EP 4259575 A1 20231018 - INTEGRATED METHOD FOR THE DECADMIATION OF PHOSPHORIC ACID
Title (en)
INTEGRATED METHOD FOR THE DECADMIATION OF PHOSPHORIC ACID
Title (de)
INTEGRIERTES VERFAHREN ZUR ENTKOFFEINIERUNG VON PHOSPHORSÄURE
Title (fr)
PROCEDE INTEGRE DE DECADMIATION D'ACIDE PHOSPHORIQUE
Publication
Application
Priority
- FR 2012986 A 20201210
- MA 2021050020 W 20211210
Abstract (en)
[origin: WO2022124875A1] The present invention relates to an integrated method for the decadmiation of phosphoric acid, which comprises: etching (1) phosphate (Ph) with sulphuric acid (SA) in a reactor so as to prepare a phosphoric acid solution containing cadmium and calcium sulphate dihydrate or hemihydrate; concentrating (2) said phosphoric acid solution, so as to form a concentrated phosphoric acid (PA) having a mass content between 42% and 61% of P2O5; adding (3) sulphuric acid (SA) in order to adjust the free sulphate content, anhydrite being formed by recrystallisation of the calcium sulphate dihydrate and hemihydrate, the cadmium co-crystallising with said anhydrite, so as to obtain decadmiated phosphoric acid and cadium-rich anhydrite sludge; - desulphating (4) the decadmiated phosphoric acid; desaturating (5) and clarifying (6) by decanting the mixture of decadmiated phosphoric acid and sludge; conditioning (7) said sludges (PS1) with a phosphoric acid solution (APd) having a titre by mass of less than or equal to 61% of P2O5; recycling the conditioned sludge (PS2) in the phosphate etching step (1).
IPC 8 full level
C01B 25/222 (2006.01); C01B 25/238 (2006.01)
CPC (source: EP)
C01B 25/222 (2013.01); C01B 25/238 (2013.01); Y02P 20/10 (2015.11)
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
Designated validation state (EPC)
KH MA MD TN
DOCDB simple family (publication)
WO 2022124875 A1 20220616; AU 2021398517 A1 20230727; CA 3202025 A1 20220616; CN 116745238 A 20230912; EP 4259575 A1 20231018; FR 3117476 A1 20220617; FR 3117476 B1 20230421; MX 2023006955 A 20230928
DOCDB simple family (application)
MA 2021050020 W 20211210; AU 2021398517 A 20211210; CA 3202025 A 20211210; CN 202180092654 A 20211210; EP 21830526 A 20211210; FR 2012986 A 20201210; MX 2023006955 A 20211210