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1. (WO1998051616) PROCESS FOR THE PRODUCTION OF GYPSUM FROM SULPHURIC ACID CONTAINING WASTE STREAMS
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1998/051616 International Application No.: PCT/AU1998/000347
Publication Date: 19.11.1998 International Filing Date: 12.05.1998
Chapter 2 Demand Filed: 10.12.1998
IPC:
C01F 11/46 (2006.01) ,C02F 1/52 (2006.01)
C CHEMISTRY; METALLURGY
01
INORGANIC CHEMISTRY
F
COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
11
Compounds of calcium, strontium, or barium
46
Sulfates
C CHEMISTRY; METALLURGY
02
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
F
TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
1
Treatment of water, waste water, or sewage
52
by flocculation or precipitation of suspended impurities
Applicants:
HOSE, Robert [AU/AU]; AU
STRAY, Gavan, J. [AU/AU]; AU
OMAHEN, Franc [DE/AU]; AU
Inventors:
HOSE, Robert; AU
STRAY, Gavan, J.; AU
OMAHEN, Franc; AU
Agent:
SLATTERY, J., M. ; Davies Collison Cave 1 Little Collins Street Melbourne, VIC 3000, AU
Priority Data:
9701492-212.05.1997SG
Title (EN) PROCESS FOR THE PRODUCTION OF GYPSUM FROM SULPHURIC ACID CONTAINING WASTE STREAMS
(FR) PROCEDE DE PRODUCTION DE GYPSE A PARTIR DE FLUX DE DECHETS CONTENANT DE L'ACIDE SULFURIQUE
Abstract:
(EN) This invention provides a process for the production of gypsum from a waste stream containing sulphuric acid including: (A) adding calcium containing basic material to said waste stream to bring pH within the range of from about 2.0 to 2.7 to precipitate gypsum, and recovering the precipitated gypsum from the waste stream, and (B) adding basic material to the waste stream to bring pH within the range of from about 3.0 to 3.4 to precipitate impurities, and removing the precipitated impurities from the waste stream, and (C) adding calcium containing basic material to said waste stream to bring pH within the range of from about 4 to 6 precipitate gypsum, and recovering the precipitated gypsum from the waste stream.
(FR) La présente invention concerne un procédé de production de gypse à partir d'un flux de déchets contenant de l'acide sulfurique. Ce procédé consiste (A) à ajouter un matériau de base contenant du calcium au flux de déchets, pour amener le pH à une valeur comprise entre 2,0 et 2,7 et assurer la précipitation du gypse, puis à récupérer le gypse précipité du flux de déchets; (B) à ajouter un matériau de base au flux de déchets pour amener le pH à une valeur comprise entre 3,0 et 3,4 pour assurer la précipitation des impuretés, et retirer les impuretés précipitées du flux de déchets; et (C) ajouter un matériau de base contenant du calcium au flux de déchets pour amener le pH à une valeur comprise entre 4 et 6 pour assurer la précipitation du gypse, et récupérer le gypse précipité du flux de déchets.
Designated States: AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, GW, HU, ID, IL, IS, JP, KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW
African Regional Intellectual Property Organization (ARIPO) (GH, GM, KE, LS, MW, SD, SZ, UG, ZW)
Eurasian Patent Organization (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM)
European Patent Office (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE)
African Intellectual Property Organization (BF, BJ, CF, CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
AU1998073253MYPI 98002114