Claims
- 1. Process for casting relatively low melting point non-ferrous type metals which comprises:
- a. fabricating a shape from a composition which comprises a major amount of aggregate and an effective bonding amount up to about 40 percent by weight of the aggregate of a binder composition which comprises:
- i. boronated aluminum phosphate containing boron in an amount from about 3 mole percent to about 40 mole percent based upon the moles of aluminum and containing a mole ratio of phosphorus to total moles of aluminum and boron of about 2:1 to about 4:1;
- ii. alkaline earth metal material containing alkaline earth metal and an oxide; and
- iii. water; wherein the amount of boronated aluminum phosphate is from about 50 to about 95 percent by weight based upon the total weight of aluminum phosphate and alkaline earth material; the amount of alkaline earth material is from about 50 to about 5 percent by weight based upon the total weight of aluminum phosphate and alkaline earth material; the amount of water is from about 15 to about 50 percent by weight based upon the total weight of boronated aluminum phosphate and water; and the aggregate has a particle size large enough to provide sufficient porosity in the foundry shape to permit escape of volatiles from the shape during the casting operation:
- b. pouring said relatively low melting point non-ferrous type metal while in the liquid state into said shape;
- c. allowing said non-ferrous type metal to cool and solidify;
- d. contacting said shape with water in an amount and for a time sufficient to cause degradation of the binder system; and
- e. then separating the molded article.
- 2. The process of claim 1 wherein said boronated aluminum phosphate contains boron in an amount from about 5 to about 30 mole percent based upon the moles of aluminum.
- 3. The process of claim 1 wherein said boronated aluminum phosphate contains boron in an amount from about 10 to about 25 mole percent based upon the moles of aluminum.
- 4. The process of claim 1 wherein said boronated aluminum phosphate contains a mole ratio of phosphorus to total moles of aluminum and boron of from about 2.5:1 to about 3.5:1.
- 5. The process of claim 1 wherein said aluminum phosphate contains a mole ratio of phosphorus to total moles of aluminum and boron of from about 2.8:1 to about 3.2:1.
- 6. The process of claim 1 wherein said boronated aluminum phosphate contains boron in an amount between about 10 and about 25 mole percent based upon the moles of aluminum, and wherein the mole ratio of phosphorus to total moles of aluminum and boron is between about 2.8:1 to about 3.2:1.
- 7. The process of claim 1 wherein the amount of boronated aluminum phosphate is from about 65 to about 90 percent by weight based upon the total weight of boronated aluminum phosphate and alkaline earth material, and the amount of alkaline earth material is from about 10 to about 35 percent by weight based upon the total weight of aluminum phosphate and alkaline earth material.
- 8. The process of claim 1 wherein said alkaline earth material includes a free alkaline earth metal oxide or a free alkaline earth metal hydroxide and wherein said oxide or hydroxide has a surface area no greater than about 8.5 m.sup.2 /gram (measured by the BET procedure).
- 9. The process of claim 8 wherein said free alkaline earth metal oxide or free alkaline earth metal hydroxide has a surface area no greater than about 3 m.sup.2 /gram.
- 10. The process of claim 1 wherein said alkaline earth metal material has a surface area no greater than about 8.5 m.sup.2 /gram.
- 11. The process of claim 1 wherein said alkaline earth metal material is a mixture of a free alkaline earth metal oxide and a material which contains the alkaline earth metal and oxide in combination with another constituent and wherein said alkaline earth metal material has a surface area no greater than about 8.5 m.sup.2 /gram.
- 12. The process of claim 11 wherein said alkaline earth metal oxide is magnesium oxide.
- 13. The process of claim 11 wherein said mixture contains from about 2 to about 8 parts by weight of the free alkaline earth metal oxide per part by weight of the material containing constituents in combination with the free metal oxide and/or hydroxide and alkaline earth metal.
- 14. The process of claim 1 wherein the amount of water is from about 20 to about 40 percent by weight based upon the total weight of the boronated aluminum phosphate and water.
- 15. The process of claim 1 wherein the aluminum phosphate has a mole ratio of phosphorus to total moles of aluminum and boron of about 2.5:1 to about 3.5:1; wherein the aluminum phosphate contains boron in an amount from about 5 to about 30 mole percent based upon the moles of aluminum; said alkaline earth compound includes free alkaline earth metal oxide and/or free alkaline earth metal hydroxide, and wherein said free alkaline earth metal oxide and/or free alkaline earth metal hydroxide has a surface area of no greater than about 3 m.sup.2 /gram.
- 16. The process of claim 1 wherein said non-ferrous type metal is aluminum.
- 17. The process of claim 1 wherein the amount of binder composition is between about 0.5 to about 7 percent by weight of the aggregate.
- 18. The process of claim 1 wherein the amount of binder composition is between about 1 to about 5 percent by weight of the aggregate.
CROSS REFERENCE TO RELATED CASES
This application is a divisional application of our copending application Ser. No. 415,852, filed Nov. 14, 1973 now U.S. Pat. No. 3,930,872, which is a continuing application of our copending application Ser. No. 351,903, filed Apr. 17, 1973, now U.S. Pat. No. 3,923,525.
US Referenced Citations (10)
Divisions (1)
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Number |
Date |
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Parent |
415852 |
Nov 1973 |
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Continuations (1)
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Number |
Date |
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Parent |
351903 |
Apr 1973 |
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