Roasting Nonmagnetic Taconites in a Fluid Bed Using Low-rank Fuels as Reductants.
Pahlman-JE; Ruzzi-PL; Schluter-RB
NTIS: PB 255 546 :15 pages
The Bureau of Mines performed research on a fluid-bed magnetic roasting process for nonmagnetic taconites that utilizes low-rank coals and lignites as reductants and fuels. Roasting tests on a Michigan nonmagnetic taconite were conducted at 600 deg to 725 deg c with lignite or subbituminous coal as reductants. Partial combustion of the reductant reduced the amount of heat externally applied to the reactor to maintain the desired reactor temperature. Cleaned, dried reactor top gases were recycled to recover a portion of the reducing potential in these gases without adversely affecting concentrate grade and iron recovery. Highest iron recoveries for magnetic concentrates were obtained at a roast temperature of 650 deg c with lignite and at a roast temperature of 725 deg c with subbituminous coal. Magnetic concentrates were obtained that were comparable with commercial concentrates.
IH; Report of Investigation;
NTIS Accession No.
NTIS: PB 255 546