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Post by boscovius on Jun 8, 2021 16:05:50 GMT -8
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Post by Deleted on Jun 10, 2021 10:41:28 GMT -8
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a pretty good accelerator.
Mixing it with very fine grog powder or other finely divided pozzolanes gives a very fast setting roman cement,
which is a calcium geopolymer.
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Post by boscovius on Jun 11, 2021 9:38:08 GMT -8
Hello Karl.
I was well on my way to experimenting with geopolymers when I stumbled upon Patent # 3,944,425 and took a detour. I had already been trying to figure out how to do the foamed clay thing and this patent provided several recipes for high temp refractories which seemed very safe, simple and straightforward. I've had some success with recipe #34, which is mostly all "Fine-Grained Brick Clay" for which I have substituted my own clay from my property. That's all documented at the Permies link. However, I do not believe I am firing this material at high enough temperatures to achieve a fully mature ceramic body. Right now I'm putting together a small foundry so I can get these small samples up to higher temps.
It's funny you mention quicklime as I had planned on making some and experimenting with it. I have access to loads of zebra mussel shells piled up on the beach from Lake Erie nearby and with the foundry, I can easily make it fresh. Do you think adding a small amount to the mix, such as 5 %, in Example #34 in the Patent would enhance setting times? My set times are much longer than what the patent suggests, but then again, I am substituting the main raw material and the cement I am using is a Calcium Aluminate, but is not the "Lumnite" cement the patent specifies.
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Post by Deleted on Jun 11, 2021 11:01:09 GMT -8
With the foundry you can not only make quicklime but also metaclay eg. metakaolin.
With metakaolin and quicklime you have basicaly a calcium aluminium cement wich is without
calcium sulfate also a calcium geopolymer.
With lye or phosphoric acid you will get other kids of geopolymers.
Some carbonic acids eg. citric acid will work with metaclays as well.
Different lyes or different acids can be mixed and thus become much more powerful than each alone.
Qicklime is a lye as well and will shorten the setting time of other lyes significantly.
carbonic acids are much better in cracking clay molecules than anorganic acids.
Heve a lot of fun.
Clay geopolymers have a high air content by nature and thus can be considered as "foamed"
Milling solid lyes or acids together with the clays will improve reativity. Respiratory protection is mandatory.
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Post by hallinen on Jun 17, 2021 7:46:59 GMT -8
What a great use for those dang zebra mussel shells!
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