公开(公告)号：US3838064A

公开(公告)日：1974-09-24

申请号：US28757872

申请日：1972-09-19

Applicant: KEWANEE OIL CO

Inventor： VOGT J ,  OWEN J

IPC: B01J2/30 ,  C09B67/00 ,  C09C3/10 ,  C09K3/22

CPC classification number: B01J2/30 ,  C01P2004/60 ,  C01P2004/61 ,  C01P2004/80 ,  C01P2006/20 ,  C01P2006/90 ,  C09B67/0094 ,  C09C3/10 ,  C09K3/22

Abstract: A METHOD FOR CONTROLLING DUST IN A NORMALLY-HIGHDUSTING MATERIAL WHICH INCLUDES WORKING THE MATERIAL WITH A MINUTE AMOUNT, LESS THAN 1% BY WEIGHT OF THE MATERIAL, OR A FINELY DIVIDED FIBRILLATABLE POLYTETRAFLUOROETHYLENE (HEREINAFTER REFERRED TO AS PTFE) TO FORM A DRY MIXTURE WITH THE MATERIAL WITHOUT CHANGING THE PRIMARY PRACTICLE SIZE OF THE MATERIAL, AND CONTINUING TO WORK THE MIXTURE SUFFICIENTLY SO AS TO ESSENTIALLY GEGATE THE DUSTING OF THE MATERIAL WITHOUT APPRECIABLY CHANGING IT PHYSICAL PROPERTIES. FINE POWDER PTFE OBTAINED BY COAGULATION OF A COLLODIAL AQUEOUS DISPERSION OF THE RESIN IS USED IN THE "DRY" TREATMENT OF NORMALLY-HIGH-DUSTING SUBMICRON AND SUPERFINE MATERIAL. AGAIN, THE NORMALLY-HIGH-DUSTING MATERIAL MAY BE MIXED WITH COLLOIDAL AQUEOUS DISPERSION OF THE RESIN, IN AN AMOUNT INSUFFICIENT TO CHANGE THE ESSENTIALLY DRY CHARACTER TO THE MATERIAL AND WORKED, AS DESCRIBED HEREIN, TO NEGATE DUSTING OF THE MATERIAL. ALTERNATIVELY, THE FINE POWDER OF THE COLLOIDAL DISPERSION MAY BE USED TO SLURRY THE MATERIAL IN A "WET" TREATMENT TO FACILITATE THE HOMOGENEOUS DISPERSION OF THE RESIN; THE SOLID CONTENT OF THE SLURRY MAY THEREAFTER BE WORKED IN THE WET STATE, PREFERABLY AS A PASTE, OR WORKED IN AN ESSENTIALLY DRY STATE, WITH A MASTICATING OR KNEADING ACTION, AS BEFORE. IN ANOTHER EMBODIMENT, FOR CONTROLLING DUSTING IN A NORMALLY-HIGH-DUSTING MATERIAL, A METHOD IS DISCLOSED WHICH INCLUDES MIXING THE MATERIAL WITH FINELY DIVIDED FIBRILLATABLE PTFE IN AN AMOUNT IN THE RANGE FROM ABOUT .02 TO ABOUT 3% BY WEIGHT IN THE PRESENCE OF A LIQUID PROCESSING AID, IN WHICH THE MATERIAL MAY OR MAY NOT BE SOLUBLE, AND SPRAY DRYING THE SOLUTION OR SLURRY SO THAT UPON SEPARATION OF THE LIQUID PROCESSING AID, A DRY TREATED SOLID MATERIAL IS RECOVERED, VIRTUALLY INDISTINQUISHABLE FROM UNTREATED MATERIAL, BUT CHARACTERIZED BY A SUBSTANTIALLY COMPLETE ELIMINATION OF ITS NORMALLY-HIGH-DUSTING NATURE. NOVEL DUSTLESS COMPOSITIONS ARE FORMED BY WORKING A NORMALLY-HIGH-DUSTING, SUBMICRON OR SUPERFINE MATERIAL WITH A FIBRILLATABLE PTFE RESIN IN AN AMOUNT FROM ABOUT 0.02 TO ABOUT 1% BY WEIGHT, BASED ON TOTAL SOLIDS, UNTIL A VISUAL INDICATION OF NON-DUSTING IS OBTAINED. EVEN COARSE, DUSTY MATERIALS UP TO ABOUT 100 TYLER MESH, WHICH CONTAIN FINES AND SUPERFINES ARE RENDERED DUSTLESS. DUSTY MATERIALS WHICH INCLUDE FINES IN THE RANGE FROM ABOUT 10U TO ABOUT 44U OR SUPERFINES UP TO ABOUT 10U IN SIZE ARE PARTICULARLY SUITABLE FOR DEDUSTING TREATMENT.

公开(公告)号：US3838092A

公开(公告)日：1974-09-24

申请号：US31687272

申请日：1972-12-20

Applicant: KEWANEE OIL CO

Inventor： VOGT J ,  OWEN J

IPC: B01J2/28 ,  C09C3/04 ,  C08F45/04

CPC classification number: C09C3/045 ,  B01J2/28 ,  C01P2004/50 ,  C01P2004/60 ,  C01P2004/61 ,  C01P2004/62 ,  C01P2004/80

Abstract: A PROCESS FOR THE CONTROL OF DUST GENERATED BY NORMALLY DUSTY SOLID PARTICULATE MATERIAL SMALLER THAN 10 MESH IN SIZE, COMPRISING MIXING FROM ABOUT 0.02 TO LESS THAN 1.0 PERCENT, AND PREFERABLY FROM ABOUT 0.02 TO ABOUT 0.75 PERCENT, BY EIGHT, FIBRILLATABLE POLYTETRAFLUOROETHYLENE (HEREINAFTER REFERRED TO AS PTFE) WITH SAID MATERIAL TO FORM AN INTIMATE MIXTURE AND THEN WORKING THE MIXTURE SUFFICIENTLY AT A TEMPERATURE ABOVE 20*C BUT BELOW THE TRANSITION POINT OF SAID PTFE TO FORM ENOUGH PTFE FIBERS TO PRODUCE A WEAK, ESSENTIALLY DUSTLESS AGGLOMERATE FROM SAID DUSTY MATERIAL. A COHERENT, WEAK AGGLOMERATED DUSTLESS SOLID PARTICULATE MASS LACKING RESISTANCE TO PRESSURE OF MECHANICAL SHOCK AND SIMULTANEOUSLU PLIABLE AND FRIABLE AT AMBIENT TEMPERATURES, YET VISUALLY DISTINGUISNABLE FROM THE NORMALLY DUSTY MATERIAL FROM A MIXTURE OF DUSTY DISCRETE AGGLOMERATE IS FORMED FROM A MIXTURE OF DUSTY DISCRETE PARTICLES IN THE SIZE RANGE FROM LESS THAN ABOUT 1 INCH TO ABOUT 2000 MICRONS, AND FIBRILLATABLE PTFE IN AN AMOUNT FROM ABOUT 0.02 BUT LESS THAN 1 PEERCENT BY WEIGHT, BASED ON TOTAL SOLIDS, BY WORKING THE MIXTURE IN A DRY OR RELATIVELY DRY STATE WITH A WORKING ACTION IN AN UNCONFINED ZONE AT A TEMPERATURE INE XCESS OF 20*C., BUT BELOW THE SINTERING TEMPERATURE OF PTFE, WITHOUT CHANGING THE PRIMARY PARTICLES SIZE RANGE OF THE MATERIAL.