Title:
METHOD FOR RECOVERING VALUABLE METAL FROM FLY ASH
Document Type and Number:
Japanese Patent JP3536901
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To efficiently recover valuable metals from fly ash at a low cost, to reduce the generation of waste liq. when the valuable metals are recovered from fly ash and the load on waste water treatment and to recover a high- quality gypsum from a calcium component contained in the fly ash.
SOLUTION: The method for recovering valuable metals from the fly ash contg. a calcium component, a chlorine component and the valuable metals includes a first stage 11 for treating the fly ash with a hydrochloric acid- acidified liq., a second stage 12 for filtering and skimming the liq. treated in the first stage, a third stage 13 for adding sulfuric acid to the liq. skimmed in the second stage to bring about a reaction and a fourth stage 14 for filtering the liq. reaction product of the third stage to form gypsum and hydrochloric acid-acidified liq. A part or the whole of the hydrochloric acid-acidified liq. formed in the fourth stage 14 is preferably used as the hydrochloric acid- acidified liq. to be used in the first stage 11.
Inventors:
Mochida, Hiromi
Tatsui, Akiyoshi
Tatsui, Akiyoshi
Application Number:
JP27961798A
Publication Date:
June 14, 2004
Filing Date:
October 01, 1998
Export Citation:
Assignee:
MITSUBISHI MATERIALS CORP
International Classes:
C22B3/04; C22B3/44; C22B7/02; C22B13/00; C22B19/00; C22B19/20; C22B19/30; B09B3/00; (IPC1-7): C22B3/04; B09B3/00; C22B3/44; C22B7/02; C22B13/00; C22B19/00; C22B19/30