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Sandro Hreglich - One of the best experts on this subject based on the ideXlab platform.

  • effect of time and furnace atmosphere on the sintering of glasses from dismantled Cathode Ray Tubes
    Journal of The European Ceramic Society, 2007
    Co-Authors: Enrico Bernardo, Sandro Hreglich, Giovanni Scarinci, G Zangiacomi
    Abstract:

    Abstract The dismantling of Cathode Ray Tubes (CRTs) represents a pressing environmental problem. CRTs consist of three distinguished glass parts. The front part is a barium–strontium glass, while the parts hidden inside the TV sets consist of lead silicate glasses. The high quality standards in manufacturing new CRTs impose a very limited amount of glasses to be recycled in the production of the original components. In addition, the presence of easily reducible oxides (like PbO) in the chemical composition of CRT glasses causes the risk of dispersing poisonous substances during remelting. Sintering of powdered glass could be a profitable way to produce new dense glass based materials without remelting. CRT glasses were found to be strongly susceptible to both the duration of the firing at the sintering temperature and the furnace atmosphere (oxygen, air, nitrogen). The evolution of the relatively large amount of dissolved oxygen, typical of CRT glasses, is found to contrast densification. Very short firing times (up to 15 min) are found to limit gas evolution. In addition, oxidative atmospheres lead to high quality sintered materials, capable of optical transparency comparable to that of pristine glasses.

  • sintered glass ceramics from mixtures of wastes
    Ceramics International, 2007
    Co-Authors: Enrico Bernardo, R Castellan, Sandro Hreglich
    Abstract:

    Abstract Panel glass from dismantled Cathode Ray Tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry have been employed as raw materials for several glass compositions. The prepared glasses were ground into fine powders and subjected to sintering treatments at low temperatures (880–930 °C), with concurrent crystallization, thus obtaining sintered glass-ceramics. The mechanical properties (for example, bending strength exceeding 100 MPa) and the aesthetic appearance of the materials, together with the simplicity of the manufacturing method, are promising for applications in the building industry.

  • sintered sanidine glass ceramics from industrial wastes
    Journal of The European Ceramic Society, 2006
    Co-Authors: Enrico Bernardo, R Castellan, Sandro Hreglich, Isabella Lancellotti
    Abstract:

    Abstract Glass obtained from melting a mixture of industrial wastes (panel glass from dismantled Cathode Ray Tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry) has been employed for the production of sanidine-based glass-ceramics. The glass-ceramics were developed by a sintering treatment with concurrent crystallization, from fine powders (

  • foam glass as a way of recycling glasses from Cathode Ray Tubes
    Glass science and technology, 2005
    Co-Authors: Enrico Bernardo, Giovanni Scarinci, Sandro Hreglich
    Abstract:

    The manufacturing of glass foams is proposed as a way of recycling glasses from Cathode Ray Tubes (CRTs), following a simple and low cost processing route. No melting of CRT glasses is required, and the foaming occurs at relatively low temperatures, thus preserving the chemical stability of glasses. The obtained foams have promising mechanical properties and chemical durability, and they could be suitable for applications in the building and chemical industries.

  • glass ceramics obtained by the recycling of end of life Cathode Ray Tubes glasses
    Waste Management, 2005
    Co-Authors: Fernanda Andreola, Luisa Barbieri, Isabella Lancellotti, Anna Bonamartini Corradi, R Falcone, Sandro Hreglich
    Abstract:

    Abstract This work is concerned with open-loop recycling of end of life Cathode Ray Tubes glass (an unsolved problem when considering that in Europe almost 90% of EOL electronic goods is disposed of in landfills), focusing on the development of glass-ceramics from panel or funnel glass with dolomite and alumina, and the evaluation of the tendency towards crystallisation with particular attention on composition and thermal treatment. Glasses were melted at a temperature of about 1500 °C and transformed into glass-ceramics by different thermal treatments (900 °C to ∼1100 °C temperature range and 0.5 to ∼8 h soaking time). By using the evaluation of thermal, mineralogical and microstructural data it has been pointed out that a good degree of crystallisation is reached at about 1000 °C and with a high proportion of waste glass (50–75%) if 40–45% of CaO and MgO bearer (dolomite) is introduced. In this way alkaline and alkaline-earth silicate and aluminosilicate mainly develop probably with a surface mechanism.

Enrico Bernardo - One of the best experts on this subject based on the ideXlab platform.

  • effect of time and furnace atmosphere on the sintering of glasses from dismantled Cathode Ray Tubes
    Journal of The European Ceramic Society, 2007
    Co-Authors: Enrico Bernardo, Sandro Hreglich, Giovanni Scarinci, G Zangiacomi
    Abstract:

    Abstract The dismantling of Cathode Ray Tubes (CRTs) represents a pressing environmental problem. CRTs consist of three distinguished glass parts. The front part is a barium–strontium glass, while the parts hidden inside the TV sets consist of lead silicate glasses. The high quality standards in manufacturing new CRTs impose a very limited amount of glasses to be recycled in the production of the original components. In addition, the presence of easily reducible oxides (like PbO) in the chemical composition of CRT glasses causes the risk of dispersing poisonous substances during remelting. Sintering of powdered glass could be a profitable way to produce new dense glass based materials without remelting. CRT glasses were found to be strongly susceptible to both the duration of the firing at the sintering temperature and the furnace atmosphere (oxygen, air, nitrogen). The evolution of the relatively large amount of dissolved oxygen, typical of CRT glasses, is found to contrast densification. Very short firing times (up to 15 min) are found to limit gas evolution. In addition, oxidative atmospheres lead to high quality sintered materials, capable of optical transparency comparable to that of pristine glasses.

  • sintered glass ceramics from mixtures of wastes
    Ceramics International, 2007
    Co-Authors: Enrico Bernardo, R Castellan, Sandro Hreglich
    Abstract:

    Abstract Panel glass from dismantled Cathode Ray Tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry have been employed as raw materials for several glass compositions. The prepared glasses were ground into fine powders and subjected to sintering treatments at low temperatures (880–930 °C), with concurrent crystallization, thus obtaining sintered glass-ceramics. The mechanical properties (for example, bending strength exceeding 100 MPa) and the aesthetic appearance of the materials, together with the simplicity of the manufacturing method, are promising for applications in the building industry.

  • sintered sanidine glass ceramics from industrial wastes
    Journal of The European Ceramic Society, 2006
    Co-Authors: Enrico Bernardo, R Castellan, Sandro Hreglich, Isabella Lancellotti
    Abstract:

    Abstract Glass obtained from melting a mixture of industrial wastes (panel glass from dismantled Cathode Ray Tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry) has been employed for the production of sanidine-based glass-ceramics. The glass-ceramics were developed by a sintering treatment with concurrent crystallization, from fine powders (

  • sintered glass ceramics and glass ceramic matrix composites from crt panel glass
    Journal of the American Ceramic Society, 2005
    Co-Authors: Enrico Bernardo, Fernanda Andreola, Luisa Barbieri, Isabella Lancellotti
    Abstract:

    Sintering with simultaneous crystallization of powdered glass represents an interesting processing route for glass–ceramics, especially originating from wastes. Highly dense glass–ceramic samples may be obtained from a simple and short treatment at a relatively low temperature. In addition, glass–ceramic matrix composites may be obtained by mixing glass with suitable reinforcements. In this work sintered nepheline glass–ceramics, based on panel glass from Cathode Ray Tubes, are illustrated. A limited addition of Al2O3 platelets caused a significant improvement in the mechanical properties (elastic modulus, bending strength, microhardness, fracture toughness), already remarkable for the un-reinforced glass–ceramic, compared with traditional nepheline glass–ceramics.

  • foam glass as a way of recycling glasses from Cathode Ray Tubes
    Glass science and technology, 2005
    Co-Authors: Enrico Bernardo, Giovanni Scarinci, Sandro Hreglich
    Abstract:

    The manufacturing of glass foams is proposed as a way of recycling glasses from Cathode Ray Tubes (CRTs), following a simple and low cost processing route. No melting of CRT glasses is required, and the foaming occurs at relatively low temperatures, thus preserving the chemical stability of glasses. The obtained foams have promising mechanical properties and chemical durability, and they could be suitable for applications in the building and chemical industries.

Isabella Lancellotti - One of the best experts on this subject based on the ideXlab platform.

  • Lead waste glasses management: Chemical pretreatment for use in cementitious composites.
    Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association ISWA, 2017
    Co-Authors: Elena Bursi, Luisa Barbieri, Isabella Lancellotti, Andrea Saccani, Maria Chiara Bignozzi
    Abstract:

    This article investigates the effect of a low-impact chemical treatment based on a nitrilotriacetic acid chelating agent on the reactivity of funnel glass derived from discarded Cathode Ray Tubes. Treated and untreated glass has been recycled either as a supplementary cementing material or as a fine aggregate in cementitious mortars. The effect of the treatment on the chemical and morphological properties of cullets, as well as on the solubility in an alkaline environment has been evaluated. Data so far collected underline a change in glass cullets characteristics that consequently affects their behaviour in cementitious mortars, reducing the pozzolanic activity as supplementary cementing material, but strongly decreasing the tendency towards alkali silica reactions when added as a fine aggregate. The leaching behaviour of lead on treated and untreated glass and on derived composites has been determined to verify the sustainability of the prepared materials.

  • crt glass state of the art a case study recycling in ceramic glazes
    Journal of The European Ceramic Society, 2007
    Co-Authors: Fernanda Andreola, Luisa Barbieri, Anna Bonamartini Corradi, Isabella Lancellotti
    Abstract:

    Abstract The management of electrical and electronic equipment waste (WEEE) is a significant problem of industrialized countries, in the last decades it has been noticed an appreciable increase of this residue, consisting of about 80% of television sets and computers containing end of life (EOL) Cathode Ray Tubes (CRT). Specific technologies permit to dismantle the kinescope, obtaining different glasses with high quality level and specific chemical compositions. The presence of dangerous elements makes critical the re-use in many fields of application. The present work proposes the feasibility of CRT glass recycling in ceramic field using it into a base glaze formulation as substitute of “ceramic frits”. The study was conducted in two phases, laboratory scale in order to study the suitable glaze formulation and semi-industrial scale with the technological support of an Italian ceramic glaze producer. The glazes obtained have aesthetic and mechanical properties extremely similar to the standard ones.

  • sintered sanidine glass ceramics from industrial wastes
    Journal of The European Ceramic Society, 2006
    Co-Authors: Enrico Bernardo, R Castellan, Sandro Hreglich, Isabella Lancellotti
    Abstract:

    Abstract Glass obtained from melting a mixture of industrial wastes (panel glass from dismantled Cathode Ray Tubes, mining residues from feldspar excavation and lime from fume abatement systems of the glass industry) has been employed for the production of sanidine-based glass-ceramics. The glass-ceramics were developed by a sintering treatment with concurrent crystallization, from fine powders (

  • sintered glass ceramics and glass ceramic matrix composites from crt panel glass
    Journal of the American Ceramic Society, 2005
    Co-Authors: Enrico Bernardo, Fernanda Andreola, Luisa Barbieri, Isabella Lancellotti
    Abstract:

    Sintering with simultaneous crystallization of powdered glass represents an interesting processing route for glass–ceramics, especially originating from wastes. Highly dense glass–ceramic samples may be obtained from a simple and short treatment at a relatively low temperature. In addition, glass–ceramic matrix composites may be obtained by mixing glass with suitable reinforcements. In this work sintered nepheline glass–ceramics, based on panel glass from Cathode Ray Tubes, are illustrated. A limited addition of Al2O3 platelets caused a significant improvement in the mechanical properties (elastic modulus, bending strength, microhardness, fracture toughness), already remarkable for the un-reinforced glass–ceramic, compared with traditional nepheline glass–ceramics.

  • glass ceramics obtained by the recycling of end of life Cathode Ray Tubes glasses
    Waste Management, 2005
    Co-Authors: Fernanda Andreola, Luisa Barbieri, Isabella Lancellotti, Anna Bonamartini Corradi, R Falcone, Sandro Hreglich
    Abstract:

    Abstract This work is concerned with open-loop recycling of end of life Cathode Ray Tubes glass (an unsolved problem when considering that in Europe almost 90% of EOL electronic goods is disposed of in landfills), focusing on the development of glass-ceramics from panel or funnel glass with dolomite and alumina, and the evaluation of the tendency towards crystallisation with particular attention on composition and thermal treatment. Glasses were melted at a temperature of about 1500 °C and transformed into glass-ceramics by different thermal treatments (900 °C to ∼1100 °C temperature range and 0.5 to ∼8 h soaking time). By using the evaluation of thermal, mineralogical and microstructural data it has been pointed out that a good degree of crystallisation is reached at about 1000 °C and with a high proportion of waste glass (50–75%) if 40–45% of CaO and MgO bearer (dolomite) is introduced. In this way alkaline and alkaline-earth silicate and aluminosilicate mainly develop probably with a surface mechanism.

Susumu Yonezawa - One of the best experts on this subject based on the ideXlab platform.

  • reduction melting combined with a na2co3 flux recycling process for lead recovery from Cathode Ray tube funnel glass
    Waste Management, 2014
    Co-Authors: Takashi Okada, Susumu Yonezawa
    Abstract:

    Abstract With large quantity of flux (Na 2 CO 3 ), lead can be recovered from the funnel glass of waste Cathode-Ray Tubes via reduction–melting at 1000 °C. To reduce flux cost, a technique to recover added flux from the generated oxide phase is also important in order to recycle the flux recovered from the reduction–melting process. In this study, the phase separation of sodium and the crystallization of water-soluble sodium silicates were induced after the reduction–melting process to enhance the leachability of sodium in the oxide phase and to extract the sodium from the phase for the recovery of Na 2 CO 3 as flux. A reductive atmosphere promoted the phase separation and crystallization, and the leachability of sodium from the oxide phase was enhanced. The optimum temperature and treatment time for increasing the leachability were 700 °C and 2 h, respectively. After treatment, more than 90% of the sodium in the oxide phase was extracted in water. NaHCO 3 can be recovered by carbonization of the solution containing sodium ions using carbon dioxide gas, decomposed to Na 2 CO 3 at 50 °C and recycled for use in the reduction–melting process.

  • energy efficient modification of reduction melting for lead recovery from Cathode Ray tube funnel glass
    Waste Management, 2013
    Co-Authors: Takashi Okada, Susumu Yonezawa
    Abstract:

    Abstract Lead can be recovered from funnel glass of waste Cathode Ray Tubes via reduction melting. While low-temperature melting is necessary for reduced energy consumption, previously proposed methods required high melting temperatures (1400 °C) for the reduction melting. In this study, the reduction melting of the funnel glass was performed at 900–1000 °C using a lab-scale reactor with varying concentrations of Na 2 CO 3 at different melting temperatures and melting times. The optimum Na 2 CO 3 dosage and melting temperature for efficient lead recovery was 0.5 g per 1 g of the funnel glass and 1000 °C respectively. By the reduction melting with the mentioned conditions, 92% of the lead in the funnel glass was recovered in 60 min. However, further lead recovery was difficult because the rate of the lead recovery decreased as with the recovery of increasing quantity of the lead from the glass. Thus, the lead remaining in the glass after the reduction melting was extracted with 1 M HCl, and the lead recovery improved to 98%.

Francois Mear - One of the best experts on this subject based on the ideXlab platform.

  • lead extraction from waste funnel Cathode Ray Tubes glasses by reaction with silicon carbide and titanium nitride
    Journal of Hazardous Materials, 2009
    Co-Authors: Pascal G Yot, Francois Mear
    Abstract:

    As a possibility to clean waste CRT glass, treatment of lead-containing glass with a reducing agent, SiC or TiN, leads to a porous material containing metallic lead, Pb(0), located on the surface of the pore, and unreduced lead, Pb(II). The influences of reducing agent content, of the time, and at last of the temperature on lead reduction were analysed. Our investigations have pointed out significant differences as a function of the used reducing agent. CRT glass heat treated with SiC lead to less Pb(0), compared to TiN as shown by X-Ray diffraction, and differential scanning calorimetry (DSC). It has been also evidenced that lead reduction occurs on randomized zones inside the sample leading to macroscopic lead beads inside glassy samples. XPS and XAS measurements were also carried out to investigate the local structure of lead and have evidenced a change of role of lead inside the glassy framework in function of the used conditions.

  • local structure around lead barium and strontium in waste Cathode Ray tube glasses
    Journal of Non-crystalline Solids, 2007
    Co-Authors: Francois Mear, Pascal G Yot, M Ribes, Alexander V Kolobov, Mariefrancoise Guimon, D Gonbeau
    Abstract:

    Abstract Cathode-Ray Tubes (CRTs) are made of two different kinds of glasses. The front part, panel, or screen, is made of barium- and strontium-containing glasses, while the rear part, the funnel, is made of lead-containing glasses. The structure and the role of these elements in the glasses are different: lead oxide is generally considered as a network intermediate whereas barium and strontium oxides as network modifiers. To study the local structure around the three aforementioned heavy elements we have used X-Ray absorption spectroscopy (XAFS) on Pb and Ba LIII-edges and Sr K-edge as well as X-Ray photoemission spectroscopy (XPS) analyzing the Pb 4f, Sr 3p, Ba 3d, Si 2p and O 1s core peaks. Due to the complex formulation of these glasses the coordination of lead and strontium could be affected compared with the local structure of binary glassy systems. We demonstrate that the average coordination number of lead is close to three (Pb–O distances being 2.24 A) as in other lead silicate glasses. In case of strontium, the coordination number is found close to five (Sr–O distances being 2.52 A) similar to that in Sr-containing glasses.

  • the characterization of waste Cathode Ray tube glass
    Waste Management, 2006
    Co-Authors: Francois Mear, Pascal G Yot, Martine Cambon, M Ribes
    Abstract:

    New re-use applications are needed to address the relatively large quantity of waste electronic products generated in the world. Cathode-Ray Tubes (CRTs) from computer monitors and TV sets are a large component of such waste. The three glass components of CRTs are the funnel, panel and neck, which are produced by various manufacturers and are now collected by asset-recovery centres. In this paper, we characterize waste funnel and panel glass from dismantled Cathode-Ray Tubes with a view to assisting the development of new re-use applications. The heavy metal (lead, barium, and strontium) content of such glass represents an acute risk to the environment. Our results of the chemical composition for different kinds of waste CRT glass including black & white and color CRTs show that CRT glass from different producers have generally similar chemical compositions. In particular, the compositions of funnel and panel black & white CRT glass are similar, but are different to those of panel and funnel color CRT glass. We also measured the following specific properties of each type of CRT glass: density, glass transition temperature, and linear coefficient of thermal expansion. It was found that the coefficients of thermal expansion of CRT glass do not vary with their composition. In contrast, the measured densities and glass transition temperatures do vary with composition. On the basis of our experimental data and data found in the literature, we outline the main properties of several waste CRT glass currently in circulation. The aim of this study was to provide the data required to determine if this kind of waste could be entirely (or partially) re-used and to aid the search for promising methods of treatment.

  • elaboration and characterisation of foam glass from Cathode Ray Tubes
    Advances in Applied Ceramics, 2005
    Co-Authors: Francois Mear, Pascal G Yot, Martine Cambon, M Ribes
    Abstract:

    AbstractResearch into the recycling of electronics waste materials, such as Cathode Ray Tubes (CRTs) and in particular their component glasses, is required by both French and European legislation. One possible solution to the problem of CRT glass waste is to convert it into foam glass, a material with very promising properties. Foam glasses can be prepared from CRT glasses containing heavy elements (lead, barium) through reaction with a reducing agent such as TiN or SiC. The present experimental study sought to determine the mechanism of foam glass formation and the structural differences between bulk and foam glasses. Additionally, the specific characteristics of bulk and foam glasses such as density, porosity, thermal and mechanical properties were determined, as well as their structural characteristics, using X-Ray diffraction, differential scanning calorimetry, photoelectron spectroscopy and scanning electron microscopy with energy dispersive spectroscopy. The results indicate that reutilisation of CR...