Reference

Regeneration of hydrogen fluoride-nitrate pickling acid

Regeneration of hydrogen fluoride-nitrate pickling acid. Walker, Roy G. (Westinghouse Electric Corp., USA). U.S. US 5082523 A 21 Jan 1992, 4 pp. (United States of America). CODEN: USXXAM. CLASS: ICM: B44C001-22. ICS: C23F001-00. NCL: 156642000. APPLICATION: US 90-615675 19 Nov 1990. 16925-26-1 and 7664-39-3 are cas registry numbers of chemicals which are used as reagents here. DOCUMENT TYPE: Patent CA Section: 49 (Industrial Inorganic Chemicals) Section cross-reference(s): 60 The process comprises adding NaNO3 to a ZrF62--contg. spent pickling acid to ppt. Na2ZrF6 and sepg. the acid from the Na2ZrF6 ppt. The Zr2+ concn. of the pickling acid is reduced from 25 g/L to 1 g/L with an increase in Na+ concn. of <200 ppm. .

Novel method for zirconium oxide synthesis from aqueous solution

Novel method for zirconium oxide synthesis from aqueous solution. Yao, Takeshi; Inui, Takashi; Ariyoshi, Akira (Dep. Fundamental Energy Sci., Kyoto Univ., Kyoto 606-01, Japan). Journal of the American Ceramic Society, 79(12), 3329-3330 (English) 1996 American Ceramic Society. CODEN: JACTAW. ISSN: 0002-7820. DOCUMENT TYPE: Journal CA Section: 57 (Ceramics) Section cross-reference(s): 49 A novel method for zirconium oxide crystal synthesis from an aq. soln. 16925-26-1 and 1314-23-4 which are cas registry numbers are also used here. at ordinary temp. and pressure has been discovered. Boric acid was added to a sodium hexafluorozirconate soln., fluoride ion was consumed by the formation of BF4- complex ion, then the hexafluorozirconate ion was hydrolyzed to zirconium oxide to increase the amt. of fluoride ion. The formation of zirconium oxide crystal was confirmed by clear X-ray diffraction peaks. This method is promising for prepg. zirconium oxide films in various applications. .