English: C 01 B 17/ 86 17/ 88 17/ 90 17/ 92 17/ 94 17/ 96 . . . . . . . . . Tower process . Concentration of sulfuric acid . Separation; Purification . . Recovery from acid tar or the like . . Recovery from nitration acids Methods for the preparation of sulfates in general (particular individual sulfates, see the relevant groups of subclasses C 01 B to G, according to the cation) . Other compounds containing sulfur and oxygen (persulfuric acids 15/06; persulfates 15/08) 21/ 44 21/ 46 21/ 48 . . . Concentration . . . Purification; Separation . . Methods for the preparation of nitrates in general (particular individual nitrates, see the relevant groups of subclasses C 01 B to G, according to the cation) . . Nitrous acid; Salts thereof Noble gases; Compounds thereof (liquefying F 25 J) Phosphorus; Compounds thereof (21/00, 23/00 take precedence; perphosphates 15/16) [3] . Treating phosphate ores or other raw phosphate materials to obtain phosphorus or phosphorus compounds [2] . Preparation of phosphorus . . of red phosphorus [2] . . of yellow phosphorus [2] . Purification of phosphorus . . of red phosphorus [2] . . of yellow phosphorus [2] . Hydrogen phosphides . Other phosphides . Halides or oxyhalides of phosphorus [2] . Oxides of phosphorus . Sulfur, selenium, or tellurium compounds of phosphorus . Oxyacids of phosphorus; Salts thereof (peroxyacids or salts thereof 15/00) . . Phosphorous acid; Salts thereof [2] . . Hypophosphorous acid; Salts thereof [2] . . Pyrophosphorous acid; Salts thereof [2] . . Phosphoric acid . . . Preparation from elemental phosphorus or phosphoric anhydride . . . Preparation by reacting phosphate containing material with an acid, e.g. wet process . . . . with sulfuric acid, a mixture of acids mainly consisting of sulfuric acid or a mixture of compounds forming it in situ, e.g. a mixture of sulfur dioxide, water and oxygen [3] . . . . . only one form of calcium sulfate being formed [3] . . . . . . Dihydrate process [3] . . . . . . Hemihydrate process [3] . . . . . one form of calcium sulfate being formed and then converted to another form [3] . . . . . . Hemihydrate-dihydrate process [3] . . . . . . Dihydrate-hemihydrate process [3] . . . . . Preparation by reacting phosphate containing material with concentrated sulfuric acid and subsequently lixiviating the obtained mass, e.g. clincker process [3] . . . Purification; Stabilisation; Concentration (purification concomitant with preparation 25/22; preparation involving solvent-solvent extraction 25/46) [3] . . . . Clarification; Stabilisation to prevent postprecipitation of dissolved impurities [3] . . . . Selective elimination of impurities [3]
French: Ses sels [2] . . Acide hypophosphoreux; Ses sels [2] . . Acide pyrophosphoreux; Ses sels [2] . . Acide phosphorique . . . Préparation à partir de phosphore élémentaire ou d’anhydride phosphorique . . . Préparation par réaction de produits contenant un phosphate avec un acide, p.ex. procédé par voie humide . . . . avec l’acide sulfurique, avec un mélange d’acides consistant principalement en acide sulfurique ou un mélange de composés formant de l’acide sulfurique in situ, p.ex. avec un mélange d’anhydride sulfureux, d’eau et d’oxygène [3] . . . . . une seule forme de sulfate de calcium étant obtenue [3] . . . . . . Procédé au dihydrate [3] . . . . . . Procédé à l’hémihydrate [3] . . . . . une forme de sulfate de calcium étant obtenue et ensuite convertie en une autre forme [3] . . . . . . Procédé du type hémihydratedihydrate [3] . . . . . . Procédé du type dihydratehémihydrate [3] . . . . . Préparation par réaction de produits contenant un phosphate avec de l’acide sulfurique concentré suivi d’une lixiviation de la masse obtenue, p.ex. procédé au clincker [3] . . . Purification; Stabilisation; Concentration (purification et préparation concomitantes 25/22; préparation comportant une extraction solvant-solvant 25/46) [3] . . . . Clarification; Stabilisation pour empêcher la précipitation ultérieure d’impuretés dissoutes [3] . . . . Elimination sélective d’impuretés [3]