SweetPDZ Zeolite geopolymer first try... Promising

[Deleted]

I have made some more tests with the Sweet PDZ powder and used up about 90% of it.

It takes just a few minutes to make a binder by first mixing dry lye and dry powder and then add a small amount of hot water
and stirr until it becomes a paste, then let it rest for a few minutes more before adding more water to prevent hardening of the concentrated paste.
If kept concentrated enough with hot water of about 60°C/140°F the powder reacts well and thickens as much as the zeolite I can buy here.
For a 4/1 ratio use not more than 27% water by weight and for a 3/1 ratio not more than 25%.
Water with a higher temperature would work even better.

Using Sweet PDZ powder to make a binder is a very simple and cheap way to make a geopolymer.
Small amounts of cement can be used as accelerator but quicklime would be the best.

MannaPro the manufacturer has a dealer locator and a list of online retailers,
however not every shop has the powder.
A direct inquiry may help.
www.mannapro.com/where-to-buy

[esbjornaneer]

Mar 8, 2018 10:51:39 GMT -8 @karl said:

The Sweet PDZ powder is fine enough to be used with KOH.

Thank you for your late posts in this thread @karl!
Would you tell us/me what the difference is between using NaOH and KOH in a SweetPDZ/zeolite geopolymer? I am asking with regards to the finished product and ease of success (no efflourecense) rather than the difference in proportions and procedure.

[Deleted]

KOH does not thicken clay as much as NaOH,
thus less water is required.
Less water results in a higher concentration,
which allows to use less chemicals.

[esbjornaneer]

Now I am getting a bit confused and therefore probably asking strange questions... my understanding (from soil science perspective) is that 'clay' is any particle <0.002mm which is the same as <2micro-meter (um), no matter what the chemical composition is. That is what you mean too?

And you have previously said:

Dec 24, 2017 6:49:06 GMT -8 @karl said:

Dec 23, 2017 10:43:10 GMT -8 esbjornaneer said:

So what proportion of this binder should I use to either soil, more of the same type of clay or builders sand (with or without bigger pieces of stone)?

For non castable mixtures like for bricks and plates the lye content of the total dry mass can vary from 1%-5%.
Zeolite as aggregate requires about 7% NaOH or 10% KOH.
The chemical reactions depend on the lye concentration, thus a higher water content requires a higher lye content as well.
For most castables a lye content of about 5% is sufficient.

which to me means I use more KOH than NaOH in a mix. What am I not understanding about using less chamicals?

Going back to my last question would the use of KOH rather than NaOH make the geopolymer more or less:
able to cope with the temperatures of rocket stoves?
insulative? (less water used should make it less insulative from what I have read)
likely to effloures?

[Deleted]

Once more again: Geopolymers do not solely depend on low density for low thermal conductivity.

The molar weight of KOH 56.1g/mol is 1.4 times the molar weight of NaOH 40g/mol,
thus for the same molar ratio 1.4 times KOH is required.
But there is more about it.

Potassium salts are heavier and larger which makes them harder to move.
The viscosity of sodium solutions is much higher than of potassium solutions
and thus require much more water, which lowers the concentration.
More water increases the likelyhood of unreacted residues.

www.researchgate.net/post/Elimination_of_efflorescence_in_Geopolymer_concrete_possible

[firewatcher]

If kept concentrated enough with hot water of about 60°C/140°F the powder reacts well and thickens as much as the zeolite I can buy here.
For a 4/1 ratio use not more than 27% water by weight and for a 3/1 ratio not more than 25%.
Water with a higher temperature would work even better.

Hi again Karl,
Can you provide a quick clarification on the amount of water used?
Is the 25% water for the finished mix (total binder + "aggregate")?
What I'm trying to clatify is if you should use 25% water in the binder and then when adding the final aggregate add enough to make 25% of the total dry weight if the mix, OR as you've mentioned before (for the binder only add enough water to make a very thick paste) and then in the final mix add only up to 25% water of the total dry weight.

Maybe an example to help clarify the question:
Let's say I want to make a 100g sample (using only sweet PDZ powder)

BINDER- 3/1 ratio
NaOH - 7g
Powder sweet PDZ - 21g
? Should i mix in 7 mL (25% of dry ingredients) hot/boiling water small amounts at a time?
...let rest overnight...
...add the "aggregate"...
Powder sweet PDZ - 72g
...add remaining water to make 25% of total dry ingredients...
Hot/boiling water - 18mL

OR

Should the 25% water be the amount used in total for the complete sample...the binder portion of the mix only using just enough to make a very thick paste and the rest of the 25mL not used in the binder added when adding the "aggregate" for the final part of the mix?

[Deleted]

The 25% respectively 27% water by weight are for making a concentrated binder with NaOH.
With KOH slightly less water may be sufficient.
The binder does not need to rest over night.
The mixture of binder and aggregate should contain just enough water to flow under vibration.

[firewatcher]

Mar 28, 2018 7:51:09 GMT -8 @karl said:

The 25% respectively 27% water by weight are for making a concentrated binder with NaOH.
With KOH slightly less water may be sufficient.
The binder does not need to rest over night.
The mixture of binder and aggregate should contain just enough water to flow under vibration.

Thank you for the clarification!

[coastalrocketeer]

So I’ve built a core, on the mold I have in photos on page 6 of this thread, and added a ceramic fiber blanket “5 minute riser,” that seems to be quite insulative and refractory, and then life got busy and it sat on sawhorses in front of my living room for a good portion of the year. I thought I had documented it on this thread, but apparently not, so I will be adding pics and videos.

Have been using it in the yard to carbonize bread ultra cheap bread from the bakery outlet store, as an aggregate to experiment with.

Have about 15 hours of burn time on it, and it seems to be holding up as a refractory rather well, in spite of it never having hardened to the kind of material that could replace fire brick for durability, at least on the outside. The innermost layer exposed to the extreme temps has hardened very nicely. (Makes me want to build a rocket powered kiln for curing geopolymers at higher temps!)

In three to four hour burns, the outside of the 1-1/4 to 1-1/2” thick “core” never got over 300F or so. I think it dissipates more heat at that temp than comes through, even with the core so hot that sticks added begin charring and outgassing, producing visible surface combustion and flames within 3-5 seconds of being put in.

The mix was high in water content, and very high in Rockwool content, which is probably what let it dry from such high water content without cracking. I created a “bottom” about 1-1/2” thick and set the mold on top... Then packed the mix around the mold like adobe... pics to come, they are in my old phone.

The inner layer of core is totally glassified, and quite hard, although there is a lack of uniformity of distribution of the binder materials in the Rockwool that makes it so that pieces in weak areas can break off.

This core will be temporary, and likely replaced as I come up with other geopolymer mixes that have equivalent inulative and refractory qualities, but are stronger.

I may have done better by more uniformly breaking down my Rockwool, since it was such a large amount of Rockwool, and the lack of uniformity of distribution led to stronger and weaker areas.

[firewatcher]

Costal, have you been able to get your speed PDZ mixes so that a lot of heating and adding water and reheating is no longer necessary?

[coastalrocketeer]

I have...

part of my confusion was that with the “grains of table salt” size of the “de-dusted” sweet PDZ powder I get, I don’t get the complete dissolution to totally smooth. There always remain grains. I got sidelined with family health issues and financial survival became the main focus for me right around the time @karl reported his success in geopolymerizing the sample of Sweet PDZ powder I sent him... I never got to ask if he achieved complete dissolution , or the “grittiness remained.... (if you’re reading this Karl, I hope life finds you doing as well as can be, and I have missed learning from you and communicating here immensely, and did you still have “grains of fine sand grittiness in the binders you made with the sample SweetPDZ I sent?))

I am testing some more zeolite binder mixes in my carbon foam aggregate experiments thread, as well as acid activated bentonite clay and will be reporting results there.

I am finding that, even with grittiness, the “thickening to a soft caramel like paste” occurs if I follow Karl’s instructions in the “LTGS binder from reactive minerals thread.

[coastalrocketeer]

I measure my desired amount of sweetPDZ powder, add the dictated amount of NaOH, and then stir it all up, even before adding water. The powder clumps onto the lye granules and begins reacting from water in the sweetPDZ powder and from the air (ALWAYS humid here on the Oregon coast.)

I have not needed to use heat, other than using hot water, as before, I was under the impression that my “fine granules” powder should become totally smooth. I gave up that notion and just went by how the consistency/thickness of the overall mix differs from how it would be with no lye, and such small amounts of H2O... (wouldn’t “wet” it all, and would remain all grit with no dissolution and “thickening”, and remain like stirring a pot of “damp sand”)

The fact that Karl is working with micronized powder means that any particles of less dissolvable minerals would not be detectable, and would just be part of a totally smooth “thick slurry” (like honey but thicker) For me, it becomes “thick honey with sand in it)

Then I measure say, 1/4 of the weight of sweet PDZ powder in water and heat it to near boiling, and add it in tiny bits to the powder/lye lumps/granules. Trying to mix it all with as little water as possible, to keep concentrations high.

After some portion of the water has been added, the whole mix becomes wet, but is still taffy like... hard to stir. I then keep stirring and wait a bit (5 minutes or so at the highest concentration I can stir,) before adding the remainder of the water.

Then add aggregate and pack into or around mold.

I am short on materials other than sweetPDZ, and bentonite clay (not very good for strength IMO) and especially, aggregates to bind. And part of it was coming up with a good mold that I can test a bunch of mixes in.

I found great little stackable plastic boxes that make a nice rectangular brick, and hold a small enough quantity that unsuccessful experiments are not wasteful, but the piece produced is big enough for mechanical strength and insulative properties testing. They are pictured in my carbon bread foam thread as well.

[coastalrocketeer]

Here are the three test samples I have curing at the moment... all have hardened to the consistency of stuff but still formable clay.

  The binder is the top half of the description on each lid 



CBF = Carbon Bread Foam (I have washed mine with lye solution, rinsed, dried, and screened to a couple of different sizes)

PDX CEM = Portland Cement

AAA Bentonite = acetic acid activated bentonite, activated with equal weight of 5% wihite vineagar

SWG = Solid Water Glass, sodium metasilicate, Red Devil TSP/90 heavy duty cleaner

[coastalrocketeer]

Closeups of samples 1-3


Z1^^^



Z2^^^



Z3^^^

[coastalrocketeer]

They are not SOLID, but definitely thickened to the hardness of halfway dry potters clay without much loss of H2O.

Am keeping them on top of a lamp shade with a paper towel and AL foil insulated “bell cover” to let them continue to cure and slowly dry... Today I started checking them periodically and wiping the condensed water droplets from the inside of the lids to allow them to lose moisture very slowly.

The lamp shade warmer keeps them at about 100F

Found they are at a good consistency for troweling the tops smooth, but are still too soft to “de-mold” I got impatient and tried to de-mold the AAB-2 sample and found it cracked in places visible trough the sides before I even got it out, so I pressed it back down to the bottom of the mold trying to compact it back together, and will continue slow cure/dry process... will get to see if I destroyed that one or if it “heals it’s self”