Sennes Phosphate geopolymer thread

[sennedp]

Hi all,

I have been reading this forum for a few months now and doing my own geopolymer experiments as I am Building a ceramics oven.
I had concluded that nothing of this geopolymer stuff actually really worked for me so I gave up.
Until I found information on chemically bonded Phosphate ceramics (CBPC). This was really the geopolymer stuff without all the magic. Straight forward chemistry. And it got me results in almost a week time. Today I made my first interesting pieces.
I will invite you to come see my experiments and share my findings.
Here is a picture of tests that I made today.

photos.app.goo.gl/CA8dH4sWHMf958r17

Some are tested in a microwave kiln for heat resistance and none of them broke. Some of them are impossible to snap by hand. They are all porous. The smooth pieces that you see are iron-calcium Phosphate and Silica materials. They set very quickly (1min) but are very strong. More work is needed to be done to make it better to handle.

Greetings from Belgium

Senne

[martyn]

Hi, we will look forward to seeing more results….

[firewatcher]

Very interested in seeing the results of your experiments. Do you have any sample "recipies" that you're willing to share based on your experiments thus far?

[sennedp]

Hi,

I am planning on making a batch box rocket mass heater. I Will be experimenting with a recipe that I found and that is the following (all by weight):
- 2 parts phosphoric acid 75%
- 1 part water
- mix the liquids
- 4 parts wollastonite (CaSiO3)
- mix rapidly
- Perlite until suitable for your application
- the material hardens in 10 minutes
It is possible tot knead the substance with safety gloves.

This material has a high insulation factor and is thermally stable.
A denser and heat conducting material is made by swapping 2 parts of wollastonite with 2 parts black iron oxide (FeO), and not using perlite.

I am planning on doing more tests tot see if all the phosphoric acid is reacted, otherwise a lower concentration of phosphoric acid is possible.
Prolonging the reaction time is probably possible with waterglass or NaOH/KOH solutions.

Greetings Senne

[firewatcher]

Nov 12, 2024 5:49:26 GMT -8 sennedp said:

Hi,

I am planning on making a batch box rocket mass heater. I Will be experimenting with a recipe that I found and that is the following (all by weight):
- 2 parts phosphoric acid 75%
- 1 part water
- mix the liquids
- 4 parts wollastonite (CaSiO3)
- mix rapidly
- Perlite until suitable for your application
- the material hardens in 10 minutes
It is possible tot knead the substance with safety gloves.

This material has a high insulation factor and is thermally stable.
A denser and heat conducting material is made by swapping 2 parts of wollastonite with 2 parts black iron oxide (FeO), and not using perlite.

I am planning on doing more tests tot see if all the phosphoric acid is reacted, otherwise a lower concentration of phosphoric acid is possible.
Prolonging the reaction time is probably possible with waterglass or NaOH/KOH solutions.

Greetings Senne

I was afraid of that...
Attempting to try the recipe that you shared would mean obtaining a lot of materials that I don't already have. Thank you for sharing though.