Papers by Keyword: Recycling

Abstract: This work aims to characterize the post-consumption plaster and compare it with virgin plaster. Burrs from plaster frames manufacturing were collected at the manufacturer. These samples were dried in a drying oven. Then, they were milled in a ball mill, until forming a fine and homogeneous powder. The samples were returned to the drying oven at three different temperatures, 100, 150 and 200°C, to define the best drying temperature, because the water removed in this process changes the structure of the semi-hydrated calcium sulfate gypsum into bihydrated. Then, vibrational Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were performed to characterize the virgin plaster and the reused plaster, making it possible to know the structure and the groups present in the components.

Abstract: Recycling is one of the important approaches to manage the waste effectively. Nowadays, many recycle bins were placed in school, university, shopping complex and housing area. Although most of them have good awareness to support these activities, yet there are still who abuse the usage of recycling bin by inserting prohibited items. To cater such an issue, a Reverse Vending Machine (RVM) with material identification module is proposed to accept only empty recycle items and reject the rest. The constructed system consists of rotating mechanism and collection of sensors to detect empty PET bottle and aluminum can respectively. From the experiment, it can be shown that the module capable to reject unwanted material with an average of 82.5% of accuracy. Such capability shows a promising outcome for preventing the abuse of recycling bins, and can be used to realize the RVM concept by introducing a reward to the person who recycle properly.

Abstract: An extensive experimental work of instrumented indentation on isolated particles of Non-Hazardous Waste Incineration bottom ash (NHWI) is presented in this paper. The aggregates studied come from the Garenne quarries at Vignoc (Brittany, France). Two spherical tungsten carbide indenters of respective 0.5 and 140 mm radius “R” were used for test series “A” and “B”. The particles studied have diameters ranging between 20 and 25 mm. With a 0.5 mm radius indenter, average reduced elastic moduli ranging from 15 to 68 GPa were found. An average reduced elastic modulus of 15 GPa was found with the 140 mm radius indenter. The experiments made it possible to highlight the particular heterogeneity that characterizes the rigidity of the types of aggregates studied.

Abstract: Material consumption of production of building materials is determined by the amount of raw materials used for their production, to the total output. One of the ways to reduce material consumption is the use of industrial waste as the main raw material for the production of new construction products. Most of the waste generated as a result of the activities of enterprises are man-made raw materials for the production of products such as brick, lime, cement, etc.Given that man-made raw materials are similar to the natural composition and physical properties and even has a number of advantages (heat treatment, increased dispersion, etc.), the manufacture of building materials from it is usually profitable and justified [4, 5].

Abstract: Composite materials continue to grow in popularity within the aerospace industry as the preferred material for manufacturing large airframe structures. However, the popularity of composite materials has also led to the increase in composite waste. As the popularity of composite materials continues to grow, the proper management and recycling of these composite waste materials becomes increasingly crucial to the sustainability of the environment. In order to investigate potential recycling techniques for composite waste, a team of Purdue University School of Aviation and Transportation Technology (SATT) faculty and students teamed up to investigate the characteristics of 3D printed recycled carbon fiber. A prototype 3D printed recycled carbon fiber part was used for the study. Through the use of microscopy and ImageJ image analyzing software, the researchers were able to determine the void content, fiber volume fraction, and fiber orientation of the prototype 3D printed recycled carbon fiber part and identified potential improvements to the 3D printing process in order to improve the 3D printed part’s characteristics.

Abstract: End-of-life tyres and elastomer products are recognised by European Union as important valuable resource for circular economy. Current work introduces an analysis of devulcanised crumb rubber comminution technique by means of semi-industrial disintegrator DESI-15. For the estimation of grindability, the main kinematic parameter in the processing of materials was given the specific energy of treatment E_s in kWh/t. Grindability of devulcanised crumb rubber aggregates as a function of particle size of the specific energy of treatment was analysed. Classified devulcanised crumb rubber will be used as a component of composite materials for oil spills remediation and for design of composite materials for civil engineering applications.

Abstract: This study examines the elimination potential of bacterial biomass (Streptomyces rimosus) against lead (II). The biomass was used in a raw state and treated with NaOH. The adsorption was influenced by pH, temperature and contact time. Treated biomass eliminates the largest amount of lead (II) compared to raw biomass. The Langmuir isotherm is the most appropriate to describe our results with maximum capacity of 47.63 mg/g for lead at 45°C. These results suggest that microbial species as bacterial biomass can be used successfully in the treatment of wastewater contaminated by pollutants such as heavy metals.

Abstract: The objective of this study was the synthesis of various activated carbons from grape marc issued from oenological by-product as a biosorbent. The biosolid was then applied to remove an industrial dye (red bemacid ETL) in aqueous solution. Activation of the synthesized charcoal was carried out using a solution of zinc chloride induced by two physical methods (microwaves and heating at 300°C). The obtained materials are characterized by FTIR and SEM methods. Results from batch adsorption tests have shown that pH solution, initial dye concentration and contact time affect the adsorption mechanism. Removal of the industrial dye revealed second order kinetics, exothermic adsorption and isothermal adsorption of BET type.

Abstract: 3D printing of plastic materials is very popular nowadays, while printing of wear resistant hard materials is still an issue. Gradient or functionally graded structures are providing improved performance in impact-abrasive application (tunnelling, geothermal drilling, mining, etc.) through the optimal positioning of areas providing high wear resistance and high resistance against impacts. However, printing of such structures by widely used powder bed selective laser sintering leads to the high consumption of raw materials (powders) that cannot be used again for next printing. A method to overcome this problem is explored in current work. The cermets were produced from following powders: (1) commercial, (2) obtained by disintegration of cutting tool inserts (recycled) and (3) reused recycled ones. Tungsten and cobalt used for the production of the majority of cermets are critical raw materials and their consumption should be reduced while the rate of recycling needs to be increased. The surfaces were studied with the help of optical microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The hardness and wear rate of samples in abrasive conditions were measured.

Abstract: This document deals with study of nanoand micro particles of artificial corundum in cement mixtures. This inert material with high hardness is usually used as fine-grained additions of concrete mixture. The most important characteristic of corundum is very high hardness (number 9 on Mohr scale). That is the reason, why is mostly added to the cement mixture primary intended for high load flooring. In this paper were studied several type of recycled corundum classified due to its origin. Because it is a recycled material, it was necessary to first examined basic physical properties such as chemical composition or granulometry. We have applied this fine grain material to cement mixes and compared their mechanical properties. For comparison measurement were used a mixture without this admixture and mixture with a corundum with similar granulometry but non-recycled origin.