Process for fabricating foundry shapes

DETAILED DESCRIPTION We claim: 1.
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.
2.
The method of claim 1 wherein about 80 percent of the foundry aggregate has an average particle size of between about 50 and about 120 mesh (Tyler screen mesh).
pg,53 3.
The method of claim 1 wherein the foundry aggregate is initially mixed with the alkaline earth metal material and is subsequently mixed with water and the boronated aluminum phosphate