7783-28-0Relevant articles and documents
PROCESS FOR RECOVERING PHOSPHORIC ACID FROM SOLID PHOSPHORUS SOURCES
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Page/Page column 12, (2020/09/08)
The invention pertains to a process for preparing phosphoric acid from a solid phosphorus-containing material, comprising the steps of: - reacting a solid phosphorus-containing material with strong acid in an amount of 1.0-15 mole acid, calculated as protons, per mole of phosphorus (calculated as P) in the solid phosphorus-containing material in a monophasic reaction medium comprising an organic solvent, to form a solution of phosphoric acid in organic solvent and remaining solid material, - separating the solution of phosphoric acid in organic solvent from the remaining solid material. It has been found that phosphoric acid can be recovered from a solid phosphorus-containing material in high purity and efficiency via a solid-state rearrangement/elution process. The process according to the invention does not require the use of the large amounts of water required by the conventional dissolution/extraction processes known in the art. The solution of phosphoric acid in organic solvent can be used as a starting material for further processes.
Method for preparing hydroxylamine
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Page/Page column 2-6, (2008/06/13)
A method for preparing hydroxylamine is provided that includes the steps of (i) pretreating an acidic buffer solution; and (ii) reducing nitrate ions in the acidic buffer solution with hydrogen to give hydroxylamine in the presence of catalysts, wherein the pretreatment is performed by adding a precipitant represented by formula (I) to the acidic buffer solution, [in-line-formulae][(A)aM(CN)6.xH2O]??(I) [/in-line-formulae] allowing the metal impurities in the acidic buffer solution to react with the precipitant to form metal complex, and then to remove the metal complex. The metal complex is formed and separated by pretreating the acidic buffer solution with a specific precipitant without adjusting pH and changing the composition of the acidic buffer solution prior to hydroxylamine synthesis, thus enhancing the selectivity of the hydroxylamine production.
Solid-Phase Interaction of Fluorapatite with Ammonium Hydrogen Difluoride
Laptash, N. M.,Kaidalova, T. A.
, p. 535 - 537 (2008/10/08)
A solid-phase interaction of fluorapatite with ammonium difluoride was studied in the temperature range 25-900°C. At room temperature, calcium fluoride and ammonium dihydrogen phosphate or isostructural ammonium florophosphate were formed as the result of grinding a mixture of theinitial components. Above 200°C, the reaction was accompanied by the formation of a volatile phosphor compound. At the final stage of th e process (above 500°C), glassy ammonium hydrogen ultrafluorophosphate of nonstoichiometric composition was formed, which again yielded fluorapatite upon reaction with calcium fluoride.