Transcription
If you add hundreds of egg shells to a furnace, and I mean really shove them in there, then set the heat to 1,000° C, it actually starts making something useful that's used around the world.
At 300°, the furnace starts producing smoke. This is from the organics burning off. At 500°, the shells are looking charred, but that's okay because at 800°, the shells are starting to convert to a new chemical. Finally, at 1,000°, the egg shells have lost carbon and oxygen atoms, leaving behind chemical called calcium oxide.
Scooping some of it up, and you can see the shells are even whiter and cleaner than they started. But, this isn't the useful chemical yet. [music] I need to add this to water to make the full conversion. That was a bad idea. Let's do it again.
This turns the calcium oxide into calcium hydroxide. This forms a watery slurry, and to demonstrate how useful this now is, I'm going to add it to some dirty water. I only added it to the glass on the right, which added positively charged ions that sticks to the negatively charged dirt particles, causing them to clump together in a process called coagulation. As they clump, they become heavier, settling out the dirt, making the water much cleaner. That's why this chemical is sometimes used in waste water treatment.