Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Alumina from fly ash

Conference ·
OSTI ID:6574483

The results of the exploratory work done so far with the lime-sinter process show that more than 50 percent of the alumina in a typical fly ash can be made soluble by sodium carbonate extraction of the sintered product. Based on work reported for other non-bauxite materials, there is every reason to expect increased yields. Fly ash can become a potential, easily available, domestic resource for alumina. At the present rate of production of fly ash, this could supply approximately 35 percent of the alumina needs of the United States at a 50 percent recovery level. With an increase in alumina recovery to 75 to 80 percent, which appears attainable as further research leads to better processing conditions, the fly ash could supply even a greater share of the country's needs. It has been proposed that the residue from the leaching step in the lime-sinter process be dried, mixed with gypsum and calcined to produce a cement clinker. Fragmentary references in the literature suggest that this has been investigated in Hungary and Poland. If the use of the residue to manufacture cement proved technically feasible, it would mean the entire fly ash could be put to use.

Research Organization:
Iowa State Univ. of Science and Technology, Ames (USA)
DOE Contract Number:
W-7405-ENG-82
OSTI ID:
6574483
Report Number(s):
IS-M-143; CONF-7703106-1
Country of Publication:
United States
Language:
English