Nowadays, reduction of amounts of CO₂ from ironmaking process is important from the aspect of prevention of the global warming. COURSE50 is Japanese national project which aims to reduce the amount of CO₂ emission from ironmaking process by 30% by 2050. In COURSE50, we try to reduce iron oxide with H₂ to decrease amounts of carbon use, by injecting large amount of gas containing H₂ and pulverized coal (PC) from tuyere. In that case, PC combustibility can be different from that in general blast furnace condition, due to high co-injected reducing gas ratio. Though a large number of researches about PC combustion around tuyere of blast furnace has been carried out, the effect of large amounts of co-injected reducing gas on PC combustibility was hardly investigated. To evaluate that, we conducted experiments with two experimental furnaces equipped with various non-contact measurement apparatus and found that;

1) The larger amounts of co-injected reducing gas were, the faster O₂ and CO₂ consumption, and CO and H₂ generation in the raceway.

2) The amounts of co-injected reducing gas should be optimized for higher PC combustibility.

3) Co-injected reducing gas activated PC combustion by raising PC temperature, and that resulted in acceleration of PC.

4) Trade-off relationship between rapid heating effect and O₂ consumption of co-injected reducing gas could determine the optimum amounts of reducing gas.

Consequently, we elucidated how we could co-inject reducing gas with PC as reducing agents without deteriorating PC combustibility.

如今，从防止全球变暖的角度来看，减少炼铁过程中的CO ₂量很重要。COURSE50是日本的一项国家级项目，旨在到2050年将炼铁过程中的CO ₂排放量减少30％。在COURSE50中，我们尝试通过注入大量的气体来减少H _2的氧化铁以减少碳的使用量。高₂和风口的粉煤（PC）。在这种情况下，由于高共注入还原性气体比例，PC的可燃性可能不同于一般的高炉条件。尽管已经对高炉风口周围的PC燃烧进行了大量研究，但几乎没有研究大量共注入还原气体对PC可燃性的影响。为了评估这一点，我们在配备有各种非接触式测量设备的两个实验炉上进行了实验，结果发现：

1）共注入还原性气体的量越大，O ₂和CO ₂消耗越快，并且在滚道中产生CO和H ₂越快。

2）应优化共注入还原气体的量，以提高PC的可燃性。

3）通过提高PC温度共同注入减少气体活化的PC燃烧，从而导致PC加速。

4）快速加热效果与共注入还原气的O ₂消耗之间的权衡关系可以确定最佳的还原气量。

因此，我们阐明了如何在不降低PC可燃性的情况下与PC作为还原剂共注入还原性气体。