Waste Pharmaceutical Blister Packages as a Source of Secondary Aluminum

Waste pharmaceutical blister packages (WPBs) are a source of solid waste, which are composed of plastics and aluminum, therefore acting as a potential source for secondary aluminum. The structure of WPBs makes the recycling of aluminum notably more complex than typical aluminum recycling. Currently, WBPs are disposed of as municipal solid waste; thus, aluminum is lost from the circulation during incineration. In this work, three types of WPBs were studied, each with two plastic layers and a metallic layer. Delamination of WPBs to separate aluminum and plastic(s) was investigated by using a solution of organic solvents. The effects of temperature (30–50°C), acetone to isopropanol ratio (0–100 vol.%) and different types of WPBs on delamination behavior were investigated. The results suggest that aluminum separation and recovery from WPBs is 100% at optimum conditions. Moreover, an overall indicative flowsheet for recycling and post-processing of segregated aluminum from the plastic is also suggested.

MICROSTRUCTURAL AND PHYSICOCHEMICAL PROPERTIES OF SOME ALUMINUM COOKING TOOLS OBTAINED BY ARTISANAL RECYCLING

Recycling metals waste is one of the ways to recover this waste, but also to preserve mining resources and fight against pollution. Aluminum is one of the most recycled metals due to its relatively low melting temperature, high conductivity, ductility, malleability and its high resistance to corrosion. In Togo, as in many West African countries, aluminum wastes are collected, melted and molded in artisanal way to make new objects for domestic use. The aim of this work is to investigate the process of artisanal aluminum recycling and use several modern techniques of characterization in order to improve thereafter products and manufacturing process. Two types of samples were subjected to a series of physicochemical analysis. One from an old aluminum pot (sample (a)) and the other cut from newly pot obtained after artisanal manufacturing (sample (b)). The measurement of the temperature inside the crucible during scarp aluminum melting operation reveals three temperatures ranges with a melting point around 750℃. Atomic absorption spectrometry (AAS) indicates that the two samples contain mostly aluminum, zinc, copper, magnesium and some traces of lead. Optical microscopy observations show that the alpha aluminum matrix was the most abundant phase with 80 to 90% of the observed area and some inclusions randomly dispersed. X- ray diffraction (XRD) confirms the presence of lines characteristic of alpha aluminum and bohemite (γ-AlOOH).

Reciclaje de aluminio y su contribución en materia de energía: caso FCITEC-UABC / Aluminum recycling and its contribution to energy: case - FCITEC-UABC

El reciclaje de aluminio ha aumentado en los últimos años en un 5% anual. El objetivo de este estudio es analizar la aportación en términos de energía potencial de acuerdo con el aluminio enviado a reciclaje, el cual es generado en las actividades diarias de la Facultad de Ciencias de la Ingeniería y Tecnología de la Universidad Autónoma de Baja California (FCITEC-UABC). La metodología empleada consistió en realizar una investigación documental de los registros de latas de aluminio enviadas a reciclaje durante 2018 y 2019 y con base en el Modelo Individual de Residuos de la Environmental Agency Protection (iWARM-EPA) determinar su equivalente en unidades de energía. De acuerdo con los registros de FCITEC-UABC durante el periodo de análisis, se enviaron a reciclaje 177.7 kilogramos de latas de aluminio, equivalente a 13, 600 unidades, con base en estos datos y el modelo utilizado, la facultad aporta con este material enviado a reciclaje, un potencial de ahorro de energía neta equivalente a 3960.3 kWh[1]. Éstos, por ejemplo, equivalen a 300,000 horas disponibles, para su uso en focos ahorradores de 60W o 79,000 en computadoras portátiles.[1] Kilovatio-hora

The Application of Two Models of Life Cycle Assessment (Lca) for Transition to the Low-Carbon Economy: a Case Study in the Aluminum Industry

This study examined two approaches that account for recycled materials in LCA studies, the recycled content (RC) approach and the end-of-life recycling (EOL) approach, which were reviewed with reference to aluminum. Interviews were conducted to obtain best practices in using these two approaches and carbon footprinting was used as an environmental performance metric. The interview results showed that across the stakeholder groups there was no unanimity or preferences regarding either approach where LCA studies involved metals/aluminum. The case study of aluminum recycling applied a custom computer model developed for a Canadian primary producer that compared the carbon emissions of producing 1 metric ton (mt) of aluminum for the two approaches. The average value of mt CO2 eq. produced per mt aluminum was lower using the EOL approach versus the RC approach in every scenario. Percentage differences indicated substantial differences in the results when the two approaches were compared.

The Application of Two Models of Life Cycle Assessment (Lca) for Transition to the Low-Carbon Economy: a Case Study in the Aluminum Industry

This study examined two approaches that account for recycled materials in LCA studies, the recycled content (RC) approach and the end-of-life recycling (EOL) approach, which were reviewed with reference to aluminum. Interviews were conducted to obtain best practices in using these two approaches and carbon footprinting was used as an environmental performance metric. The interview results showed that across the stakeholder groups there was no unanimity or preferences regarding either approach where LCA studies involved metals/aluminum. The case study of aluminum recycling applied a custom computer model developed for a Canadian primary producer that compared the carbon emissions of producing 1 metric ton (mt) of aluminum for the two approaches. The average value of mt CO2 eq. produced per mt aluminum was lower using the EOL approach versus the RC approach in every scenario. Percentage differences indicated substantial differences in the results when the two approaches were compared.

Synthesis of Cryolite (Na3AlF6) from Secondary Aluminum Dross Generated in the Aluminum Recycling Process

Secondary aluminum dross (SAD) is regarded as a solid waste of aluminum recycling process that creates serious environmental and health concerns. However, SAD can also be used as a good source of aluminum, so that utilizing the SAD for the production of valuable products is a promising approach of recycling such waste. In the present work, a novel eco-friendly three-step process was proposed for the synthesis of cryolite (Na3AlF6) from the SAD, and it consisted of (1) water-washing pretreatment of SAD, (2) extraction of Al component via pyro-hydrometallurgy, including low-temperature alkaline smelting, water leaching and purification of leachate in sequence, (3) precipitation of cryolite from the purified NaAlO2 solution using the carbonation method. By analysis of the parameter optimization for each procedure, it was found that the maximum hydrolysis efficiency of aluminum nitride (AlN) in the SAD was around 68.3% accompanied with an extraction efficiency of Al reaching 91.5%. On this basis, the cryolite of high quality was synthesized under the following optimal carbonation conditions: reaction temperature of 75 °C, NaAlO2 concentration of 0.11 mol/L, F/(6Al) molar ratio of 1.10, and 99.99% CO2 gas pressure, and flow rate of 0.2 MPa and 0.5 L/min respectively. The formation of Na3AlF6 phase can be detected by XRD. The morphological feature observed by SEM revealed that the as-synthesized cryolite had a polyhedral shape (~1 μm size) with obvious agglomeration. The chemical composition and ignition loss of the as-synthesized cryolite complied well with the requirements of the Chinese national standard (GB/T 4291-2017).