Preparation process of cold bonded pellets with iron-bearing dust and sludge from steel production process

Abstract

Blast furnace dust (BFD) and converter sludge (CS) were used as raw materials for preparing of cold bonded pellets (CBPs). The results showed that BFD contained high content of C, Fe and harmful element of Zn. Conversely, the CS had more Fe and Ca content and less Zn. BFD particles are mostly large and irregular in shape with poor hydrophilicity, whereas CS particles are generally smaller spherical and could bond together easily. Additionally, the main factors influencing the performance of CBPs are the binder, moisture, and pressing pressure. By controlling the mixing ratio of BFD and CS, selecting the appropriate binder and binder amount, and controlling the moisture and pressure, CBPs with a compressive strength and a falling strength of up to 142.7 N and 8.34 times, respectively, can be prepared, thus meeting the requirements of the rotary hearth furnace and the OxyCup production process.