Scrap Processing Research Articles

Reuse and upcycling of thermoset prepreg scrap: Case study with out-of-autoclave carbon fiber/epoxy prepreg

A large amount of uncured thermoset prepreg scrap is generated during manufacturing, including both ply cutter trim waste and out-of-spec material. While techniques to recycle end-of-life cured composite waste and reclaim carbon fiber are well established and commercialized, there is little effort made presently towards reusing uncured scrap prepreg. Here, we present a viable and scalable technique to process scrap prepreg into intermediate forms that can be readily manufactured into commercial end-products. Using out-of-autoclave carbon fiber/epoxy prepreg as an example, we report the mechanical properties, microstructure, and performance of composite laminates fabricated with scrap prepreg under various processing conditions. Demonstrator parts manufactured with scrap prepreg are also presented.

Influence of Internal Scrap on Mechanical Properties of Selected Cobalt Alloys

This paper presents the results of mechanical tests carried out on two different commercially available cobalt alloys applied indental prosthetics for the production of frame dentures. The test samples were obtained by the method of investment casting using as a charge pure primary materials and pure primary materials mixed with various additions of process scrap (25, 50, and 75%). The tests showed that the alloys could not reach the mechanical properties reported by the manufacturer in either case. In the case of the alloy without the addition of tantalum, the general conclusion was that both the plastic and strength properties decreased with increasing amounts of the introduced process scrap. The mechanical properties (mainly elongation) of the alloy containing Ta reached the highest values in the samples containing 75% of the process scrap. Examinations of fractures carried out by SEM have revealed their varied character – ductile or transcrystalline. All of the samples tested showed the presence of dendrites and solidification areas, with shrinkage porosity occurring in the internal sample zones.

The Application of Nano Porous Pvdf Beads in Solder Paste Printing

Abstract The porous beads were better crystallized and possessed greater relative surface than ordinary PVDF. With the 64G U disk (01005 more chip devices) production practice experience, analysis of characteristics of the equipment types, main parameters and manual solder paste printing, explore a path from the solder paste selection, storage, use to process printing stencil printing manual. Solder paste printing process is very strong, in addition to the above reasons, there are many other factors affecting the quality of solder paste printing. According to the practical training requirement for solder paste, select suitable packaging specifications, generally 250g, 500g packaging, to avoid losses caused by failure of solder paste. Strict implementation of the first principle, and give priority to the use of recycled (old) solder paste, but can only be used once, then the remaining scrap processing.

Evaluation of the Sanitary Conditions of Head Meat, Esophagus, Diaphragm Meat, and Boning Scrap Processing

Enterobacteriaceae, coliforms, and Escherichia coli counts are important hygiene indicators and may be pathogenic. Thus, the aim of the present study was to determine microbiological contamination in head meat, the esophagus, diaphragm, and boning scraps and evaluate the hygienic conditions of the processing of these products. The Petrifilm® (3M) method for determining Enterobacteriaceae, total coliforms, and E. coli was applied for 104 samples. APHA, European Union, PAHO/WHO, and Brazil/MAPA recommendations were followed. Bleeding and skinning knives were contaminated with E. coli (61.5%). Regarding the meat cuts, 30.76% samples from head meat, the esophagus and the boning flap showed the presence of E. coli in counts up to 2 log CFU/g, while 15.3% of the diaphragm samples showed up to 1.85 log CFU/g. The analyzed comminuted meat was, therefore, shown to be contaminated with E. coli during processing, indicating that end-products from this raw material can offer biological risks.

Polychlorinated naphthalene (PCN) emissions from scrap processing steel plants with electric-arc furnaces

Polychlorinated naphthalene (PCN) emissions of scrap iron processing steel plants were explored by measuring concentrations in stack gases of five plants, in the atmosphere (n=11) at a site close to those plants, and in soil at several sites in the region (n=40) in Aliaga, Izmir, Turkey. Observed stack-gas Σ32PCN levels from the plants without scrap preheating (189±157ngNm−3, average±SD, n=4) showed that they are substantial PCN emitting sources. Stack-gas Σ32PCN level for the plant with scrap preheating was considerably higher (1262ngNm−3). Similarly, Σ32PCN emission factor for this plant was substantially higher (11.9mgton−1) compared to those without scrap preheating (1.30±0.98mgton−1). Results have also suggested that the investigated steel plants emit large quantities of fugitive particle-phase PCNs. Measured soil Σ32PCN concentrations that are considered to be representative of the atmospheric levels were greatly variable in the region, ranging between 0.003 and 10.02μgkg−1 (dry wt). Their spatial distribution showed that main PCN sources in the region were the iron-steel plants. Ambient air levels (1620±800pgm−3) were substantially higher than ones observed around the world and in the study area verifying that the steel plants with electric arc furnaces (EAFs) are important PCN sources. Investigation of possible mechanisms suggested that the combustion processes also contribute to emissions from EAFs in addition to evaporation of PCNs present in the scrap iron.

Polychlorinated biphenyls and organochlorine pesticides in River Brahmaputra from the outer Himalayan Range and River Hooghly emptying into the Bay of Bengal: Occurrence, sources and ecotoxicological risk assessment

River Brahmaputra (RB) from the outer Himalayan Range and River Hooghly (RH), a distributary of River Ganga, are the two largest transboundary perennial rivers supplying freshwater to the northeastern and eastern states of India. Given the history of extensive usage of organochlorine pesticides and increasing industrialization along the banks of these rivers we investigated selected organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the surface water of River Brahmaputra and River Hooghly. Geomean of ΣOCPs (53 ng L−1) and Σ19PCBs (108 ng L−1) was higher in RH compared with geomean of ΣOCPs (24 ng L−1) and Σ19PCBs (77 ng L−1) in RB. Among OCPs, γ-HCH showed maximum detection frequency in both the rivers reflecting ongoing lindane usage. DDT and endosulfan residues were observed at specific locations where past or ongoing sources exist. Elevated concentrations of heavier congeners (penta-hepta) were observed in those sites along RH where port and industrial activities were prevalent including informal electronic waste scrap processing units. Furthermore along River Hooghly PCB-126 was high in the suburban industrial belt of Howrah district. PCBs were found to be ubiquitously distributed in RB. Atmospheric transport of tri- and tetra-PCB congeners from the primary source regions might be a major contributor for PCBs in RB. Heavier congeners (penta-nona) in the urban centers of RB were likely due to industrial wastewater runoff from the oil refineries in the Brahmaputra valley. Σ19PCBs concentrations in this study exceeded the USEPA recommended limit for freshwater. Ecotoxicological risk assessment showed the possibility of adverse impact on the organisms in the lower trophic level due to DDT and lindane contamination. Impact of endosulfan on fishes might be of considerable concern for aquatic environment.

Leaching Behavior of Al, Co and W from the Al-Alloying Treated WC-Co Tool as a New Recycling Process for WC Hard Scrap

The Al-alloying treated tungsten carbide (WC)-Co tool was subjected to grinding using a jaw crusher and planetary mill followed by three wet chemical treatment steps to establish an effective recycling process for WC scraps, especially those generated as bulky and hard scrap. This alloyed WC tool was readily ground to a powder of 1 mm or less and divided into two portions that were 150 µm in size. The wet chemical treatments enabled us to recover W to 69.44% from the under-sized 150 µm and also obtain WC powders from the over-sized 150 µm with a high purity of 98.9% or more.

Life cycle assessment of steel in the ship recycling industry in Bangladesh

The ship recycling industry in Bangladesh provides necessary scrap metal for domestic steel products, such as rebar for construction. These recycled products may represent a dramatic reduction in energy consumption and ecological footprint when compared to production from virgin iron ore. A life cycle assessment approach is used to evaluate energy use and emissions, from when the ships is transported from the originating country for dismantling of retired ships in Chittagong, to the end recyclers (rerolling mills and light engineering shops) in Dhaka. The secondary rebar produced from the scraps saves 16.5 GJ of primary energy per ton of rebar and 1965 kg of CO2eq greenhouse gas emissions per ton of rebar when compared to primary rebar. This study compared different unit operations of steel scrap processing to assess their relative environmental impacts, including Global Warming Potential (GWP), resource use in terms of MJ primary energy, human health, and ecosystem quality. This study finds that the rerolling activities that happen outside of the yards are responsible for the most damage. Adverse impacts in in-yard processing and beached ship cutting are generated by the use of liquid oxygen and the use of gas torches. Changes in cutting methods or use of protective gear during cutting will largely reduce the local environmental and health impacts.

Source apportionment analyses for fine (PM2.5) and coarse (PM2.5–10) mode particulate matter (PM) measured in an urban area in southwestern Nigeria

To determine the influence of regional and local sources of the fine and coarse fractions of airborne particulate matter (PM), samples were collected in 2006, 2007, 2010, and 2013 covering the 2 major seasons (wet and dry) at multiple locations in Ile-Ife, Nigeria. A total of 216 samples for each of the PM2.5 and PM2.5–10 were collected on polycarbonate filters using low volume Gent samplers. Elements and black carbon was measured using x-ray fluorescence (XRF) spectrometry and optical transmissometry, respectively. The average mass concentration for the PM2.5 and PM2.5–10 at Obafemi Awolowo University (OAU) in 2006, 2007, and 2010 exceeded the annual National Ambient Air Quality Standards (NAAQS) of 15 and 60 μg/m3 for PM2.5 and PM2.5–10, respectively. At the Obafemi Awolowo University Teaching Hospital Complex (OAUTHC) sites, the PM2.5 and PM2.5–10 mass fractions also exceeded the NAAQS standards except at the urban background site. Positive matrix factorization (PMF) was used to identify and apportion the PM sources for the combined data from these sampling sites. Four sources each were identified for both PM2.5 and PM2.5–10. The sources are soil (44%), savannah burning (26%), scrap processing (18%) and vehicular emissions (12%) for PM2.5 and soil plus biomass burning (71%), sea salt (22%), scrap processing (5%) and vehicle emissions (tire wear) (2%) for PM2.5–10. Most of the PM mass originated from anthropogenic contributions. The highest contributions were associated with northwesterly wind from the urbanized areas of Ile-Ife.

Gestión de subproductos e impacto ambiental de la chatarrización vehicular del sector transporte público en Bogotá

ONTARE. REVISTA DE INVESTIGACIÓN DE LA FACULTAD DE INGENIERÍA
 El proceso de chatarrización a nivel internacional, tiene incluido como alternativas de manejo la reutilización, tratamiento y aprovechamiento de los residuos con potencial de retorno al ciclo económico, lo que a su vez conlleva a la disminución de pasivos ambientales generados por la disposición de grandes volúmenes que disminuyen la vida útil de los rellenos sanitarios.Colombia cuenta con el aprovechamiento de los materiales ferrosos, pero se dejan de percibir ingresos por los no ferrosos, debido a que no se cuenta con la infraestructura para realizar el aprovechamiento y no se ha incurrido en estudios que vislumbren alternativas que disminuyan los residuos llevados a disposición final. El presente estudio realiza el análisis del proceso de chatarrización para el sector público, en este caso taxis, realizado por la empresa Sidenal, autorizada por la legislación colombiana para tal fin.Para el análisis de la composición de los residuos generados en el proceso se utilizó el vehículo SPARK que tiene mayor participación en la chatarrización, teniendo en cuenta las cifras aportadas por la empresa Sidenal.

Effects of microaerobic fermentation and black soldier fly larvae food scrap processing residues on the growth of corn plants (Zea mays)

Solid residues produced by processing food waste via Microaerobic Fermentation (MF) and by Black Soldier Fly larvae (BSFL) have been proposed as soil fertilizers. Yet, little is known about their effects on plant growth. This study compares the growth of corn plants ( Zea mays ) in soil amended with MF or BSFL residue, with effects of aerated compost on corn growth over ten weeks. Corn plants grown in soil amended with MF residues were 109% taller and had 14% more leaves than those grown in traditional aerated compost (Cedar Grove). But plants grown in BSFL residues were stunted, growing 39% shorter and having 19% fewer leaves on average. Only height data was statistically significant. Results indicate that MF produced from food scraps is a suitable soil amendment product, but BSFL solid residue from a similar source is phytotoxic when amended, untreated, into soil in a ratio of one part residue to two parts soil. More research on additional post-processing methods for BSFL solid residue is needed.

A COMPACTING PROCESS OF THE EN AW 6060 ALLOY

<p>This study reports on an investigation of factors affect the process of compacting Al chips which are used to direct scrap processing through the forward extrusion method. EN AW 6060 chips of different geometry and types were mainly used as the experimental material. The chips were compacted in a die with a vertical channel (10.3mm in diameter). To provide a range of processing conditions, three different weights were selected and compacting was performed under five, different compacting pressures. The movement of the chips within the die during compacting was analysed through numerical simulations using Deform 2D software. Study of the compacting process optimal parameters for increasing the density and enhancing the density distribution were defined. The results from our study clearly show that optimal conditions are obtained when the proportion of D/h is 1/1.1. Moreover, it was recognized that in the process of small chips compacting, there was obtained lower density than in the case of large chips.</p>

Modelling metal flows in the Australian economy

The modelling of metal flows provides a comprehensive picture of metal use in the economy and allows for effective investigation into barriers and enablers to increase the recycling rates. In the export-oriented economy, such as Australia, the modelling requires clearly distinguishing the cycles within and outside of a country, and needs an adequate metrics to assess the country's targets in “closing the material loop”. This article investigates Australian position in the global cycles of metals production and use, and assesses the potential for circularity of metals within the country based on data from 2002 onwards. The analysis shows that over the period from 2002 to 2011 the overall estimate of metals final consumption grew from 8.8 million tonnes to 12.3 million tonnes, or from 445 to 551 kg per person. Similarly, the amount of generated waste metal is estimated to have grown from approximately 5 million tonnes to 6 million tonnes, or 250–270 kg per person respectively. The amount of collected metal scrap grew from 3.3 Mt to 3.9 Mt, with the overall collection rates being relatively stable at about 70%. However, the domestic processing of collected scrap decreased significantly – from 67% in early 2000s to 41% in early 2010s, while the export of scrap increased accordingly. The current levels of waste metal generation, metal scrap collection, and domestic processing of metal scrap in Australia equal approximately 50%, 35%, and 15% of the country's metals final consumption respectively.

Remanufacturing Aided Added-Value Creation, Innovations Meeting to Deliver Sustainable Manufacturing

End-of-life scrap steel such as vehicles bulks and bodies, steel wheel and shells are easily land filled at the end-of-life when treated in a developing country with non-industrial infrastructure. Research idea is about composite shape steel remanufacturing to be sheet steel for construction application through nested recovered pieces of scrap steel within new sheet steel base to meet innovation value creation of remanufactured steel and innovation eco-design of steel products to close supply chain through linkage developed and developing countries of non-industrial infrastructure economy. That can be satisfied through comprehensive business- education-training model conduction firstly at the developing countries to reduce costs and change the intensive labour remanufacturing paradigm collaboratively. Sustainable remanufacturing business model can be applied based on infrastructure of educational institutions such as institutes of technology to adopt environmental, economic, and social developments as triple bottom line sustainability. Such innovation value creation is driven by eco-design and eco-innovation enabling where the meet to deliver human development, employment, and education conscious environment and bench mark recommendations of development directions for upgrading to apply business that allows eco-societies to emerge, through cooperative steel scrap processing.

CIRCUIT TITANIUM IN RUSSIAN INDUSTRY

In the article the author designed the circuit diagram of titanium in the Industry, and the prospects for the use of different types of waste in the production of titanium products. It is noted that the assessment metallofonda titanium, note the following: – in the circuit must be considered export titanium titanium products, which determines the use of imported recycled materials; – perspective direction produce recycled titanium in the near future should be to engage in the processing of obsolete scrap, especially in the aircraft industry. The methodical approach to assess the return period of titanium materials. Found that the creation of titanium clus­ter can dramatically change the situation in the use of recycled titanium, since it is possible to create a uniform system of accounting, collection and processing of information on the production, circulation, consumption and accumulation of titanium based on the evolving relationship in the titanium cluster of producers and consumers of titanium products (both domestic and foreign).

Quality, sources and balancing of iron and steel scrap

Besides iron ore, the main raw material of iron and steel production is steel scrap. This paper presents the quality and sources of creation the iron and steel scrap and estimation of their creation in the future. The content of impurities and trace elements to the scrap is very important and influencing to the quality of the obtained steel. Alloyed steel scrap known composition can often be used as an addition to a metal charge for steel production of the desired composition. Considering the steel scrap formation, the three major groups are elaborated: own scrap or circulation scrap, processing scrap and amortization scrap. The balancing model for estimating of steel scrap creation is based on the calculating the coefficients of the generation circulation, processing and amortization scrap, which are used as the basis for successful modelling.

ИНФОРМАЦИОННЫЙ АНАЛИЗ ИННОВАЦИОННЫХ ТЕХНОЛОГИЙ УТИЛИЗАЦИОННОЙ ПЕРЕРАБОТКИ АВТОМОБИЛЬНЫХ АККУМУЛЯТОРНЫХ БАТАРЕЙ

The article considers the crucial task of determining a strategy for effective and ecologically friendly utilization of automobile accumulator batteries (AAB) being one of the most dangerous for the environment recoverable vehicle components. For this purpose, basing on the descriptions of invention patents, the authors carried out the general information analysis of known innovative AAB utilization technologies and considered the technological procedures of AAB recycling utilization represented in descriptions of national patents for inventions of methods and technical devices used for their implementation. Moreover, a patent search was performed and the numbers of patents and patent applications for inventions on this topic of leading Western countries were identified. They include both the methods and technical devices for AAB utilization separation into individual constituent components – plumbiferous (zinc-containing), electrolyte solutions, polymeric housing elements, and the direct utilization recycled processing of each noted AAB constituent element. There is a great variety of well-known technological procedures for utilization processing of plumbiferous battery scrap that are based on the implementation of various thermochemical transformations in order to get raw materials suitable for reuse. The procedures of utilization processing of AAB electrolyte solutions and polymeric housing elements are represented least of all. Obviously, it is caused by the demand and economic interest in obtaining a much more valuable commodity product from plumbiferous (zinc-containing) scrap. At the same time, the more stringent environmental legislation forces AAB developers and manufacturers to create more efficient technological procedures of utilization processing of all AAB components. The authors highlighted the feasibly prospective way of development of ecologically friendly disposal of polymeric solid waste, which is based on materials recycling resulting into production of corresponding semi finished polymeric crushed fragments which can be used as the effective sound-absorbing substances within different types of noise reducing device constructions.

Melting Features of Electronic Scrap Concentrates

Binary constitution diagrams are considered for Fe–Ni, Co–Ni, and Cu–Zn-systems that are typical for the elemental composition of electronic scrap. Chemical compositions are determined for iron-nickel and copper-zinc concentrates obtained during electric scrap processing. Concentrate melting temperature parameters are determined. It is established that for oxidizing melting of bulk electronic scrap and partly copper-zinc concentrate from electronic scrap it is possible to use melting with supply of high-pressure air streams. It is shown that oxidation of iron-nickel concentrate impurities is possible using saltpeter as an oxidizing agent.

PHYSICAL-MECHANICAL PROPERTIES OF NEW GREEN BUILDING MATERIALS BASED ON GLASS WASTE

Recently several innovative suggestions on how industrial wastes can be utilised in new products have been presented in literature, e.g. as filler or additives in concrete, incorporated in ceramic materials to produce glass-ceramics and pavement construction. In this work, metallurgical materials from secondary aluminium scrap processing and glass waste derived from treatments of packaging and fluorescent lamps were considered for fabrication of new ceramic materials using powder technology and sintering process. The effect of composition and heat treatment temperature, on the sintering process and then final properties, were evaluated. The results showed that, with the proper firing temperature, lightweight ceramic materials containing high amount of glass waste and an innovative product resulting from the processing of secondary aluminum (ArgAlum.) can be produced. The low water absorption (. 1%), low density (. 2 g/cm3) and the good flexural strength (16-20 MPa) associated to relatively low sintering temperatures obtained with the addition of ArgAlum. can be considered as promising initial results to obtain new green building materials.

Environmental assessment of solid state recycling routes for aluminium alloys: Can solid state processes significantly reduce the environmental impact of aluminium recycling?

Solid state recycling techniques allow the manufacture of high density aluminium alloy parts directly from production scrap. In this paper the environmental impacts associated with ‘meltless’ scrap processing routes based on three different techniques, namely hot extrusion, screw extrusion and spark plasma sintering (SPS), are compared with the corresponding remelting route as reference. Analysis of the obtained results allows clear conclusions on the perspectives offered by solid state recycling for systematic environmental impact reduction of aluminium recycling with material and energy savings as most important influencing factors. An overall impact reduction with a factor 2 for the SPS route and 3–4 for the extrusion routes is found to be realistic.