Basic properties of steel plant dust and technological properties of direct reduction

Xue-feng She1), Jing-song Wang1), Qing-guo Xue1), Yin-gui Ding1), Sheng-sheng Zhang2), Jie-ji Dong2), and Hui Zeng2) 1) School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 2) Shandong Laiwu Iron and Steel Co. Ltd., Laiwu 271104, China

摘 要：Basic physicochemical properties of the dust from Laiwu Iron and Steel Co. Ltd. were studied. It is found that C, Zn, K, Na, etc. exist in the fabric filter dust, off gas （OG） sludge, fine ash in converter, and electrical field dust in sinter. Among these, OG sludge gives the finest particle, more than 90% of which is less than 2.51 mm. The dust can lead to a serious negative influence on the production of sintering and blast furnaces （BF） if it is recycled in sintering. The briquette and reduction experimental results showed that the qualified strength could be obtained in the case of 8wt% molasses or 4wt% QT-10 added as binders. Also, more than 75% of metallization ratio, more than 95% of dezincing ratio, as well as more than 80% of K and Na removal rates were achieved for the briquettes kept at 1250℃ for 15 min during the direct reduction process. SEM observation indicated that the rates of indirect reduction and carbonization became dominating when the bri-quettes were kept at 1250℃ for 6 min.

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