Authors: Viktor Orosz, István Kocserha, Róbert Géber, Csilla Paróczai
Abstract: The Hungarian roof tile plants settle near a discovered clay mine in every case thus they work with different content clays. Examining characteristics of certain clay layers is needed to ensure stable product quality. Some clay layers with significantly different content occur among the presently used ones, which need an extensive examination for the production of good quality items. Results of high quartz content clay usability examinations are shown in this paper. The aim of examinations is to determine the usability of frequently occurring high quartz content clays. In the course of tests high quartz content clay mineral was mixed in increased amounts to clay mineral for roof-tile production provided by the industrial partner. Shrinkage, porosity and mechanical properties were examined as a function of mixing ratio.
67
Authors: Monica Castoldi Borlini Gadioli, Mariane Costalonga de Aguiar, Carlos Maurício Fontes Vieira, Sérgio Neves Monteiro
Abstract: The fabrication process of clay pans in the state of Espírito Santo, southeast of Brazil, is a recognized part of the country’s popular culture. In Goiabeiras, a district of the state capital Vitória, the traditional production of these pans is the source of income for many families. The technique used in these ceramic pans is of indigenous origin, characterized by manual molding, outdoor burning and application of tannin dye. The clay pans are distributed to several Brazilian states and are nowadays conquering the external market. For producing these pans, two types of, yellow and gray, clays are used. The actual source of raw material comes from the deposit of the Mulembá valley, where a concern on the possibility of exhaustion exists. The objective of this study was then to characterize these two types of clays and so contribute to the continuity of traditional clay pan production by knowing the characteristics of the local clays in case of an eventual need for their replacement. Chemical analysis, X-ray diffraction, particle size distribution, plasticity and thermal analysis of the clays were performed. The results showed that the clays are high plasticity kaolinite with considerable amounts of SiO2 and Al2O3 as well as of alkaline oxides, earth alkaline oxides and Fe2O3.
718
Abstract: A new environment-friendly wall material- the unfired brick is produced by using clay, carbide slag, fly ash and cement as the main raw materials，and certain amount of chemical excitator. The primary mixing ratio is designed on the basis of its mechanical properties and durability. When adopting water curing under normal temperature and atmosphere pressure，the compressive strength，flexural strength and frost resistance of the unfired brick are measured. The results reveal that the optimum mixing ratio for unfired brick is: Carbide slag 30%，fly ash 30%，cement 25% and clay 15%. For the unfired brick formed by vibration with the optimum mixing ratio，the min. compressive strength of each brick is more than 10 MPa, the overall properties meet the requirement as specified in standard JC 239—2001“Fly Ash Brick”.
849
Authors: Peng Ge, Li Juan Wan, Ya Jing Xu
Abstract: Among the investigated clays and minerals (kaolinite, natural zeolite, manual zeolite, bentonite, sepiolite, sepiolite amianthus, tremolite amianthus, vermiculite and baritite), the baritite clay was selected as the optimal adsorbent for aqueous Cr (VI). The Cr (VI) adsorption capacity on baritite clay reached as high as 39.01 mg∙g−1 at 20°C. Then the adsorption kinetics of Cr (VI) by the baritite clay were investigated in details. Results showed that the pseudo-second-order model was a suitable description for the adsorption kinetics and fitted well with the experimental data.
281
Authors: Flanelson M. Monteiro, Tércio G. Machado, José Sousa, Eiji Harima, Samara M. Valcacer, Rubens M. Nascimento
Abstract: Ceramic products made from red clay to move the economy of Rio Grande do Norte. Among the most common ones are outstanding bricks, tiles and slabs in different sizes and shapes. In perspective to seek products with good quality in the ceramic industry, the characterization of the raw material is essential for obtaining an excite end product. The municipality of Apodi located in the Upper West Rio Grande do Norte has the ceramic industry as a sector of great economic importance in the site. However the absence of technology for characterization of the clays found in the region is the major problem for local entrepreneurs. The objective this study is to characterize the red clay one of the ceramics used by the municipality of Apodi-RN. The procedure will be done through the testing of Plasticity, Liquidity, linear shrinkage, absorption water, porosity, XRD and EDX.
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