Process for removing lead from sandblasting wastes containing paint chips
AssigneeHenkel Corporation
InventorsWilliam E. Fristad, Michael J. Virnig, Dana K. Elliott
Life of this patent
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Abstract
Heavy metals are efficiently removed from contaminated soil by a process which comprises leaching or washing the soil with a mild leachant solution comprised of an aqueous solution of an acid and a salt. Heavy metals are also efficiently removed from paint chips by washing with an aqueous acid. The heavy metals are recovered from the leachant be cementation.
Claims7
A process for removing lead from sandblasting wastes comprised of sand and lead containing solid paint chips, which process comprises (1) contacting the sand and solid paint chips with a liquid leachant comprised of (a) a strong mineral acid selected from the group consisting of hydrochloric acid and sulfuric acid in a concentration of 0.01M to about 1.0M and (b) from 1 to about 20% by weight of an alkali metal, alkaline earth metal, or ammonium salt having one or more anions which form water soluble salts with lead, in such a manner so as to disperse at least a part of the sand and solid paint chips in the leachant to form a liquid phase containing dispersed sand and paint solids and for a period of time sufficient to render at least a portion of the lead from the dispersed solids to a soluble species in the liquid, and (2) recovering the lead from the liquid phase.
Dependencies are inferred from the claim text.