A Kinetic Study on Selective Leaching of Phosphorus from Dephosphorization Slag
- PDF / 2,587,512 Bytes
- 15 Pages / 595.276 x 790.866 pts Page_size
- 73 Downloads / 199 Views
RESEARCH ARTICLE
A Kinetic Study on Selective Leaching of Phosphorus from Dephosphorization Slag Chuan‑ming Du1 · Xu Gao2,3 · Shigeru Ueda3 · Shin‑ya Kitamura3 Received: 16 August 2020 / Accepted: 19 October 2020 © The Minerals, Metals & Materials Society 2020
Abstract Phosphorus recovery from dephosphorization slag generated during steelmaking has enormous potential to secure a stable supply of phosphate. Because P and Fe in slag are concentrated in different mineral phases, P can be recovered by separation of the P-bearing phase, and the residue can be reutilized in steel plant at the same time. In the present study, we adopted selective leaching of P and investigated the effects of leaching parameters on the dissolution behavior of slag. It was determined that with the decrease in particle size and increase in stirring speed, the P dissolution ratio increased significantly. When particle size was less than 53 μm and stirring speed exceeded 200 rpm, most of the P-bearing C 2S−C3P solid solution was dissolved and separated. Increasing temperature and decreasing the mass ratio of slag to liquid had a slight influence on promoting P dissolution, while the Si dissolution was significantly suppressed in the case of high temperature and mass ratio due to the formation of silica gel. The P dissolution ratio reached 84.9%, and the Fe dissolution was negligible. Through selective leaching, the residue primarily consisting of magnesioferrite could be used as a flux in steelmaking process. The shrinking core model was successfully used to describe the dissolution kinetics of P. As temperature increased, apparent rate constant increased slightly. The calculated activation energy was 9.23 kJ/mol, demonstrating that the P dissolution was controlled by diffusion in the residue layer.
The contributing editor for this article was Hiromichi Takebe. * Xu Gao [email protected] 1
School of Metallurgy, Northeastern University, Shenyang 110819, China
2
School of Metallurgy and Environment, Central South University, Changsha 410083, P.R. China
3
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2‑1‑1 Katahira, Aoba‑ku, Sendai 980‑8577, Japan
13
Vol.:(0123456789)
Journal of Sustainable Metallurgy
Graphical Abstract Most of the P-bearing solid solution in dephosphorization slag was dissolved and the dissolution of Fe-bearing phase was negligible, achieving selective leaching of P. The P dissolution from slag was controlled by diffusion in the residue layer.
Keywords Dephosphorization slag · Phosphorus recovery · C2S−C3P solid solution · Selective leaching · Kinetics
Introduction Phosphorus (P) is a vital element for all living organisms, and a significant ingredient of commercial fertilizers. With the increase in the world’s population, the agricultural sector requires large amounts of phosphate fertilizer to boost food production [1]. However, the reserve of high-grade phosphate ores, which is the primarily raw material to produce phosphate fertilizer, will be depleted in th
Data Loading...
