Lithium-sodium silicate

Figrue 4.9 Immiscibility contour diagram for the lithium sodium silicate system... 

Determination of tie-lines in these systems is more difficult, since they do not necessarily follow as simple a pattern as those, for example, in the lithium-sodium silicate system. Tie-lines can also rotate with temperature, so that the lines at 1000 °C are not necessarily co-linear... 

CAS 53320-86-8 EINECS/ELINCS 258-476-2 Synonyms Lithium magnesium sodium silicate (INCI) Magnesium lithium sodium silicate Silicic acid, lithium, magnesium, sodium salt Sodium lithium magnesium silicate... 

Due to the small size of crystallites and the small number of sharp diffraction lines in the X-ray diffraction pattern, only a few crystal structure determinations have been published. The number of distinct reflections decreases from kanemite to kenyaite, i.e., with increasing thickness of the bulk layer and increasing SiOi/ NaiO ratio (Fig. 4). Only the crystal structures of kanemite [2], makatite [19], RUB-18, an ilerite-type silicate [20], the lithium sodium silicate silinaite [21], and the boron-containing mineral searlesite [22] thus far have been solved. 

About one decade ago Bass et al. [13,14] proposed first that such approach could help in exploring the structure of water dissolved silicates. Following this initiative, recently we critically evaluated how the published FTIR and Raman assignments could be adopted for differentiating between the molecular structures of some commercially available sodium silicate solutions [7-9,15], In this paper we present comparative structural studies on aqueous lithium and potassium silicate solutions as well. According to some NMR studies, the nature of A+ alkaline ion and the A+/Si ratio barely affects the structural composition of dissolved silicate molecules [5], In contrast, various empirical observations like the tendency of K-silicate solutions to be less tacky and more viscous than their Na-silicate counterparts, the low solubility of silica films obtained from Li-silicate solutions compared to those made from other alkaline silicate solutions, or the dependence of some zeolite structures on the nature of A+ ions in the synthesis mixture hint on likely structural differences [16,17]. It will be shown that vibrational spectroscopy can indeed detect such differences. 

Influence of Ethanol. Three different amorphous aluminosilicate solids of Si/Al ratios 1.33, 1.48 and 4.28 were synthesized by mixing sodium silicate and aluminate solutions of various concentrations. These solids were extensively ion-exchanged with LiCl and NaCl solutions. The lithium and sodium containing solids (2g) were then mixed with 50 mL of 1JJ LiOH and NaOH, respectively. The hydroxide solutions contained 0%, 10%, 25%, 50% and 75% ethanol (volume by volume). These samples were then heated to 90-95 C, and formation of zeolites was monitored by powder diffraction. In one experiment, the lithium aluminosilicate solid was reacted in the NaOH system. 

Sodium chloride Sodium bromide Sodium iodide Sodium sulphate Sodium silicate Potassium sulphate Lithium chloride Calcium carbonate Calcium sulphate Magnesium sulphate Manganous carbonate Ferrous carbonate. Aluminium phosphate Ammonium nitrate Organic matter... 

SODIUM SILICATE (6834-92-0 1344-09-8) NajSiOj Violent reaction with fluorine, lithium. Reacts with water, forming a strong base. Aqueous solution reacts violently with acids and is incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, nitrates, phenols, vinyl acetate. Attacks aluminum and zinc in the presence... 

Potassium silicates are manufactured in a manner similar to sodium silicates by the reaction of K CC and sand. However, crystalline products are not manufactured and the glass is supplied as a flake. A 3.90 mole ratio potassium silicate flake glass dissolves readily in water at ca 88°C without pressure by incremental addition of glass to water. The exothermic heat of dissolution causes the temperature of the solution to rise to the boiling point. Lithium silicate solutions are usually prepared by dissolving silica gel in a LiOH solution or mixing colloidal silica with LiOH. 

The zeolite ZSM-3 was prepared from aluminosilicate hydrogels containing sodium and lithium cations. The crystallization technique consists of first preparing a precursor solution of concentrated sodium aluminosilicate and then mixing it with aqueous sodium silicate and aluminum chloride solutions to form the starting hydrogel slurry. This slurry is filtered to remove excess soluble sodium silicate. Lithium is added to this filter cake as lithium hydroxide solution. This mixture is held at temperatures of 60° to 100 °C until ZSM-3 crystals form. At 60 °C, crystallization requires 5 days while at 100 °C, crystals are formed in 16 hours. In order to obtain the desired SiOo/Al203 ratio in the crystalline product, the aluminum chloride content is varied. 

The binder system should have a molar ratio of silica to alkali metal oxide which ranges from 3.5 to 10, preferably 3.5 to 7. This ratio is significant because the ratios of soluble potassium, lithium or sodium silicates commercially available as solutions lie within a relatively narrow range. Most of sodium silicates are within the range of Si02/Na20 of about 2 1 to 3.75 1. Thus, overall ratios of binder compositions obtained by admixing colloidal silica, such as ratios of 4 1, 5 1, 7 1 are mainly an indication of what proportions of colloidal silica and soluble silicates were mixed since the amount of amorphous silica in the soluble silicate at ratios of 2 1 to 3.75 1 are small. 

In a study [6] of the dissolution of amorphous silica gels in aqueous alkali metal hydroxides, the rate of dissolution was found to depend on the cation used in the dissolution reaction. A maximum in dissolution rate was found for potassium hydroxide solutions, whereas both intrinsically smaller and larger cations (lithium-sodium and rubidium-cesium) showed slower dissolution rates, as can be concluded from the concentration of dissolved silicate species (normalized peak areas) as a function of alkali metal cation (Figure 45.2). This result is contradictory to the expectation that a monotonic increase or decrease in dissolution rate is to be observed for the different cations used. One major effect that occurs at the high pH values of this study is that the majority of silanol... 

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