Process for solubilizing, reducing and fixing hexavalent chromium contained in chromite ore processing residue into trivalent chromium
OwnerRobert Stanforthinventor
Life of this patent
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Abstract
A process for reducing hexavalent chromium, Cr(VI), contained within a chromite ore processing residue matrix comprising the sequential steps of providing a chromite ore processing residue matrix containing Cr(VI), solubilizing the matrix to release Cr(VI), reducing the Cr(VI) to Cr(III) using Fe(II), and, fixing the residual Fe(II) using a effective amount of a Fe(II) precipitating agent to make a Fe(II) precipitate.
Claims20
A process for reducing hexavalent chromium, Cr(VI), contained within a chromite ore processing residue matrix comprising the sequential steps of:
- providing a chromite ore processing residue matrix having a particle size containing Cr(VI),
- solubilizing the matrix using a dissolution effective amount of FeSO4,
- reducing the Cr(VI) to Cr(III) using Fe(II), and,
- fixing the Fe(II) using a fixation effective amount of a Fe(II) precipitating agent to make a Fe(II) precipitate.
A process for reducing hexavalent chromium, Cr(VI), contained within a chromite ore processing residue matrix, the process comprising:
- providing a chromite ore processing residue matrix having a particle size containing Cr(VI),
- solubilizing the Cr(VI) to trivalent chromium, Cr(III), using at least about two times the stoichiometric requirement for Fe(II) based on the Cr(VI) concentration of anhydrous FeSO4 or an equivalent amount of hydrated FeSO4 solids, and
- reducing the Cr(VI) to Cr(III) using Fe(II).
Dependencies are inferred from the claim text.