Traditional Ceramic Industry Research Articles

3D printing of kaolinite clay with small additions of lime, fly ash and talc ceramic powders

Direct ink writing technique, an extrusion based additive manufacturing process, has been used to fabricate kaolinite clay based-ceramics with several inexpensive ceramic powders: lime, fly ash and talc. All the above materials are commonly used in the traditional ceramics industry, in both small and large industries, and therefore available worldwide. This research shows the simplicity of the process feasible not only for companies but also for individual users. The samples were fabricated with water to clay ratios (W/C) between 0.68 and 0.72. Additives were tested in 3.0, 5.0 and 7.0wt.% with respect to the clay contents, although 3 wt.% of additives worked best. Cylindrical samples were fabricated with 20mm in diameter and 20mm in height in order to test their compressive strength and density. Measurement samples were previously cured for three days at room temperature and then exposed to 1100?C for 1 h. The powdered additives and their corresponding mixtures with clay were characterized with scanning electron microscopy, X-ray fluorescence and X-ray diffraction techniques. Results showed that samples with 0.70 W/C ratio and using fly ash as an additive were the best in terms of workability, mechanical properties and surface finishing.

Adaptability of sediment from Joumine reservoir, Tunisia, as a ceramic raw material

Sediment occupies the storage capacity of reservoirs and reduces the sustainability of the surface water resource. A countermeasure is simply dredging, but this has often not been carried out because of financial reasons, especially in developing countries. One solution is to convert the sediment into a valuable commodity. This study examined the adaptability of the sediment in Joumine reservoir as a ceramic raw material. The sediment particles were plate-like in shape. Their size was around 0.5 µm, which is much smaller than the Japanese traditional ceramic raw material. The appropriate water content for forming was around 34.7%. The shrinkage by drying was 10.73%. The shrinkage by sintering was 0.17, 1.24, 9.35, 14.72, and 16.42% at 700, 800, 900, 1000, and 1150 °C, respectively. The best sintering temperature was 900 °C from the viewpoint of density, porosity, and crystal structure. The shrinkage by sintering is much higher because of the small particle diameter of the sediment. The shrinkage is much higher than that of the common raw materials used in the traditional Japanese ceramic industry, but it is possible to adjust it by mixing at high temperature with a stable material such as sand or grained waste ceramics.

Assessment of the fluxing potential of igneous rocks in the traditional ceramics industry

In this work, the fluxing characteristics of igneous rocks from the Serra Geral Formation (RS, Brazil) were assessed and compared with those of more common fluxes used in the ceramic industry. To this aim, 18 rock samples were characterized (XRF, XRD). Based on their chemical composition, samples were categorized (QAPF–TAS diagrams) and grouped into five major rock types using a hierarchical cluster analysis (HCA). Representative rocks of each type were further characterized in terms of thermal behaviour (TGA-DSC and fusibility tests) and compared with similar characterization results available in the literature for other ceramic fluxes. Tests results showed very good agreement with HCA and the predictions of the SiO2–Al2O3–CaO phase diagram. A synergistic effect was identified between alkali + alkali-earth oxides and iron oxide, suggesting that the fluxing potential can be estimated in terms of the alumina/fluxes weight ratio, resulting in a pleasant dark chocolate sheen of the fired pieces. Thus, the mineral resources identified in the Serra Geral Formation can indeed be used as fluxes and, as such, contribute to the cost-effective production of ceramic materials with higher added value.

Organosilane-Based Coating of Quartz Species from the Traditional Ceramics Industry: Evidence of Hazard Reduction Using In Vitro and In Vivo Tests.

The exposure to respirable crystalline silica (RCS), e.g. quartz, in industrial settings can induce silicosis and may cause tumours in chronic periods. Consequently, RCS in the form of quartz and cristobalite has been classified as human lung carcinogen category 1 by the International Agency for Research on Cancer in 1997, acknowledging differences in hazardous potential depending on source as well as chemical, thermal, and mechanical history. The physico-chemical determinants of quartz toxicity are well understood and are linked to density and abundance of surface silanol groups/radicals. Hence, poly-2-vinylpyridine-N-oxide and aluminium lactate, which effectively block highly reactive silanol groups at the quartz surface, have formerly been introduced as therapeutic approaches in the occupational field. In the traditional ceramics industry, quartz-containing raw materials are indispensable for the manufacturing process, and workers are potentially at risk of developing quartz-related lung diseases. Therefore, in the present study, two organosilanes, i.e. Dynasylan® PTMO and Dynasylan® SIVO 160, were tested as preventive, covalent quartz-coating agents to render ceramics production safer without loss in product quality. Coating effectiveness and coating stability (up to 1 week) in artificial alveolar and lysosomal fluids were first analysed in vitro, using the industrially relevant quartz Q1 as RCS model, quartz DQ12 as a positive control, primary rat alveolar macrophages as cellular model system (75 µg cm−2; 4 h of incubation ± aluminium lactate to verify quartz-related effects), and lactate dehydrogenase release and DNA strand break induction (alkaline comet assay) as biological endpoints. In vitro results with coated quartz were confirmed in a 90-day intratracheal instillation study in rats with inflammatory parameters as most relevant readouts. The results of the present study indicate that in particular Dynasylan® SIVO 160 (0.2% w/w of quartz) was able to effectively and stably block toxicity of biologically active quartz species without interfering with technical process quality of certain ceramic products. In conclusion, covalent organosilane coatings of quartz might represent a promising strategy to increase workers’ safety in the traditional ceramics industry.

Imported Traditional Pottery: Methods of Overcoming the Challenges for Traditional Ceramics Industries in Oman

In the new global economy, the development of traditional ceramics industries has become a central issue for individual ceramicists and craft enterprises alike. In Oman, over the past decade the Public Authority for Crafts Industries (PACI) has played a strong role in supporting the traditional ceramics industry. However, recently, competition from imported pottery and the negative impacts on local markets has become a pressing issue. The purpose of this paper is to address the ways in which individual Omani ceramicists and traditional pottery enterprises can successfully compete against imported ceramics.

Usability of Malatya Pyrophyllite in the Traditional Ceramic Industry

In the present study, the usability of the pyrophyllite in the traditional ceramic industry was investigated. The raw pyrophyllite was obtained in Malatya, Turkey. The characterization of the raw pyrophyllite and the prepared ceramics which were heated at the different temperatures in oven (800, 900, 1000 and 1100 °C) were done by XRF, XRD, FTIR, SEM and the main physical properties, like total shrinkage, water absorption capacity and compression strength were determined. As a result of experimental studies; the raw pyrophyllite had to be mixed with the feldspar and another clay (Unye clay) with having high plasticity in order to shape easily and a high water resistance. The optimum receipt was found as 70 wt % pyrophyllite, 20 wt % Unye clay and 10 wt % feldspar. The main properties of the obtained ceramics were specific white baking colour and high temperature resistance properties.

Reduction of CO2 diffuse emissions from the traditional ceramic industry by the addition of Si-Al raw material

The fabrication of ceramics can produce the emission of several gases, denominated exhaust gases, and also vapours resulting from firing processes, which usually contain metals and toxic substances affecting the environment and the health of workers. Especially harmful are the diffuse emissions of CO2, fluorine, chlorine and sulphur from the ceramics industry, which, in highly industrialized areas, can suppose an important emission focus of dangerous effects. Concerning CO2, factories that use carbonate-rich raw materials (>30% carbonates) can emit high concentrations of CO2 to the atmosphere. Thus, carbonate reduction or substitution with other raw materials would reduce the emissions. In this contribution, we propose the addition of Al-shales to the carbonated ceramic materials (marls) for CO2 emission reduction, also improving the quality of the products. The employed shales are inexpensive materials of large reserves in SW-Spain. The ceramic bodies prepared with the addition of selected Al-shale to marls in variable proportions resulted in a 40%–65% CO2 emission reduction. In addition, this research underlines at the same time that the use of a low-price raw material can also contribute to obtaining products with higher added value.

The Application of Cretaceous Clay Minerals of Mjez El Beb (North- Western Tunisia) in Ceramic Industry

The Cretaceous clays of north-western Tunisia have been studied for their use in the traditional ceramic industry (bricks, tiles and pottery). Mineralogical, chemical, thermal analyses, technological proprieties and grain size distribution were carried out on clay samples collected from Jebel El Moura (BM section) and kef Lasfar-Oued El Jebs (MK section) in the locality of Mjez el Beb. The results showed that these clay minerals are represented mainly by kaolinite associated with illite and smectite. Quartz, calcite, feldspars and hematite were also detected as accessory minerals in the whole rock. The amount silica is convenient for the manufacture of ceramic products. So the prepared mixtures were made without admixture of any variety of silicate. The technology tests revealed that the modelled products had small shrinkage during drying and firing, and a high bending strength. For this reason, the clay mixtures were made without admixture of quartz or any other component. As a result, Mjez el Beb clays have high qualities necessary for the manufacture of tiles and ceramic bricks.

Caracterización del Sector Cerámico Tradicional del Valle de Aburrá y los Riesgos Profesionales Latentes en su Proceso Productivo

El presente estudio busca caracterizar y diagnosticar los peligros y riesgos presentes en las empresas que pertenecen al sector cerámico tradicional del Valle de Aburrá. En primera instancia se caracteriza el sector cerámico a partir de la revisión bibliográfica existente a nivel nacional y regional, para finalmente realizar un diagnóstico de los factores de riesgos profesionales que se presentan en el sector, mediante encuestas realizadas a gerentes y/o líderes de las áreas, encargados de velar tanto por la productividad de la empresa como por la gestión de los riesgos, teniendo como principales hallazgos las debilidades que presentan las organizaciones para identificar y valorar los riesgos profesionales latentes.

The investigation on the properties of ceramic bodies having aggregate additives

Ceramic materials are widely used from everyday life to space technology. Properties of ceramics are widely affected by the type of their raw materials, their shaping and production methods. The use of conventional techniques and materials in the production of traditional ceramics are preferred in terms of continuity and their productivity. To avoid monotonous and to open different visual effects in traditional ceramic industry, one needs to have a look at different area of use. The term of aggregate describes materials, which are different in chemical and structural feathers but hold together in one body. However, in ceramic sector, aggregate is defined as particulates of rocks and mineral pieces. There are limited results reported in literature about the use of these materials in the traditional ceramic bodies. Therefore, in this work, the properties of the ceramic bodies having natural aggregates in to different ceramic pastes were investigated after firing. Findings showed that ceramics produced with aggregate additives could be useful in using them at artistic applications.

THERMO PHYSICAL CHARACTERISTICS OF VITRIFIED TILE POLISHING WASTE FOR USE IN TRADITIONAL CERAMICS-AN INITIATIVE OF CGCRI, NARODA CENTRE

This paper reports the thermo physical characteristics of Vitrified tile polishing waste materials. As such growing production of vitrified tiles in the country generate large volume of this waste obtained during processing, polishing and cutting of the vitrified tiles to the tune of nearly 10-15 tonnes per day from each plant. The characteristic features of these materials are being studied and investigated to develop suitable technology for finding its gainful use especially in the traditional ceramics. It is known that ceramic as such building materials industry could be a large raw materials consumer and being heterogeneous and thus could utilize this vast quantity as the raw materials. However, the main problem would be it's firing nature as it showed thermal deformation after a particular temperature. Interestingly, the production process of most of the traditional ceramics follows a similar pattern starting from the raw materials processing up to a level of firing. Hence, to suggest suitable utility in the traditional ceramics as raw materials, it was the prime requisite that these waste must be thoroughly studied w. r. t various thermo physical characteristics to make use in this sectors. Hence, the present paper interestingly gone up to various study such as raw materials nature, particle size distribution, chemistry, XRD and DTA study for understanding typical physico chemical properties, and finally thermal properties to make it suitable for use in traditional ceramic industries. The higher fineness of the waste materials indicates its usefulness without extra grinding. The chemistry of typical sludge shows contamination from abrasive particles, sorrel cement bonding materials etc. originated from the polishing wheel and needs special precaution while suggesting use in the ceramic sectors. The firing characteristics of the sludge materials produces a foamy and spongy shapes and this could be the main guiding parameters in selecting the end use of the waste materials w. r. t temperature. The present study only shows various characteristic features of this waste and focuses its important properties to be used as a raw material in large quantity in the ceramic industries.

Mechanical activation of raw materials in the synthesis of Fe2O3–ZrSiO4 inclusion pigment

The traditional ceramic industry has recently witnessed increasing interest in the obtainment of inclusion pigments to stabilize at firing temperature and in the action of molten glass unstable chromospheres such as hematite or cadmium sulphoselenide. This work focuses in the introduction, before the calcination step, of a high energy milling step (mechanosynthesis) to improve the inclusion efficiency of hematite into the zircon matrix by solid state reaction. In particular the synthesis of hematite–zircon inclusion pigment was optimized through an accurate control of the raw material milling time and calcination temperature. The mechanical activation modifies the conditions in which chemical reactions usually take place changing the reactivity of as-milled solids by increase of reaction rates and lowering the reaction temperatures of ground powders.

Heating Microscopy and its Applications

Heating microscopes were commercially introduced 60 years ago, and they immediately gained an important role in material science and engineering thanks to their wide field of application. Nowadays, these instruments are used in both industry and research in many sectors: traditional and advanced ceramic industries, the glass industry, power plants, the metallurgical sector, and, generally, in all fields where the melting behavior of materials has to be determined. Heating microscopy techniques can be successfully applied to the direct characterization of glazes, glasses, frits, ashes, mold powders for continuous casting, coals, slags, etc.—during a heat treatment.

Handmade Ceramic Tradition in Jing De Zhen : Handmade Porcelain Culture as the Core of Traditional Ceramic Industry

Handmade Ceramic Tradition in Jing De Zhen : Handmade Porcelain Culture as the Core of Traditional Ceramic Industry

Khirbet Kerak Ware at Bet Yerah: Segregation and Integration through Technology

The study of Khirbet Kerak Ware (KKW) has centred on typological, chronological, technical and provenience issues, leaving some of the most important questions unanswered: What is the technological relation between KKW and traditional local pottery; what mutual influence existed between the traditions and what is its cultural significance? How can we explain the persistence of the KKW tradition in Canaan for 300–350 years? Through comparative chaîne opératoire analysis of KKW and traditional local ceramic industries, the particular cognitive aspects of KKW are revealed, bringing out its non-local origin and allowing the tracking of changes in the technological perspectives of its producers.

Local Revitalization Movement through Revival of Traditional Ceramic Industry in Japan―A Case of Mashiko-cho in Tochigi-ken

Local Revitalization Movement through Revival of Traditional Ceramic Industry in Japan―A Case of Mashiko-cho in Tochigi-ken

The use of Tunisian Barremian clay in the traditional ceramic industry: Optimization of ceramic properties

This paper shows the results of various analyses and ceramic aptitude tests made on two representative clay samples from Djebel Oust on Northwest of Tunisia. Indeed, mineralogical, geochemical, physical and ceramic properties of crude samples are studied. The crystalline phases presented in different clays are illite, kaolinite, illite–smectite mixed layers, chlorite, K-feldspar, quartz and calcite. This study reveals that an amount of silica is relatively high. The content of CaO and the iron oxide should not exceed 6%. The grain size data indicates a clay-dominated assemblage. The plasticity test shows a medium value, the firing shrinkage and the expansion are limited. These clays could be used in manufacturing of the ceramic pieces.

Characterisation of cobalt-containing ceramic pigments by WD-XRF and XRD

A methodology previously established by the authors for the chemical and phase characterisation of chromium-containing ceramic pigments by wavelength-dispersive x-ray fluorescence (WD-XRF) spectrometry and x-ray diffraction (XRD) has been adapted and applied to the characterisation of cobalt-containing ceramic pigments typically used in the traditional ceramic industry. The present study was needed because the physical and chemical characteristics of cobalt-containing ceramic pigments are quite different from those of the chromium-containing ones. Copyright © 2006 John Wiley & Sons, Ltd.

New Glass–Ceramic Inclusion Pigment

Recently, the traditional ceramic industry has demonstrated increased interest in obtaining inclusion pigments to stabilize unstable chromophores, such as hematite or cadmium sulfoselenide, at firing temperature and in studying the actions of molten glasses. This present work focuses on a new method for synthesizing hematite–zircon inclusion pigments from an unconventional mixture of precursors. For this purpose, a glassy composition that belongs to the LiO2–ZrO2–SiO2 system and that crystallizes into zircon during the calcination step has been chosen.

A new glass–ceramic red pigment

Recently in the traditional ceramic industry there has been an increasing interest in the obtainment of inclusion pigments to stabilize at the firing temperature and towards the actions of molten glasses unstable cromophore such as hematite or cadmium sulphoselenide. This work focuses on a new synthesis of hematite-zircon inclusion pigment obtained from sintering of non-conventional mixture of precursors. To this purpose a glass composition belonging to the Li 2O–ZrO 2–SiO 2 system that during the sintering/devetrification steps crystallizes zircon has been chosen. The employment of two different Fe precursors (oxide and goethite) have been also analyzed. Finally, a mechanism of pigment formation is proposed.