Title:
TREATMENT OF FLUORINE-CONTAINING WASTE WATER
Document Type and Number:
Japanese Patent JP2839001
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce sludge generated at the time of heating a fluorine-containing waste water and to reduce a load on environment by converting a gel like aluminum hydroxide, on which fluorine is adsorbed, to a crystalline aluminum compound and then disposing it.
SOLUTION: Calcium chloride is added into the fluorine-containing waste water in a primary treating tank 1 to solid-liquid separate calcium fluoride in a 1st settling tank 2. Aluminum sulfate is added in the supernatant liquid in an advanced treating tank 3 and the gel like aluminum hydroxide is produced by adjusting it to pH7 with sodium hydroxide. The gel like aluminum hydroxide is stirred to adsorb fluorine and aluminum hydroxide 5, on which fluorine is adsorbed, is solid-liquid separated in a 2nd settling tank 4. The supernatant liquid is discharged and on the other hand, the slurry of the aluminum hydroxide 5 is taken out to a dissolving tank 7 and is adjusted to ≥ pH11 to make an aluminate solution 8. Next, the crystalline aluminum hydroxide 9 produced by passing carbon dioxide gas is solid-liquid separated and is decreased in the water content up to about 37% with a filter press.
Inventors:
TOYODA ARATA
Application Number:
JP5863096A
Publication Date:
December 16, 1998
Filing Date:
March 15, 1996
Export Citation:
Assignee:
NIPPON DENKI KK
International Classes:
C02F1/28; C02F1/58; (IPC1-7): C02F1/58; C02F1/28
Domestic Patent References:
| JP1107890A | ||||
| JP811232B2 | ||||
| JP5535994B2 | ||||
| JP6258794B2 | ||||
| JP736911B2 |
Attorney, Agent or Firm:
Naoki Kyomoto (2 outside)