Limestone Crushing Plant in the Lines Indicate

Cross-connecting line 37 connects line 25 to duct 38 leading from windbox area 21 under the downdraft firing zone. Duct 38 connects with the intake of a scrubbercooler 39 and thence through a discharge duct 39a to a blower 40, which supplies cooled gases to windboxes 23 and 24 of the first and second cooling stages respectively via lines 42 and 43. Line 41 to windbox 22 in the updraft firing zone carries a selected mixture of gases from blower 44, which mixture may comprise gases from scrubber-cooler 39 via line 39a, blower 40 and line 41a,limestone crushing plant gases from downdraft firing windbox 21 via line 38 and scrubber-cooler by-pass line 45a, and air through line 45. Blower 46 discharges air into line 43 through air inlet line 47. 48 are dampers in the various lines for regulating or proportioning the flow of gases therethrough. The arrow in the lines indicate the direction of flow of gases in the various lines.

The operation of the apparatus will be more completely described in connection with the following description of the process of the invention.The pellets are comprised of oxidic iron ore fines such as hematite or magnetite, intimately admixed with a finely-divided carbonaceous fuel or reducing agent, such as coke breeze, char, anthracite, bituminous coal, lignite or combinations thereof. The ore concentrate is ground to 60% or more of 325 mesh. A typical ore concentrate may contain about 60 to 70% iron. The carbonaceous fuel is ground to a fineness of about 100 to 200 mesh and thoroughly mixed with the ore along with water and a binder, such as Bentonite. The resulting mixture contains iron ore, fuel in the preferred range of about 12 to 25% by weight of the ore, water of about 8 to 12% by weight of the ore, and a binder of about -1% by weight of ore.

This mixture is then balled or pelletized in a suitable balling or pelletizing apparatus of a conventional type (not shown). The pellets are then rolled in carbonaceous fuel fines to add an...