GB884598A - Improvements relating to the reduction of metallic oxides in a shaft furnace - Google Patents

Abstract

884,598. Reducing iron ore. ELEKTROKEMISK A. S. Jan. 20, 1959 [Jan. 22, 1958; Feb. 21, 1958; Sept. 25, 1958], No. 2121/59. Class 72. [Also in Group XII] Briquettes of metallic oxide and reducing agent are reduced in a shaft furnace by the combustion of gases in contact with the briquettes, in which an oxygen containing gas such as air is introduced into the furnace at three different levels. As shown, briquettes from hopper 2 are reduced in shaft 1, air being supplied from pipes 4 and two-way valves 5 to nozzles 6-9. The nozzles are coupled in pairs diametrically opposite each other and the air is supplied to each pair alternately, e.g. 6 and 7 blow for say 5 minutes and then 8 and 9 for 5 minutes. The reduced briquettes are discharged by way of turntable 18 and flap valve 20. Shaft 1 may be made rotatable through an angle of 90 degrees to prevent local overheating at the mouths of the injection nozzles. A modification (Fig. 3) includes a central air injection pipe 22 with nozzles at four levels. This pipe may also be rotatable through 90 degrees. In a further modification (Fig. 4 not shown) centrally disposed air injection pipes may extend both from the top and the bottom of shaft 1. The discharged briquettes may be delivered directly to an electric melting furnace, reducing gas evolved therein being returned to the shaft furnace via pipe 21. Specification 717,851 is referred to.