Process for fabricating foundry shapes

A process for the fabrication of foundry shapes which comprises:

• a. mixing foundry aggregate having an average particle size of no less than about 150 mesh (Tyler Screen Mesh) with a bonding amount of up to about 10 percent by weight based upon the weight of the aggregate of the 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. an oxygen-containing alkaline earth metal compound capable of reacting with the aluminum phosphate and which contains alkaline earth metal and an oxide;
• and
• iii. water;
• wherein the amount of boronated aluminum phosphate is from about 50 to about 95% by weight based upon the total weight of aluminum phosphate and alkaline earth compound;
• the amount of alkaline earth compound is from about 50 to about 5% by weight based upon the total weight of aluminum phosphate and alkaline earth compound;
• and the amount of water is from about 15 to about 50% by weight based upon the total weight of boronated aluminum phosphate and water;
• and wherein the quantity and particle size of said aggregate are such to provide sufficient porosity in the foundry shape to permit escape of volatiles from the shape during casting;
• B. introducing the foundry mix obtained from step (A) into a pattern;
• C. allowing the foundry mix to remain in the pattern for a time at least sufficient for the mix to become self-supporting;
• and
• D. thereafter removing the shaped foundry mix of step (C) from the pattern, and allowing it to cure at room temperature, thereby obtaining a hard, solid, cured foundry shape.