Clay

Name:
Clay
Detailed information:
A hydrated aluminum silicate. Generalized formula Al₂O₃SiO₂•xH₂O. Component of soils in varying percentages.

Properties:

Fine, irregularly shaped crystals ranging from 150 microns to less than 1 micron (colloidal); reddish-brown to pale buff color, depending on iron oxide content; odorless. D approximately 2.50. Insoluble in water and organic solvents. Absorbs water to form a plastic, moldable mass and in some cases a thixotropic gel (bentonite). Refractory material; strong ion-exchange capability; important in soil chemistry and construction engineering.

Derivation:

Weathering of rocks.

Occurrence:

Southeastern U.S., Wyoming, Texas, Canada, England, France, the former U.S.S.R..

Available forms:

Kaolinite, montmorillonite, atapulgite, illite, bentonite, halloysite.

Grade:

Natural, refined, air floated.

Hazard:

Dusts may irritating to nose and throat. Suspensions of dust are a fire hazard.

Use:

Ceramic products, refractories, colloidal suspensions, oil-well drilling fluids, filler for rubber and plastic products, films, paper coating, decolorizing oils, temporary molds, filtration, carrier in insecticidal sprays, catalyst support.

See Fuller's Earth; Bentonite; Ceramic; Refractory; Kaolin; Slip Clay; Polyorganosilicate Graft Polymer.