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Study on Cracking Control of Cold Bonded Pellets Containing Converter Dust Based on Nonhydraulic Hardening Principle

  • Xiang Li
  • Ping TangEmail author
  • Xueqin Zhu
  • Pengpeng Qin
  • Guanghua Wen
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

Converter dust is a kind of solid waste in the metallurgical steelmaking process. It can make cold bonded pellets via adding binder return to converter for recycling, because of its high content of total iron (TFe) and alkaline oxide. Due to the expansion of digestion reaction of ƒ-CaO and MgO in the converter dust, the pellets are cracked and the strength is reduced. The study compared the effects of sodium silicate, sodium humate, and MgO-based binders on the strength, cracking rate, and moisture content of cold bonded pellets. The results show that the pellets prepared by the MgO-based binder have no cracking, high strength, and low moisture content. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to clarify the principle of MgO-based binder controlling cracking. It is a hydration reaction with MgO in the converter dust, which absorbs a large amount of free water and avoids the digestion and cracking. Meanwhile, it generates the adhesive nonhydraulic gels, which form a connecting bridge after solidification to increase the pellet strength.

Keywords

Converter dust Cold bonded pellet Cracking Bonding mechanism 

Notes

Acknowledgements

Financial support from National Natural Science Foundation of China (grant No. 51574050) is greatly acknowledged.

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Copyright information

© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  • Xiang Li
    • 1
  • Ping Tang
    • 1
    Email author
  • Xueqin Zhu
    • 1
  • Pengpeng Qin
    • 1
  • Guanghua Wen
    • 1
  1. 1.College of Materials Science and Engineering, Chongqing UniversityShapingba District, ChongqingChina

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