Molten aluminum filtration

1. A method of filtering molten aluminum containing suspended particles using a filter material dissolvable in molten aluminum to recover aluminum occluded in said filter material after filtering, the method comprising the steps of:

(a) providing a source of molten aluminum to be filtered;

(b) providing a filter material dissolvable in molten aluminum;

(c) providing a casting mold having a sprue and gating system for casting aluminum products, said sprue and gating system containing said filter material;

(d) introducing molten aluminum through said sprue, filter material and gating system to said mold;

(e) solidifying said molten aluminum in said sprue, gating system and mold to provide a cast product having solidified metal in said sprue and gating system attached thereto;

(f) separating said solid aluminum in said sprue and gating system from said cast product to provide solid aluminum containing said filter material embedded therein; and

(g) dissolving said solid aluminum and filter material in molten aluminum, thereby recovering said aluminum occluded in said filter material.

2. The method in accordance with claim 1 wherein said filter material is comprised of copper.

3. The method in accordance with claim 1 wherein said filter material is comprised of titanium aluminide.

4. The method in accordance with claim 1 wherein said filter material has a coating thereon which becomes sticky at molten aluminum temperatures and having the ability to bond particles thereto.

5. The method in accordance with claim 1 wherein said filter material is comprised of a reticulated copper material.

6. In a method of casting aluminum products employing a sprue and gate system where a filter material is used, the material subsequently dissolvable in molten aluminum to recover aluminum captured in the filter material, the method comprising:

(a) providing a source of molten aluminum to be cast;

(b) providing a filter material dissolvable in molten aluminum;

(c) providing a casting mold having a sprue and gating system for casting aluminum products, said sprue and gating system having said filter material;

(d) introducing molten aluminum through said sprue, filter material and gating system to said mold;

(e) solidifying said molten aluminum in said sprue, gating system and mold to provide a cast product having solidified metal in said sprue and gating system attached thereto;

(f) separating said solid aluminum in said sprue and gating system from said cast product to provide solid aluminum containing said filter material embedded therein; and

(g) dissolving said solid aluminum and filter material in molten aluminum, thereby recovering said aluminum occluded in said filter material.

7. The method in accordance with claim 6 wherein said filter material is comprised of copper.

8. The method in accordance with claim 6 wherein said filter material is comprised of titanium aluminide.

9. The method in accordance with claim 6 wherein said filter material has a coating thereon which becomes sticky at molten aluminum temperatures and having the ability to bond particles thereto.

10. The method in accordance with claim 6 wherein said filter material is comprised of a reticulated copper material.

11. In a method of casting aluminum products employing a sprue and gate system where a flow stabilization material is used, the material subsequently dissolvable in molten aluminum to recover aluminum captured in the filter material, the method comprising:

(a) providing a source of molten aluminum to be cast;

(b) providing a flow stabilization material dissolvable in molten aluminum;

(c) providing a casting mold having a sprue and gating system for casting aluminum products, said sprue and gating system having said flow stabilization material;

(d) introducing molten aluminum through said sprue, flow stabilization material and gating system to said mold;

(e) solidifying said molten aluminum in said sprue, gating system and mold to provide a cast product having solidified metal in said sprue and gating system attached thereto;

(f) separating said solid aluminum in said sprue and gating system from said cast product to provide solid aluminum containing said flow stabilization material embedded therein; and

(g) dissolving said solid aluminum and flow stabilization material in molten aluminum, thereby recovering said aluminum occluded in said flow stabilization material.