding of how separation efficiencies are influenced and develop a performance profile of the Rare Earth Roller to generalize the behavior of other separators used in the recycling industry. Several operating parameters were explored, including input material concentration, splitter position and feed rate. Experimental design for the tests is presented. Separation performance appears to be dependent on splitter position, a subjective parameter determined by the characteristics of the machine. The separation process was less sensitive to material concentration and feed rate which are specifiable. The results from this study suggest that the Rare Earth Roller can operate at larger volumes of variable concentrations of aluminum and maintain industry standard separation efficiencies.by Esther Hu.S.B

A computer-aided methodology for the optimization of electrostatic separation processes in recycling

The rapid growth of technological products has led to an increasing volume of waste electrical and electronic equipments (WEEE), which could represent a valuable source of critical raw materials. However, current mechanical separation processes for recycling are typically poorly operated, making it impossible to modify the process parameters as a function of the materials under treatment, thus resulting in untapped separation potentials. Corona electrostatic separation (CES) is one of the most popular processes for separating fine metal and nonmetal particles derived from WEEE. In order to optimize the process operating conditions (i.e., variables) for a given multi-material mixture under treatment, several technological and economical criteria should be jointly considered. This translates into a complex optimization problem that can be hardly solved by a purely experimental approach. As a result, practitioners tend to assign process parameters by few experiments based on a small material sample and to keep these parameters fixed during the process life-cycle. The use of computer experiments for parameter optimization is a mostly unexplored area in this field. In this work, a computer-aided approach is proposed to the problem of optimizing the operational parameters in CES processes. Three metamodels, developed starting from a multi-body simulation model of the process physics, are presented and compared by means of a numerical and simulation study. Our approach proves to be an effective framework to optimize the CES process performance. Furthermore, by comparing the predicted response surfaces of the metamodels, additional insight into the process behavior over the operating region is obtained

Postupci razvrstavanja otpada kod postupka recikliranja proizvoda

In the process of waste management, there is the need to separate and sort waste products, which consist of different materials that have different properties, so that the recycling process could be carried out successfully. Here are described manual sorting procedures and mechanical classification of waste products, which are based on the various properties of materials, such as sorting by shape, magnetic separation procedures, classification based on electrical conductivity and classification based on density. As much as the mechanical procedures contributed to the sophistication of waste classification, in special cases, such as in the presence of dirt, oil and other contaminants that cannot be completely removed by mechanical methods, manual sorting remains the main option.Kod prerade otpada potrebno je otpadne proizvode, koji se sastoje od raznih vrsta materijala raznih svojstava, razdvojiti te nakon toga razvrstati kako bi se što uspješnije proveo postupak recikliranja. Opisano je ručno razvrstavanje te postupci mehaničkog razvrstavanja otpada koja se temelje na različitim svojstvima materijala kao što su razvrstavanje oblikom, magnetni postupci razvrstavanja, razvrstavanje na osnovi električne vodljivosti te razvrstavanje na osnovi gustoće. Mehanički postupci doprinose sofisticiranju razvrstavanja otpada, ali u posebnim slučajevima kod prisutnosti nečistoća, ulja i drugih zagađenja koja se ne mogu potpuno ukloniti mehaničkim postupcima, ručno razvrstavanje ima velik značaj i često ostaje glavna opcija

Systematic selection of perspective solid waste mechanical separation technologies for material recovery

Material recovery from waste streams is an important element of the circular economy. It relies on efficient liberation and separation of materials, which remains challenging for commingled solid waste streams. LUT University intends to research and develop new mechanical separation technologies, so an understanding of the state of the art, as well as research and development in the field in industry and academia is required. For objective review and comparison of available and emerging mechanical separation technologies, a database of a new tree-like structure was created and filled with performance figures achieved by different technologies. Custom software written in Julia parsed the database into a tabular format for easy filtering and visualization. The database allowed to describe technologies in terms of separation efficiency, suitable particle size, material categories and connections between these and other parameters. Alongside with technology performance, their underlying principles were characterized in terms of used effects, target material properties and affecting factors, that has led to insight into new possibilities for research. Considering both existing and future technologies, a feasible arsenal of techniques for separation of construction and demolition waste was proposed. Limits of direct sorting methods were identified. Ways to achieve economical multimaterial separation with sensors were discussed. The database showed potential as a decision support tool suitable for systematic selection and comparison of technologies, extendable to keep up with future technological progress

Recovery of metals and valuable chemicals from waste electric and electronic materials: a critical review of existing technologies

The growing development of technology has increased the amount of waste generated by electrical and electronic equipment (WEEE) every year. WEEE contains valuable metals and hazardous materials which, if not properly recovered, may drastically contribute to the depletion of natural resources while posing threat to the environment. The recent escalation of geopolitical tensions has fueled a growing spike in commodity and energy prices. In today's world, the recycling technologies have already evolved from primitive methods to more sophisticated techniques such as automatic disassembly, chemical leaching, electrolysis and so on. It is mandatory that researchers will develop novel technologies to tackle the complexity of WEEE treatment and material recovery. This analysis critically reviews the accomplishments in the field of e-waste recycling and further assesses the principles of recycling, separation, and optimized parameters of different technologies. The application of conventional techniques like pyrometallurgy and chemical leaching (non-cyanide, reduced wastewater) results in an active recovery of various materials. Compared to cyanide and strong acid leading, thiourea and thiosulphate have achieved significant advancements in environmental protection. Additionally, novel technologies like bio-metallurgy cryo-milling, siderophores and supercritical extraction technology also resulted in enhanced recovery efficiencies for base and precious metals, along with metal recovery techniques using recyclable lixiviates. However, the application of these technologies is restricted due to the heterogeneous nature of WEEE. Therefore, this review focuses on the deficiencies of each of them and further discusses the interpretation of future urgent developments in the WEEE recycling sector

Technical, environmental, and economic analysis of required pretreatments for recycling different wastes to be utilized as raw material for producing geocomposite

High consumption of raw materials producing vast amount of wastes has become a major concern in the world. Recycling is one of the discussed solutions for this problem. Different recycled waste materials are nowadays substituted virgin ones in various applications. This study aims to detect the required pretreatments for recycling five different wastes to be used as raw material for producing geocomposites. Moreover, the needed annual investment for initiating and running such a project as well as the environmental effects of the selected processes in terms of energy consumption are investigated. This study develops the earlier researches regarding this scope which are presented as literature review. Results indicate considerable differences regarding investment cost and environmental effects for diverse waste materials owing to their required pretreatments in which the flotation sand from the mining industry contributes to the least risks for the environment with the lowest required investment

Modeling and Design of Material Separation Systems with Applications to Recycling

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (p. 179-193).Material separation technology is critical to the success of the material recycling industry. End-of-life products, post-consumer waste, industrial excess, or otherwise collected materials for reuse are typically mixed with other incompatible materials. These materials must be segregated using material separation processes. This thesis investigates the performance and design of material separation systems for recycling through modeling material flows within these systems. The material separation system models developed here are suited to material recycling because they encompass all types of separation process and any configuration of those processes as well as treat binary and multi-material streams. These models capture the material behavior of separation systems through mass ow balance equations constructed using system configuration and process performance data. The Bayesian material separation model is used to capture the performance of separation stages processing a binary material mixture, while the material separation matrix model, developed here, captures the performance of stages processing multi-material mixtures. A network routing model is used to describe the links between processes within a separation system. The governing mass ow balance equations constructed from the process performance and routing data form systems of linear equations. These equations can be generated and solved programatically. Separation performance can be captured through experimental methods or through physical modeling, but an investigation with either suggests that performance can vary under differing material input conditions and operational settings. Techniques for coping with these effects and potentially using them to tailor system behavior are discussed in a case study on the magnetic roller separation of beverage container shreds. Two case studies use tailored economic metrics to evaluate decisions in the design of separation systems. The effects of operating decisions on an existing plastic container separating line are quantified by evaluating the additional profit from plastics-capture decisions. The second case study investigates the economics of installing a plastics separating line at an energy from waste facility. Modeling suggests several possible configurations for a plastics separating line that outperform configurations suggested by industry experts, showing that the material separation system models developed in this work can provide design guidance in the recycling industry.by Malima Isabelle Wolf.Ph.D

EUROPEAN METTTES PROJECT: METTTES Technology Offers (TOs) PORTFOLIO - Regional Demand Profiles collection

The METTTES (More Efficient Transnational Technologies Transfer in the Environmental Sector) Project,focused specifically on the environmental sector, is characterized by a new approach to estimate technological development needs, basing on an analysis of what current or forthcoming EU/national legislation stimulates demand for innovative solutions. This technology demand will be derived at regional level. The regional demand is analyzed in depth and expressed in a detailed document, Regional Demand Profile (RDP), with high-quality, commercially interesting Technology Requests which address both current and future demand (foresight).In this document are presented, for each RDP, technological solutions which have been identified, assessed and collated in a Technological Offer Portfolio. Potential donors and recipients, following intensive preparation, exchange of information and pre-qualification, were brought together at tailor-made matching events in the demand regions

Mining and Beneficiation of Phosphate Ore

The first commercial production of phosphate rock began in England in 1847. A wide variety of techniques and equipment is used to mine and process phosphate rocks in order to beneficiate low-grade ores and remove impurities. The eighth chapter of this book deals with mining and beneficiation of phosphate ore. The principle and operating conditions of important parts of manufacturing process including separation, classification, removing of carbonates, calcination and flotation was described. The chapter ends with description of techniques used for extraction of rare earth element

Nonterrestrial utilization of materials: Automated space manufacturing facility

Four areas related to the nonterrestrial use of materials are included: (1) material resources needed for feedstock in an orbital manufacturing facility, (2) required initial components of a nonterrestrial manufacturing facility, (3) growth and productive capability of such a facility, and (4) automation and robotics requirements of the facility