Practice of smelting technology with high scrap ratio and direct-reduced iron
In order to achieve the development goal of high-quality green steel,a series of measures have been implemented to reduce carbon emissions in the long process steel manufacturing using high scrap ratio technology.The results indicate that scrap ratio has increased from 10％to over 30％through the adoption of the process design involving empty iron ladle plus scrap→blast furnace iron extraction→hot metal pretreatment→ converter smelting→post-steel extraction and scrap addition,which provides a strong assurance for green steel production.In the case of a high scrap ratio,with less than 15 t of direct-reduced iron,the blowing process remains stable,with a deviation of±5℃ between the converter's end temperature and the target set temperature,and endpoint double hit rate(endpoint carbon deviation±0.012％,endpoint temperature deviation±12℃)of 90.70％.Through the development of a high scrap ratio blowing model,an increase in oxygen flow rate during the converter smelting process has led to a reduction in low-temperature spatter at early stages and post-blowing scrap occurrences.This has resulted in a 100％match between final temperature and converter oxygen activity.Through process adjustments such as increasing the scrap ratio and incorporating direct reduced iron,CO2 emissions from the production of 1 t of low-alloyed high-strength steel in Tangshan Iron and Steel Group Co.,Ltd.in 2023 were 1.94 t,a decrease of about 13％compared to 2022.
万方数据
维普
