Methods of Treatment of Chromite Ore Processing Residue
AssigneeRedox Solutions, LLC
InventorsSteven A. Chisick, Timothy Clark Heffernan, Thomas P. McCullough, Gary Joel Meyer
Life of this patent
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Abstract
Methods to reduce hexavalent chromium (Cr(VI)) in chromite processing wastes include one or more of the following steps: contacting the chromite processing wastes with an oxygen scavenger or chemical reducer; permitting the chromite processing wastes to react with the oxygen scavenger or chemical reducer; contacting the chromite processing wastes with ferrous ion; contacting the chromite processing wastes with sulfide ion; and, contacting the chromite processing wastes with ferrous sulfide.
Claims8
1-75. (canceled)
A method for reducing chromium (VI) in an underground deposit of chromium ore processing residue, comprising:
- injecting a ferrous liquid into the underground deposit of chromium ore processing residue, with the underground deposit comprising solid residue particles, and with pore spaces between particles, with the ferrous liquid reducing the pH of the pore water to less than about 7, and with the volume of ferrous liquid injected sufficient to substantially fill the pore spaces between the particles;
- waiting until the pH of the injected ferrous liquid increases to a pH of about 9;
- and then injecting a sulfide solution into the underground deposit.
Dependencies are inferred from the claim text.