GB1202971A - REDUCING TO MnO THE MnO<2> OF A MANGANESE ORE - Google Patents

Abstract

1,202,971. Reduction of higher oxides of Mn to MnO. PICKANDS MATHER & CO. 26 Jan., 1968, No. 4142/68. Heading CIA. Higher oxides of Mn in an Mn ore are reduced to MnO by passing a methane rich hydrocarbonaceous gas air mixture in which the ratio of air to methane is within the range of 2 : 1 to 4 : 1 preferably 2À4 : 1 and 3.5 : 1 into and through a body of heated reduced Mn ore, at 1000-2000‹ F., whose oxide content is in the form of MnO, to form an active reducing gas including H 2 and CO, the resulting gas mixture being passed into and through a layer of initially unreduced Mn ore contiguous to the body of reduced ore whereby to raise the temperature of the unreduced ore to 1300- 2000‹ F. and to reduce to MnO the higher oxides in the layer. After termination of the introduction of air and methane, the reduced ore may be cooled by passing a current of cool non-oxidizing gas through the reduced ore. The body of unreduced ore may be progressively enlarged by successive additions of fresh layers of unreduced ore as the higher oxide content of the ore in the underlying layers becomes reduced to MnO. The size of the body may be maintained within predetermined limits by with drawing reduced ore in amounts equivalent to the amounts of unreduced ore added. The above described process may be used in a pile reduction process after two layers, one of unreduced Mn ore and one of reduced Mn ore have been established by forming a small pile of unreduced Mn ore on a grating which is over a gas distribution chamber, heating the small pile of ore with gases passing outwardly from the vicinity of the chamber by burning a carbonaceous fuel with air adjacent to the chamber, continuing heating until at least the interior of the pile reaches at least 800‹ F., progressively feeding ore to the top and sides of the pile in order to maintain a substantially uniform temperature over the peripheral -portion of the pile while simultaneously passing a reduced gas mixture rich in CO and H 2 outwardly through the pile so as to form a zone of active reduction of the higher oxide of Mn to MnO, which zone gradually moves outwardly throughout the pile leaving a mass of hot freshly reduced MnO; when such a mass has been created the passage of reducing gas is terminated and a flow of methane-rich gas in air is established.