Disposal of fluorine wastes

Claim 1

A PROCESS FOR EFFICIENTLY DEFLUORINATING FUMES CONTAINING HF AND SIF4 COMPRISING INTRODUCING THE FUMES INTO THE LOWER PORTION OF AN ABSORPTION ZONE, COUNTERCURRENTLY SCRUBBING SAID FUMES THEREIN WITH A DILUTE AMMONIACAL SOLUTION CONTAINING AMMONIUM FLUORIDE AND AMMONIUM FLUOSILICATE AND HAVING AN AMMONIA CONCENTRATION OF BETWEEN ABOUT 0.01 AND ABOUT 5 PERCENT BY WEIGHT WHEREBY SAID HF AND SIF4 ARE NEUTRALIZED TO FORM AMMONIUM FLUORIDE AND AMMONIUM FLUOSILICATE, SAID AMMONIACAL SOLUTION BEING MAINTAINED AT AN ELEVATED TEMPERATURE AND PREVENTING FORMATION OF INSOLUBLE ORTHOSILICIC ACID, CONTINUOUSLY WITHDRAWING SOLUTION HAVING AN AMMONIA CONCENTRATION OF BETWEEN ABOUT PH4 AND ABOUT 0.1 POUND OF UNREACTED AMMONIA PER GALLON OF SOLUTION POROUS, FROM THE BASE OF THE ABSORPTION ZONE, RECYCLING A PORTION THEREOF TO THE UPPER PORTION OF SAID ZONE WHEREBY THE CONCENTRATION OF WATER IN THE WITHDRAWN SOLUTION IS DECREASED WITH RESPECT TO THE CONCENTRATION WITHOUT RECYCLING, PASSING THE REMAINDER OF THE WITHDRAWN SOLUTION TO A DIGESTION ZONE MAINTAINED AT A TEMPERATURE OF 100 TO 212*F., ADMITTING ADDITIONAL AMMONIACAL SOLUTION TO SAID