Kinetics Investigation of Phosphorus Leaching from Steelmaking Slag

ABSTRACT

The removal of phosphorus is essential to recycling steelmaking slag in metallurgical processes. In this study, dilute nitric acid was selected as the leaching agent for dissolving steelmaking slag. The effects of the variables on leaching percentage of phosphorus were investigated. Experimental results showed that, the leaching percentages of phosphorus increase as the concentration of nitric acid increases. Increasing the liquid/solid ratio and decreasing the slag particle size increased the leaching percentages of the phosphorus. However, the temperature and stirring speed had minor effects on the dissolution of phosphorus. Diffusion through the product layer was the rate-limiting step of the leaching process, and the corresponding apparent activation energy was determined to be 1.61 kJ/mol. Based on experimental results, a semi-empirical kinetic equation was established.

KEYWORDS:

• Steelmaking slag
• phosphorus removal
• leaching kinetics
• acid leaching

Disclosure statement

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

Additional information

Funding

This work was financially supported by Key Laboratory Open Project Fund of Metallurgical Emission Reduction and Resources Recycling (Anhui University of Technology), Ministry of Education [JKF18-02]; National Natural Science Foundation of China [52074004], Natural Science Research Project of Anhui Province Universities [KJ2021A0357].