Mercury collection system

Abstract

A system for collecting mercury from feed material that can be tailings comprises: a water inlet for forming a slurry containing the tailings; at least one screen for separating tailings from the slurry to form a screened slurry; a rotatable collection chamber containing at least one plate, a drive for rotating the collection chamber for collecting mercury on the plate to provide a discharge material comprising water and treated tailings, the treated tailings containing less mercury than in the feed material.

What is claimed is: 
     
         1 . Apparatus for collecting mercury from a feed material containing mercury, the apparatus comprising:
 a) a rotatable collection chamber having a wall and a longitudinal axis;   b) a feed material inlet for introducing the feed material into the chamber;   c) a drive for rotating the chamber;   d) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof;   e) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber;   f) a plurality of weirs extending inwardly from the chamber wall; and   g) a feed chamber upstream of the collection chamber and connected to the collection chamber to rotate with the collection chamber.   wherein the apparatus is inside an enclosure and the apparatus is removable from the enclosure for removing mercury from the plate.   
     
     
         2 . Apparatus for collecting mercury from a feed material containing mercury, the apparatus comprising:
 a) a rotatable collection chamber having a wall and a longitudinal axis;   b) a feed material inlet for introducing the feed material into the chamber;   c) a drive for rotating the chamber;   d) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof; and   e) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber.   
     
     
         3 . The apparatus of  claim 2  comprising a plurality of weirs extending inwardly from the chamber wall. 
     
     
         4 . Apparatus for collecting mercury from a feed material containing mercury, the apparatus comprising:
 a) a rotatable collection chamber having a wall and a longitudinal axis;   b) a feed material inlet for introducing the feed material into the chamber;   c) a drive for rotating the chamber;   d) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof;   e) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber; and   f) a feed chamber upstream of the collection chamber and connected to the collection chamber to rotate with the collection chamber.   
     
     
         5 . The apparatus of  claim 4  wherein the feed material inlet is connected to the feed chamber. 
     
     
         6 . The apparatus for  claim 4  wherein the feed material is a slurry comprising liquid and a solid, and wherein the feed chamber contains a material for comminuting the solid. 
     
     
         7 . The apparatus of  claim 6 , wherein the material for comminuting the solid comprises one or more of the following: stones, steel balls and ceramic balls. 
     
     
         8 . Apparatus for collecting mercury from a feed material containing mercury, the apparatus comprising:
 a) a rotatable collection chamber having a wall and a longitudinal axis;   b) a feed material inlet for introducing the feed material into the chamber;   c) a drive for rotating the chamber;   d) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof; and   e) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber.   wherein the apparatus is inside an enclosure and the apparatus is removable from the enclosure for removing mercury from the plate.   
     
     
         9 . A system comprising the apparatus of  claim 2  with a water inlet upstream of the collection chamber and a line for introducing water to the water inlet. 
     
     
         10 . The apparatus of  claim 2  wherein the feed material is a slurry and the feed material inlet is adapted for introducing a slurry into the chamber. 
     
     
         11 . A method for collecting mercury from a feed material comprising the steps of:
 a) feeding the feed material into the collection chamber of the apparatus of  claim 2  through the feed material inlet;   b) rotating the collection chamber with the drive;   c) collecting mercury on the exterior surface of the plates thereby producing a discharge material containing less mercury than the feed material; and   d) withdrawing the discharge material from the collection chamber through the outlet.   
     
     
         12 . A method for collecting mercury from a feed material comprising the steps of:
 a) providing an apparatus for collecting mercury from the feed material containing mercury, the apparatus comprising:
 i) a rotatable collection chamber having a wall and a longitudinal axis; 
 ii) a feed material inlet for introducing the feed material into the chamber; 
 iii) a drive for rotating the chamber; 
 iv) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof; 
 v) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber; and 
 vi) a feed chamber upstream of the collection chamber; 
   b) feeding the feed material into the feed chamber of the apparatus through the feed material inlet;   c) rotating the feed chamber with the collection chamber with the drive;   d) collecting mercury on the exterior surface of the plates thereby producing a discharge material containing less mercury than the feed material; and   e) withdrawing the discharge material from the collection chamber through the outlet.   
     
     
         13 . The method of  claim 12  wherein the feed material comprises a solid and the apparatus comprises a material for comminuting the solid in the feed chamber, and wherein rotation of the feed chamber results in comminution of the solid. 
     
     
         14 . A method for collecting mercury from a feed material comprising the steps of:
 a) providing an apparatus for collecting mercury from a feed material containing mercury, the apparatus comprising:
 i) a rotatable collection chamber having a wall and a longitudinal axis; 
 ii) a feed material inlet for introducing the feed material into the chamber; 
 iii) a drive for rotating the chamber; 
 iv) at least one plate in the chamber, the plate having an exterior surface formed of a collection material for collecting mercury from the feed material, the plate being in a plane intersecting the longitudinal axis, wherein the collection material is selected from the group consisting of copper, silver, gold, and combinations thereof; and 
 v) an outlet from the chamber for having feed material from which mercury has been collected removed from the chamber; 
   wherein the apparatus is inside an enclosure and the apparatus is removable from the enclosure for removing mercury from the plate;   b) feeding the feed material into the chamber of the apparatus through the feed material inlet;   c) rotating the chamber with the drive;   d) collecting mercury on the exterior surface of each plate, thereby producing a discharge material containing less mercury than the feed material;   e) withdrawing the discharge material from the chamber through the outlet;   f) removing the apparatus from the enclosure; and   g) after step (f), removing mercury from the plates.   
     
     
         14 . A method for collecting mercury from tailings comprising the steps of:
 a) forming a slurry comprising the tailings and water, wherein the tailings in the formed slurry, and wherein the tailings in the slurry contain a first percentage by weight of mercury;   b) introducing the slurry into a rotatable collection chamber containing at least one plate, the plate having an exterior surface with a collection material thereon, the collection material selected from the group consisting of gold, silver, and copper, each plate having mercury on an exterior surface;   c) rotating the chamber wherein mercury collects on the plate providing a discharge material comprising water and treated tailings, the treated tailings containing substantially no mercury or a second percentage by weight of mercury, the second percentage being less than the first percentage;   d) discharging the discharge material from the chamber; and   e) separating the water from the treated tailings.   
     
     
         15 . The method of  claim 14  wherein the mercury collected on the plate comprises an amalgam comprising mercury with gold or silver or both gold and silver. 
     
     
         16 . A method for collecting mercury from tailings comprising the steps of:
 a) forming a slurry comprising the tailings and water, wherein the tailings in the formed slurry, and wherein the tailings in the slurry contain a first percentage by weight of mercury;   b) introducing the slurry into a rotatable collection chamber in an enclosure, the collection chamber containing at least one plate, the plate having an exterior surface with a collection material thereon, the collection material selected from the group consisting of gold, silver, and copper, the plate having mercury on an exterior surface;   c) rotating the chamber wherein mercury collects on the plate providing a discharge material comprising water and treated tailings, the treated tailings containing substantially no mercury or a second percentage by weight of mercury, the second percentage being less than the first percentage;   d) discharging the discharge material from the chamber;   e) separating the water from the treated tailings;   f) removing the chamber from the enclosure; and   g) after step f), removing mercury from the plate.   
     
     
         17 . The method of  claim 16  wherein the tailings comprise mercury oxide, and the method comprises the step of including in the slurry an organic compound to reduce the mercury oxide. 
     
     
         18 . The method of  claim 16  wherein the organic compound comprises an organic acid. 
     
     
         19 . The method of  claim 18 , wherein the organic acid is oxalic acid or citric acid. 
     
     
         20 . The method of  claim 16  wherein the step of introducing comprises introducing the organic compound into the slurry before step (b). 
     
     
         21 . A system for collecting mercury from tailings, the tailings containing a first percentage by weight of mercury, the system comprising:
 a) a water inlet for forming a slurry containing the tailings;   b) at least one screen for separating tailings from the slurry to form a screened slurry;   c) a rotatable collection chamber having a longitudinal axis and containing at least one plate, the plate extending in a direction to intersect the longitudinal axis;   d) a collection chamber inlet for introducing the screened slurry into the chamber;   e) a drive for rotating the collection chamber for collecting mercury on the plate to provide a discharge material comprising water and treated tailings, the treated tailings containing substantially no mercury or a second percentage by weight of mercury, the second percentage being less than the first percentage;   f) an outlet from the collection chamber for discharging the discharge material from the collection chamber; and   g) a separation system for separating the treated tailings from the water in the discharge material.   
     
     
         22 . The system of  claim 21  wherein the collection chamber comprises a wall and a plurality of weirs extending inwardly from the chamber wall. 
     
     
         23 . The system of  claim 21  comprising a feed chamber upstream of the collection chamber and connected to the collection chamber to rotate with the collection chamber and in fluid flow with the chamber inlet for introducing the screened slurry into the collection chamber. 
     
     
         24 . The system for  claim 23  wherein the feed chamber contains a material for comminuting the solid. 
     
     
         25 . The system of  claim 21  wherein the collection chamber is inside an enclosure, and wherein the collection chamber is removable from the enclosure for removing mercury from the plate. 
     
     
         26 . The system of  claim 21  comprising a water inlet upstream of the collection chamber and a line for introducing water to the water inlet. 
     
     
         27 . The system of  claim 21  comprising an inlet for an organic material for introducing an inorganic compound for reducing mercury compounds in the tailings, the inlet for the organic material being upstream of the collection chamber. 
     
     
         28 . The apparatus of  claim 2  wherein the plates are made of copper, silver, gold or combinations thereof. 
     
     
         29 . The method of  claim 13  wherein the collection material is copper, silver, gold or combination thereof. 
     
     
         30 . The apparatus of  claim 1 , wherein there is a metallic mesh on the exterior surface of the plate.