Many radio components contain precious and semi-precious metals: silver, gold and platinum. You can extract these metals at home, but this requires time and effort. In addition, you will need certain reagents.
Take the gold plated brass and copper radio parts. Make a solution of hydrochloric and sulfuric acids (1 liter of sulfuric acid with a density of 1.8 g / cm3 and 250 ml of hydrochloric acid with a density of 1.19 g / cm3). Heat the solution to a temperature of 60-70 degrees Celsius. Dip the details into it. Add a small amount of nitric acid. The resulting "aqua regia" will dissolve the gold.
In the absence of nitric acid, remove the gold plating by anodic dissolution in a solution of sulfuric or hydrochloric acid at a temperature of 15 to 25 degrees Celsius. In this case, the current strength should be 0.1–1 A / dm2, and the cathode should be lead or iron. You see that the current has dropped - the gold is dissolved.
Extract the platinum with nitric acid. Throw platinum-containing radio parts into it. The precious metal will precipitate. Drain the acid into another container. Neutralize the sediment with a baking soda solution. Gold can be recovered in the same way.
Remove the silver. Take copper or brass radio parts in which silver is applied to the case or contacts. Make a mixture of sulfuric acid and nitric acid (19 to 1, 2). Heat the mixture to 80 degrees. Remove the silver from this solution by reducing it with the same amount of zinc chips or dust.
Pay attention to the silver content in some radio parts. Silver is contained in a fairly large amount in capacitors. For example, K15-5 contains 29, 901 grams, and K10-7 contains 13, 652 grams. silver (the calculation is taken for 1000 pieces). You can also take almost any radio parts of the Soviet era, they also contain silver in sufficient quantities.
Remove the silver from the relay. They contain it in its purest form. For example, in RES6 - 157 gr. silver, and in RSCh52 its content is 688 grams, and in RVM the share of semiprecious metal is 897.4 grams. (data is given for 1000 pieces).
And the last thing. As you can see, precious metals are mainly extracted using various acids. It is necessary to work with acids very carefully, observing all safety rules. Remember, acid is not only dangerous if it comes into contact with the skin, you can get burns even if you inhale its vapors. Take care of yourself!