Search

Particulate composites based on poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) biopolymers have been formulated. Silver skin (SSK), the by‐product derived from the roasting of coffee beans, has been milled to micrometric size and added up to a 30 wt% of loading, without any previous treatment. The dynamic mechanical properties of the composites have been investigated, as well as the stability toward UV and IR radiation. The filler improves some mechanical properties such as the elastic modulus (E′) mostly in PBS. Photoaging experiments demonstrate that SSK, due to its polyphenols content and antioxidant activity, is able to protect both PLA and PBS from UV degradation, highlighting an added value of SSK waste‐based composites. [ABSTRACT FROM AUTHOR]

River maintenance is required for environmental risk management; however, the resulting vegetable biomass owns poor properties that preclude its treatment in an energy power plant. Nevertheless, the large availability of river biomass and a possible valorization of the by product from the gasification process (namely char, a fine‐grained vegetable carbon) can encourage and make this operation more sustainable. If the use of char as soil or substrate improver has been widely studied in the last 15 years, the application of this substance for construction materials or composites is starting to gain more attention recently. Indeed, in addition to the great advantage of carbon sequestration, the use of char can reduce the energy associated with the production process of such materials by decreasing the consumption of raw materials. In this work, char deriving from the gasification process of local river biomasses is fully characterized and used in different ratios in polyurethane panels for insulating purpose. Remarkably, polyurethane panels show an enhancement in thermal insulating power and electric conductivity by increasing the char content. Enhancements in terms of mechanical properties are also observed for maximum char content up to 1 wt%. In contrast, higher content results in preventing a good development of polymerization and consequently of good properties. Precisely, the char use significantly increases the maximum load in stress‐relaxation tests and improves the load recovery after 10 min, whereas higher elastic modulus and compressive strength values are observed in compressive tests. The char effectiveness toward more sustainable and performant insulating materials is demonstrated. [ABSTRACT FROM AUTHOR]

Within a circular economy approach, this study investigates the environmental impact of lightweight aggregates (LWAs) produced starting from different mixes of different clays with brewery sludge and cattle bone flour ash (CBA), used as poring and fertilizing agents, respectively. The environmental impact was evaluated by means of release tests, insulation capacity, carbon footprint (CFP), and particulate matter emission during pellet firing. Release tests representative of LWAs realistic application showed very high release of phosphate and satisfactory release of potassium. The thermal insulation of the LWAs was tested by thermal imaging camera and resulted highly variable depending on the composition, with the mix containing CBA performing best. This latter composition leads also to the smallest CO2 equivalent emission, due to the calorific power of CBA, allowing lower consumption of fossil fuels during the LWA production. Finally, total particulate emissions during the thermal treatment resulted similar in terms of mass for all mixes, while differences in terms of particle morphology and composition occurred. Samples containing residue resulted with a quite good release behavior, CFP, and insulation properties, but higher emission of particles, particularly when glass is added. [ABSTRACT FROM AUTHOR]

The paper analyzes a solution in green manufacturing of foamed or cellular ceramics. The objective of this study was to determine the technical solution for rice husk ash and "tales" of mixed glass cullet reusing based on the specific properties of these materials for creation of spherical holes inside ceramic using the process of coalescence of cellular glass. The paper reports on experimental results obtained from the production of lightweight cellular glass granules produced using glass cullet and rice husk ash. Lightweight cellular glass granules were mixed with clay, pressed and fired in air at 920°C. Clay sintering and the formation of ceramic were followed with the coalescence of cellular structure of glass granules and with the formation of spherical hollows inside the matrix. Density and strength of the fired ceramic bodies were determined. It is observed that the lightweight ceramics with density 900 ÷ 920 kg/m3 possess a compressive strength of about 5 MPa that is acceptable for bricks or tiles manufacture. The utilization of amorphous silica waste for lightweight ceramics manufacture helps in reducing waste disposal concerns and costs associated, and also transforms the waste into an alternative raw material with added value, moreover making the final product cheap. [ABSTRACT FROM AUTHOR]

This work reports the results of an investigation aimed at the development of sintered glass‐ceramic tiles by the sinter‐crystallization of mixtures composed of aluminum slag and reclaimed packaging glass. The thermal behaviors of mixtures incorporating 50 and 60 wt% Al slag were established by differential thermal analysis (DTA). Green compacts were sintered in a temperature range of 800°C‐1050°C and then soaked for 10‐60 minutes. The mineralogical characterizations of the sintered materials were obtained by X‐ray diffraction (XRD). The achieved results indicated that the sintering of aluminum slag and packaging glass reclaimed led to a glass‐ceramic material composed mainly of needle‐like crystals of wollastonite (CaSiO3). The bloating of samples during firing was evaluated according to a Cougny predictive diagram. After initial observations and according to bending strength characterizations, sintered tiles prepared from aluminum slag and glassy sand are appropriate for floor pavement and wall covering. [ABSTRACT FROM AUTHOR]

The circular economy in the area of waste management implies their re‐use as a raw material in different production cycles. Both the qualitative and quantitative characteristics of the residues from the agro sector and those of the products of the ceramics sector make possible to think of a feasible application. This review will illustrate some examples of recycling of residues deriving from animal and vegetable sectors (and two post consume products, spent coffee grounds, and packaging glass cullet), studied by the authors, falling within the concept of urban and agricultural sustainable development. Not only the most traditional products such as glass‐ceramics, glazes, bricks, but also the most innovative lightweight aggregates for plant structures or in and out soil cultivation, as well as additives such as deflocculants for ceramic suspensions, which will be illustrated from the design/production, characterization, and comparison with commercial products. [ABSTRACT FROM AUTHOR]

In this study, we reported the studies on a glass-ceramic foam with wollastonite and cristobalite micrometric crystals prepared by sintering a borosilicate glass waste with organic binder as foaming agent. The waste glass, coming from the dismantling of washing machine, was characterized by high CaO content and low-temperature sinterability. The effect of the temperature on the sinter-crystallization ability of the borosilicate glass waste was followed with thermal analysis, heating microscopy, and electron scanning microscopy (ESEM) observations. Additionally, the effect of temperature on the evolution of crystalline phases and density variation was monitored with XRD and density measurements. The softening started at 800°C and crystallization at 845°C to be completed at 900°C with a linear expansion of 38-40% in the range 850-900°C. Wollastonite and cristobalite were identified as crystalline phases in variable proportions dependently upon temperature. No crack evidence was found at high ESEM magnification even though cristobalite crystals were present. The final products showed a total porosity around 78-79% and an apparent density of about 0.5 g/cm3, in line with common porous closed-cell glass foams used for thermal insulation. [ABSTRACT FROM AUTHOR]

The cleaned cathode ray tube (CRT) glass comes from the dismantling plant of TV and PC color kinescopes and has been used to completely replace both feldspathic and inert components of a traditional ceramic body. Panel glass has been added (up to 20 wt%) to a mixture of two commercial ball clays in order to obtain laboratory tiles sintered at 1210°C. Densification has been studied according to ISO rules, while sinterability has been estimated by optical dilatometry. The samples obtained showed main properties similar to commercial ceramic floor and/or wall tiles. [ABSTRACT FROM AUTHOR]

Waste generated in ceramic tiles manufacturing is not usually recycled inside the productive plant, but rather disposed to landfill. This paper deals with ceramic residues from polishing and glazing processes, as constituents for innovative blended cements. New binders made up of 75% CEM I 52.5 R and 25% residues were chemically, physically, and mechanically characterized with reference to EN 197-1 requirements and the results compared with ordinary Portland cement. Mechanical strength development and microstructure of the relevant mortar have been investigated up to 90 days of curing, and the behavior of polishing and glazing residues as cement constituents is reported. [ABSTRACT FROM AUTHOR]

This article presents the results of an experimental activity aimed at investigating the technical feasibility and the environmental performance of using municipal solid waste incineration bottom ash to produce glass frit for ceramic glaze (glaze frit). The process includes an industrial pretreatment of bottom ash that renders the material suitable for use in glaze frit production and allows recovery of aluminum and iron. The environmental performance of this treatment option is assessed with the life cycle assessment (LCA) methodology. The goal of the LCA study is to assess and compare the environmental impacts of two scenarios of end of life of bottom ash from municipal solid waste incineration (MSWI): landfill disposal (conventional scenario) and bottom ash recovery for glaze frit production (innovative scenario). The main results of the laboratory tests, industrial simulations, and LCA study are presented and discussed, and the environmental advantages of recycling versus landfill disposal are highlighted. [ABSTRACT FROM AUTHOR]

In this work a complete characterization of rice husk ash (RHA) was conducted in order to evaluate mainly the composition and the thermal reactivity in terms of crystalline phase evolution. Moreover, the screening results of the research conducted on the possibility to use RHA as silica precursor in ceramic materials, such as ceramic glazes, were reported. The selected frits were prepared in a semiindustrial furnace and the obtained glasses were investigated in comparison with the frits prepared from pure quartz. Besides, laboratory glazes were obtained and characterized following the technical rules. This work allows to confirm the possibility to use RHA as silica precursor for the development of glazes for ceramic tile. The results evidenced, however, that it is not possible for a generalized production substitution of quartz with RHA. [ABSTRACT FROM AUTHOR]

The crystallization behavior of 10 binary glasses belonging to the CaO–MgO–Al2O3–SiO2 quaternary system and two glasses corresponding to anorthite and diopside composition was investigated by X-ray diffraction, thermal, and thermomechanical analyses, and scanning electron microscopy. Particular emphasis is laid on the quantitative X-ray diffraction analysis by the Rietveld–reference intensity ratio combined procedure, which seems to be a useful tool to obtain time–temperature–transformation diagrams. Results showed that to obtain glass–ceramics with a significant crystalline phase presence, it is necessary to treat samples at 1000°C for 4 h or at 1100°C for 1 h. [ABSTRACT FROM AUTHOR]

Examines the nucleation and crystal growth of diopside Ca(Mg,Al)(Si,Al)[sub 2])[sub 6] crystals. Completion of crystallization; Assessment of the activation energy; Reduction on the volume of residue.

Examines the nucleation and crystallization kinetics of glasses from fly ash. Susceptibility of glasses to controlled crystallization; Development of acicular and branched wollastonite crystals; Temperature rate of crystallization kinetics and cooling rate.

Examines the development of calcium aluminosilicate glass-ceramics from waste materials with iron oxides. Suitability of vitrification/devitrification techniques for recycling and exploitation; Implication for waste disposal problems; Range of crystallization activation energy values; Role of ions in the crystallization tendency.

The article discusses the provision concerning the budget of Italy which stipulates that no taxes or expenditures may be established by the law approving the budget nor may the law approving the budget amend existing legislation. The norms that discipline the compilation of the national budget of Italy are contained in Article 81 of the Constitution. This provision stipulates that no new taxes or expenditures may be established by the law approving the budget, nor may the law approving the budget amend existing spending legislation. The national budget is, therefore, an executive act with a pre-established content and a limited scope. In fact, during the thawing up of and debate on the budget, the government and Parliament may exercise their respective decision-making powers over an extremely limited area of spending. This provision does not permit the budget law to be used as an instrument of economic policy. In particular, the multiyear budget must, according to the new law, provide that the growth of current expenditures is matched by the growth of revenues and does not continue, as in the past, to expand the deficit. This new and more stringent norm on covering expenditure reinforces the already existing checks in the Italian Constitution.