Some people collect stamps, some collect coins, some even collect barbed wire. But the aptly named [Plutonium Bunny] is an element collector, as in one who seeks a sample of as many elements on the periodic table as possible. Whatever, we don’t judge – after all, there are more than a few Hackaday readers who collect lots of silicon, right?
So what’s a collector to do when he gets to the 25th place on the periodic table? Easy – harvest manganese from alkaline batteries with a thermite reaction. There’s a surprising amount of manganese in depleted alkaline batteries, which of course are easy to come by in bulk. The chemistry of [Plutonium Bunny]’s process is pretty straightforward and easy to reproduce with common ingredients, but you’ll want to be careful with a few steps – chlorine gas is not something to trifle with. The basic idea is to solubilize and purify the manganese dioxide from the other materials in the battery cathodes, recrystallize it, and mix it with aluminum powder. The aluminum acts as the fuel, the manganese dioxide is the oxidizer, and once the satisfyingly exothermic reaction shown in the video below is over, the collector-grade elemental manganese can be chipped away from the aluminum oxide slag.
So once you’ve got a few manganese nuggets, what can you do with them? Not much really – it turns out the oxides recovered from the battery are far more useful for things like supercapacitors. But it’s still a neat trick.