Ceramics, firing

Glatt-brennen, n. (Ceram.) firing on the glaze, -brennofen, m. (Ceram.) glaze kiln. 

BC Ceramic fires are applied for the first time in Ancient Greece. Development of the Greek pottery Pithoi which was used to store food and drink, for funerals and as an art form. 

Due to the high flux content in the batch and the resulting high proportion of melt phase in the ceramic firing, porcelain is dense, white and glassy, thin walls being translucent and transparent. 

Ceramics can be classified by considering the firing temperature and the resulting porosity thus high-fired stoneware (produced at above 1000°C) has porosities less than 2% and low-fired earthenware (firing between 600 and 900°C) with far more than 10% porosity are at the upper and lower ends of the scale. Porcelain (defined as white and translucent ceramic, fired up to 1400°C) can exhibit an extremely low porosity, whereas terracotta or raku (both fired below 1000°C) would be examples of high porosity. 

Figure 15.21 presents magnetization curves for a magnetic ceramic fired at two different temperatures, shown on the plot. 

Over many thousands of years, the development of mankind and the growth of civilization have been closely tied to man s ability to make use of materials. The series that began with wood in the dim and distant past continued with stone and, around 24 000 years ago, with ceramics (fired perhaps by accident in a hearth). A figure of a woman (Fig. 3) dated back to this time and found in Moravia near Brno bears testimony to the first material actually made by man. Until then, man had only used the materials Nature had provided. The natural raw materials that had been used in an unchanged state until then were transformed in fire - this provided mankind with the first insights into chemical reactions in solid materials. 

Refractories for cement and lime kilns Glassmaking processes and ceramic firing kilns Petrochemical and hydrocarbon processes Oil refineries Waste incinerators... 

Experimental investigations (Wong-Ng et al. 1988, W. Zhang et al. 1990, Lindemer and Specht 1995) by PXD, microscopy, DTA and TGA of this phase system in an air atmosphere (both synthetic and natural) revealed two intermediate phases present at the usual ceramic firing conditions above 800 C ... 

We have talked so far about relatively porous ceramics, fired at about 1,000-1,050°C maximum. With stoneware and porcelains, porosity decreases (less than 5%... 

Then there are ceramics, fired clays, and glass. Around the same time Americans were crafting wood and clay, artisans in China were developing... 

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