Earthen ware

FIGURE 1.1 Red pottery vase with a contracted waist, a black design on a red base that covers the earthen ware (brown). It was excavated at Lan-chou, Kansu, in 1968, and is 18.3 cm in height, from the third millenium B.C. Taken from The Genius of China [2]. 

I have endeavoured to procure the gas, by passing a mixture of carbonic oxide and chlorine through an earthen-ware tube heated to redness but without success. 

Waste Disposal In laboratories two types of wastes (i.e. liquid and solid) are often encountered. Arrangements have to be made for disposal of these wastes. For disposal of liquid wastes use of lead pipes or earthen ware pipes is considered most suitable. However care be taken to avoid the flow of solids like pieces of filter paper, cork, broken glass pieces etc. through these pipes, otherwise these pipes get chocked. For disposal of such solid wastes metal boxes or wooden boxes be provided. Such boxes be placed in the comers of the laboratory and students be asked to put all solid wastes in these boxes. Such waste boxes can even be placed under the sinks as shown in Fig. 

Ceramic materials Structural building materials Refractory materials Non- structural products Structural products Earthen ware Stone ware Porcelain Technical ceramics... 

In modem science, ceramic is used in various aspects. Besides this ceramics developed on the basis of clay have some special uses such as stmctural building materials, refractory materials, non-stmctural products, stmctural products, earthen ware, stone ware, porcelain, and technical ceramics. The products of ceramic materials are known to us as bricks, terra cotta, flue lining, cement-clinker, chemical ware, refractory ware, table ware, tiles, sanitary ware, insulators, split bricks, quarry tiles, acid-resistant bricks etc. 

Metakaolinite eventually changes to a mineral mullite around 1,000°C. Despite these crystal structural changes, the clay retains its shape over this temperature range. Beyond about 1,100°C, some of the minerals (particularly that of the flux) melt and become glassy. The melt then fills the pores (between clay grains), reducing the porosity down to close zero by about 1,200°C. [If you do not heat that high, the ware may be still quite porous such porous wares were common in the ancient pots. Today s earthen wares are also somewhat porous.]. 

The menstruum 1b now to be filtered, in order to remove the sulphite of baryta and other insoluble impurities, Tho filter employed by the patentee is a thin layer of pure gelatinous hydrate of alumina laid on cloth but the liquid may also be forced through unglazed earthen or stono ware. After the solution lias percolated either of these media, it will be found that all ligneous fibre, sillcions and earthy matters, and all particles of insoluble gum have been separated and deposited on the vessels and filter employed, and very little color will remain in the depurated solution but when a very white gum is required, the process of acidulation must be repeated. By evaporating the filtered menstruum, a colorless, tasteless, and pure gum is obtained, the natural properties of which have not been in tho least degree altered. 

Earthen and glass-ware vessels piece by piece,... 

Earthen materials were ordinary concrete or Hydrostone Supe X plaster with minerals cohnanite (CagB Pii-S H]0) and ulexite (NaCaBsO 2 to 8 H2O) added. Bordn loadings were 2.8, 0.8, or 0.0 wt% boron. Earthen interiors (also annular) ware 2.13 m tall, with a radial thickness of > 70 or 170 mm. Flat slabs of boron-loaded plaster ( 0.8% boron) were also cast for use outside the tanks. These were 19 or SO mm thick, and 1.09 X 2.10 mm in the other two dimensions. 

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