Method for the treatment, by percolation, of a felt element by means of electrode-position

1. Method for manufacturing a metallized or metallizable felt by percolation of at least one felt element by electrodeposition comprising:

a step for maintaining said at least one felt element in a metallization reactor comprising a support, wholly or partly made of electrically conductive material, for said at least one felt element and defining a first compartment and a second compartment separated by said at least one felt element, said support being electrically linked to a counter-electrode;

a step in which an electrolyte solution comprising at least one electroactive metal ion salt is made to travel through said at least one felt element;

a step for making at least one electric current pass through said at least one felt element;

said step for making an electrolyte solution travel through said at least one felt element consisting in making at least a part of this electrolyte solution pass at least once in a direction going from said first compartment to said second compartment and in the reverse direction going from the second compartment to said first compartment of said metallization reactor; and

said first compartment is placed in fluid communication with a first tank and in that said second compartment is placed in fluid communication with a second tank, the electrolyte solution travelling at least once via said compartments of said reactor in a path going from said first tank to said second tank and from said second tank to said first tank.

2. Method according to claim 1 wherein said at least one the felt element is a graphite felt element.

3. Method according to claim 1 characterized in that the method comprises a preliminary step of pre-metallization of said at least one felt element.

4. Method according to claim 1 characterized in that said electroactive metal ion is chosen from among the elements of the periods 4 to 6 of the periodic table.

5. Method according to claim 1 characterized in that said electrolyte solution has a concentration in electroactive metal ions salt ranging from 50 mg/l to 10 g/l.

6. Method according to claim 1 characterized in that said step for making an electric current pass through said at least one felt element is carried out by using an electric current the intensity of which is proportional to the volume of said at least at least one felt element according to the formula:

I=i k ×V felt

where I is the intensity of the current in amperes,

i k =0.1 A/cm 3

V felt is the volume of the felt in cm 3 .

7. Method according to claim 1 characterized in that said at least one felt element has a thickness of 1 mm to 6 mm and in that said step for making an electrolyte solution pass through said at least one felt element is implemented according to a maximum flow rate d max of the electrolyte solution computed according to the following formula:

d max =2× V felt /a

where d max is expressed in ml/min,

V felt is the volume of the felt in cm 3 , and

a is equal to 1 min.

8. Method according to claim 1 characterized in that said at least one felt element has a thickness of 6 mm to 12 mm and in that the step for making an electrolyte solution pass through said at least one felt element is implemented at a maximum flow rate d max of electrolyte solution computed according to the following formula:

d max =V felt /a

where d max is expressed in ml/min,

V felt is the volume of the felt in cm 3 , and

a is equal to 1 min.

9. Method according to claim 1 characterized in that said step for making an electric current pass through said at least one felt element is interrupted by idle times during which the intensity of the current is zero.

10. Method according to claim 9 wherein said idle time between each imposition of current is computed according to the relationship:

t

r

=

V

felt

nd

×

60

where t r is the idle time between each imposition of current in seconds,

V felt is the volume of the felt in cm 3 ,

n is an integer,

d is the flow rate of the electrolyte solution in ml/min.

11. Method according to claim 9 wherein said time of imposition of the current is computed according to the relationship:

t

i

=

t

r

2

where t i is the time of imposition of the current in seconds,

t r is the idle time between each imposition of current in seconds.

12. Method according to claim 4 characterized in that said electroactive metal ion is chosen from among nickel, copper, cobalt, silver, bismuth or lead.