Platinum #78 – Pt
Group:	10 (nickel group)
Period:	6
Atomic Weight:	195.08
Relative Density:	21.45
Melting point:	1768 °C / 3214 °F
Boiling point:	3825 °C / 6917 °F

Platinum (Pl), from the Spanish word for little silver, platino, is a precious metal that is worth more than gold. In fact, platinum is about 15 times as rare as gold on Earth. Like gold, platinum is soft, malleable, rather unreactive, and will not corrode. the most common use of platinum is for catalytic convertors on automobiles. However, it can also be found elsewhere on automobiles: spark plugs. It is far easier to extract the platinum rods out of spark plugs than to try to disassemble a catalytic convertor.

Platinum spark plugs are almost always marked as such. The actual platinum is only a small disk mounted on the electrode, which is generally copper coated with nickel. The part marked “copper core central electrode in the image above usuall also has a platinum disk at its tip.

To separate the platinum from the copper, steel, and nickel, you are going to need to have nitric acid and hydrochloric acid. Begin by using end cutting pliers to snip off the electrodes from each spark plug.

Next you must dissolve out the other metals – copper, steel, palladium, etc. Put all your tips into a glass beaker and add nitric acid. Warming the acid will speed up the chemical reaction, but it may take several hours.

A makeshift heater can be made with a crockpot partially filled with sand.

Pour off the acid, rinse the remaining metal with water, and repeat with hydrochloric acid. Pour off the acid and rinse again.

With the remaining metal in a glass beaker, prepare aqua regia, which will dissolve platinum. This reaction will take up to several hours, and is again sped up by heating. The solution will turn orange; cover it as it reacts.

Iridium, another metal found on spark plug tips, will not dissolve in aqua regia: any metal left is iridium or titanium.

Once the reaction is complete, uncover it, and allow it to evaporate while still heating. Eventually you will be left with a dry paste at the bottom of your beaker.

Reconstitute the platinum paste into solution with some distilled water, and add ammonium chloride. Platinum metal beads will precipitate out of solution.

It will take approximately 75 spark plugs to extract 1 gram of platinum.