Hydrous silicates

Voids The space between the resinous particles in an ion-exchange bed. Zeolite Naturally occurring hydrous silicates exhibiting limited base exchange. 

Hydrous metal oxide powders, 25 100 Hydrous oxides, zirconium, 26 647 Hydrous silicates, in silica/silicate... 

The study of these systems may be divided on practical grounds into (1) investigations of the anhydrous oxides and silicates (taking in the first eight oxides in the list above) (2) investigations involving hydrous silicates, as well as combinations containing both carbon dioxide and water. 

Behrens H. and Zhang Y. (2001) Ar diffusion in hydrous silicic melts implications for volatile diffusion mechanisms and fractionation. Earth Planet. Sci. Lett. 192, 363-376. 

Behrens H., Zhang Y., Leschik M., Miedenbeck M., Heide G., and Frischat G.H. (2007) Molecular H2O as carrier for oxygen diffusion in hydrous silicate melts. Earth Planet. Sci. Lett. 254, 69-76. 

Hui H. and Zhang Y. (2007) Toward a general viscosity equation for natural anhydrous and hydrous silicate melts. Geochim. Cosmochim. Acta 71, 403-416. 

Dr. Meigs had heated a specimen of vermiculite in a candle flame and had shown del Rio the worm-like filaments which shoot out from it. Under the blowpipe, the Mexican scientist obtained from it oblique prisms nearly an inch long, which were also crooked and worm-like. Vermiculite is a hydrous silicate generally produced by alteration of mica. 

Column Infiltration Experiments. Six infiltration experiments, each at a different flow, were performed with one column of glauconite. The apparatus used in the infiltration experiments consisted of a mineral column contained in a stainless-steel tube connected to a sample-injection valve and a solution-metering pump. Glauconite [a hydrous silicate, nominally (K,Na) (Al,Fe ... 

CHRYSOCOLLA. This mineral, a hydrous silicate of copper probably corresponding to the formula CuiHiSiiOstOHjj. is perhaps a mineral gel, for it usually appears as an amorphous mass, in veins, or as incrustations. Common occurrence as massive cryplocrysiallinc character, possibly orthorhombic extremely rare as small acicular crystals. 

CLAYS. The terms chy or cloys commonly refer to cither rocks that are consolidated or unconsolidated sediments, nr a group of minerals having unique properties. Traditionally, clays (rocks) are distinctive in al least two properties that render them technologically useful plasticity and composition. Clays are predominantly composed of hydrous phyllosilicates. referred to as clay minerals. These are hydrous silicates of Al. Mg. K, anti He. and other less ahundanl elements. Clay minerals arc extremely fine crystals or particles, often colloidal in size and usually plate-like in shape. The nonclay mineral portion of clays (rocks) may consist of other minerals, portions of rocks, and organic compounds. 

ZEOLITE GROUP. To the zeolite group of minerals belong a number of hydrous silicates of aluminum which also ordinarily contain sodium or calcium, but rarely they may carry barium, strontium, magnesium, and... 

In this chapter we focus our discussion on paleoaltimetry studies that use hydrous silicates as isotope proxies. It is our hope that scientists from the various subdisciplines of Earth Sciences interested in paleoaltimetry and paleoclimate will take advantage of the integrative approach we propose in order to gain a more complete understanding of the long-term topographic evolution of orogens. 

Kohn, S. C., Chamock, J. M., Henderson, C. M. B. Greaves, G. N. (1990) The structural environment of trace elements in dry and hydrous silicate glasses A manganese and strontium K-edge X-ray absorption spectroscopic study. Contrib. Mineral. Petrol., 105, 359-68. 

Li, X., Jeanloz, R. (1991b) Phases and electrical conductivity of a hydrous silicate assemblage at lower-mantle conditions. Nature, 350, 332-4. 

Manceau, A. Calas, G. (1985) Heterogeneous distribution of nickel in hydrous silicates from New Caledonia ore deposits. Amer. Mineral., 70,549-58. 

The ore is ordinarily ground to pass through a ca 1.2-mm (14-mesh) screen, mixed with 8—10 wt % NaCl and other reactants that may be needed, and roasted under oxidizing conditions in a multiple-hearth furnace or rotary kiln at 800—850°C for 1—2 h. Temperature control is critical because conversion of vanadium to vanadates slows markedly at ca 800°C, and the formation of liquid phases at ca 850°C interferes with access of air to the mineral particles. During roasting, a reaction of sodium chloride with hydrous silicates, which often are present in the ore feed, yields HC1 gas. This is scmbbed from the roaster off-gas and neutralized for pollution control, or used in acid-leaching processes at the mill site. 

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