Process for producing dry, free-flowing, thermosetting resin-coated sand granules

Claim 1

A PROCESS FOR THE PRODUCTIN OF DRY, FREE-FLOWING THERMOSETTING RESIN COATED SAND GRANULES ADAPTED FOR USE IN A SHELL MOLDING PROCESS FOR THE PRODUCTION OF FOUNDRY MOLDS AND CORES WHICH COMPRISES INTIMATELY MIXING AT A TEMPERATURE BELOW ABOUT 50*C. A MECHANICALLY AGITATED CONTIGUOUSLY CONSTITUTED BED OF PARTICULATE SAND GRANULES AND A THERMOSETTING RESIN DISSOLVED IN A LIQUID SOLVENT HAVING A BOILING POINT ABOVE THE TEMPERATURE OF SAID SAND AND WITHIN THE RANGE OF 40-115*C. UNTIL THE GRANULES OF SAND ARE COATED WITH THE THERMOSETTING RESIN SOLUTION, CONTINUING THE MIXING, AND WHILE CONTINUING THE MIXING PASSING A STREAM OF GAS AT A TEMPERATURE BELOW ABOUT 40*C. IN CONTACT WITH THE MECHANICALLY AGITATED CONTIGUOUSLY CONSTITUTED BED OF PARTICULATE SAND-THERMOSETTING RESIN SOLUTION UNDERGOING MIXING UNTIL THE LIQUID SOLVENT IS REMOVED BY EVAPORATION INTO THE GAS STREAM, CONTINUING THE MIXING AND PASSAGE OF GAS IN CONTACT WITH THE MIXTURE UNTIL THE THERMOSETTING RESIN COATED SAND GANULES ARE DRY AND FREE-FLOWING, AND RECOVERING THE DRY, FREE-FLOWING THERMOSETTING RESIN COATED SAND GRANULES.