摘要 |
A method and means for maintaining optimum operation of the process for directly reducing iron oxides in a rotary kiln, using a solid carbonaceous reducing agent, such as coal fed at both the charge feed end and discharge end as the source of fuel and reductant, and oxygen-containing gases is disclosed wherein the DRI product, charred coal or char, and fine waste found in the kiln discharge materials from the discharge end are separated and measured for fixed carbon content and the process parameters may be adjusted to optimum by establishing an appropriate percentage by weight, in the range from 5% to 15%, of fixed carbon in the total of these discharge materials. This optimum condition may be monitored by establishing a particular level of char in the char recycle bin once the appropriate percentage by weight of fixed carbon is established in these discharge materials and optimum operation is maintained by maintaining the particular level of the char in the recycle bin and appropriately adjusting the coal feed and related parameters of the process if the char level rises or drops within the bin. |