BOPI 07 BR/2023 REPERTOIRE NUMERIQUE 24 Consulter le mémoire ________________________________________ (11) 21050 (51) B09B 3/00 (2018.01); C01B 25/234 (2018.01); C01G 11/00 (2018.01); C01G 13/00 (2018.01); C01G 21/00 (2018.01); C22B 3/16 (2018.01); C22B 3/44 (2018.01) ; C22B 7/00 (2018.01) (21) 1202200435 - PCT/EP2021/066244 (22) 16/06/2021 (30) EP n° 20180341.8 du 16/06/2020 (54) Method for treating solid hazardous heavy metal-containing compositions. (72) KITA, Patrycja (PL); VOJNOVIC, Tanja (NO); SUND, Lene (NO); JØRGENSEN, Tom Rames (NO) et BØYESEN, Katrine Lie (NO) (73) YARA INTERNATIONAL ASA, Drammensveien 131, 0277 OSLO (NO) (74) Cabinet BONNY & ASSOCIÉS, LAW FIRM, B.P. 35349, YAOUNDE (CM). (57) The present disclosure discloses a method for converting a solid hazardous heavy metalcontaining composition into a solid non-hazardous heavy metal-containing composition and an aqueous composition essentially free of heavy metal. The method comprises the steps of a) mixing and dissolving the solid hazardous heavy metal-containing composition with an acid solution, thereby obtaining an hazardous heavy metal acid composition; b) precipitating the heavy metal from the hazardous heavy metal acid composition by: measuring the pH of the acid composition after a 13-fold dilution by volume using water, and adjusting the pH of the solid hazardous heavy metal-containing composition to at least 0.9 if the measured pH is below 0.9; and by reacting the hazardous heavy metal acid composition with a heavy metal-precipitation agent; and c) precipitating the heavy metal from the hazardous heavy metal acid composition by adjusting the pH value of the composition to a value of at least 0.9 if the pH measured in step b) is below 0.9 and by reacting with a heavy metalprecipitation agent; and d) separating out the heavy metal precipitate from the aqueous supernatant, whereby the solid inert heavy metalcontaining composition comprises the heavy metal precipitate and the aqueous composition essentially free of heavy metal comprises the aqueous supernatant. The heavy metalprecipitation agent comprises a diorganodithiophosphinic acid or the alkali metal or ammonia salts thereof represented by Formula 1 wherein R is a linear or branched hydrocarbon group selected from alkyl, aryl, alkylaryl, or aralkyl, and wherein the hydrocarbon group contains 3 to 20 carbon atoms, and M is H, alkali metal or ammonia. The present disclosure further relates to the use of the heavy metal-precipitation agent for converting the solid hazardous heavy metal-containing composition into the solid nonhazardous heavy metal-containing composition and the aqueous composition essentially free of heavy metal.
RkJQdWJsaXNoZXIy MTM1NDc3MA==