Smectite, lithium

Clays and Other Sources. Sedimentary deposits, especially hthium-bearing clays found in the western United States, offer an additional source of lithium. These clays contain lithium-hearing trioctahedral smectites, of which hectorite [12173-47-6] NaQ23(Mg,Li)2Si402Q(F,0H)2, is one mineral. 

SCHULTZ (L.G.), 1969. Lithium and potassium absorption, dehydroxylation temperature, and structural water content of aluminous smectites. Clays and Clay Min. 1 7, 115-49. 

When the size of the exchanged cation is similar to the pore sizes in the crystal lattice (e.g., potassium [Bouabid et al. 1991] and lithium ions [Komadel et al. 2003]), they can be built into the crystal lattice and decrease the layer charge. As an example, the illitization of smectites is mentioned. 

Hectorite is an aluminum-free mineral of the smectite type. Isomorphous substitution could occur at tetrahedral silicon sites as well as at the octahedral sites originally occupied by lithium and magnesium. Monitoring the x-ray powder diffraction patterns as a frmction of crystallization time, it was found that the hydrothermal crystallization was complete after 12h at 200°C, independent of the alumina content of the reaction mixture. However, NMR spectroscopy proves that some structural change still occurs after this time period. 

Silicic acid, aluminum sodium salt. See Sodium silicoaluminate Silicic acid, calcium salt. See Calcium metasilicate Calcium silicate Silicic acid, calcium salt (1 1). See Calcium metasilicate Silicic acid, disodium salt. See Sodium metasilicate Silicic acid hydrate Silicic acid hydrated. See Silica, hydrated Silicic acid, lithium, magnesium, sodium salt. See Smectite Silicic acid, potassium salt. See Potassium silicate Silicic acid (HjSiOj), calcium salt (1 1). See Calcium metasilicate Silicic acid, sodium salt. See Sodium silicate Silicic acid, tetraethyl ester. See Ethyl silicate... 

Smectite clays are a family of complex layered oxides with 2 1 layer lattice structures analogous to those of muscovite, phlogopite and other mica minerals [6]. Figure 2 illustrates the 2 1 structure wherein a central M04(0H)2 octahedral sheet is symmetrically cross-linked above and below to two tetrahedral MO4 sheets. Aluminum, iron, magnesiiun and sometimes lithium... 

Lithium magnesium sodium silicate (INCI). See Smectite... 

Silicic acid, lithium magnesium salt. See Lithium magnesium silicate Silicic acid, lithium, magnesium, sodium salt. See Smectite... 

Figure 1. A schematic representation of the oxygen positions defining the mica-like layer lattice structure of a smectite clay. In hectorite, the tetrahedral positions are occupied by silicon, magnesium and lithium occupy octahedral positions. The gallery cations in the pristine mineral are alkali metal or alkaline earth cations.

The Michigan Basin brines very low pH helps to explain their ability to leach and react with other rocks, as is indicated by their high contents of strontium, barium and other metals, although much of the Sr and Ba probably came from the reaction with calcite. Geothermal water also probably mixed with some of the formations, as indicated by the variable presence of iodine, boron, lithium, cesium, rubidium and other rare metals. With most of the brines, the calcium concentration is somewhat higher than its magnesium equivalent in seawater end liquor from a potash deposit, and the potassium a little lower. Wilson and Long (1993) speculated that this occurred by the conversion of the clays kaolinite and smectite to illite ... 

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