| 摘要 |
PURPOSE:To improve the yield of the carbonaceous material to be internally charged to the surface layer part of preheated pellets and to improve reducibility by successively providing a preheating chamber for the pellets and rotary kiln and controlling the temp. of the waste combustion gas to be admitted from the rotary kiln to the preheating chamber. CONSTITUTION:The green pellets are produced by mixing the granular chromium ore, reducing agent and binder at a prescribed ratio and humidifying and pelletizing the mixture by a disk pelletizer 1. The green pellets are conveyed by a grate conveyor 3 into a preheater 2 and are successively passed through a 3rd chamber, 2nd chamber and 1st chamber by which the pellets are gradually heated to higher temps. and are preheated. The waste combustion gas 8 is directly fed from the rotary kiln 4 into the 1st chamber and, therefore, said gas contains an oxidative gas and has the higher temp. A spray nozzle 7 is, therefore, disposed in the 1st chamber and the gas temp. is lowered by direct spraying of water by which the decarburization reaction is suppressed and the yield of the carbonaceous material in the surface layer part of the pellets is improved to a remarkably higher level.
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