Title:
飛灰からの重金属回収方法
Document Type and Number:
Japanese Patent JP4277108
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce recovery cost of useful heavy metals while lightening the excessive treatment burden due to a flux component, which is a large quantity of calcium oxide, or the like, contained in fly ash together with the useful heavy metals and chlorine discharged from an incinerator, or the like, when the fly ash is treated. SOLUTION: The fly ash containing the useful heavy metal component such as zinc, copper and lead, the flux component such as calcium oxide and the chlorine is classified by a cyclone or another means to fractionate it into a fine particle part containing the heavy metal component mainly and a coarse particle part containing the flux component mainly. Water or a mineral acid is added to the obtained fine particle part to prepare slurry and the chlorine is separated from the acidic slurry by adjusting the pH of the slurry and the heavy metals are recovered as precipitates of their oxide or sulfide states from the slurry of an alkaline state. The obtained heavy metal-containing precipitates can be fed to a smelting process or can be fractionated into a lead product and a copper/zinc product. The coarse particle part obtained by the fractionation is reused as the flux component without any treatment in the original heating furnace.
Inventors:
Ryuji Arakawa
Miyazaki Masahisa
Miyazaki Masahisa
Application Number:
JP27279499A
Publication Date:
June 10, 2009
Filing Date:
September 27, 1999
Export Citation:
Assignee:
DOWA ECO-SYSTEM Co., Ltd.
International Classes:
C22B3/04; B09B3/00; C22B7/00; C22B13/00; C22B15/00; C22B19/20; F23J1/00
Domestic Patent References:
| JP8267046A | ||||
| JP8141539A | ||||
| JP8290145A | ||||
| JP8117724A |
Attorney, Agent or Firm:
Kenji Wada
Komatsu Taka
Komatsu Taka