|Statement||by G. L. Flemmert.|
|Series||Proceedings - Fertiliser Society ; no. 163|
|LC Classifications||S631 .F37 no. 163, QD181.F1 .F37 no. 163|
|The Physical Object|
|Pagination||, 23 p. :|
|Number of Pages||23|
|LC Control Number||77368685|
A procedure is presented for utilization of waste silicas from hydrogen fluoride synthesis and aluminum fluoride production. A method of purifying silica from fluorine impurities is given. Results of studies on application of by-product silicas from the fluorine processing as fillers for rubber mixtures and urethan elastomers is by: The technology has been upgraded by Wengfu Group for producing hydrogen fluoride by fluosilicic acid, imported from Switzerland, using the one-step process to decompose fluosilicic acid into hydrogen fluoride and silica. Compared with the two-step method of hydrogen fluoride production by fluosilicic acid that is under research in the nation. The ammonium fluoride and the ammonia evolved in steps (d) and (e) of the sodium bifluoride route of the invention are recycled to the heating stage of step (c) of the process. Sufficient ammonium fluoride is evolved in steps (d) and (e) to provide the ammonium fluoride necessary in step (c).Cited by: Photometric Determination of Fluosilicic Acid in Hydrofluoric Acid.
Safe Handling of Hydrogen Fluoride and Hydrofluoric Acid. Hydrogen Fluoride (HF) is a commonly used substance on campus, but a very dangerous one. As an anhydrous material, it is a colorless gas or fuming liquid. Anhydrous HF has a boiling point of °C or 67°F. 1,, tonnes of hydrogen fluoride is 1,, tonnes of FSA % H 2SiF 6. Hence it would be possible to manufacture most of the world’s hydrogen fluoride demand by starting from by-product FSA. Up to now, fluorspar of acid grade has been the only fluorine-containing raw material used for the production of hydrogen fluoride. The potassium bisulfate and sulfuric acid mixture remaining in the vented vessel after removal of the hydrogen fluoride, which amounts to about parts, or 90% of theory, is recycled to the first operation where it is held as the precipitant for the succeeding batch of fluosilicic acid. Synonym: Potassium acid bifluoride solution, Potassium acid fluoride solution, Potassium bifluoride, Potassium fluoride hydrofluoride solution, Potassium hydrogen difluoride, Potassium monohydrogen difluoride solution.
action of hydrogen fluoride or concentrated sulfuric acid & a metallic fluoride on silica or silicates. Lewis, R.J., Sr (Ed.). Hawley's Condensed Chemical Dictionary. 12th ed. Fluorosilicic Acid Hydrogen hexafluorosilicate 40% Hydrofluorosilicic acid, Fluosilicic acid, Hexafluosilicic acid, Silicofluoric acid, Sand acid UN No: CAS-No: 3. HAZARDS IDENTIFICATION EMERGENCY OVERVIEW Corrosive. Causes burns. Decomposes when heated, with possible emanation of toxic hydrofluoric acid vapours. 4. A product containing up to o fluosilicic acid is recovered in the fluoride recovery system at atmospheric pressure and the removal efficiency is better than 99Vo (9OVo wrlh one absorber). Fluosilicic acid Hydroflurosilicic acid (%) and silica, also present as an impurity, form fluorosilicic acid. Ca3(PO4)2 + 3H2SO4 → 2H3PO4 + 3CaSO4. SiO2 + 6F-(fluorine) + 2H+ (acid) → H 2SiF6 + O2. Page 3 of 7 hydrogen fluoride vapor can be generated if FSA .