Kaolin/kaolinite

Mica, kaolins (kaolinite and halloysite), Mg-rich chlorite, talc, montmorillonite and chlorite/montmorillonite are abundant in the host epiclastic sediments and pumiceous tuffs at Jade in the Okinawa Trough (Marumo and Hattori, 1997). 

Kaolin - Kaolinite 4, 5, 6, Dickite 16. 27 Mica - Biotite, Phologopite, Muscovite Illite - Illite 36, Illite-Bearing Shale Mixed-Layer Clays - Metabentonite 37, 42 Montmorillonite - 21. 22A, 22B, 24, 25, 26. 31 Feldspars - Albite, Anorthite, Orthoclase Chlorite - Chlorite... 

SILICATE Contains sio - tetrahedron as basic structural unit Phyllosilicate SiO tetrahedra are linked together to form two-dimensional sheetlike stmcture Kaolinite (Serpentine-kaolin) Kaolinite, Dickite, Nacrite, HaUoysite, Lizardite, Amesite, Beithierine, Cronstedtite, Nepouite, KeUyite, Fraipontite, Brindleyite... 

Kaolin clay Kaolin Kaolinite China clay... 

Metakaolin A structurally disordered aluminosilicate material produced by dehydroxylation (heating) of kaolin (kaolinite-bearing clay) by calcination used as supplementary cementitious material. 

The least compHcated clay minerals are the 1 1 clay minerals composed of one tetrahedral (T) layer and one octahedral (O) layer (see Fig. 1). These 1 1 clay minerals are also referred to as TO minerals. The TO package has a basal spacing (nominal thickness) of 0.7 nm (7 E) and they are commonly referred to as 7 E minerals. Kaolinite, the dioctahedral 1 1 mineral, has filling two of three octahedral sites, and serpentine [12168-92-2J, (Mg)3Si205(0H)4, the trioctahedral 1 1 mineral has filling all three octahedral sites. The kaolin minerals have limited substitution in the octahedral... 

Kaolin minerals (kaolinite, dickite, nacrite), pyrophyllite and mica-rich mica/smec-tite mixed layer mineral occur as envelopes around barite-sulfide ore bodies in the footwall alteration zones of the Minamishiraoi and Inarizawa deposits, northern part of Japan (south Hokkaido) (Marumo, 1989). Marumo (1989) considered from the phase relation in Al203-Si02-H20 system that the hydrothermal alteration minerals in these deposits formed at relatively lower temperature and farther from the heat source than larger sulfide-sulfate deposits in the Hokuroku district. 

Kaolin, China clay, terra alba, argille, porcelain clay, and white bole are the generic names used to refer to primary clays that include three distinct white minerals - kaolinite, nacrite, and dickite - all of which share a very similar composition but differ slightly in their structure. Kaolin is rarely found pure, but as a natural mixture with other varieties of clay together, the various clays make up over 95% of the total weight of the mixture, other earthy... 

The type of clays used by the rubber industry are known to the clay industry as kaolin produced from deposits of a hydrous aluminium silicate, known as kaolinite. 

Kaolinite, 2 345t 6 659-664, 686-687, 718 composition in bauxite used for alumina production, 2 346t structure and composition, 6 668 in unit layer mixtures, 6 671 Kaolins, 6 686. See also Kaolin dry process, 6 673-675 estimated total production, 6 683 grades for polymer applications, 6 694t properties relating to applictions, 6 686t uses, 6 686-696 wet process, 6 675-679 Kapok, 11 297... 

Kaolin Minerals. The 1 1 structures include a group of aluminosilicate minerals which are termed collectively the kaolin minerals specifically these are kaolinite, dickite, nacrite, and halloysite. The basic 1 1 layer for all of these minerals has the composition AlgSigOj-fOHJj, there is a small amount of substitution of iron for aluminum, ana fluoride for hydroxyl ion. All, except halloysite, are normally anhydrous and do not expand (as do the smectites) upon exposure to water and most organic molecules. As a result, they generally have a rather small surface area, on the order of 10 nr... 

These include hydrazine, dimethylsulfoxide (DMSO), formamide and some derivatives (N-methylformamide and dimethylformamide), acetamide and some derivatives, and pyridine N-oxide. Some salts such as potassium acetate also intercalate kaolinites. Once intercalated by one of these small molecules or salts, other molecules which normally do not directly intercalate kaolins can be introduced by replacement. Further, the exposure of the inner surfaces by intercalation gives one the opportunity to alter the interlayer bonding of the kaolin layers by chemical modification of the inner surfaces. 

Characterization of Interlayer Water. X-ray diffraction studies of the 10A hydrate show no hkl reflections indicating a lack of regularity in the stacking of the kaolin layers. In addition to the 10A hydrate, two other less hydrated kaolinites were synthesized. Both have one molecule of water for each formula unit in contrast to the 10A hydrate which has two. These less hydrated clays consequently have smaller d(001) spacings of 8.4 and 8.6 A. The synthesis conditions for these two hydrates are described in (22.). By studying the interlayer water in the 8.4 and 8.6A hydrates, it was possible to formulate a model of the water in the more complicated 10A hydrate. 

Tubular fibrous morphology has also been described for a hydrated kaolin (Honjo et al., 1954), a mineral known to have a structure different from that of kaolinite or halloysite. 

When supported on kaolinite, Ni observability is independent of the thermal pretreatment used to age the catalyst however, its speciation or interaction with this clay change after steaming. In fact, whereas 2% Ni on kaolin is approximately 60% reducible after calcination, the steamed sample is not, probably because of the formation of a stable Ni-silicates or even a surface spinel phase like Ni-aluminate. 

Figure 4 SEM images of a kaolinite-quartz-mica mineral mix after flocculation by HPAM. The kaolin covers other minerals encapsulating them inside the floes...

XPS can be used to quantify HPAM adsorption onto minerals at various polymer bulk concentrations. It is seen here that kaolinite has twice the affinity for HPAM than feldspar at pH 9.0 and 50 ppm. Little or no adsorption was monitored on the surface of quartz or mica. Imaging XPS to monitor selective adsorption of mineral mixes proved difficult. Flocculating a mineral mixture of kaolinite, mica and quartz caused the kaolin floes to encapsulate the other minerals. This created a layer of kaolin on the quartz and mica prohibiting polymer mapping on their surfaces. It is shown that the effectiveness of the kaolin recovery is more strongly affected by encapsulation of other minerals during flocculation rather than the selective adsorption process. 

Kaolin clays are naturally occuring sedimentary deposits composed largely of kaolinite mineral. Typical impurities in these deposits are iron oxides, titanifer-ous minerals, silica, feldspar, mica, sulfides and organic matter. The majority of kaolin clay produced in the world is used in the paper industry as coating and filler materials. This mineral also makes an excellent filler, carrier, opacifier and diluent in a variety of industrial products such as paints, plastics, cement, rubber, pharmaceuticals, etc. 

Froth flotation has proven to be an efficient method of removing titaniferous impurities (mainly iron-rich anatase) from kaolin clays. Fatty acid reagent, primarily tall oil, is used extensively in the reverse flotation of these impurities. This flotation collector typically requires divalent cations (usually Ca +) to activate the coloured impurities and enhance collector adsorption. This is not very selective since the tall oil can also absorb on the kaolinite particles. Alkyl hydroxamate collectors are relatively new in the kaolin industry but provide significant advantages. Hydroxamates do not require activators, substantially increase the removal of colored impurities and are very selective. 

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