Method of production of metal particles through electrolysis

• US 20050098442A1
• Filed: 04/24/2003
• Published: 05/12/2005
• Est. Priority Date: 09/12/2002
• Status: Active Grant

• Current Assignee: Zinc8 Energy Solutions, Inc.
• Original Assignee: Teck Cominco Metals Ltd.
• Inventors: Smedley, Stuart I., Des Jardins, Stephen R., Gulino, Ronald, Pinto, Martin De Tezanos, Novkov, Donald James
• Granted Patent: US 7,273,537 B2
• Time in Patent Office: Days
• US Class Current: 205/369
• CPC Class Codes: C25C 5/02 from solutions
• CPC Class Codes: C25C 7/06 Operating or servicing

Abstract

A method of producing metal particles through electrolysis. A cathode having a plurality of active zones on a surface thereof is at least partially immersed in a reaction solution. The cathode is spaced from an anode also at least partially immersed in the reaction solution. A voltage potential is applied between the anode and cathode. Metal particles form on the active zones of the cathode. In order to promote the formation of good quality particles, a turbulent flow of the solution is maintained past one or more the active zones, and the current density in the active zones is maintained greater than about 5 kA/m². The particles may be dislodged from the cathode after they have achieved a desired size.

Claims

1. A method of producing metal particles comprising:

containing a solution including dissolved metal;

maintaining the solution at a temperature between about 0 and about 100 degrees Centigrade;

immersing an anode at least partly in the solution;

immersing a cathode at least partly in the solution, the cathode having a plurality of active zones separated from each other by an insulator, said active zones electrically coupled to a conductor;

maintaining turbulent flow of the solution past one or more of the active zones; and

applying an electric potential across the anode and cathode sufficient to create a current density greater than about 5 kA/m² in the active zones, thereby causing metal particles to form on the active zones of the cathode through electrolysis.

2. The method of claim 1 further comprising containing a dissolved metal solution of a molarity sufficient to prevent the formation of dendrites on the active zones.

3. The method of claim 2 wherein the molarity of the dissolved metal is between about 0.1M and about 4.5M.

4. The method of claim 1 further comprising maintaining an electric current from the anode to the cathode sufficient to prevent the formation of dendrites on the active zones.

5. The method of claim 4 wherein the current is between 0 and about 300 amps.

6. The method of claim 4 wherein the solution flow has a Reynolds number greater than about 1500.

7. The method of claim 1 wherein the dissolved metal is in a form of one or more oxides of the metal.

8. The method of claim 1 wherein the solution is a reaction product of an electrochemical reaction in a metal/air fuel cell.

9. The method of claim 1 wherein the dissolved metal is zinc.

10. The method of claim 1 wherein the solution is an aqueous solution.

11. The method of claim 10 wherein the aqueous solution comprises dissolved electrolyte and a suspension of metal oxide.

12. The method of claim 11 wherein the dissolved electrolyte has an initial concentration between about 25 and about 55 weight percent.

13. The method of claim 1 wherein the solution is a non-aqueous solution.

14. The method of claim 1 further comprising forming metal particles of a size that generally relates to the size of the active zones.

15. The method of claim 1 further comprising collecting the metal particles from the active zones when said particles achieve a desired size.

16. The method of claim 15 further comprising relatively moving the active zones and a scraping device, such that the particles are dislodged and directed to a collection area.

17. The method of claim 15 further comprising relatively moving the active zones and the insulator, such that the particles are dislodged and directed to a collection area.

18. The method of claim 15 further comprising dislodging the particles by vibrating the cathode.

19. The method of claim 15 further comprising dislodging the particles by mechanically shocking the cathode.

20. The method of claim 15 further comprising dislodging the particles by increasing the flow of the solution.

21. The method of either of claims 16, 17, 18, 19, or 20 further comprising directing the dislodged particles to the collection area by means of a flow of the solution.

22. The method of either of claims 16, 17, 18, 19, or 20 further comprising directing the dislodged particles to the collection area by means of gravity.

23. The method of claim 1 wherein the current density in the active zones is maintained between about 10 kA/m² and about 40 kA/m².

24. The method of claim 1 wherein the temperature is maintained between about 20 and about 80 degrees C.

25. The method of claim 1 wherein the temperature is maintained between about 40 and about 55 degrees C.

26. The method of claim 1 wherein the solution flow has a Reynolds number greater than about 3000.

27. A method for producing metal particles by electrolysis of a dissolved metal solution flowing past a cathode, the cathode having a plurality of active zones exposed to the solution and electrically insulated from one another, comprising:

maintaining a solution temperature between about 0 and about 100 degrees Centigrade;

causing a turbulent flow of the solution past one or more of the active zones; and

applying an electric potential across the cathode and an anode at least partly immersed in the solution to create a current density in the active zones greater than about 5 kA/m², thereby causing metal particles to form on the active zones through electrolysis.

28. The method of claim 27 further comprising containing a solution having a dissolved metal molarity sufficient to prevent the formation of dendrites on the active zones.

29. The method of claim 28 wherein the molarity is between about 0.1M and about 4.5M.

30. The method of claim 27 further comprising maintaining an electric current from the anode to the cathode sufficient to prevent the formation of dendrites on the active zones.

31. The method of claim 30 wherein the current is between 0 and about 300 amps.

32. The method of claim 27 wherein the solution flow has a Reynolds number greater than about 1500.

33. The method of claim 27 wherein the dissolved metal is in a form of one or more oxides of the metal.

34. The method of claim 27 wherein the solution is a reaction product of an electrochemical reaction in a metal/air fuel cell.

35. The method of claim 27 wherein the dissolved metal is zinc.

36. The method of claim 27 wherein the solution is an aqueous solution.

37. The method of claim 36 wherein the aqueous solution comprises dissolved electrolyte and a suspension of metal oxide.

38. The method of claim 37 wherein the dissolved electrolyte has an initial concentration between about 25 and about 55 weight percent.

39. The method of claim 27 wherein the solution is a non-aqueous solution.

40. The method of claim 27 further comprising forming metal particles of a size that generally relates to the size of the active zones.

41. The method of claim 27 further comprising collecting the metal particles from the active zones when said particles achieve a desired size.

42. The method of claim 27 further comprising relatively moving the active zones and a scraping device, such that the particles are dislodged and directed to a collection area.

43. The method of claim 27 further comprising relatively moving the active zones and the insulator, such that the particles are dislodged and directed to a collection area.

44. The method of claim 27 further comprising dislodging the particles by vibrating the cathode.

45. The method of claim 27 further comprising dislodging the particles by mechanically shocking the cathode.

46. The method of claim 27 further comprising dislodging the particles by increasing the flow of the solution.

47. The method of either of claims 42, 43, 45, or 46 further comprising directing the dislodged particles to the collection area by means of a flow of the solution.

48. The method of either of claims 42, 43, 44, 45, or 46 further comprising directing the dislodged particles to the collection area by means of gravity.

49. The method of claim 27 wherein the current density in the active zones is maintained between about 10 kA/m² and about 40 kA/m².

50. The method of claim 27 wherein the temperature is maintained between about 20 and about 80 degrees C.

51. The method of claim 27 wherein the temperature is maintained between about 40 and about 55 degrees C.

52. The method of claim 27 wherein the solution flow has a Reynolds number greater than about 3000.

53. A process for producing metal particles, comprising:

a step for containing a solution including dissolved metal, the solution having a molarity between about 0.1M and about 4.5M;

a step for maintaining the solution at a temperature between about 0 and about 100 degrees Centigrade;

a step for immersing an anode at least partly in the solution;

a step for immersing a cathode at least partly in the solution, the cathode having a plurality of active zones separated from each other by an insulator, said active zones electrically coupled to a conductor;

a step for causing a turbulent flow of the solution past one or more of the active zones; and

a step for applying an electric potential across the anode and cathode sufficient to create a current density greater than about 5 kA/m² in the active zones, thereby causing metal particles to form on the active zones of the cathode through electrolysis.

54. The process of claim 53 wherein the flow has a Reynolds number greater than about 1500.

55. The process of claim 53 wherein the flow has a Reynolds number greater than about 3000.

56. The process of claim 53 wherein the electrical potential causes an electric current between 0 and about 300 amps.

57. The process of claim 53 wherein the dissolved metal is in a form of one or more oxides of the metal.

58. The process of claim 53 wherein the solution is a reaction product of an electrochemical reaction in a metal/air fuel cell.

59. The process of claim 53 wherein the dissolved metal is zinc.

60. The process of claim 53 wherein the solution is an aqueous solution.

61. The process of claim 60 wherein the aqueous solution comprises dissolved electrolyte and a suspension of metal oxide.

62. The process of claim 61 wherein the dissolved electrolyte has an initial concentration between about 25 and about 55 weight percent.

63. The process of claim 53 wherein the solution is a non-aqueous solution.

64. The process of claim 53 further comprising a step for forming metal particles of a size that generally relates to the size of the active zones.

65. The process of claim 53 further comprising a step for collecting the metal particles from the active zones when said particles achieve a desired size.

66. The process of claim 65 further comprising a step for relatively moving the active zones and a particle dislodging device, such that the particles are dislodged and directed to a collection area.

67. The process of claim 65 further comprising a step for relatively moving the active zones and an insulator separating the active zones from one another, such that the particles are dislodged and directed to a collection area.

68. The process of either of claims 66 or 67 further comprising a step for directing the dislodged particles to the collection area by means of a flow of the solution.

69. The process of either of claims 66 or 67 further comprising a step for directing the dislodged particles to the collection area by means of gravity.

70. The process of claim 53 wherein the applying step further comprises maintaining the current density in the active zones between about 10 kA/m² and about 40 kA/m².

71. The process of claim 53 wherein the temperature is maintained between about 20 and about 80 degrees C.

72. The process of claim 53 wherein the temperature is maintained between about 40 and about 55 degrees C.