FOUNDRY MIXES CONTAIING CARBONATE SALTS AND THEIR USES
Disclosed is a foundry mix containing a carbonate salt and its use to make foundry shapes by the warm-box, hot-box, no-bake, and cold-box process, the use of these foundry shapes to make metal castings, and the metal castings prepared by the process.
1 . A foundry mix comprising:
(a) foundry aggregate; and
(b) a carbonate salt in an amount effective to reduce the veining of a metal casting prepared with the foundry mix.
2 . The foundry mix of claim 1 which further comprises an iron oxide selected from the group consisting of red iron oxide, black iron oxide, and mixtures thereof.
3 . The foundry mix of claim 2 wherein the iron oxide is red iron oxide.
4 . The foundry mix of claim 3 wherein the foundry aggregate comprises silica sand.
5 . The foundry mix of claim 4 wherein the salt is selected from the group consisting of calcium carbonate, magnesium carbonate, and mixtures thereof.
6 . The foundry mix of claim 5 wherein dolomite is used in the foundry mix as the source for the calcium and/or magnesium carbonate.
7 . The foundry mix of claim 4 wherein the foundry mix also contains gypsum.
8 . The foundry mix of claim 5 , 6 , or 7 wherein the weight ratio of carbonate salt to red iron oxide is from 1:1 to 4:1.
9 . The foundry mix of claim 8 wherein the weight ratio of carbonate salt to red iron oxide is from 1:1 to 2:1.
10 . The foundry mix of claim 9 wherein the foundry mix contains an organic binder.
11 . The foundry mix of claim 10 wherein the binder is a phenolic urethane binder or an epoxy acrylate binder.
12 . The foundry mix of claim 11 wherein the foundry mix contains a catalyst.
13 . The foundry mix of claim 11 wherein the amount of salt in the foundry mix is from 0.5 percent by weight to 4.0 percent by weight based upon the weight of the foundry aggregate.
14 . The foundry mix of claim 12 wherein the amount of salt in the foundry mix is from 0.5 percent by weight to 4.0 percent by weight based upon the weight of the foundry aggregate.
15 . The foundry mix of claim 11 wherein the amount of salt in the foundry mix is from 0.5 percent by weight to 2.5 percent by weight based upon the weight of the foundry aggregate.
16 . The foundry mix of claim 12 wherein the amount of salt in the foundry mix is from 0.5 percent by weight to 2.5 percent by weight based upon the weight of the foundry aggregate.
17 . A cold-box process for preparing a foundry shape comprising:
(a) introducing the foundry mix of claim 15 into pattern to form a foundry shape;
(b) contacting the foundry shape of (A) with a vaporous curing catalyst capable of curing the shape;
(c) allowing said shape resulting from (B) to cure until said shape becomes handleable; and
(d) removing said shape from the pattern.
18 . A process for casting a metal part which comprises:
(a) inserting a foundry shape prepared by the process of claim 15 into a mold assembly;
(b) pouring metal, while in the liquid state, into said mold assembly;
(c) allowing said metal to cool and solidify; and
(d) then separating the cast metal part from the mold assembly.
19 . A metal part prepared in accordance with claim 18 .
20 . A no-bake process for preparing a foundry shape comprising:
(a) introducing a foundry mix of claim 12 into a pattern to form a foundry shape:
(b) allowing said shape of (A) to cure until said shape becomes handleable; and
(c) removing said shape from the pattern.
21 . A process for casting a metal part which comprises:
(a) inserting a foundry shape prepared by the process of claim 20 into a mold assembly;
(b) pouring metal, while in the liquid state, into said mold assembly;
allowing said metal to cool and solidify; and
(d) then separating the cast metal part from the mold assembly
22 . A metal part prepared in accordance with claim 20 .
23 . A warm-box process for preparing a foundry shape comprising:
(a) introducing a foundry mix of claim 12 into a pattern to form a foundry shape:
(b) heating said shape to a temperature from150 ° C. to 260° C.;
(c) allowing said shape of (A) to cure until said shape becomes handleable; and
(d) removing said shape from the pattern.
24 . A process for casting a metal part which comprises:
(a) inserting a foundry shape prepared by the process of claim 22 into a mold assembly;
(b) pouring metal, while in the liquid state, into said mold assembly;
(c) allowing said metal to cool and solidify; and
(d) then separating the cast metal part from the mold assembly
25 . A metal part prepared in accordance with claim 23 .