Idea for producing refractory cement bricks
I've been slowly dissolving aluminum cans in a NaOH solution for a while now. My plan is, once the solution is unable to dissolve anymore aluminum, to dry the powder and then cinter it in my microwave kiln to convert the aluminum hydroxide into alumina, then add that to my dry mix as the primary refractory agent. For my other ingredients, I plan to use a mix of silica sand and portland cement as well as a foam produced by blending air into a solution of dish soap and xanthum gum following this video by NightHawkInLight to produce aerocrete.
My idea essentially is just to have light bricks with lots of air and alumina to insulate. I'm aware that the calcium carbonate can break down at extreme temperatures, but the insulation value from the air and alumina should help to prevent this. I'm new to making bricks and just looking to experiment using cheap materials I can obtain locally without needing to source them from expensive sources or online companies.
Any ideas or feedback would be greatly appreciated.