[TexanToTheCore]

Lime kilns are a later technology. The article says that they may have dissolved soft limestone in ponds of water and then taken the resulting slurry uptop to pour it in the molds.

This really looks possible. The Egyptians were quite good stone workers. Their word for potter was actually "stone worker".

[GSlob]

"The article says that they may have dissolved soft limestone in ponds of water and then taken the resulting slurry uptop to pour it in the molds."
Then they would have ended up with a soft chalk, similar to what was used in elementary school on a blackboard. Now, how long would a chalk pyramid stand there before being ground to dust by blowing sand? And the grave robbers, too, would have long ago made every pyramid into a big Swiss cheeze, all full of holes.