Study on Reduction Method of Carbon-Dioxide Gas Generation Using Wastes in Iron-Making process

本研究旨在提出以废代煤减少钢铁生产过程中二氧化碳气体产生的方法，为遏制全球变暖做出贡献。研究成果如下：1.还原铁的生产1.废渣的气化和还原气制铁提出了将铁弧还原到废气中的还原方法。提出了还原反应模型，并进行了还原实验，以获得合适的还原条件。数据表明还原确实发生了，但反应速率很小。1.2废铁混合球团还原试验为了提高还原铁产率，对粉碎废铁球团和铁粉混合球团进行了研究。实验结果表明，还原的最佳条件是铁粉的混合比例为50%左右，加热温度为1400℃左右。粒度分布的影响不是很大。对还原后的铁进行了化学分析和电子探针分析，结果表明，还原后的铁中金属铁含量为95%，且还原均匀。此外，还对塑料和餐厨垃圾中的还原剂进行了研究。塑料在高温下蒸发，不可能还原铁矿石。日本和加拿大每年产生的废物量分别为2100万吨、20万吨和1000万吨。在加拿大，日本每年产生25%的废物。然而，在加拿大收集废物的成本太高，无法有效地利用它们。

This study aimed to propose the method of reduction of carbon-dioxide gas generation in iron and steel making processes using wastes instead of coals and to contribute the suppression of global warming. The studies achieved are as follows ;1. Production of reduced iron1.1 Gasification of wastes and reduced iron production by reducing gasThe reducing method to put the iron are into the reducing gas made by wastes was proposed. The model of reduction reaction was proposed and the reduction experiments to obtain the suitable reduction conditions were carried out. The data showed that reduction actually occurred, but the reaction rate was very small.1.2 Reduction experiments using pellets of wastes and iron are mixturesIn order to increase productivity of reduced iron, pellets of crashed wastes and iron are mixtures were examined. The experiments revealed that the best conditions for reduction were mixing ratio of iron are of about 50% and heating temperature of around 1400℃. The effect of grain size distribution was not so important. Chemical and EPMA analysis was carried out to evaluate the quality of the reduced iron, and the data showed that the iron had the metallic Fe content of 95% and was reduced uniformly in it.Plastics and food wastes were also investigated for reducing agents. The plastic was vaporized in high temperature and it was impossible to reduce iron ore. On the other hand, the food wastes were found a good reducing agent.2 Amount of wastes in Japan and CanadaIn Japan wastes of woods, tires and plastics were generated 21 million tons, 200 thousand tons and 10 million tons every year. In Canada 25% of wastes in Japan was generated every year. However, the cost of collecting the wastes in Canada is too high to use them effectively.