Filtration and purification method for aqueous acids
AssigneeMykrolis Corporation
InventorsBipin S. Parekh, Anthony J. DiLeo, Edward Deane, Ronald L. Bruening
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Abstract
The invention pertains to a method for removing metallic ions and/or particulate material from an aqueous acid solution using particle removing membranes (e.g., ultra high molecular weight polyethylene) having immobilized ligand groups (e.g., macrocycle or other similar chelating ligands) that possess high equilibrium binding constants for ion and particulate removal. The method is particularly useful for simultaneously filtering/purifying aqueous hydrofluoric or hydrochloric acid.
Claims19
A method for simultaneously removing metallic ions and particulate material from an aqueous acid solution, comprising contacting said solution with a composition suitable for simultaneously removing metallic ions and particulate material contained in said solution and recovering a purified and filtered solution essentially depleted of metallic ions and particulate material to sub-parts-per-billion;
- wherein the composition comprises a membrane ligand combination represented by the formula:
- M—B—L
- wherein M is a membrane or composite membrane having a hydrophilic or partially hydrophilic surface and containing polar functional groups and having a pore size sufficient to filter particulate material contained in said solution;
- L is a ligand having an affinity for metallic ions and containing a functional group reactive with an activated polar group from the membrane;
- and
- B is a covalent linkage formed by the reaction between the activated polar group and the functional group of the ligand.
A method for simultaneously removing metallic ions and particulate material from an aqueous hydrofluoric acid solution, comprising contacting said solution with a composition suitable for simultaneously removing metallic ions and particulate material contained in said solution and recovering a purified and filtered solution essentially depleted of metallic ions and particulate material to sub-parts-per-billion;
- wherein the composition comprises a membrane ligand combination represented by the formula:
- M—B—L
- wherein M is a membrane or composite membrane having a hydrophilic or partially hydrophilic surface and containing polar functional groups and having a pore size sufficient to filter particulate material contained in said solution;
- L is a ligand having an affinity for metallic ions and containing a functional group reactive with an activated polar group from the membrane;
- and
- B is a covalent linkage formed by the reaction between the activated polar group and the functional group of the ligand.
A method for simultaneously removing metallic ions and particulate material from an aqueous hydrochloric acid solution, comprising contacting said solution with a composition suitable for simultaneously removing metallic ions and particulate material contained in said solution and recovering a purified and filtered solution essentially depleted of metallic ions and particulate material to sub-parts-per-billion;
- wherein the composition comprises a membrane ligand combination represented by the formula:
- M—B—L
- wherein M is a membrane or composite membrane having a hydrophilic or partially hydrophilic surface and containing polar functional groups and having a pore size sufficient to filter particulate material contained in said solution;
- L is a ligand having an affinity for metallic ions and containing a functional group reactive with an activated polar group from the membrane;
- and
- B is a covalent linkage formed by the reaction between the activated polar group and the functional group of the ligand.
Dependencies are inferred from the claim text.