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1. WO2000040507 - METHOD FOR PURIFICATION OF PHOSPHORIC ACID AND HIGH PURITY POLYPHOSPHORIC ACID

Publication Number WO/2000/040507
Publication Date 13.07.2000
International Application No. PCT/JP1999/007312
International Filing Date 24.12.1999
Chapter 2 Demand Filed 17.05.2000
IPC
C01B 25/237 2006.01
CCHEMISTRY; METALLURGY
01INORGANIC CHEMISTRY
BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF
25Phosphorus; Compounds thereof
16Oxyacids of phosphorus; Salts thereof
18Phosphoric acid
234Purification; Stabilisation; Concentration
237Selective elimination of impurities
C01B 25/24 2006.01
CCHEMISTRY; METALLURGY
01INORGANIC CHEMISTRY
BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF
25Phosphorus; Compounds thereof
16Oxyacids of phosphorus; Salts thereof
24Condensed phosphoric acids
CPC
C01B 25/237
CCHEMISTRY; METALLURGY
01INORGANIC CHEMISTRY
BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; ; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
25Phosphorus; Compounds thereof
16Oxyacids of phosphorus; Salts thereof
18Phosphoric acid
234Purification; Stabilisation; Concentration
237Selective elimination of impurities
C01B 25/24
CCHEMISTRY; METALLURGY
01INORGANIC CHEMISTRY
BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; ; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
25Phosphorus; Compounds thereof
16Oxyacids of phosphorus; Salts thereof
24Condensed phosphoric acids
Applicants
  • TOYO BOSEKI KABUSHIKI KAISHA [JP/JP]; 2-8, Dojimahama 2-chome, Kita-ku Osaka-shi, Osaka 530-0004, JP (AllExceptUS)
  • HOTTA, Kiyoshi [JP/JP]; JP (UsOnly)
  • KUBOTA, Fuyuhiko [JP/JP]; JP (UsOnly)
Inventors
  • HOTTA, Kiyoshi; JP
  • KUBOTA, Fuyuhiko; JP
Agents
  • TAKASHIMA, Hajime; Yuki Building 3-9, Hiranomachi 3-chome Chuo-ku Osaka-shi Osaka 541-0046, JP
Priority Data
10/37369628.12.1998JP
11/23062817.08.1999JP
Publication Language Japanese (JA)
Filing Language Japanese (JA)
Designated States
Title
(EN) METHOD FOR PURIFICATION OF PHOSPHORIC ACID AND HIGH PURITY POLYPHOSPHORIC ACID
(FR) PROCEDE DE PURIFICATION DE L'ACIDE PHOSPHORIQUE ET ACIDE POLYPHOSPHORIQUE DE GRANDE PURETE
Abstract
(EN)
A method for purification of phosphoric acid, characterized as comprising contacting a crude phosphoric acid containing arsenic with hydrogen halide to remove the arsenic from the crude phosphoric acid; and a method for purification of phosphoric acid, characterized as comprising contacting a crude phosphoric acid containing arsenic with hydrogen halide in the presence of a compound which can produce hydrogen halide under an acidic condition. The above methods provide novel methods for removing arsenic from a crude phosphoric acid which does not require any of a filtering and a degassing processes which are necessary in the sulfide precipitation method, does not give a large amount of residual sodium, can be applied to a crude phosphoric acid having a high concentration of phosphorus pentoxide, particularly to polyphosphoric acid, and can be practiced at a low cost; and thus they can be used for producing a high purity polyphosphoric acid having an arsenic (As) content of 1 ppm or less and also low contents of heavy metals, silica, sodium and the like.
(FR)
Cette invention concerne un procédé de purification de l'acide phosphorique, qui consiste à mettre en contact un acide phosphorique brut renfermant de l'arsenic avec un halogénure d'hydrogène pour éliminer l'arsenic de l'acide phosphorique brut. Elle concerne également un procédé de purification de l'acide phosphorique, qui consiste à mettre en contact un acide phosphorique brut renfermant de l'arsenic et un halogénure d'hydrogène en présence d'un composé pouvant produite un halogénure d'hydrogène en conditions acides. La nouveauté des procédés susmentionnés tient au fait qu'ils permettent d'extraire l'arsenic d'un acide phosphorique brut sans les opérations de filtrage et de dégazage requises avec la méthode de précipité de sulfure, qu'ils ne laissent pas un volume important de sodium résiduel, qu'ils conviennent pour un acide phosphorique brut à forte teneur en anhydride phosphoreux, en particulier pour un acide polyphosphorique, et qu'ils peuvent être mis en oeuvre pour un faible coût. Ainsi, ces procédés conviennent pour la production d'acide polyphosphorique de grande pureté dont la teneur en arsenic (As) est de 1ppm ou moins, avec en outre de faibles teneurs en métaux, silice, soude et analogues.
Also published as
ININ/PCT/2001/1065/CHE
ZA200106211
Latest bibliographic data on file with the International Bureau