Method of converting volcanic ash to cellular particles

Claim 1

A PROCESS FOR CELLULATING AND EXPANDING PARTICLES OF GLASSY VOLCANIC ROCK OF RHYOLITIC COMPOSITION AND CONTAINING MORE THAN 1 PER CENT WATER BY WEIGHT, THE WATER-IMPERMEABLE PORTION OF SAID PARTICLE HAVING A WEIGHT PER UNIT VOLUME GREATER THAN 2 AND PARTICLE SIZE THAT WILL PASS THROUGH A SIEVE HAVING OPENINGS NOT GREATER THAN 1.0 MILLIMETE, CONSISTING IN INTIMATELY MIXING THE PARTICLES WHILE AT A TEMPERATURE NOT EXCEEDING 400* C. WITH A COMBUSTIBLE AIR-FUEL MIXTURE, IN PROPORTIONS THAT WILL YIELD A TEMPERATURE IN THE IGNITED MIXTURE IN THE RANGE FROM 1250 TO 1400* C., IGNITING THE RESULTING MIXTURE AND CONTROLLING THE PRESSURE AND LENGTH OF FLAME SO THE TIME THE PARTICLES ARE EXPOSED TO THE PROCESSING TEMPERATURE WILL BE LESS THAN 0.1 SECOND, PASSING THE PRODUCTS OF COMBUSTION IN A HORIZONTAL DIRECTION AND IMMEDIATELY MIXING THE HORIZONTALLY FLOWING COMBUSTION PRODUCTS WITH COOLER SURROUNDING AIR ON LEAVING THE FLAME SO AS TO QUICKLY CHILL THE THERMOPLASTIC PARTICLES THEREIN TO A TEMPERATURE BELOW 1100* C., THEREBY CHILLING AND RETAINING THE CELLUATED AND EXPANDED CONDITON DUE TO THE THERMOSPLASTIC STATE AND VAPORIZED WATER OBTAINED AT THE ABOVE TEMPERATURE AND IN THE SPECIFIED TIME.