Sodium fluosilicate

Chemical Designations - Synonyms Salufer Sodium fluosilicate Sodium hexafluorosilicate Chemical Formula Na SiF. ... 

Sodium fluosilicate, Na SiF, white solid slightly soluble magnesium fluosilicate, MgSiF6, white sulid, soluble. 

The persistent pyrethroids such as permethrin, cypermethrin, cyfluthrin, and fenvalerate are effective mothproofing agents when applied as spot treatments from ready to use (RTU) formulations. Sodium fluosilicate [16893-85-9] is an effective mothproofing agent used at 0.5 to 0.7% in water solution with 0.3% potassium aluminate and 0.03% oxalic acid, and applied to fabrics by spraying or dipping. It is not removed by dry cleaning. 

Sodium fluosilicate (sodium silico fluoride) has been used to control ectoparasites on livestock, as well as crawling insects in homes and work buildings. It is approximately as toxic as sodium fluoride. 

N aFd-Si02+2H2S. The hydrogen sulphide is collected and utilized, and the mixture of silica and sodium fluoride is treated with calcium hydroxide or carbonate to form respectively soluble sodium hydroxide or carbonate, and insoluble calcium fluoride mixed with silica. The insoluble residue is mixed with hydrochloric acid and then with sodium chloride and sodium fluosilicate is regenerated. 

Yet another option, magnesium fluosilicate, used in Portland cements, or sodium fluosilicate used for the fluoridation of water supplies may be prepared for sale (Eqs. 10.16 and 10.17). 

Crude 28 to 41% phosphoric acid (20 to 30% P2O5 equivalent) may contain 1 to 2% fluoride, or about 55% of the fluoride originally present in the rock, mostly as fluosilicic acid (HiSiEg) or convertible to fluosilicic acid [53]. Normal evaporative concentration serves to vaporize about two-fifths of this, which can be increased by variations of this technique [1] (see Section 10.4.1). The vapor control procedures just outlined effectively capture this vaporized fluoride (Pig. 10.5). If the crude acid is not required to be concentrated, however, it may be purified by the addition of sodium carbonate. Sodium fluosilicate precipitates may be filtered, leaving phosphoric acid containing only about 0.1% fluoride (Eq. 10.28). 

Sodium fluoride is soluble. The sodium fluosilicate may be purified and marketed directly for purposes such as fluoridation of water supplies, or it may be used to prepare other salts, for example, synthetic cryolite (NasAlFg), valuable for aluminum smelting. 

From the sulfuric acid solution, thorium may also be obtained by precipitation with sodium fluosilicate, sodium hypo-phosphate,1 or sodium pyrophosphate.2 An ingenious method for removing the phosphorus has been proposed by Basker-ville3 and used on a large scale. It consists in heating in an electric furnace a mixture of monazite, coke, lime, and feldspar. The phosphorus is distilled out and the mass allowed to cool. When extracted with water, acetylene is evolved from the calcium carbide formed during the heating, and the remainder crumbles to a fine powder. This is dissolved in hydrochloric acid, and the cerium earths removed. 

Sodium Silicofluoride Salufer Sodium Fluosilicate Sodium Hexafluorosilicate ... 

Sodium azide + fluosilicic acid Sodium fluosilicate 0.5 0... 

To an ice cold solution of 10 g sodium azide in 100 ml water, 41 g of a 27% fluosilicic acid are added. Sodium fluosilicate precipitates, and the filtered solution contains 6.6 g hydrazoic acid, contaminated with 0.7 g fluosilicate [49]. 

The fluosilicate method involves reacting silica in a previously neutralized solution with sodium fluoride to form sodium fluosilicate and sodium hydroxide by the following reaction ... 

Fluorine is usually recovered in the form of an aqueous solution of fluosilicic acid, H2S1F6. The concentration may be as high as 20%-25%. In some countries the fluosilicic acid is used directly for fluoridation of municipal water supplies to prevent tooth decay. The acid is shipped to various municipalities in rubber-lined rail-cars. Salts of fluosilicic acid, such as sodium, potassium, and ammonium fluosilicates, have various uses and can be readily produced from the acid. Sodium fluosilicate is... 

Bergman, in his examination of volcanic minerals, noticed the gelatinisation of silica when some silicates (zeolites) are treated with acids. He showed that the waters of several springs contain dissolved silica. He obtained artificial quartz ciystals by letting powdered quartz stand in a corked bottle for two years with hydrofluoric acid (containing hydrofluosilicic acid), and he emphasised that the precipitate (potassium or sodium fluosilicate) formed from the solution by vegetable or mineral alkali (potash or soda) is a triple salt of a peculiar kind, composed of siliceous earth, fluor acid, and fixed alkali, which dissolves with difficulty in warm water , whilst the precipitate with ammonia is pure silica. ... 

Thrash et al studied the analysis of phenylmethyldichloro-silane by reaction chromatography with sodium fluosilicate involving an on column conversation in a pre-column to the corresponding fluorosilanes which are then separated on the chromatographic column. Due to the similarity of their boiling points, phenyl methyl silicon dichloride and phenyl silicon trichloride cannot be separated by normal chromatographic procedures. 

Silver Fluoride Silver Fluoride Sodium Fluosilicate Sodium Silicofluoride... 

SODIUM FLUOSILICATE. NajfSiFJ. Alloys 3003 and 5154 were resistant to solid sodium fluosilicate in laboratory tests conducted under conditions of 100% relative humidity at ambient temperature. See also Ref (2) p. 688, (3) p. 69. 

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