SweetPDZ Zeolite geopolymer first try... Promising

[coastalrocketeer]

This is the "top side" that I pressed on to the plastic with my fingers... You can see it is kind of uneven as the tufts of mineral wool dictated...



And this is the back side where it was against the plastic... Smoother, and undergoes different color changes on the part that I "torch flame tested".

[coastalrocketeer]

I can pinch the middle of the dried but not torched areas and cannot crumble or break it pinching as hard as I can. It seems to glassify where it gets torched and actually gets harder there.

Some of the pits and breaks in the surface of the torched halves is where I was testing to compare the two halves by pushing a utility knife blade into the surface...

[coastalrocketeer]

Here is the video of the torch test of this zeolite/bentonite/basalt rock wool hybrid... When I sound like a chipmunk, it's at 2x speed so that the 8 or so minutes of torching would not become too incredibly boring... Which also means I am moving the torch around at half the speed... The heat resistance of the mineral wool bare is night and day versus that embedded in geopolymer.

youtu.be/1DIPQfjqs-I

[Deleted]

Thanks for sharing.
A mixture with clay and feldspar can be made very liquid to protect rock wool,
but even clays with a low water demand alone are sufficient.

[coastalrocketeer]

Jan 7, 2018 8:54:25 GMT -8 @karl said:

Thanks for sharing.
A mixture with clay and feldspar can be made very liquid to protect rock wool,
but even clays with a low water demand alone are sufficient.

I started with bentonite because it was a resource I could quickly and easily put my hands on for a few bucks.

When I am flush enough to make it to the valley with more than a few bucks in my pocket I will be picking up many of the ingedients you have suggested working with in other places from the pottery supplier two hours away.

Current experiments are oriented toward getting a Jtube built that is "good enough" to start warming my house with our excessive coastal rainforest branch-fall, as we are almost out of cord wood, and the "highly efficient" Scandinavian box stove we have, consumes the stuff by the wheel barrow load, is A LOT of work to keep fed, and barely keeps us warm.

I am also keeping my eye out for a good local clay soil source to experiment with as well...

I had previously invested $200 in a 48"x25' roll of 8lb ceramic fiber blanket, and what I need from the geopolymer is a refractory form that can stand up to the heat, hold it's shape, and be backed by CF blanket for additional high heat insulation, in the feed and burn tunnel sections. I am covered for the riser with the blanket.

Rest assured that even after I have achieved that, I will be continuing to experiment with more types of geopolymers from the vast wealth of options you have shared with us, as I am able to come up with additional suitable materials.

Thank you Karl, for all of your efforts to educate and inform, and inspire research by others, even if mine does not come close to embodying the higher end of what is possible!

[coastalrocketeer]

Karl, I had a few questions for you that I didn't want to clog another's thread with.

1) would dolomite lime as it comes in the bag, have any application in geopolymers in general as a binder ingredient, or aggregate, or more specifically, in my rockwool "hardening" zeolite betonite experiments or other zeolite based geopolymers?

This is the product I have:




Am I correct in my assumption that I could apply high heat to calcine this lime product into quick lime?


2) would any form of acid activation of part or all of my bentonite clay before adding as aggregate, or as a component in my zeolite binder potentially improve my results with it?

I have as acid sources a roughly 45% phosphoric acid based rust treatment product, and acetic from 5% white vinegar, and ascorbic/citric acid available as 1 gram vitamin C tablets I can crush up for small batch experimentation purposes.

3) would calcining my bentonite clay make the above or any other novel applications possible, which might not be possible in it's present state?

4) If heat and lye concentration benefits dissolution of available minerals in a geopolymer binder, and one has added "too much water" to the mix, or too much early on, would it be reasonable to boil out the excess water to re-concentrate the lye to levels at which it has the desired reaction, and then back off the heat inputs as it becomes closer to being a thick paste again?

I realize this method might make knowing accurately how much water is in one's mix impossible, but could still allow "doing it by texture and feel" of the binder during the process, rather than knowing specific amounts of water added for the binder "activation" stage of the process.

If so, I would think this could be a helpful technique both to those of us like me who feel we failing through technique or quality of available materials to achieve optimum levels of dissolution of minerals in our chosen binder material, or others who are minimizing water perhaps more than necessary, to the point of having doubts as to whether we have even successfully dissolved all the lye to allow even distributions and reactions throughout the binder mix.

Not as easy as "mix with the right amount of water for two minutes and rest for some hours" zeolite:Lye method, but perhaps a way to confidently achieve both complete suspension, and even distribution of the lye, as well as maintaining heat that promotes the desired effects of the lye in the binder, as well as presenting an ability to "recover" from the early addition of too much water.

I have an outdoor "crab cooker" burner and enough large (gallon+) stainless pots that I am willing to use one of the lesser quality ones to experiment with this technique at "build level" scale for improvement of my geopolymer results, if you think this idea could/would work as I envision.

[coastalrocketeer]

BTW, Karl, I am jazzed to see geopolymers under it 's own section in the refractories section of the forum. When did that happen?

Not sure who instigated the change but I am thankful for the categorization and separation from other subjects of discussion, even though these compositions likely have import and application to almost any subject it seems.

[esbjornaneer]

When you let the binder rest over night (some hours). At what stage was the binder before the rest (had it gine stiff and you added the "100%binder weight" of water already)? And what had happened during the rest?
I realise I have not really been resting my binders before mixing in aggregate...!

[peterberg]

Jan 8, 2018 18:32:55 GMT -8 coastalrocketeer said:

I am jazzed to see geopolymers under it 's own section in the refractories section of the forum. When did that happen?

A couple of days ago, Donkey added the subject on my request and I moved all the relevant threads one by one.
Normal moderator's work, also splitting drifting threads, weeding out spammers and banning members who repeatedly insults other members.

[coastalrocketeer]

Jan 9, 2018 2:46:16 GMT -8 peterberg said:

Jan 8, 2018 18:32:55 GMT -8 coastalrocketeer said:

I am jazzed to see geopolymers under it 's own section in the refractories section of the forum. When did that happen?

A couple of days ago, Donkey added the subject on my request and I moved all the relevant threads one by one.
Normal moderator's work, also splitting drifting threads, weeding out spammers and banning members who repeatedly insults other members.

Thank you for your most beneficial efforts Peter!

I think it will really help the geopolymer research expand, and become fruitful for people in many localities with different feedstock and aggregate materials available, and reduce the clutter in the main area for people NOT interested in experimenting with geopolymers!

[Deleted]

Jan 8, 2018 18:29:23 GMT -8 coastalrocketeer said:

1) would dolomite lime as it comes in the bag, have any application in geopolymers in general as a binder ingredient, or aggregate, or more specifically, in my rockwool "hardening" zeolite betonite experiments or other zeolite based geopolymers?
Am I correct in my assumption that I could apply high heat to calcine this lime product into quick lime?

Dolomite needs to be decarbonated by calcining or reaction with an acid.
Calcination in the range 700–900 °C.

See alse phosphate cements:
www.google.com/search?dcr=0&ei=KeBUWrTlHtDPkgWXl4CgAQ&q=phosphate+cements&oq=phosphate+cements&gs_l=psy-ab.3..0i22i30k1l4j0i22i10i30k1j0i22i30k1l5.21334.21334.0.26229.1.1.0.0.0.0.338.338.3-1.1.0....0...1c..64.psy-ab..0.1.333....0.u9rpbSwPIh0&gws_rd=cr

H3PO4 = phosphoric acid.

May set before completely decarbonated or leave very little time.
Magnesium
2 H3PO4 + 3 MgCO3 =   Mg3(PO4)2 + 3 CO2 + 3 H2O
Calcium
2 H3PO4 + 3 CaCO3 +  = Ca3(PO4)2 + 3 CO2 + 3 H2O

Decarbonated
Magnesium
2 H3PO4 + 3 Mg(OH)2 = Mg3(PO4)2 + 6 H2O
Calcium
2 H3PO4 + 3 Ca(OH)2 = Ca3(PO4)2 + 6 H2O

In the calcined form it can also be reacted with phosphate fertilizers like monopotassium phosphate.

Dead-burned dolomite is produced when dolomite is calcined at very high temperatures.
Dead-burned dolomite is used in refractories.

2) would any form of acid activation of part or all of my bentonite clay before adding as aggregate, or as a component in my zeolite binder potentially improve my results with it?

I have as acid sources a roughly 45% phosphoric acid based rust treatment product, and acetic from 5% white vinegar, and ascorbic/citric acid available as 1 gram vitamin C tablets I can crush up for small batch experimentation purposes.

Bentonite can be activated with acids.
Bentonite may contain calcium and cat litter is very likely a calcium bentonite.
Calcium and acetic acid is a very bad combination.

3) would calcining my bentonite clay make the above or any other novel applications possible, which might not be possible in it's present state?

It would not solve the main problem of bentonite: Extreme water demand.
Bentonite in larger amounts requires highly concentrated waterglass.

4) If heat and lye concentration benefits dissolution of available minerals in a geopolymer binder, and one has added "too much water" to the mix, or too much early on, would it be reasonable to boil out the excess water to re-concentrate the lye to levels at which it has the desired reaction, and then back off the heat inputs as it becomes closer to being a thick paste again?

I realize this method might make knowing accurately how much water is in one's mix impossible, but could still allow "doing it by texture and feel" of the binder during the process, rather than knowing specific amounts of water added for the binder "activation" stage of the process.

If so, I would think this could be a helpful technique both to those of us like me who feel we failing through technique or quality of available materials to achieve optimum levels of dissolution of minerals in our chosen binder material, or others who are minimizing water perhaps more than necessary, to the point of having doubts as to whether we have even successfully dissolved all the lye to allow even distributions and reactions throughout the binder mix.

Not as easy as "mix with the right amount of water for two minutes and rest for some hours" zeolite:Lye method, but perhaps a way to confidently achieve both complete suspension, and even distribution of the lye, as well as maintaining heat that promotes the desired effects of the lye in the binder, as well as presenting an ability to "recover" from the early addition of too much water.

I have an outdoor "crab cooker" burner and enough large (gallon+) stainless pots that I am willing to use one of the lesser quality ones to experiment with this technique at "build level" scale for improvement of my geopolymer results, if you think this idea could/would work as I envision.

If no accelerator was used some water reduction by exvaporation under continuous stirring may be possible

[coastalrocketeer]

Karl: Thank you so much for the answers!

1) Thank you, that gives me a concise guide on what I could do with calcining Dolomite, and other forms of lime I could purchase, or process with a shoebox kiln.


2) The bentonite is described as sodium bentonite on the company's website, and is the only ingredient, no scent control or other additives.

Although I realize as a mined natural deposit, it likely has various minerals and possibly some proportion of calcium, just likely not as much as one that would be sold as calcium betonite. I may try some batches with 10% of the clay aggregate portion, activated with an appropriate amount of my phosphoric, ascorbic, and acetic to learn what each does to the resultant mix.

My intent would be to combine this 2nd "binder" after separate mixing of a zeolite binder portion, with my aggregate water (aggregate being the rest of the bentonite to obtain my desired consistency for saturating rockwool.) Is there any research you've done or chemistry based reason why this would not work (the fact that one is acid and one alkaline makes me think this is likely and perhaps one binder material or the other would need to be used instead of a combination, or is combined binders like this a potential avenue to research?)

Could also mix the un-activated aggregate clay with the zeolite binder and aggregate water mix, and then mix in the acid activated binder clay right before mixing with/saturation of the rockwool tufts, and drying/curing, if you think that could work where the other "combined opposite ph binders" process I described above would not.

And in time I will definitely be getting other locally collected and commercial clays and mineral sources for binder and aggregate to experiment with, and trying things more like hard brick structural elements, and castings and slabs, both high and low mass, and conductive or insulative as needed, rather than just my currently intended goal of a "high water content,thin binder/aggregate mix with high percentage of rockwool for reduced weight/volume of binder needed, while retaining enough structural integrity to meet the need and last at least one heating season", in this one stove build, which is what I'm shooting for right now as I have plenty of ceramic refractory wool to use as the riser and backer on the core I will make from this mix, to increase insulation value, in the J-tube I hope to have warming my buns within the near future.

3) thank you... Yes, I found the mix is too thick to use much heat input without stirring constantly, or you get binder dried/cured onto the bottom of your pot. So I just kept water to a minimum... Even keeping the zeolite from becoming fully saturated for a while and adding the water bit by bit. When doing it that way the heat produced in the 2kg of binder I mixed last night was quite evident, getting up to 140 to 150F by the time I had all of the zeolite saturated with just enough water to make a thick but stir-able paste a little thinner than peanut butter. I then added the rest of one L of water which brought it to the thickness of mayonnaise. At that point it would become thicker when I hadn't stirred it. Tried heating and keeping it at 160F or so, and it got thicker after an hour or so, but found it was also overheating and sticking to the pot on the bottom, due to my laziness in not continually stirring.

So I used a water mister/spray bottle to add maybe 100ml of water and bring it back to the original consistency then let it rest overnight, as I needed sleep at that point. Used 10% lye in this mix and will be chopping rockwool and mixing in less clay and water and seeing what I get after I've shaped it around my burnable inner form, and how it performs after I've dried it, added a riser and fired it a few times.

My only real requirements for this build are "makes the rockwool refractory temp capable, structural enough, and that hold it's shape if kept dry..." so maybe not a proper geopolymer to pass the water soak test but good enough for my needs with this first build.

The mix is definitely thixotropic, and gets "thinner/more liquid" where I stir it, but I can't say how it compares to the level of that property in just the SweetPDZ and a similar amount of water with no lye, to know whether this is any indication of mineral dissolution in my binder.

I also did not let the successful portion of my previous experiment cure other than what I did by drying it in the oven at 180F or whatever temp I used. Also have not done any water tests, so can't say whether that mix became a proper geopolymer, but it is stiff and refractory enough that I think it will make a core that will work with the ceramic fiber blanket I have to get and keep me warm for further research and testing, so I am going for it with this method just for an immediate heat source.

Thank you again, Karl for all of your answers and sharing. I do so much appreciate it and hope to do further research to actually advance the use of these materials in rocket heaters and accross the board in all of the various GP applications that I have use for in my life.

Esbjorneer:

If your mix is not "too thick" to stir, and your caustic is fully dissolved and evenly spread throughout the water in the mix, I believe things are good, and you want to "let it rest" in as high a concentration as possible, optionally, with any heat you can provide, if you are not using accelerators, without drying it (low temp oven in an oven bag?) for maximum mineral dissolution from your feedstock, and then add just enough water to evenly dilute the binder to the appropriate level for your desired working consistency after aggregate addition, which is dependent on "water binding"/absorptive qualities of your chosen mix of aggregates, and possibly other factors...

I also noticed a big difference between my mixing a certain portion of water with bentonite clay to examine it's "water demand" and finding that the proportion changed to needing a higher proportion of clay for the total amount of water that has gone into the binder initially, and then the aggregate water addition, to achieve a similarly thick and pasty consistency, when the water was in a diluted geopolymer binder, which seemed counter intuitive as the diluted binder presumably still had some amount of increased "viscosity" before the addition same proportion of clay as my water only viscosity experiment with the clay.

With 1000g/1 L of water, 200g bentonite by it's self made a viscosity close to what I thought was appropriate (and wasn't for my primary mineral blanket saturation test, when compounded by technique deficiencies.)

When it was a binder solution, with 600 total liters of water, 225 grams of bentonite had to be mixed in before it got close to as thick a consistency.

I think the high water demand of bentonite is not the cause, but may be part of why the difference was SO large, and that it may be there, but less noticeable with other lower water-demand/water-binding aggregates and other types of clay, and perhaps not there at a noticeable level at all, with some aggregate material choices.

I think I might have done the mixing and resting as you describe, but can't exactly remember the order of the process I used now. Will have to read back through my mixing process description, and see if that jogs my memory to be able to confirm one way or the other.

[coastalrocketeer]

Sorry if I'm repetitive or unclear at any point in the above... Sometimes miss corrections scanning through what I've written before sending, with the size of the edit window available on the tapatalk app on my phone. Hopefully all is clear enough and I didn't miss too much repetitive stuff in my final edit of the above.

[coastalrocketeer]

Following few posts copied from another thread but related to this line of experimentation, so placed here for continuity of learning for those reading this thread ...

Jan 7, 2018 17:11:53 GMT -8 firewatcher said:

Thanks for providing the info on where you found the rockwool and the cost. Finding materials (the same materials that others use...hoping to duplicate other people's results) has been difficult in the past.

How do you "shred" it up for use in a mix?

I have only made a small maybe 75cc puck by this method as my main experiment with it was a flop, and the "chopped rock-wool" experiment was what I did with the small remainder of my zeolite/bentonite GP mix. I just chopped up the handful I used for the successful bit with scissors.

You can read about my method and observations in my last couple of posts here:
SweetPDZ Zeolite geopolymer first try... Promising
donkey32.proboards.com/thread/2418/sweetpdz-zeolite-geopolymer-first-promising

Thinking about it for my next attempt, I decided I will use a bread knife to "split" the 3" thick batts into 1" to 1-1/2" thick sheets I can more easily cut with standard size scissors.

Or I may use a paper cutter if I still have the right one laying around here...

The kind with a square platform with a metal cutting edge and a long blade with a handle at the end that pivots along that metal platform edge to cut. Have to look at it as it may have a guard that keeps me from putting anything taller than 1/2 or 3/4 inch in that I will have to remove.

[coastalrocketeer]

Jan 7, 2018 17:26:43 GMT -8 coastalrocketeer said:

Karl has advised 8-10mm length, and I found cutting the rock-wool with binder insulation material I'm using into pea to grape size pieces worked well...

You can also buy rockwool in blown/loose fill insulation format which might come in desirable sized pieces already, but I had to choose between "buying what I can find easily and spending a few hours chopping it up with scissors" and "spending a few hours finding and travelling to where I can buy it already chopped."

Unless I can find and get the paper cutter to work, I expect to spend a few hours chopping a couple of these mineral wool blankets into appropriate sized pieces...

I did not mix the GP binder and rock wool tufts vigorously or mechanically, but more gently stirred with a spoon my small sample, that the individual tufts would become saturated but remain bound in the shape they had via whatever binder is used to make the fibers join into the blankets I purchased in their manufacture.

What has been your experience with breaking your test pieces (do they have good strength)?
The curing of my one pick that I tried last month was done 100% at ambient temperature. Breaking the puck was difficult. After applying a propane torch to one of the broken pieces and letting it cool, I broke that piece with ease (relative to the amount of force used to brake the original piece that no heat had been applied to).
Maybe I still don’t have a recipe that’s quite where it needs to be...no fibers were used and my addition of water to the “final mix” was not done before adding the zeolite aggregate to the prepared binder.