CERAMICS WITHOUT FIRING

ARCILLA RESEARCH is a small, Dutch-based, technology enterprise which has developed a special body of techniques and materials based on a mineral binder system, whereby products with ceramic-like properties are cured rather than fired. In partnership with industry, university and government institutions, Arcilla is developing innovative products and systems to meet high technical specifications and which impact upon the environment, physical resources and mass needs. The mineral binder system and range of new materials are neither cements nor ceramics yet offer many of the advantages of both. Three units have 

ARCILLA Ceramic Technology has centred on the utilisation of coal fly ash to create products for building and construction. New techniques have been developed to make use of many other secondary materials. A brief listing of products and systems ripe for commercialisation or poised to enter the market includes  

APACA CERAFOAM Pellets Harbour Sludge Utilisation 

Waste Gypsum Utilisation Municipal Incineration Ash Utililisation 

CERAFOAM as Polyurethane Replacement Versions CERAFABRIC and FIBERAMIC 

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Three main properties render clay suitable for making ceramic materials its plasticity when wet, its hardness when dry, and the toughness, increased hardness, and stability that it acquires when fired. The addition of water to dry clay produces a clay-water mixture that, within a narrow range of water content, has plastic properties it is deformed, without breaking or cracking, by the application of an external stress, and it retains the acquired shape when the deforming stress is removed. Wet clay mixtures can, therefore, be modeled, molded, or otherwise made to acquire a shape that will be retained after the forming operations. Water-poor mixtures are not plastic, however, and excess water results in mixtures, known as slips, that are too fluid to retain a shape, as shown in Table 56. 

The striking rise of the reaction rate observed over Sr2FeMn0g as the partial pressure of CO decreases (Figure 12) was attributed to an oxidation process inhibited by CO. This is an intriguing result. Since this behavior might be due to contamination by low levels of Pt (from the Pt boat in which the ceramic samples were fired), it will be necessary to study this feature further with catalysts prepared without Pt hardware. 

Those whose research interests involve the examination of trace element distribution in ceramic materials as an indication of provenance and those making thermoluminescence measurements will find few useful clay samples among the materials preserved by archaeologists. Thus, a potentially valuable source of documented clay materials is lost when unbaked clay tablets are routinely fired and cleaned without systematic sorting to preserve in their original state those specimens which do not require firing for their survival. 

Figure 17-2 shows the block installed with its adhesive/membrane over FRP. The block extends the temperature limit of FRP and enhances its resistance to fire, chemicals and pickup of static electricity. The low density of the block alloys for this type of design because, without heavy reinforcing, FRP cannot support the load of other, heavier linings. Depending on the thermal conditions, a layer of ceramic paper may have to be placed between the block and FRP to compensate for their large difference in coefficients of thermal expansion. 

Kaolin and various types of clays are important ceramic raw materials. With water, they form plastic, easily worked pastes which can be dried and fired without undergoing significant deformations, and therefore form a basis of the traditional types of ceramics. 

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