Effect of preheating upon metallization of iron ore pellets.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 7612, 1972 Jan; :1-22
Drying and preheating (partial induration) of green, unfired iron ore pellets is a means of reducing the energy required to produce metallized pellets. The Bureau of Mines processed three magnetite and two hematite concentrates through the unit operations of pelletizing, preheating in air, and reduction to metal to determine the effects of preheating upon the properties of the metallized pellets. The pellets were prepared in a 16-inch-diameter laboratory balling drum. Preheating and metallization were carried out in an externally heated 4-inch-id by 4-inch-long stainless steel drum using air for the preheating atmosphere and lignite char as a reductant. The results varied considerably; two of the magnetites spalled when preheated in air at temperatures of 900 deg C and above, and the third magnetite and the hematite flotation concentrate required complete induration at 1,300 deg C to produce satisfactory pellets. The earthy hematite ore yielded excellent pellets at all preheat temperatures.
Mining-industry; Mineral-processing; Metals
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 7612