| 摘要 |
A method and apparatus for producing cement which includes intermixing the cement forming raw materials with water, coal or coke and cement as a binder and forming this mixture of materials into nodules by pelletizing or extrusion. The system is particularly designed for use in making white cement where raw materials low in coloring compound are used as raw feed. The nodules are then sized to obtain a feed material having a size range on the order of one quarter inch by 14 mesh which is suitable for use in a fluidized bed reactor. The nodulized raw material is thermally processed in a fluidized bed reactor at temperatures in the range of approximately 2500 DEG to 2700 DEG F. for white cement and 2350 DEG -2450 DEG F. for typical gray Portland Cement. The coal or coke mixed with the raw material serves to supply between 60% and 90% precent of the fuel required for the process with the remainder being supplied directly to the fludized bed. This fuel serves to provide internal reduction conditions within the particles of material. The product is discharged from a fluidized bed and cooled in an indirect heat exchanger.
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