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Title: Direct acid dissolution of aluminum and other metals from fly ash

Conference ·
OSTI ID:6670624

Fly ash could provide a significant domestic source of alumina and thus supply a large part of the US needs for aluminum and possibly also several other metals. The aluminum and other metals can be solubilized from fly ash by acid dissolution methods. The aluminum may be present in any or all of three solid phases: (1) crystalline; (2) glassy amorphous; and (3) irregular, spongy amorphous. The chemistry of these phases controls the solubilization behavior. The aluminum in high-calcium western ashes is primarily found in the amorphous phases, and much of it can be solubilized by using short-time, ambient-temperature leaching. Little of the aluminum in the low-calcium eastern ashes is solubilized under ambient-temperature conditions, and only a portion can be solubilized even at reflux temperature conditions. Some of the aluminum in these eastern ashes is present as mullite, while some is found in the amorphous material. The fraction contained in mullite is relativey acid insoluble, and only partial solubilization can be achieved even under vigorous acid leach conditions.

Research Organization:
Oak Ridge National Lab., TN (USA)
DOE Contract Number:
W-7405-ENG-26
OSTI ID:
6670624
Report Number(s):
CONF-810203-6
Resource Relation:
Conference: AIME annual meeting, Chicago, IL, USA, 22 Feb 1981
Country of Publication:
United States
Language:
English