> The key is to add an ingredient called potassium alum. Alum calms the surface and helps the pyramids form.
Does anyone know of scientific article where I can read more about this? I've never heard of alum's water calming abilities.
back
2 comments
Not an expert, but probably in relation to this[1]:
> In water, most of the particles are negative charged, to neutralize the charge a positive ion (cation) may be used as a coagulant. Potassium hydroxide contributes a mono-valent ion, K+. Calcium hydroxide gives a divalent ion, Ca2+. Aluminum coagulants give trivalent aluminum ions, Al3+. According to Schultz in 1882 and Hardy in 1900, higher the charge of cation, more effective is charge neutralization.
This charge would be present at the surface[2] if not dealt with via the alum, and I imagine that could disrupt the crystallization process happening there.
[1] https://link.springer.com/article/10.1007/s13201-018-0662-5 [2] https://en.m.wikipedia.org/wiki/Surface_charge
An excellent question, it seems way outside my high school chemistry knowledge that you could calm water with a tiny amount of anything, be it alum or otherwise.