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烧结过程余热资源的高效回收与利用是目前钢铁企业降低烧结工序能耗的主要措施之一。从热工角度总结分析了我国烧结余热回收与利用过程中存在的主要问题及其成因，在此基础上，根据热力学第一和第二定律，提出了分级回收与梯级利用技术，即在优先考虑改善烧结工艺条件的前提下，将温度较高的余热实施动力回收，将温度较中和较低的余热实施直接热回收，用于预热干燥烧结原料、点火炉的助燃空气、为热风烧结提供热风等。在此基础上，讨论了分级回收与梯级利用的关键问题：设置适宜的冷却风流量和冷却机内料层厚度是烧结矿显热回收最为关键的两个因素；减小烧结漏风与冷却漏风是分级回收与梯级利用另外一个关键因素。

It is an important measure to recovery and utilize the waste/residual heat resource of sintering-cooling process in cogeneration system for modern iron and steel enterprises nowadays. In the paper, the key problems and causes of recovery and utilization of sintering waste heat were analyzed firstly, and then the method and technique of “grade recovery and cascade utilization(GRUC)” was put forward according to the first and second laws of thermodynamics. The waste heat is recovered in grades according to the quality firstly, and then different qualities of residual heat recovered are utilized in cascades. The higher-temperature part of sinter cooling waste gas is used for power recovery, the medium or lower-temperature parts are used for direct thermal utilizations, such as drying and preheating of sinter mixture, combustion-supporting for ignition, hot-air sintering and so on. It is notable that the waste heat should be satisfied for the direct thermal utilizations first of all. In addition, the key problems of GRUC were researched. The results show that flow-rate of cooling air and height of sinter layer are main influencing factors on the recovery and utilization of waste heat; Moreover, the leakage of sintering-cooling system is another aspect influencing waste heat recovery and utilization.