Hexafluorozirconate

Hexafluorozirconic acid [12021 -95-3]], H2ZrP, is formed by dissolving freshly prepared oxide, fluoride, or carbonate of zirconium in aqueous HP. This acid is produced commercially in a concentration range of 10 to 47%. The acid can be stored at ambient temperatures in polyethylene or Teflon containers... 

Hexafluorozirconic acid is used ia metal finishing and cleaning of metal surfaces, whereas the fluorozirconates are used in the manufacture of abrasive grinding wheels, in aluminum metallurgy, ceramics industry, glass manufacturing, in electrolytic cells, in the preparation of fluxes, and as a fire retardant (see Abrasives Metal surface treati nts). 

High purity hexafluorozirconic acid and its salts are produced by Advance Research Chemicals of the United States, and Akita and Moritta of Japan. The technical-grade green-colored material is suppHed by Cabot Corp. of the United States. In 1993, the U.S. market for fluorozirconic acid was about 250,000 kg/yr the world market was less than 500,000 kg/yr. A principal part of this production is consumed by the wool, garment, and upholstery industries. The 1993 price varied between 2.4 to 6.6/kg depending on the quaUty and quantity required. Potassium fluorozirconate [16923-95-8], K ZrF, is commercially important the world market is about 750,000 kg/yr. The most important appHcation is as a fire-retardant material in the wool (qv) industry, for the manufacture of garments, upholstery for aeroplane industry, and children s clothes (see Flame retardants). The 1993 unit price was between 5.0 and 6.6/kg. 

Fluorozirconate Crystallization. Repeated dissolution and fractional crystallization of potassium hexafluorozirconate was the method first used to separate hafnium and zirconium (15), potassium fluorohafnate solubility being higher. This process is used in the Prinieprovsky Chemical Plant in Dnieprodzerzhinsk, Ukraine, to produce hafnium-free zirconium. Hafnium-enriched (about 6%) zirconium hydrous oxide is precipitated from the first-stage mother Hquors, and redissolved in acid to feed ion-exchange columns to obtain pure hafnium (10). 

Fluorosilicate Fusion. The fusion reaction of milled zircon with potassium hydrogen fluoride was used to prepare potassium hexafluorozirconate [16923-95-8] for studies leading to the first separation of hafnium and zirconium (30). Similar reactions using potassium hexafluorosihcate have been used (31,32) commercially in the United States and the former USSR ... 

The use of potassium hexafluorosihcate is preferred over sodium hexafluorosihcate because of the lower tendency of the potassium compound to dissociate the lose sihcon tetrafluoride by sublimation. The addition of potassium carbonate or chloride to the fusion mix further reduces this tendency and promotes completion of the reaction. The reaction is conducted in a rotary furnace operating at 700°C. The product is cmshed prior to leaching with acidified hot water. The hot slurry is filtered to remove the sihca, and potassium hexafluorozirconate crystallizes as the solution cools. 

Potassium hexafluorozirconate (K2ZrF6) is leached with hot 1% hydrochloric acid. The hafnium present in the ore undergoes a similar reaction, forms potassium hexafluorohafnate (K2HfF6), and enters the solution during leaching. These two compounds, K2ZrF6 and... 

Zirpro A process for flame-proofing textiles by treating them with aqueous solutions of zirconium complexes. Wool is treated with aqueous potassium hexafluorozirconate and citric acid. Developed by the International Wool Secretariat, Yorkshire, now based in Melbourne, Australia. 

Fluorosilicate Fusion. Milled zircon and potassium hexafluorosflicate are heated together to yield potassium hexafluorozirconate and silica... 

The fused product is cooled, cmshed, and leached with acidified hot water. The resulting hot solution of potassium hexafluorozirconate—hafnate is filtered to remove silica, then cooled to allow crystallization of the potassium hexafluorozirconate—hafnate. Many of the impurity metals remain in solution. 

Zirconium-alizarin lake test Hydrochloric acid solutions of zirconium salts are coloured reddish-violet by alizarin-S or by alizarin (see under Aluminium, Section III.23, reactions 8 and 9 and under Zirconium, Section VII.18, reaction 8) upon adding a solution of a fluoride the colour of such solutions changes immediately to a pale yellow (that of the liberated alizarin sulphonic acid or alizarin) because of the formation of the colourless hexafluorozirconate(IV) ion... 

Note Stannous hexafluorozirconate is said to be more effective than the fluoride in preventing dental caries. 

Aflammit ZR Dipotassium hexafluorozirconate(2-) Dipotassium zirconium hexafluoride EINECS 240-985-6 HSDB 2019 NSC 310011 Potassium fluorozirconate Potassium fluorozirconate (K2ZrF6) Potassium hexafluorozirconate Potassium zirconifluoride Potassium zirconium fluoride Potassium zirconium hexafluoride Zirconate(2-), hexafluoro-, dipotassium Zirconium potassium fluoride, Flameprooflng agent used in wool processing. Also used in manufacture of zirconium. Solid slightly soluble in cold H2O, Thor Chemicals (UK) Ltd. 

The lithium (249) and copper(II) (138, 180) hexafluorozirconates have been shown to contain the 6-coordinate ZrF, in contrast to the ZrF% found in potassium salt. The compound Li4ZrFg has been obtained from aqueous solutions of LiF and ZrF4 (316). It has been reported to be tetragonal, with four molecules in the unit cell which has dimensions a = 9.633 0.003 A and c = 5.672 0.001 A. Whether this compound contains the ZrF ion or not is not known, but the compound, LigBeF4-ZrFg, which is obtained from a fused system does (484). The crystal is... 

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