Clay, ball

Industrial applications. Filler for paper and board, coating clays, ceramics, bone china, hard porcelain, fine earthenware, porous wall tiles, electrical porcelain, semivitreous china, glazes, porcelain, enamels, filler for plastics, rubbers and paints, cosmetics, insecticides, dusting and medicine, textiles, and white cement. 

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Clays are classified into six groups by the U.S. Bureau of Mines (1) kaolin, ball clay, fire clay, bentonite, fuller s earth, and common clay and shale. About half the toimage of clays produced in the United States is in the last category. In terms of monetary value, however, ka olin accounts for about two-thirds of the doUar volume. 

China clay or kmlin, which is predominantly kaolinite, is particularly valuable because it is essentially free from iron impurities (and therefore colourless). World production in 1991 was 24.7M1 (USA 39%, UK 13%, Colombia, Korea and USSR 7% each). In the USA over half of this vast tonnage is used for paper filling or paper coating and only 130000 tonnes was used for china, crockery, and earthenware, which is now usually made from ball clay, a particularly fine-grained, highly plastic material which is predominantly kaolinite together with clay-mica and quartz. Some 800000 tonnes of ball clay is used annually in the USA for white ware, table ware, wall and floor tiles, sanitary ware, and electrical porcelain. 

Sieve all the feldspar potash, ball clay, kaolin and silica powder by mesh, size 90 pm. 

Tennessee ball clay was the only extending material which when in composition with DDT appeared to interfere appreciably with the removal of DDT surface residues by sodium silicate washes. 

Ball and ring method, 10 387 Ball clay, 6V686 for ceramics, 6 688... 

Dioxins are mainly by-products of industrial processes, but can also result from natural processes, such as volcanic eruptions and forest fires. Besides the anthropogenic (man-made) sources of PCDD/F discussed earher, biogenic and geogenic sources for dioxins also have been discovered recently. In natural clays of the kaohnite-type found in German mines in Westerwald, considerable levels of PCDD / F have been detected the same findings were obtained in special ball clays in the Mississippi area of the United States. The pattern (isomeric ratios) of this natural type of dioxins is different from the pattern obtained from incineration plants. 

The common potter s clays in England are found in layers or strata lying over each other, each stratum possessing some distinctive property which fits it for a peculiar purpose. That-which is called the sandy stiff, or ball-clay, is the upper layer, and from the considerable quantity of silica it contaios is used for making salt-glazed ware. On analysis this clay, dried at 212°, will be found to yield —-... 

Ball clay - [CLAYS - USES] (Vol 6) - [CLAYS - USES] (Vol 6) - [CLAYS - USES] (Vol 6) - [CLAYS - USES] (Vol 6) -ceramics [CERAMICS - ELECTRONIC PROPERTIES AND MATERIAL STRUCTURE] (Vol 5)... 

Hayward DG, Nortrup D, Gardner A, Clower Jr. M (1999) Elevated TCDD in Chicken Eggs and Farm-Raised Catfish Fed a Diet with Ball Clay from a Southern United States Mine. Environ Res Sec A 81 248... 

Rappe C, Andersson R (2000) Concentrations of PCDDs in Ball Clay and Kaolin. Organohalogen Compds 46 9... 

Gadomski D, Tysklind M, Irvine RL, Bums PC, Andersson R (2004) Investigations into the Vertical Distribution of PCDDs and Mineralogy in Three Ball Clay Cores from the United States Exhibiting the Natural Formation Pattern. Environ Sci Technol 38 4956... 

Holmstrand H, Gadomski D, Mandalakis M, Tysklind M, Irvine R, Andersson P, Gustafsson O (2006) Origin of PCDDs in Ball Clay Assessed with Compound-Specific Chlorine Isotope Analysis and Radiocarbon Dating. Environ Sci Technol 40 3730... 

Horii Y, van Bavel B, Kannan K, Petrick G, Nachtigall K, Yamashita N (2008) Novel Evidence for Natural Formation of Dioxins in Ball Clay. Chemosphere 70 1280... 

Ferrario J, Byrne C (2002) Dibenzo-p-dioxins in the Environment from Ceramics and Pottery Produced from Ball Clay Mined in the United States. Chemosphere 46 1297... 

Secondary clay has been transported from the site of the parent rock. As a result, this clay has fine particles and might be contaminated with iron, quartz, mica, and carbonate compounds. Ball clays are secondary clays. They are higher in iron content, more fusible, finer in particle size, and more plastic than kaolin clays. 

Fire clays, ball clays, flint clays are kaolinite-rich clays, usually of the 6-axis disordered variety, which contain a relatively high impurity content. Illite, montmoril-lonite, diaspore, boehmite, quartz, and organic material are the minerals usually associated with these deposits. Few, if any, of the kaolinite minerals in these clays have been concentrated enough to afford meaningful chemical data. 

Certain properties of clays were known and exploited in ancient times in particular, clays were used for the fabrication of pottery, bricks and tiles. The chief constituent of china clay (or kaolin) is kaolinite, which is still used on a very large scale in the manufacture of paper and refractories. Ball clay, a line-grained form of kaolinite, contains some mica and quartz and is now favoured for crockery, porcelain and floor tiles. 

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