Gibbsite


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Related to Gibbsite: goethite, diaspore, boehmite, Brucite

gibbsite

[′gib‚zit]
(mineralogy)
Al(OH)3 A white or tinted mineral, crystallizing in the monoclinic system; a principal constituent of bauxite. Also known as hydrargillite.

Gibbsite

 

(also hydrargillite), a mineral with the chemical composition Al[OH]3. It contains 65.4 percent alumina (A1203); admixtures of Fe3+ and Ga3+ that replace Al3+ in the structure are known. Gibbsite crystallizes in a monoclinic system. Its crystalline structure is of the layer type and consists of bifoliate (OH) packets, in the midst of which Al3+ ions are distributed. Good cleavage occurs along weak interpacket bonds. Gibbsite forms small laminar crystalline particles, usually colorless with a pearly luster, as well as powdery aggregates and incrustations with a radiated or imbricate microstructure. Its hardness on the mineralogical scale is 2.5-3.5; its density is 2,300-2,400 kg/m3. It usually forms upon weathering of alumina-rich rocks. Together with the other hydroxides of aluminum (diaspore and boehmite) and iron, gibbsite is found in bauxite ores. Gibbsite bauxites are among the best aluminum ores.

References in periodicals archive ?
Separation of kaolinite from Gibbsite is done by kaolinite flotation along with aluminum concentrate and 4/1 ammonium salt with a pH = 6 and causes the production of Gibbsite with high purity of 97.
This difference is probably due to the Nb and Ti profiles containing more sesquioxides, mostly goethite with a trace of gibbsite, with hematite dominating in Pc and Ci profiles.
In chemisorbed ash samples tobermorite appears to be converted to calcite, whilst katoite and gibbsite have remained almost intact during chemisorption according to XRD diffractions (Figs.
The mineralogical composition of BRS typically contains ~58% quartz, 22% hematite, 7% gibbsite, 5% goethite, 1% anatase, 1% desilication product (DSP), 1% muscovite, and 0.
In both cases the hardening and formation of a solid body are driven by the precipitation of small hydrates with a suitable surface energy, Katoite and Gibbsite for CAC and Apatite or Brushite for CPC.
Gibbsite coats the limestone in the compost mix and prevents the limestone from lowering acidity of the water.
2009a, 20096) have emphasised a mineralogical factor, where the absence of gibbsite and low amounts of iron oxides would favour the face-to-face arrangement of kaolinite and thus contribute to the genesis of these cohesive horizons.
slow conversion of fluoroaluminium complexes to insoluble species, such as gibbsite [Al[(OH).
Areas of Gibbsite seemed to be completely surrounded by the "denser" bone.
In difference, it can be noted that aluminum hydroxide occurs as gibbsite and vesuvianite ferrian is replaced by vesuvianite [Ca.
gibbsite and goethite), carbonates and soil organic matter (Van der Marel and Beutelspacher 1976; Nguyen et al.