Sintered ores with superior high-temperature reducibility can enhance indirect reduction at the shaft and permeability at the cohesive zone through improving the softening-melting behavior, resulting in stable operation of the blast furnace at low coke rates. As the depletion of high-grade ore deposits limits control of the chemical composition of sintered ores, small pores less than 10 µm in diameter in the microstructure of sintered ores were focused on to increase the high-temperature reducibility. Sintering conditions for increasing small pores in constant raw material conditions were examined. Furthermore, considering the heterogeneous structure of the sintered ores, reduction behaviors of relict ores and assimilated structures were estimated individually. The contribution of each structure to small pore formation during sintering and their influence on high-temperature reducibility was discussed.

Sintering with a sharp temperature profile led to many small pores in the sintered ores by increasing the amount of relict ores with small pores even in constant raw material conditions. Both, for relict ores and assimilated structures, low-temperature reducibility was determined by the total porosity including large pores, whereas the Al₂O₃ content in gangue minerals, the <10 µm pore volume fraction, and the amount of gangue mineral influenced high-temperature reducibility. Assimilated structures involving granular hematite contained many small pores, compared with other types of assimilated structures. Results of plant trials for two different methods to increase small pores, in relict ores and in assimilated structures, revealed their potential for improving the high-temperature reducibility of sintered ores without controlling the chemical composition.

具有优良的高温还原性的烧结矿可通过改善软熔特性来提高竖井的间接还原率和粘结区的渗透率，从而使高炉在低焦化率下稳定运行。由于高品位矿床的枯竭限制了烧结矿化学成分的控制，因此小于10 µm的小孔为了提高高温还原性，着眼于烧结矿的微结构的直径m。检查了在恒定的原材料条件下增加小孔的烧结条件。此外，考虑到烧结矿的异质结构，分别估算了残矿和还原结构的还原行为。讨论了每种结构对烧结过程中小孔形成的贡献及其对高温还原性的影响。

即使在原材料条件不变的情况下，具有尖锐温度曲线的烧结也会通过增加带有小孔的残渣矿石的数量而导致烧结矿中出现许多小孔。对于残余矿石和同化结构而言，低温还原性均取决于包括大孔在内的总孔隙度，而脉石矿物中的Al ₂ O ₃含量<10 µm。孔体积分数和煤ue石矿物的量影响高温还原性。与其他类型的同化结构相比，涉及粒状赤铁矿的同化结构包含许多小孔。两种不同方法来增加残矿和同质结构中小孔的植物试验结果表明，它们有潜力在不控制化学成分的情况下提高烧结矿的高温还原性。