Old Batteries Yield Thermite and Manganese

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.

15 thoughts on “Old Batteries Yield Thermite and Manganese

    1. That thermite stage? That is what I was concerned about, that an the gratuitous deployment of a chemical weapon at the end.

      I think you can go from the chloride salt to the metal directly by heating it in a ceramic tube with hydrogen flowing over it, the hydrogen flow can be low to keep things safe and as a bonus you get to recover your hydrochloric acid, you just need to keep other gases out.

    2. Again an element which is absolutely essential for life (several enzymes in plants and animals and the photosynthesis in plants) and has toxic properties. Selenium is another one which comes to my mind in this respect.

  1. I believe you mean zinc carbon batteries, not alkaline. When I did more chemistry experiments at home, I harvested the manganese dioxide and carbon rods from them. Carbon rods were useful for high temperature electrodes, and manganese dioxide is useful as a catalyst to split hydrogen peroxide into free oxygen and water. Fueled my first oxy-butane blowpipe from peroxide/manganese dioxide oxygen!

    1. zinc and manganese dioxide are used in both types of batteries. In the acidic chloride electrolyte a carbon rod is used as current collector, in the alkaline cell these are metallic (the stainless steel outer shell for positive and a brass wire in the zinc powder for the negative pole.

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