Role of self-disintegrating effect produced by decomposition of limestone core on accelerating dissolution of lime in CaO–SiO₂–FeO_x slag

ABSTRACT

The dissolution behaviours of lime, limestone and lime sample with limestone core-lime shell structure in CaO–SiO₂–FeO_x slag were investigated. The results show that dissolution of lime slows down once 2CaO·SiO₂ layer is formed at slag/lime interface. Self-disintegrating effect produced by decomposition of limestone core can accelerate dissolution, but dissolution rate firstly increases, and then decreases with the CaCO₃ content of samples increasing. Limestone must decompose to form lime before dissolution, and too much CO₂ generated by decomposition of limestone bearing 98.9 wt% CaCO₃ blocks the contact between molten slag and lime layer. Thus, limestone hardly dissolves after 60s contacted with molten slag. For lime sample with core–shell structure, the surface of sample is lime layer that can be directly dissolved in molten slag. Meanwhile, self-disintegrating effect produced by decomposition of limestone core enhances slag penetration, and accelerate dissolution. The optimum CaCO₃ content in lime sample is 22.7 wt%.

KEYWORDS:

• Converter slagging
• self-disintegrating effect
• lime
• dissolution
• limestone
• core-shell structure
• 2CaO·SiO₂
• CaCO₃ content

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by National Natural Science Foundation of China [grant number 52274305]; National Natural Science Foundation of China [grant number 52004189]; Project of Hubei Provincial Department of Science and Technology [grant number 2022BAA021]; Project of Hubei Provincial Department of Science and Technology [grant number 2022CFB051]; China Postdoctoral Science Foundation [grant number 2022M721109]; Young Elite Scientists Sponsorship Program by CAST [grant number 2022QNRC001].