Removing finely dispersed particulate matter from a fluid stream

Abstract

Disclosed herein are systems and methods for removing fine particulate matter from a fluid, comprising a separator that separates an inflow fluid stream into an overflow fluid path and an underflow fluid path, where the underflow fluid path is treated with a tethering material that attaches to the coarse particulate matter to form tether-bearing anchor particles and where the overflow fluid path is treated with an activating material so that the activating material interacts with the fine particulate matter to form activated particles. After these treatments, the underflow fluid path containing the tether-bearing anchor particles is commingled with the overflow fluid path containing the activated particles, so that a removable complex is produced that can be removed in a settling facility, thereby removing the fine particulate matter from the fluid. The systems and methods are particularly advantageous for removing particulate matter from a fluid waste stream following mining or ore processing operations, such as oil sands mining or processing.

1 . A system for removing fine particulate matter from a fluid, comprising:
 an inflow fluid stream comprising fine particulate matter and coarse particulate matter suspended therein;   an initial separator for separating the inflow fluid stream into an overflow fluid path comprising the suspended fine particulate matter and an underflow fluid path comprising the suspended coarse particulate matter;   a tether injector that introduces into the underflow path a tethering material capable of being affixed to the coarse particulate matter to form tether-bearing anchor particles, said tether-bearing anchor particles being suspended in a treated fluid stream, said treated fluid stream admixing with the overflow fluid path to form a conjoined fluid stream;   an activator injector that introduces into the conjoined fluid stream an activating material capable of being affixed to the fine particulate matter to form activated particles, said activated particles interacting with the tether-bearing anchor particles to form removable complexes; and   a settling facility, where the removable complexes are separated from the conjoined treated fluid stream, thereby removing fine particulate matter from the fluid.   
     
     
         2 . The system of  claim 1 , wherein the initial separator is a hydrocyclone. 
     
     
         3 . The system of  claim 1 , wherein the underflow fluid path is split into a plurality of underflow fluid subpaths. 
     
     
         4 . The system of  claim 3 , wherein a first underflow subpath contains untreated cyclone underflow fluid. 
     
     
         5 . The system of  claim 3 , wherein a second underflow subpath is directed to a second separator that produces cyclone overflow and cyclone underflow. 
     
     
         6 . The system of  claim 5 , wherein the second separator is a hydrocyclone. 
     
     
         7 . The system of  claim 3 , wherein one of the plurality of underflow subpaths is treated with the tethering material. 
     
     
         8 . The system of  claim 5 , wherein cyclone underflow from the second separator is treated with the tethering material. 
     
     
         9 . The system of  claim 5 , wherein cyclone overflow from the second separator is mixed with the cyclone overflow from the initial separator. 
     
     
         10 . A system for removing fine particulate matter from a fluid, comprising:
 a separator that separates an inflow fluid stream into an overflow fluid path containing suspended fine particulate matter, and an underflow fluid path;   a tether injector for injecting tether-bearing anchor particles into the underflow fluid path to form a treated underflow fluid path;   a first activator injector for injecting a first activator material into the overflow fluid path to form a treated overflow fluid path, wherein the first activator material complexes with the fine particulate matter to form a first set of activated particles;   a commingler to join the treated underflow fluid path and the treated overflow fluid path to form a conjoined fluid stream;   a second activator injector for injecting a second activator material into the conjoined fluid stream, wherein the second activator material complexes with residual fine particulate matter to form a second set of activated particles;   wherein the tether-bearing anchor particles interact with the first and second sets of activated particles to form removable complexes; and   a settling facility where the removable complexes are separated from the conjoined treated fluid stream, thereby removing fine particulate matter from the fluid.   
     
     
         11 . The system of  claim 10 , wherein the first activator material and the second activator material are the same. 
     
     
         12 . A method for removing fine particulate matter from a fluid, comprising:
 separating an inflow fluid stream comprising fine particulate matter and coarse particulate matter suspended therein into an overflow fluid path, comprising the suspended fine particulate matter and an underflow fluid path comprising the suspended coarse particulate matter;   introducing into the underflow path a tethering material capable of being affixed to the coarse particulate matter to form tether-bearing anchor particles, said tether-bearing anchor particles being suspended in a treated fluid stream;   admixing the overflow fluid path with the treated fluid stream to form a conjoined fluid stream;   introducing into the conjoined fluid stream an activating material capable of being affixed to the fine particulate matter to form activated particles, wherein said activated particles are capable of interacting with the tether-bearing anchor particles to form removable complexes;   combining the activated particles with the tether-bearing anchor particles to form removable complexes; and   separating the removable complexes from the conjoined fluid stream, thereby removing fine particulate matter from the fluid.   
     
     
         13 . The method of  claim 12 , further comprising removing bitumen from the fluid before the addition of the activating material. 
     
     
         14 . The method of  claim 12 , further comprising adding an additional activating material to the overflow fluid path before admixing the overflow fluid path with the treated fluid stream. 
     
     
         15 . The method of  claim 14  wherein the activating material introduced into the conjoined fluid stream and the additional activating material are the same. 
     
     
         16 . The method of  claim 12 , wherein the inflow fluid stream is separated into an overflow path and an underflow path using a hydrocyclone. 
     
     
         17 . The method of  claim 12 , wherein the underflow fluid path is split into a plurality of underflow fluid subpaths. 
     
     
         18 . The method of  claim 17 , wherein a first underflow subpath contains untreated cyclone underflow fluid. 
     
     
         19 . The method of  claim 16 , wherein a second underflow subpath is directed to a second separator that produces cyclone overflow and cyclone underflow. 
     
     
         20 . The method of  claim 19 , wherein the second separator is a hydrocyclone. 
     
     
         21 . The method of  claim 17 , wherein one of the plurality of underflow subpaths is treated with the tethering material. 
     
     
         22 . The method of  claim 19 , wherein cyclone underflow from the second separator is treated with the tethering material. 
     
     
         23 . A method for removing fine particulate matter from a fluid comprising:
 separating an inflow fluid stream into an overflow fluid path containing suspended fine particulate matter, and an underflow fluid path;   introducing tether-bearing anchor particles into the underflow fluid path to form a treated underflow fluid path;   introducing a first activator material into the overflow fluid path to form a treated overflow fluid path, wherein the first activator material complexes with the fine particulate matter to form a first set of activated particles;   admixing the treated underflow fluid path and the treated overflow fluid path to form a conjoined fluid stream;   introducing a second activator material into the conjoined fluid stream, wherein the second activator material complexes with residual fine particulate matter to form a second set of activated particles, wherein the tether-bearing anchor particles interact with the first and second sets of activated particles to form removable complexes; and   separating the removable complexes from the conjoined treated fluid stream, thereby removing fine particulate matter from the fluid.   
     
     
         24 . The method of  claim 22 , wherein the first activator material and the second activator material are the same.