Symposium CO
Science and Technology for Silicate Ceramics
ABSTRACTS
CO-1:IL01 Wastes as Sustainable Raw Materials for the Manufacture of Fired Clay Bricks. Towards a Circular Economy
P. Muñoz VELASCO, R. Sanchez-Vázquez, L. Muñoz-Velasco, V. Letelier-Gonzalez, Universidad Internacional de La Rioja, Logroño, Spain
We are all living now in a climate emergency which must be faced by implementing an urgent decarbonisation strategy towards an economic system that promptly reduces CO2. Within this framework, oriented to be applied worldwide in any supply chain, the construction and building sector certainly plays a major role due to its large CO2 footprint (i.e. up to 50% of total CO2 emissions in Europe). It is forecasted that CO2 emission rates due to the HVAC requirements might be increased up to 84% by 2050. Besides, it must be also considered the embodied CO2 footprint of used construction and buildings materials, whose initial and end use phase’s impact may represent up to 80% of total CO2 footprint over the building life span. Therefore a cornerstone for boosting up the decarbonisation goal consists in the development of construction materials with low carbon footprint, good thermal performance and easy treatment after its life span. In particular, European fired clay brick industry produces more than 1700 Mill. tones per year and may play a key role on the decarbonization strategy. Actually, several researches have demonstrated the feasibility of replacing natural clay by certain wastes which eventually leads to reduce thermal conductivity which leads to reduce CO2 footprint.
CO-1:IL02 Influence of Coal Ashes on Fired Clay Brick Quality using Random Forest Method
M.V. Vasić1, L.L. PEZO2, Z.M. Radojević1, 1Institute for Testing of Materials IMS, Belgrade, Serbia; 2University of Belgrade, Institute of General and Physical Chemistry, Belgrade, Serbia
Abstract Coal ashes have been extensively explored to be used in bricks. Some studies report the improvement of the quality while others claim the opposite. It is still unknown what are the factors that most affect the quality of the products. The database gathered 302 cases obtained from the literature containing the chemical composition of brick clays and the ashes and other relevant parameters like peak firing temperature and soaking time, to understand the quality of the fired bricks. The behavior of developed products is followed through bulk density, open porosity, water absorption, and compressive strength. The overall conclusions were that the compressive strengths were the highest after firing in tunnel kilns, and that class F ashes are highly suitable to be used in the brick industry as a replacement material for brick clay. The random forest method was employed and showed that the highest influence to the quality of coal-clay products was owed to the contents of Fe2O3 and K2O coming from brick clays, and Na2O, Fe2O3, and K2O from the ashes. The comparison of different mathematical models was done, such as the support vector machine, random forest, boosted trees, and artificial neural network.
CO-1:L03 Valorization of Eggshell Waste, as a Source of Calcium Carbonate, in Ceramic Wall Tiles
I. VILARINHO, E. Filippi, M.P. Seabra, CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, Aveiro, Portugal
The unsustainable use of natural resources is causing several environmental problems. Therefore, interest in waste valorization is increasing due to both environmental and economic benefits. In 2018, approximately 8.5 million tons of eggshell waste per year were generated worldwide and, usually, landfilling is the only option. Therefore, the development of added value applications for eggshell waste is of utmost importance. The present work aims to study ceramic wall tiles prepared with bio-CaCO3 from eggshell wastes. Firstly, the eggshell residue was characterized and then, different levels of substitution (0, 25, 50, 75 and 100 wt.%) were tested. The specimens were sintered, in both laboratory and industrial furnaces, and their properties were evaluated. Through specimens’ characterization, total substitution leads to an increase of at least 19%, in the flexural strength, without affecting the other properties, and all values are within industrial limits. Therefore, this work proved that limestone can be totally substituted by bio calcium carbonate from eggshell waste. Further, the developed ceramic wall tiles can contribute to reduce the amount of waste deposited in landfills and the consumption of virgin raw materials.
CO-1:L04 Exploring Waste-based Body Formulations for Porcelain Stoneware Tiles
C. ZANELLI, S. Conte, C. Molinari, G. Guarini, M. Dondi, CNR-ISTEC, Faenza, Italy
Waste recycling in vitrified ceramic bodies is getting a growing concern in the literature, where a wide range of residues have been proposed as raw materials for porcelain stoneware tiles, with promising results in terms of base properties. However, drawbacks arose about technological behavior of waste-bearing bodies and actual cases of transfer to the tile-making industry seem to be limited to cannibalization of residues of the ceramic process itself. In the present contribution, the main chemical and physical properties of a dozen samples of residues, recycled from Emilia-Romagna region and suitable as ceramic raw materials were characterized. Introduced as fluxes in replacement of feldspathic raw materials in a standard porcelain stoneware batch, contents up to 60% were reached. Bodies underwent a laboratory simulation of the industrial process, stressing on technological obstacles to a large-scale utilization and fully evaluating their behavior. Thus, a waste classification was allowed: the obtained technological profiles summarize preliminary treatments needed, compositional features and effects on grindability, compressibility and sintering by means of variation indexes based on particle size distribution, bulk density, firing shrinkage and water absorption.
CO-1:IL05 A New Paradigm to Satisfy the Global Expectation of Economically Reasonable Slip Resistance Life Cycle Performance
R. Bowman, Intertile Research, Brighton East, VIC, Australia
When the EU announced in 1989 that floors must be adequately safe at the end of an economically reasonable life cycle, they sought a single slip resistance test method. Australian specifiers are now using the wet pendulum test to carefully select tiles that should provide effective life cycle performance based on accelerated wear conditioning results. The test cost of is about that of a ramp test. The real value is in the predictability of a long-term slip resistant outcome, assuming compatible maintenance procedures are specified and then competently performed. Given the accelerated wear data predicts the life cycle performance, wet pendulum audits then provide useful data about the maintenance regime, informing decisions throughout the facility life cycle. An obvious advantage of integrating accelerated wear conditioning protocols into the testing regime is that a tile manufacturer can individually and collectively assess the relative short- and long-term efficacy of different slip resistance design strategies (surface structural topographical aspects such as geometry, shape, height, spacing between elements, etc.; surface microroughness characteristics; material formulations; product application technologies, etc.), together with factors such as the ease of cleaning.
CO-1:IL06 Circular Economy in Ceramic Production: Examples
L. PEREZ VILLAREJO, S. Bueno-Rodríguez, D. Eliche-Quesada, Department of Chemical, Environmental, and Materials Engineering, Higher Polytechnic School of Jaén, University of Jaen, Jaén, Spain
The current industrial model of the economy driven society is based on the linear concept of “take-make-dispose”. A new concept known as circular economy aims to gradually minimize the negative impacts of the linear model. In this framework, fundamental and applied research related to the treatment and management of wastes and by-product streams is widely conducted with the perspective to find possible alternatives to natural raw materials. The aim is to encourage and support the implementation of mature research results in areas related to circular economy, the valorization of waste biomass, industrial, agro-industrial and by-products in order to produce new, high added value eco-friendly materials. Based on the principle that by-products from industrial streams are not considered as wastes but are being treated as raw materials, the heavy clay industries are potential sectors that can absorb significant quantities of them due to the massive nature of their production.
Acknowledgements: This work has been funded by the project Development and characterization of new geopolymerical composites based on waste from the olive industry. Towards a sustainable construction (MAT2017-88097-R), FEDER/Ministry of Science, Innovation and Universities, State Research Agency.
CO-1:L07 Bottom Ashes from Biomass Combustion as Secondary Raw Materials in Porcelain Stoneware Bodies
S. CONTE1, D. Buonamico2, T. Magni2, R. Arletti2, M. Dondi1, G. Guarini1, C. Zanelli1, 1ISTEC-CNR, Faenza, Italy; 2Università degli Studi di Modena e Reggio Emilia, Italy
The ceramic industry is going to be deeply involved in the transition to a circular economy, in order to improve its environmental sustainability. Although this industry is able to recycle its own residues, the recourse to wastes from other sectors is still quite limited, mainly due to lack of knowledge about their effects on the technological behavior and technical performance of products. This study investigated the feasibility of the biomass bottom ash recycling in porcelain stoneware bodies. The work was carried out by simulating the industrial cycle at the laboratory scale. Due to their physical-chemical properties the ashes were introduced in the ceramic batch in partial substitution of feldspars (2-4-6wt%). The characterization of semi-finished products indicated that the ashes did not induce any significant variation, apart from an increase in the viscosity of the slip during the wet milling, easily manageable by a slight deflocculant addiction. The compacts were fired at different T°C in order to follow the evolution of the technological properties and determine the gresification temperature (1200°C for the waste-free body and 1180°C for bodies with ashes). The fired specimens were further characterised for their microstructure (SEM) and mineralogy (Rietveld-XRPD).
CO-2:IL01 Ceramic Frit Containing Copper Slags: Application and Life Cycle Assessment
C. Siligardi, Department of Engineering Enzo Ferrari, University of Modena and Reggio Emilia, Modena, Italy; A.M. Ferrari, Department of Sciences and Methods for Engineering, University of Modena and Reggio Emilia, Reggio Emilia, Italy
Large quantities of waste materials are produced as by-products from metallurgical operations. An important environmental concern derived from copper metallurgy is the slag (usually named copper slag) produced during the primary extraction of copper in pyrometallurgical processes. The slag phase consists predominantly of FeO, Fe2O3 and SiO2 with small amounts of Al2O3, CaO and MgO as well as metals such as Cu, Co and Ni in metallic or oxide form. The aim of this work is to study the feasibility to obtain frits and glazes for floor and wall tiles containing high amount of copper slag and having particular aesthetic and electromagnetic shielding properties. The “frits” are glass mixtures melted and quenched in cold water, which are the main components of glazes and enamels for ceramic and metallic substrates. This work thus reports the feasibility of developing iron-rich frits starting from high amount of copper slags (65, 70,75 wt.%), a soda-lime glass cullet and small amount (10 wt.%) of Na2O. The obtained frits were used to prepare glazes and their characterization was performed by using several experimental techniques. A final LCA analysis was performed, to evaluate the environmental impact of the studied glaze production and to compare it with a traditional one.
CO-2:IL02 A New Concept for Inkjet Technology-based Coatings
J.L. Amorós, A. Moreno, E. Blasco, Instituto de Tecnología Cerámica (ITC), Asociación de Investigación de las Industrias Cerámicas (AICE), Universitat Jaume I de Castellón, Castellón, Spain
Inkjet technology is at present widely used for decorating ceramic tiles. However, owing to the small particle size of the ink used relative to the size of the pores that form between the unfired glaze particles, ink penetration can be regulated. Appropriate selection of both underlying glaze and ink particle size and of the composition of the two materials enables surface coatings, with the targeted aesthetic and technical characteristics, to be obtained by reaction between these materials. In this study, the influence of some operating variables on ink penetration was examined, first, and a model was developed that satisfactorily describes this phenomenon. Two examples were then analysed. In the first, the effect of ink penetration on the aesthetic appearance of the resulting surface was studied. In the second, the improvement of the mechanical properties of a glaze surface, on applying an inkjet ink of defined composition and characteristics, was analysed and discussed.
CO-2:L03 Effect of Ink Micronization on Pigments Physical and Technological Properties
C. Molinari, C. Zanelli, S. CONTE, M. Dondi, CNR-ISTEC, Faenza, Italy; M. Ardit, G. Cruciani, Dept. Physics and Earth Sciences, University of Ferrara, Ferrara, Italy
The advent of ceramic digital decoration has deeply modified the pigment technological requirements, affecting the production process to meet inks required properties. A micronization process is necessary to reduce the particle size (~300 nm). Pigment grindability is a key parameter. The reasons behind different milling behavior are still unknown. To point out the relation between pigment nature and milling behaviour, five different pigments were selected. Reproducing the industrial micronization process, model inks with different particle size were prepared. During the process, particle size distribution and energy consumption were controlled. The effect of the process on phase composition and crystal structure parameters was followed by XRD analysis. Micronized pigments were characterized by optical spectroscopy and colourimetry. Finally, a detailed microstructural characterization was performed. Every pigment exhibits a distinct behaviuonr with non-linear trends of comminution rate and specific energy consumption with particle size. A limited amorphization was observed. Optical spectra and microstructures suggest a specific effect of milling for each pigment. Preliminary results draw a complex dependence of grinding efficiency on the pigment.
CO-2:L05 High Reflective Engobes for Ink-jet Printed Colored Porcelain Stoneware Tiles
E.I. Cedillo-González, M. Governatori, C. Siligardi, Department of Engineering “Enzo Ferrari”, University of Modena and Reggio Emilia, Modena, Italy
Ink-jet decoration is a technology suitable for designing ceramic tiles with solar reflectance (SR) characteristics. SR is the ratio between the solar energy reflected by a surface and the total incident energy. If incorporated into the cities’ building envelope, solar reflective tiles mitigate the Urban Heat Island phenomenon, which is known for making urban centres hotter than rural areas. Here, the fabrication of solar reflective ink-jet decorated tiles using a reflective engobe was investigated. Firstly, six engobe compositions with variable wt.% of a CaO-ZrO2-Al2O3-SiO2 frit and a high refraction index (n) pigment (ZrSiO4) were tested. The engobe having the highest SR was applied into porcelain stoneware tiles, ink-jet printed using the CMYK colour model, glazed and fired at 1205 ºC. The SR ability of the surface’s tiles was evaluated in terms of several variables (pigment and glaze frit wt.%, porosity, thickness, type of glaze matt or glossy). It was found that increasing the wt.% of the frit and ZrSiO4 raises the SR of the tiles. Light colours and the growth of crystals with high n after firing also increases SR, but open porosity and glossy glazes instead decrease SR. Thus, solar reflective tiles can be obtained by ink-jet printing if using a highly reflective engobe.
CO-3:IL01 New Challenges and Opportunities for Sustainable Ceramic Tiles Fighting Viruses and Bacteria
E. Rambaldi, ITALCER Group, Rubiera (RE), Italy
The recent health emergency due to the Covid-19 pandemic has pushed for higher standards of healthiness in environments, in relation to the risk of surface contamination. In general, porcelain stoneware tiles are already known as surfaces that are easy to clean and, consequently, to sanitise. But what happens if the composition of the mix changes and an innovative high recycled content mix is used? And also, what is meant by sustainable ceramic tiles? In this work, the path towards sustainable ceramic tiles with a high recycling content is shown on the basis of a research project carried out in synergy with a ceramic company. Cleanability, antibacterial and antiviral efficacy were assessed according to standard protocols. The results showed that the attitude to cleaning and, consequently, to sanitising are related to the microstructure and surface texture rather than to the composition of the ceramic body. In conclusion, sustainable ceramic tiles with high recycled content can, like traditional ones, achieve high technical performance making them suitable for different destination environments. In addition, effective antiviral, antibacterial and antipollution properties ensure greater surface protection and healthier spaces.
CO-3:IL02 Photo-catalytic Coatings for Water Treatment
U. Lavrencic Stangar, L. Matoh, B. Zener, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia; K. Maver, University of Nova Gorica, Slovenia; I. Arcon, University of Nova Gorica, Slovenia and Jozef Stefan Institute, Ljubljana, Slovenia
Implementation of semiconductor photocatalysis for water treatment is challenging. Post-separation of the catalyst nanoparticles remains the major obstacle, and therefore immobilized photocatalysts are much more desired despite their lower efficiency compared to suspended analogues. Due to its exceptional stability and good performance, TiO2 is still the most suitable photocatalyst for large-area deposition. It was prepared by low-temperature wet chemistry routes and with a silica binder efficiently supported on glass and ceramic substrates. Some strategies to modify TiO2 were employed to overcome its two main limitations, wide bandgap and high degree of recombination. The Sn-modified TiO2 photocatalysts were prepared by sol-gel processing with varied Sn content. The improvement of photocatalytic activity with respect to the unmodified anatase titania was obtained at low Sn concentrations (0.1-1 mol.%). Sn cations promote the formation of nanocrystalline TiO2 rutile phase. The coupling of anatase and rutile in optimal ratio facilitates charge separation and has therefore a beneficial effect on photocatalytic activity.
Acknowledgements: Slovenian Research Agency (P1-0134, L7-1848, P1-0112), CALIPSOplus project (GA 730872, H2020), SR facilities of ELETTRA and PETRAIII at DESY.
CO-3:IL03 Textured Clay Composite Materials and Improved Mechanical Properties
N. Tessier-Doyen, G. Lecomte-Nana, I. DAOU, P. Blanchart, J. Bourret, D.S. Smith, C. Peyratout, R. Guinebretière, C. Pagnoux, P.-M. Geffroy, University of Limoges, Limoges Cedex, France
Conventional shaping techniques such as uniaxial pressing, tape casting or extrusion are promising methods to enhance mechanical properties of silicate ceramics by promoting the orientation of clay platelets. Indeed, kaolinite, halloysite or muscovite phyllosilicates as natural raw materials exhibit an anisotropic structure which can induce significant differences in the final properties of materials depending on the considered direction. However, monitoring thermal treatment is also essential in such materials to favour the organization and to optimize the amount and the size of the mullite phase occurring after sintering. Moreover, adding a slight proportion of a second phase such as low cost silicate-based long fibres or combining different silicate materials with controlled thermal expansion mismatch also contributes to improve the final mechanical properties. In this presentation, different types of silicate ceramic materials are presented: i) clay-based materials obtained by pressing, extrusion or tape-casting processing and ii) mono/multi-layered ceramic composites reinforced with phyllosilicates and silicate fibres or exhibiting internal thermal stresses. Young’s modulus, fracture strength and fracture toughness have been investigated in relation with the microstructure.
CO-3:IL05 The Influence of Surface Microstructure on Ceramic Tile Life Cycle Performance
M. Engels, Forschungsinstitut für Anorganische Werkstoffe-Glas-Keramik-GmbH, Höhr-Grenzhausen, Germany
The European Building Products Directive by the European Building Products Regulation has put pressure on the manufacturers and installers of flooring materials to concern themselves with the life cycle performance regarding slip resistance and cleaning. The presentation addresses the potential of the investigation of the durability of the performance of ceramic surfaces and its correlation with surface topography, measured using non-contact optical measurement methods. New insights in the mechanisms influencing especially slip resistance and cleanability are highlighted as a basis to differentiate between surfaces and to explain their functional behavior as well as their durability. A relevant grouping of surfaces regarding their expected behavior and its implications on the relevance of correlation studies regarding wear properties.will be discussed, A method, developed to simulate the actual wear behavior on site will be discussed. It has been validated by comparing the changes in topography in the laboratory with the actual changes in topography on site, using a duplication method of the surface. The latest developments of this method, using this non-destructive evaluation of the situation on-site to support the assessment of actual changes will be highlighted.
CO-3:IL07 Microstructure-oriented Porcelain Stoneware Tile Composition Design
A. DE NONI Jr., Rodrigo Ramos Silva, Chemical Engineering Department, Federal University of Santa Catarina, Florianopolis, Brazil
A typical porcelain stoneware tile microstructure is typically reported as a combination of its primary components. Glassy matrix 50-65%, dispersed quartz particles 10-25%, mullite crystals <10%, closed porosity 4-6%, open porosity 1.2%. To achieve such properties, a mixture of clay, feldspar, and quartz sand is prepared. Other raw materials can be used to improve certain properties or process parameters. Local availability and raw material prices are also important factors to consider when designing the starting composition and process parameters. The task of creating an acceptable composition is complex. Finally, the microstructure is the last and least important factor to be considered. It is not uncommon for industrial processes to face issues with processing stability. Mechanical property degradation and planarity are two common examples. This is where a microstructure-oriented composition can help. This paper describes a procedure that begins with a microstructure as a target. The target is broken down into a mineralogical composition of four major components: non-plastic flux agents, quartz, kaolinite, and plastic clay. As a result, various combinations of several raw materials can be obtained, followed by laboratory experiments to validate the results.
CO-4:IL01 Detailed Characterization of Amorphous and Crystalline Phases Coupled with Size-strain Analysis by Rietveld Refinement
F. Kristály, Institute of Mineralogy and Geology, University of Miskolc, Miskolc-Egyetemváros, Hungary
Although Rietveld refinement on X-ray powder diffraction data is not a new method, some possibilities for detailed material characterization have not been deeply exploited. Such a possibility is the detailed characterization of amorphous phases or complex evaluation of crystallite size and lattice strain, beyond dislocation density and log-normal size distribution. With Rietveld refinement we can find valuable information beyond phase composition, related to properties and behavior of products. Experiments revealed that we can directly discriminate for multimodal crystallite size distribution of phases, obtaining weight or volume percentage for each size fraction. Similarly, strain and chemical substitution may be defined for several fractions of a given phase. Phase fractions are defined as function of lattice strain or crystallite shape, with the assigned size and chemical information. Performing X-ray diffraction on ceramic slabs, crystallite orientation can be quantified as a function of size and shape. In-situ firing measurements in heating chamber allow to observe the evolution of above-mentioned properties as a function of temperature and time. Selected area measurements with pinhole collimators allow the phase mapping of ceramic bodies.
CO-4:L03 Feasibility of using Waste Clays as Lightweight Aggregates
T. Kronberg, J.-E. Eriksson, L. Hupa, Åbo Akademi University, Turku, Finland
Clay is used as a raw material in production of lightweight expanded aggregates because it forms low-density but high strength particles when sintered above 1200 C. There are major challenges in utilization of clays excavated from building foundations. The use of these waste clays to make lightweight aggregates has a positive environmental impact and contributes towards a more circular economy. The use of surplus excavated clays from Southern Finland as a raw material in the production of lightweight expanded clay aggregates has been studied. Clay properties such as chemical composition, particle size distribution, water content and loss of ignition were measured. The sintering and bloating behaviors were studied by hot-stage microscopy. The firing in laboratory scale was carried out in two steps: pre-heating at 350 C at different dwell times, followed by firing at temperatures > 1100 C. the density of the aggregates was determined. The morphology of the aggregates was studied by SEM/EDS. Densities less than 500 kg/m3 were measured for several clays. Both the peak temperature and the pre-heating was important for the bloating properties of the clays.
CO-4:IL05 New Parameters for Assessing Brick Resistance to Freeze-thaw Cycles
I. Netinger Grubeša, J.J. Strossmayer, University of Osijek, Faculty of Civil Engineering and Architecture Osijek, Osijek, Croatia
The aim of this research is to analyse the reliability of the existing methods, and find new ones, for assessing brick resistance to freeze-thaw cycles. A series of bricks were tested against a range of properties; compressive strength ratios pre-to post-freezing and Maage’s factor, were calculated. Using a database created in this way, an analysis of existing classifiers was carried out and new ones were established based on which bricks could be classified into resistant and non-resistant to freeze-thaw cycles. The median pore radius, the ratio of compressive strengths pre-to post-freezing and the water desorption coefficient at 180-360 minutes proved to be good classifiers with a clearly specified cut-off for the distinction between resistant and non-resistant bricks with an acceptable risk of a wrong decision. The ratio of compressive strengths pre to post freezing and the water desorption coefficient at 180-360 minutes were described using the pore system in the brick.
CO-4:IL06 Evolution of Thermophysical Properties of Kaolin Based Clay Materials
D.S. Smith, Institut de Recherche sur les Céramiques (CNRS 7315), University of Limoges, Limoges, France
Kaolin based clays have been exploited since antiquity for applications involving heat exchanges such as building materials, cooking items and refractories. The thermophysical properties in terms of thermal conductivity and heat capacity reveal considerable complexity due to:
- Presence of minor phases
- Anisotropy of the kaolinite phase
- Microstructural aspects such as orientation and porosity
- Forming conditions
- Heat treatment of the green body
Thermal conductivity measurements on uniaxially pressed samples with a high kaolinite ratio content yield values in the range 0.4 to 1.2 Wm-1K-1 depending on the moisture content and applied pressure. The anisotropy ratio can attain a factor of 2.5. With thermal treatment upto 700°C the thermal conductivity and heat capacity decrease with dehydroxylation and formation of metakaolin. Finally thermal treatments for firing (1000°C to 1400°C) remove anisotropy and yield strong increases of thermal conductivity to > 2.5 Wm-1K-1 due to formation of crystallized phases such as mullite. The roles of porosity and grain size are also discussed in the paper.
CO-4:L08 Numerical Analysis of Porcelain Tile Manufacturing by Integrated Process Simulation
C.L. ALVES1, A. De Noni Jr.2, D. Hotza2,4, J.B. Rodrigues Neto4, S.Y. Gómez González2, R. Janssen3, S. Heinrich1, M. Dosta1, 1Institute of Solids Process Engineering and Particle Technology, Hamburg University of Technology (TUHH), Hamburg, Germany; 2Department of Chemical Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil; 3Institute of Advanced Ceramics, Hamburg University of Technology (TUHH), Hamburg, Germany; 4Graduate Program in Materials Science and Engineering (PGMAT), Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
Porcelain tiles, a high added-value traditional ceramic product, are produced by a sequence of steps, including powder processing (wet milling and spray drying), shaping through pressing; and thermal treatments, as drying and sintering. Up to now, this manufacturing process is guided by insights, material characterization and trial and error approaches that are time-consuming and expensive. Determining optimal processing parameters from simulations for the whole process chain may avoid expensive experimentation. In this contribution, flowsheet calculations were successfully applied for macroscale modeling of the complete process chain of porcelain tile manufacturing. For this goal, a set of semi-empirical models of the different equipment and processing steps has been implemented into the simulation framework Dyssol. The whole process chain starting with the initial powder mixture as well as the resulting product performance has been investigated. In particular, an analysis of the consumed energy and the influence of different process parameters has been performed. The flowsheet simulation demonstrated to be effective in establishing a digital twin of ceramic fabrication, allowing to forecast outcomes and to optimize the energy consumption during the manufacturing chain.