Silver Recovery Unit Operating Procedures

TM 11-6780-225-12

operate the silver recovery unit with

(3) Drain the water supply system when the

the operating control set to LOW for

space heater is not in use.

30 minutes.

This will coat the

(4) Store the chemicals in a warm place.

cathode with a hard, metallic silver

(5) Operate the immersion heater in the sink

deposit.

and melt snow to provide water for the water tank if

g. Set the silver recovery unit control on HIGH and

required.

operate the unit for the amount of time calculated in d

2-11. Silver Recovery Unit Operating Procedures

above.

a. Place the silver recovery unit in a convenient

h. Disconnect the power cord; set the control to

place in the shelter.

OFF and remove the power head and check the fixer

b. Lift off the power head of the silver recovery

solution in the silver recovery unit tank to insure that the

unit (fig. 2-17) and fill the tank to approximately 1-inch

silver has been completely recovered. If silver remains

of the top with exhausted fixer solution.

in the fixer, recalculate the time required as described in

c. Test the exhausted fixer solution for silver

d above and repeat g above.

concentration with silver estimating papers.

NOTE

d. Calculate the operating time required in

If a black deposit accumulates on the

accordance with the following example:

cathode it may indicate that the

NOTE

exhausted fixer did not contain

The capacity of the silver recovery

silver.

Check the fixer solution

unit tank is 2 gallons.

carefully for silver content and if

Number of

none is indicated discard the fixer

Silver

gallons

Recovery

solution. If silver is present, repeat d

concentration

of fixer

capacity

above and set the silver recovery

÷ 1/2 troy, ounce/hour

0.64 troy ounces/per

unit control to LOW. Do not discard

gallon x

= 2.5 hours

the soft, black deposit accumulated

on the cathode or that may have

e. Replace the power head.

fallen to the bottom of the tank.

f. Connect the power cord into a convenience

Refer to paragraph 2-12.

outlet.

i. After the silver has been completely stripped

NOTE

from the solution, disconnect the silver recovery unit

When the server recovery unit is first

from the power source, remove the power head and

placed into operation, or after the

empty the tank into a drain.

cathode (fig. 2-18) is changed,

Figure 2-17. Silver recovery unit.

desilvered. To desilver the cathode, proceed as follows:

2-12. Removal of Silver and Sliver Recovery Unit

When the thickness of the cathode and silver plate is

a. Turn the unit off and disconnect it from the

between 3/8- and 1/2-inch thick the cathode should be

power source.

Change 6 2-22