Dissolution behavior of dicalcium silicate and tricalcium phosphate solid solution and other phases of steelmaking slag in an aqueous solution

Takuya Teratoko, Nobuhiro Maruoka, Hiroyuki Shibata, Shin Ya Kitamura

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Most of the phosphorus in slag forms a solid solution of dicalcium silicate (C2S) and tricalcium phosphate (C3P), and the process used to separate this solid solution from the matrix phase is the same technology used to separate P from other valuable elements such as Mn and Cr containing in the matrix phase. Although it is known that the solubility of C2S in an aqueous solution is much greater than that of C 3P, the solubility of the solid solution and that of the matrix phase have yet to be investigated. To clarify the possibility of selectively extracting P from slag through a leaching process, the dissolution behaviors of the solid solution at various compositions and that of the matrix phase were investigated. The following results were obtained: The dissolution ratio of Ca to the aqueous solution at pH D 7 was close to 1.0 in the case of pure C 2S and decreased greatly with increasing C3P content. The dissolution ratio of P was about 0.1 and did not change relative to the C 3P content. When the ratio of C3P in the solid solution was higher than 0.3, hydroxyapatite (HAP) formation was observed in the residue. The dissolution ratio of P increased for 30 min, and after reaching the maximum value, started to decrease owing to the precipitation of HAP. The dissolution ratio of each element from a glassy slag sample (matrix phase) was lower than that from the solid solution at every pH level. In this study, the possibility to extract a solid solution containing P without dissolving the matrix phase was found through the use of an aqueous solution at pH D 7, although the dissolution ratio of P was not sufficiently high.

Original languageEnglish
Pages (from-to)329-338
Number of pages10
JournalHigh Temperature Materials and Processes
Volume31
Issue number4-5
DOIs
Publication statusPublished - 2012 Oct 1

Keywords

  • Extraction
  • Leaching
  • PH
  • Phosphorus
  • Steelmaking slag

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Dissolution behavior of dicalcium silicate and tricalcium phosphate solid solution and other phases of steelmaking slag in an aqueous solution'. Together they form a unique fingerprint.

  • Cite this