Extraction of sulphur

Claim 1

A METHOD OF REFINING SULPHUR WHICH COMPRISES PROVIDING A SULPHUR CONCENTRATE CONTAINING NOT LESS THAN ABOUT 50% OF ELEMENTAL SULPHUR TOGETHER WITH IMPURITIES WHICH ARE SUBSTANTIALLY COMPLETELY INSOLUBLE IN HYDROCARBON SOLVENTS, SAID CONCENTRATE BEING IN THE FORM OF PARTICLES NOT EXCEEDING ABOUT 1/4 INCH, PROVIDING ALSO A SULPHUR SOLVENT IN THE FORM OF A PETROLEUM HYDROCARBON MIXTURE HAVING A MIXED ANILINE POINT LESS THAN ABOUT 50* F, AND BOILING SUBSTANTIALLY COMPLETELY WITHIN THE RANGE OF 250*F. TO 450*F., HEATING SAID SOLVENT TO ABOUT 230* F., HEATING SAID CONCENTRATE TO EXPEL FREE MOISTURE THEREFROM AND TO RAISE THE TEMPERATURE THEREOF TO ABOUT 230* F., PASSING THE HEATED SOLVENT AND DRY, HEATED CONCENTRATE COUNTERCURRENTLY THROUGH AN EXTRACTION APPARATUS, MEANWHILE MAINTAINING THE TEMPERATURE OF THE SOLVENT AND OF THE CONCENTRATE AT NOT LESS THAN ABOUT 230*F., MAINTAINING SUCH COUNTERCURRENT CONTACT UNDER CONDITIONS OF AGITATION SUFFICIENT TO INTIMATELY CONTACT THE SOLVENT WITH THE CONCENTRATE, SEPARATING CONCENTRATE FROM THE SOLVENT AT AT LEAST ONE POINT BETWEEN THE POINT OF INTRODUCTION OF THE CONCENTRATE INTO AND ITS POINT OF REMOVAL FROM SAID EXTRACTION APPARATUS, AND DRAINING THE SEPARATED CONCENTRATE, APPLYING ADHERING SOLVENT THEREFROM, SEPARATING ENTO REMOVE ADHERING SOLVENT THEREFROM, SEPARATING ENRICHED SOLVENT AT ONE END OF THE EXTRACTION APPARATUS AND EXTRACTED SOLIDS FROM THE OTHER END THEREOF, DRAINING AND APPLYING SUCTION TO THE THUS SEPARATED, EXTRACTED SOLIDS, CHILLING THE ENRICHED SOLVENT TO PRODUCE A SLURRY OF SULPHUR AND SOLVENT, FILTERING SUCH SLURRY TO SEPARATE SOLID SULPHUR FROM LIQUID SOLVENT, CONDENSING SOLVENT VAPORS RECOVERED IN THE PROCESS, AND RECYCLING THE FILTERED SOLVENT AND CONDENSED VAPORS TO THE EXTRACTION APPARATUS AFTER HEATING THE SAME.

Claim 2

A METHOD OF REFINING SULPHUR WHICH COMPRISES PROVIDING A SULPHUR CONCENTRATE CONTAINING NOT LESS THAN ABOUT 50% OF ELEMENTAL SULPHUR TOGETHER WITH IMPURITIES WHICH ARE SUBSTANTIALLY COMPLETELY INSOLUBLE IN HYDROCARBON SOLVENTS, SAID CONCENTRATE BEING IN THE FORM OF PARTICLES NOT EXCEEDING ABOUT 1/4 INCH, PROVIDING ALSO A SULPHUR SOLVENT IN THE FORM OF A PETROLEUM HYDROCARBON MIXTURE HAVING A MIXED ANILINE POINT LESS THAN ABOUT 50* F, AND BOILING SUBSTANTIALLY COMPLETELY WITHIN THE RANGE OF 250*F. TO 450*F., HEATING SAID SOLVENT TO ABOUT 230* F., HEATING SAID CONCENTRATE TO EXPEL FREE MOISTURE THEREFROM AND TO RAISE THE TEMPERATURE THEREOF TO ABOUT 230* F., PASSING THE HEATED SOLVENT AND DRY, HEATED CONCENTRATE COUNTERCURRENTLY THROUGH AN EXTRACTION APPARATUS, MEANWHILE MAINTAINING THE TEMPERATURE OF THE SOLVENT AND OF THE CONCENTRATE AT NOT LESS THAN ABOUT 230*F., MAINTAINING SUCH COUNTERCURRENT CONTACT UNDER CONDITIONS OF AGITATION SUFFICIENT TO INTIMATELY CONTACT THE SOLVENT WITH THE CONCENTRATE, SEPARATING CONCENTRATE FROM THE SOLVENT AT AT LEAST ONE POINT BETWEEN THE POINT OF INTRODUCTION OF THE CONCENTRATE INTO AND ITS POINT OF REMOVAL FROM SAID EXTRACTION APPARATUS, AND DRAINING THE SEPARATED CONCENTRATE, APPLYING ADHERING SOLVENT THEREFROM, SEPARATING ENTO REMOVE ADHERING SOLVENT THEREFROM, SEPARATING ENRICHED SOLVENT AT ONE END OF THE EXTRACTION APPARATUS AND EXTRACTED SOLIDS FROM THE OTHER END THEREOF, DRAINING AND APPLYING SUCTION TO THE THUS SEPARATED, EXTRACTED SOLIDS, CHILLING THE ENRICHED SOLVENT TO PRODUCE A SLURRY OF SULPHUR AND SOLVENT, FILTERING SUCH SLURRY TO SEPARATE SOLID SULPHUR FROM LIQUID SOLVENT, CONDENSING SOLVENT VAPORS RECOVERED IN THE PROCESS, AND RECYCLING THE FILTERED SOLVENT AND CONDENSED VAPORS TO THE EXTRACTION APPARATUS AFTER HEATING THE SAME.