skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Dissolution and recovery of aluminum and other metals from Calsinter process sinter product

Conference ·
OSTI ID:5538325

In the Calsinter process for the recovery of aluminum and other metals, fly ash is sintered with a source of calcium oxide at 1000 to 1200/sup 0/C, and the sinter product leached with dilute sulfuric acid. The leach step parameters have been optimized following a sinter of eastern Tennessee fly ash with limestone. Batch rate studies have shown that near maximum aluminum solubilization was achieved in 1 h at ambient temperature with 4N H/sub 2/SO/sub 4/ at 20% pulp density. A three-stage batch countercurrent leach system was operated under steady-state conditions in which only 2.2 moles of H/sub 2/SO/sub 4/ were required per mole of Al/sub 2/O/sub 3/ solubilized. Solubilization of aluminum (97%), iron (97%), titanium (82%), and a number of trace metals was obtained. Solvent extraction, employing a primary amine, removed 100% of the iron and 95% of several other metals present in significant concentration from the leach solution and rejected >90% of the aluminum. A cursory examination of the crystallization of ammonium alum from the solvent extraction raffinate showed product decontamination, with respect to Fe/sub 2/O/sub 3/, K/sub 2/O, MnO/sub 2/, and P/sub 2/O/sub 5/, to be excellent. Concentrations of CaO and Na/sub 2/O, however, were above specification limits.

Research Organization:
Oak Ridge National Lab., TN (USA)
DOE Contract Number:
W-7405-ENG-26
OSTI ID:
5538325
Report Number(s):
CONF-810203-20; ON: DE83015512
Resource Relation:
Conference: AIME annual meeting, Chicago, IL, USA, 22 Feb 1981
Country of Publication:
United States
Language:
English