Ceramic porcelain stoneware production with Spanish clays purified by means of the removal of iron compounds and organic matter using physical methods

As the production of ceramic porcelain stoneware in Spain is totally conditioned by the importation of ball clays, because of the lack of adequate Spanish ball clays, this work has focused on the formulation of ceramic porcelain body from Spanish clays purified by means of physical removal processes. This method was applied to three Spanish clays containing common clay impurities of iron (hematite and siderite) and organic matter. Iron removal was carried out using the wet sieve method, the hydrocycloning method and the electromagnetic filtering method, obtaining a reduction in iron content of up to 80 wt%, while the clay containing organic matter was treated thermally at 400 °C for 30 min so as to leave it almost completely purified. These treated clays, after being characterized (chemical and mineralogical composition, plasticity, organic carbon, thermal behaviour and colour), were used in the porcelain stoneware body composition instead of imported clays, the result being a composition capable of substituting the standard porcelain stoneware formulation in terms of sintering, morphology, colour, flexural strength and dilatometry

Potencialidad de un residuo de frita procedente del sector cerámico como materia prima para la producción de material vitrocerámico

This work consists of studying the devitrification capacity of a residue from sodium-calcium frit, using the vitreous powder sintering method, which follows the traditional ceramic processing route, including a specific heat treatment to generate the appearance of crystals from the original glass phase. Initially the frit residue has been characterized by instrumental techniques such as XRF, XRD and DTA/TG. Furthermore, the chemical analysis (XRF) has allowed the prediction of devitrification potentiality of this residue by theoretical approaches represented by Gingsberg, Raschin-Tschetverikov and Lebedeva ternary diagrams. Then, this residue was subjected to traditional ceramic method, by changing the grinding time, the pressing pressure and prepared samples were obtained at different temperatures. In this part, the techniques for measuring particle size by laser diffraction and XRD and SEM to evaluate the generated crystalline phases, were applied. Finally, it has been found that this frit residue works as glass-ceramic precursor, devitrifying in wollastonite crystals as majority phase and without being subjected to the melting step of the glass-ceramic typical method.Este trabajo ha sido financiado por el Ministerio de Economía y Competitividad Español a través del Proyecto titulado «Desarrollo de nuevos revestimientos fotovoltaicos ecológicos utilizando materiales reciclados para integración arquitectónica, basados en tecnologías de calcogenuros» (ECOART), cuyo número de expediente es RTC-2014-2294-3

Developing CIGS solar cells on glass-ceramic substrates

Cu(In,Ga)Se2 (CIGS) is a p-type semiconductor material and an attractive absorber for thin films solar cells due to its unique optical and electrical properties. The low cost of this technology is based on its application on ecological substrates (glass, ceramic or glass-ceramic materials), effective uses of raw materials and lower thickness of the film (range from 1.5 to 3 µm). In this work, a new glass-ceramic substrate has been developed using industrial wastes materials (recycled glass, bottom ash and fly ash from a thermal power plant) used as support in thin film solar cell technology. The CIGS absorber has been synthesized by an easy and low-cost way of preparation using the co-precipitation method. The solar cell device has been completed and fully characterized. The obtained films were characterized by X-Ray diffraction (XRD), scanning electron microscope (SEM) and electrical characterization. The short circuit current (Jsc), open circuit voltage (Voc), fill factor (FF), and total area power conversion efficiency (η) of the device are 8,11 mA/cm2, 168,2 mV, 27,6% and 0,4% respectively

Development of a glass-ceramic glaze formulated from industrial residues to improve the mechanical properties of the porcelain stoneware tiles

In this research a mixture of 90%wt of industrial residues (recycled soda-lime glass and ashes from a coalpower thermal plant) have been vitrified for their use as ‘‘secondary raw material”. Then, a glaze suspen-sion was prepared to be applied on the porcelain stoneware tile. The tested pieces have been fired by aconventional porcelain cycle at 1180 °C of maximum temperature. The XRD, XRF, SEM/EDS and thedilatometric analysis have been the instrumental techniques used to characterize the material. Finally,an ecological glass-ceramic glaze perfectly fitting on porcelain ceramic tile has been produced, exhibitinga unique phase, anorthite, which ensures a high flexural strength (around 96 MPa) and a significantVickers microhardness of 250 GPa, improving the mechanical properties of a conventional the porcelainceramic tile

Vitrification and sinter-crystallization of fly ash with glass cullet

The synthesis of a new glass-ceramic obtained by sinter-crystallization has been investigated by using soda-lime-silicate glass waste and fly ashes from a coal power thermal station located in Andorra (Teruel, Spain). An original glass as frit with composition of 50wt% recycled soda-lime glass, 25wt% bottom ash, 15wt% fly ash and 10wt% CaCO3 has been melted. After sinter-crystallization at 850ºC, it has precipitated two main crystalline phases: sodium anorthite and the hedenbergite. The linear shrinkage is 1/3 of the value of conventional porcelainized stoneware and the water absorption of this glass-ceramic is similar to a conventional porcelainized stoneware tile (less than 1wt%), being the apparent density slightly higher than this type of tiles (2.6g/cm3 instead of 2.4g/cm3 ). Flexural strength is near twice than porcelainized stoneware (around 950kg/cm2 instead of 550kg/ cm2 ) (95MPa in the new glass- ceramic with respect to 55MPa for the above mentioned as reference material)

Crystal structure of NaCd(H2PO3)3·H2O and spectroscopic study of NaM(H2PO3)3·H2O, M= Mn, Co, Ni, Zn, Mg and Cd

NaCd(H2PO3)3·H2O was synthesized in solution and its structure was studied by single-crystal X-ray diffraction. It crystallizes in the orthorhombic system (Pbca, Z = 8) with the cell parameters: a = 9.2895(14) Å, b = 15.124(2) Å, c = 15.0592(12) Å. Final residual factors R/Rw are 0.0297/0.0790. Both Na+ and Cd2+ are octahedrally coordinated, [NaO6] and [CdO6] share edges to form zigzag chains along [1 0 0]. The 3D framework is build upon these chains which are interconnected by H2PO3 pseudo-pyramids and an intricate network of weak hydrogen bonds. NaCd(H2PO3)3·H2O belongs the series of isostructural phosphites NaM(H2PO3)3·H2O (M = Mn, Co, Ni, Zn and Mg). IR spectroscopic studies show the bands confirming the presence of the phosphite H2PO32− anion in the whole series NaM(H2PO3)3·H2O, M = Mn, Co, Ni, Zn, Mg and Cd. The UV–Vis spectroscopy was used for characterizing the d–d transitions in the Mn, Co and Ni phosphites.The financial support from Centre National de Recherche Scientifique et Technique (CNRST) (Morocco) (URAC 19). The institutional research plan No. AVOZ10100521 of the Institute of Physics and the grant “Praemium Academiae” of the Academy of Sciences of the Czech Republic

Effect of alkali doping on CIGS photovoltaic ceramic tiles

This report studies the influence of alkali elements (Na, K) to morphological, structural and optoelectronic properties of CIGS ceramic tile solar cell. Several ceramic enamels with altered chemical composition in terms of amount of alkali elements have been tested and compared. The influences of alkali type, its quantity and transfer mechanism have been investigated. The solar cell device has been assembled and characterized. The achieved results indicate that alkali elements (Na and K combination) modified the surface roughness and its diffusion from the enamel toward the absorber affect to the structural and final optoelectronic properties of the device. The alkali doping improve the Ga incorporation in the crystal lattice and an increasing in open circuit voltage (Voc) values, fill factor (FF) and the device efficiency. Optimal alkali quantities have been also determined. The best conversion efficiency is achieved for the cell with 4% wt Na2O and 3.2 % wt K2O (Eff. = 3,5 %), which presents an improvement of 30 % in efficiency relative to the standard (STD) solar cell sample chosen for comparative purposes

Práctica de laboratorio: Síntesis y depósito de capas fotoabsorbentes tipo CIGS para dispositivos fotovoltaicos

Departament de Química Inorgànica i Orgànica . Codi d’assignatura: QU0902

The Ceramic Industry in Spain: Challenges and Opportunities in Times of Crisis

In the last few years, the Spanish ceramic industry has gone through a severe crisis, which has led to great market loss and reduction in profi ts. Nevertheless, the ceramic industries in Spain have always characterised themselves as an innovative sector, highly predisposed to changes. It is precisely in times of crisis that the industries most seek to break new ground in their quest for new innovations that will give them an edge over competitors. This study provides an overview of the advances that have recently materialised in the ceramic tile industry. Various technological issues are thus highlighted, such as tile decoration by inkjet printing, laser technology, physical vapour deposition (PVD) technology, fi ring using laser technology (laser­fi ring project), etc. These techniques are being used to develop innovative products, thus obtaining tiles with bactericidal capability, conductive glazes, anti­electrostatic tiles, etc

Elaboration of advanced glass-ceramic glaze for anti-slip porcelain stoneware

The present communication describes the synthesis of anti-slip enamel exhibiting glass-ceramic nature using new matte frits and raw materials. The glass-ceramic glazes obtained are characterized by various instrumental techniques (X-ray fluorescence (XRF), scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical profilometry and microhardness measurements) to elucidate the nature of the crystallized phases, their morphology, surface roughness and the finished tile microhardness. The quality of the glazed piece is evaluated by the regulations of chemical resistance, stain-resistance and slipperiness. The enamel obtained devitrifies in crystals of calcium and barium silicoaluminates. It complies with anti-slip and stain-resistance standards, because its surface roughness is similar to that of non-slip enamel