Electrolytic process for the recovery of mercury

Claim 1

A METHOD OF OPERATING AN ELECTROLYTIC FLOWING MERCURY CATHODE CELL FOR THE ELECTROLYSIS OF ALKALI METAL CHLORIDE BRINES, WHICH COMPRISES INTRODUCING A SUBSTANTIALLY SATURATED AQUEOUS SOLUTION OF AN ALKALI METAL CHLORIDE BRINE INTO A FLOWING MERCURY CATHODE CELL, ELECTROLYZING SAID BRINE IN SAID CELL TO PRODUCE AN ALKALI METAL AMALGAM AND CHLORINE, THEREBY DEPLETING THE ALKALI METAL CHLORIDE CONTENT OF SAID BRINE, REMOVING THE THUS-DEPLETED ALKALI METAL CHLORINE BRINE FROM SAID CELL, WHICH BRINE CONTAINS DISSOLVED CHLORINE AND BERCURY IMPURITIES PICKED UP FROM THE FLOWING MERCURY CATHODE, RESATURATING THE MAJOR PORTION OF THE THUS-REMOVED DEPLETED ALKALI METAL CHLORINE BRINE WITH ALKALI METAL CHLORIDE, AND RETURNING THE THUS-RESATURATED MAIN STREAM OF ALKALI METAL CHLORIDE BRINE TO THE FLOWING MERCURY CATHODE CELL FOR ELECTROLYSIS, REMOVING, AS A SIDE STREAM, A PORTION OF THE DEPLETED ALKALI METAL CHLORIDE BRINE FROM THE MAIN STREAM PRIOR TO RESATURATION THEREOF, DECHLORINATING THE SAID SIDE STREAM OF DEPLETED BRINE, PASSING THE THUS-DECHLORINATED BRINE IN ADSORPTIVE CONTACT WITH A STRONG ANIONIC EXCHANGE ORGANIC RESIN OF THE QUATERNARY AMMONIUM, CROSS-LINKED TYPE, THEREBY ABSORBING THE MERCURY COMPOUNDS CONTAINED IN SAID BRINE ON SAID ANION EXCHANGE RESIN, ELUTRIATING SAID ANION EXCHANGE RESIN CONTAINING ABSORBED MERCURY COMPOUNDS WITH AN AQUEOUS SOLUTION OF SODIUM SULFIDE, THEREBY TO TRANSFER SAID ABSORBED MERCURY COMPOUNDS TO THE ELUTRIATOR, MIXING SAID ELUUTRIATOR WITH A PORTION OF THE MAIN STREAM OF DEPLETED BRINE REOVED FROM SAID ELECTROLYTIC FLOWING MERCURY CATHODE CELL, SAID DEPLETED BRINE HAVING CHLORINE GAS DISSOLVED THEREIN IN AN AMOUNT SUFFICIENT TO PROVIDE A STOICHIOMETRIC EXCESS OVER THAT REQUIRED TO CONVERT THE MERCURY COMPOUNDS IN SAID ELUTRIATOR TO MERCURIC CHLORIDES, PASSING THE THUS-OBTAINED BRINE MIXTURE, WITH THE MERCURY CONTAINED THEREIN, TO THE FEED STREAM OF THE ELECTROLYTIC, FLOWING MERCURY CATHODE CELL, AND PASSING AN ELECTRIC CURRENT THROUGH SAID CELL SO AS TO PROVIDE A CATHODIC CHARGE AT THE SURFACE OF SAID FLOWING MERCURY AND PLATE THE MERCURY CONTAINED IN SAID MIXTURE ON THE SURFACE OF SAID CATHODE.

Claim 2

A METHOD OF OPERATING AN ELECTROLYTIC FLOWING MERCURY CATHODE CELL FOR THE ELECTROLYSIS OF ALKALI METAL CHLORIDE BRINES, WHICH COMPRISES INTRODUCING A SUBSTANTIALLY SATURATED AQUEOUS SOLUTION OF AN ALKALI METAL CHLORIDE BRINE INTO A FLOWING MERCURY CATHODE CELL, ELECTROLYZING SAID BRINE IN SAID CELL TO PRODUCE AN ALKALI METAL AMALGAM AND CHLORINE, THEREBY DEPLETING THE ALKALI METAL CHLORIDE CONTENT OF SAID BRINE, REMOVING THE THUS-DEPLETED ALKALI METAL CHLORINE BRINE FROM SAID CELL, WHICH BRINE CONTAINS DISSOLVED CHLORINE AND BERCURY IMPURITIES PICKED UP FROM THE FLOWING MERCURY CATHODE, RESATURATING THE MAJOR PORTION OF THE THUS-REMOVED DEPLETED ALKALI METAL CHLORINE BRINE WITH ALKALI METAL CHLORIDE, AND RETURNING THE THUS-RESATURATED MAIN STREAM OF ALKALI METAL CHLORIDE BRINE TO THE FLOWING MERCURY CATHODE CELL FOR ELECTROLYSIS, REMOVING, AS A SIDE STREAM, A PORTION OF THE DEPLETED ALKALI METAL CHLORIDE BRINE FROM THE MAIN STREAM PRIOR TO RESATURATION THEREOF, DECHLORINATING THE SAID SIDE STREAM OF DEPLETED BRINE, PASSING THE THUS-DECHLORINATED BRINE IN ADSORPTIVE CONTACT WITH A STRONG ANIONIC EXCHANGE ORGANIC RESIN OF THE QUATERNARY AMMONIUM, CROSS-LINKED TYPE, THEREBY ABSORBING THE MERCURY COMPOUNDS CONTAINED IN SAID BRINE ON SAID ANION EXCHANGE RESIN, ELUTRIATING SAID ANION EXCHANGE RESIN CONTAINING ABSORBED MERCURY COMPOUNDS WITH AN AQUEOUS SOLUTION OF SODIUM SULFIDE, THEREBY TO TRANSFER SAID ABSORBED MERCURY COMPOUNDS TO THE ELUTRIATOR, MIXING SAID ELUUTRIATOR WITH A PORTION OF THE MAIN STREAM OF DEPLETED BRINE REOVED FROM SAID ELECTROLYTIC FLOWING MERCURY CATHODE CELL, SAID DEPLETED BRINE HAVING CHLORINE GAS DISSOLVED THEREIN IN AN AMOUNT SUFFICIENT TO PROVIDE A STOICHIOMETRIC EXCESS OVER THAT REQUIRED TO CONVERT THE MERCURY COMPOUNDS IN SAID ELUTRIATOR TO MERCURIC CHLORIDES, PASSING THE THUS-OBTAINED BRINE MIXTURE, WITH THE MERCURY CONTAINED THEREIN, TO THE FEED STREAM OF THE ELECTROLYTIC, FLOWING MERCURY CATHODE CELL, AND PASSING AN ELECTRIC CURRENT THROUGH SAID CELL SO AS TO PROVIDE A CATHODIC CHARGE AT THE SURFACE OF SAID FLOWING MERCURY AND PLATE THE MERCURY CONTAINED IN SAID MIXTURE ON THE SURFACE OF SAID CATHODE.