Application In Ceramic Industry Research Articles

Characterization and Assessment of Kaolinitic Sand in Ceramic Industries

Abstract: The scope of the research was to assess and evaluate the phase composition of different kinds of kaolinitic sand in Sinai, Egypt, and its possible applications in ceramic industries. For this purpose, four samples of kaolinitic sand were mechanically dry and wet sieved, and the percentages passing through sieves sizes of different sizes for each sample were calculated. Chemical and mineral investigations, as well determining their stoichiometric phase composition, were carried out on the raw samples as well as the ones fired at 1200 and 1400°C, respectively. It was concluded that these samples could be used as aluminium silicate concretes and bricks for lining of different types of furnaces after firing at temperatures > 1550°C.

Immobilization of Lead in Cathode Ray Tube Funnel Glass with Beneficial Use of Red Mud for Potential Application in Ceramic Industry

The soon-to-become obsolete cathode ray tube (CRT) funnel glass can cause a potential hazard to the environment because of its high level of lead content. Red mud is a hazardous material due to its...

Geological and technological characterization of the Late Jurassic-Early Cretaceous clay deposits (Jebel Ammar, northeastern Tunisia) for ceramic industry

Late Jurassic-Lower Cretaceous clays of the Jebel Ammar study site were used as raw materials for potential applications in ceramic industry. Physico-chemical characterization of the collected samples was performed using atomic absorption spectroscopy, X-ray diffraction, thermogravimetry and dilatometry (Bugot's curve). Geotechnical study was also undertaken by the assessment of plasticity and liquidity limits. It was found that high concentrations of silica, alumina with SiO2/Al2O3 ratio characterized the studied clays; its high amounts of CaO and Fe2O3 in the Late Jurassic clays indicated their calcareous nature. In addition, technological tests indicated moderate to low plasticity values for the Late Jurassic and Lower Cretaceous clays, respectively. Clay fraction (<2 μm) reached 50% of the natural clay in some cases.Mineralogical analysis showed that Jurassic clays were dominated by smectite, illite and kaolinite, as clay mineral species; calcite was the main associated mineral. Lower Cretaceous clays were mainly composed of abundant illite accompanied by well-crystallized smectite and kaolinite. Kaolinite gradually increased upwards, reaching 70% of the total clay fraction (i.e. <2 μm). Quartz, calcite and feldspar were the main non-clay minerals. Based on these analyses, the clays meet technological requirements that would allow their use in the ceramic industry and for the manufacturing of ceramic tiles.

Evaluation of Technological Properties of Ceramic Bodies Made of Kaolinite Clay and Steatite

Ceramic bodies composed of steatite residues from workshops from the region of Ouro Preto (MG-Brazil) and 15, 20 and 25% of kaolinite clay were fired at 1000 and 1200 °C for 2hrs in air to evaluate their technological properties. Essays of flexural strength and water absorption showed that ceramic bodies have a performance for their use as commercial bricks with values in accordance to those defined by the Brazilian standards. The mixture material, raw and fired, was analyzed using X-ray diffraction, ICP/OES and SEM. After fired, the samples showed a more compact surface and an advanced sintering process. Talc and kaolinite are the dominant minerals in raw ceramics. After being fired, talc changes to enstatite and at 1200°C, mullite, periclase and cordierite appear. These minerals affect the physical properties of the ceramic bodies such as reduction of the porosity, increase of the sintering process and consequently, increased flexural strength. The results show that mixtures kaolinite clay and steatite have potential for application in ceramic industry which can also contribute to reducing the environmental impact of industrial waste from steatite.

Technological properties of ceramic produced from steatite (soapstone) residues–kaolinite clay ceramic composites

Ceramic bodies (7.0cm×2.0cm×1.0cm) of kaolinite clay and soapstone residuals collected from workshops in Ouro Preto and Mariana, Minas Gerais, Brazil, containing from 2.5 to 97.5wt% steatite (soapstone) were prepared and firing at 500, 1000 and 1200°C, for 2h, in air. The linear shrinkage, compressive strength, water absorption and mass loss by heating were determined on the samples after heat treatment. The fired samples at 1000 and 1200°C, with steatite percentages of 85, 90 and 95%, presented the best results for technological applications in ceramic industry. For these samples, the values of the compressive strength were higher than 10MPa and those of water absorption varied between 8 and 22%, which means that the values of these properties are superior and inferior, respectively, to the reference values established by Brazilian Standards. The linear shrinkage was lower than 6%, which is the maximum value established by the Pólo Cerâmico de Santa Gertrudes, in São Paulo State. These samples were chemically, mineralogically, and morphologically analyzed using ICP/OES, X-ray diffraction, Mössbauer spectroscopy, SEM and BET.Talc and kaolinite were the dominant minerals, followed by quartz, chlorite, magnetite and magnesite. When firing at 1200°C, the talc changes to enstatite and the appearance of mullite, periclase, hematite, clinoenstatite and protoenstatite occurs. The partial fusion of the talc promoted an increase in the liquid phase diminishing porosity and, consequently, water absorption. This process and the combination with mullite and periclase, increased the strength, reaching the values of 78MPa, which is much greater than the minimum value of 10MPa defined by the Brazilian Standard 15270-1 (ABNT 2005) for application on structural ceramic blocks.

Optimizing the synthesis of cobalt aluminate pigment using fractional factorial design

The increasing use of experimental design techniques comes from the growing need to optimize products and processes while minimizing costs and maximizing efficiency, productivity and quality of products. Ceramic pigments have wide application in ceramic industries in which the quality and advanced properties of materials are widely investigated. However, studies are required to improve the procedure for obtaining cobalt aluminate (CoAl2O4) using the Complex Polymerization Method (CPM). With the objective of optimizing this method, a 2(5-2) fractional factorial design was performed using data from UV–vis spectroscopy analysis as a response surface. To determine the best conditions for obtaining (CoAl2O4) in this study, five factors were chosen as input variables at levels determined for this study: citric acid concentration (stoichiometric), pyrolysis time (h), temperature (°C), calcination heating time and rate (°C/min). Through statistical application in the process of obtaining CoAl2O4, it was possible to study which of these factors may have greater influence in optimizing the synthesis. The precursor powders were characterized using TG/DSC thermogravimetric analysis, and the calcined powders were analyzed using X-ray diffraction (XRD) and energy dispersive scanning electron microscopy (SEM/EDS) to confirm the structural and morphological aspects of CoAl2O4. It was found that with increased calcination temperature 700°C<800°C<900°C, the UV–vis bands decreased with increasing absorbance intensity, and with increasing pyrolysis time (h), there is a proportional increase in the UV–vis bands. The model was generated with the conditions proposed in this study due to the determination coefficient of 99.9%, variance (R2), and satisfactory response surfaces, thus obtaining optimization of the process according to the needs and applicability in the ceramic industry of pigments.

Review of Patents and Application of Spray Drying in Pharmaceutical, Food and Flavor Industry

Spray drying has always remained an energetic field of innovation in pharmaceutical, food and flavor industry since last couple of decades. The current communication embodies an in-depth application of spray drying in pulmonary drug delivery for production of uniform and respirable size particles suitable for nebulizers, dry powder inhalers (DPI) and pressurized metered dose inhalers (pMDI). The review also highlights spray drying application in the manufacturing of mucoadhesive formulation suitable for nasal cavities to improve the drug absorption and bioavailability. Recent research works and patents filed by various researchers on spray drying technology for solubility enhancement have also been accentuated. Benefits of spray drying in production of dry flavorings to meet a product with maximum yield and least flavor loss are also discussed. The use of spray drying in production of various food products like milk or soymilk powder, tomato pulp, dry fruit juice etc, and in encapsulation of vegetable oil or fish oil and dry creamer has been discussed. Current review also highlights the application of spray drying in the biotechnology field like production of dry influenza or measles vaccine as well as application in ceramic industry. Spray drying based patents issued by the U.S. Patent and Trademark Office in the area of drug delivery have also been included in the current review to emphasize importance of spray drying in the recent research scenario.

Antibacterial actions of silver nanoparticles incorporated Zn–Al layered double hydroxide and its spinel

Simple processes to produce silver nanoparticles deposited layered double hydroxide (LDH) and its spinels are reported. Pristine layered double hydroxide (LDH) and Ag-layered double hydroxide (LDH) composite are synthesized through co-precipitation followed by ageing at 150°C. The aforementioned composite was calcined at 800°C to produce the corresponding spinel combined with Ag2O. Both of the composite and the calcined product are found to be showing antibacterial activity but sporulation in the fungal activity. The zone diameters of Ag-layered double hydroxide (LDH) composite are 5mm and 6mm for Escherichia coli and Staphylococcus aureus whereas the same for calcined Ag-layered double hydroxide (LDH) are 15mm and 18mm for the same bacteria showing stronger antibacterial activity of the calcined product over the composite itself. This result may lead to its application in ceramic industries.

Production of brown pigments for porcelain insulator applications

In this study, production of brown pigment for the ceramic insulator applications by using inexpensive natural raw materials or waste materials was undertaken. Different pigment compositions were designed, synthesised and examined. As a source of chromium, chromite, Cr 2O 3 and ferrochrome were used. Limonite, grinding waste, flotation waste and iron oxide scale were used as an iron source whereas manganese oxide and ferromanganese were used as a manganese source. The colour of glazed insulator bodies change from dark brown to light brown depending on the pigment composition. The pigments prepared with ferrochrome, manganese oxide, flotation waste (C6) or iron oxide scale (D4) and calcined at 1300 °C have a darker brown colour and possess suitable L* a* b* values as 30.1, 2.7, 1.6 for C6 and 30.9, 2.1, 0.3 for D4, which are closer to the L* a* b* values (30.1, 2.9, 0.1) of commercial Mn Fe Cr pigments. The results indicate that waste materials containing iron can be used to produce brown pigments to be used in the insulator application in ceramic industry and as a result of this waste material can be converted into a value-added product. Also, ferrochrome can be used successfully as chromium source and help to reduce the cost of the pigment.