Coastal Rocketeer’s acid activated experiments

[coastalrocketeer]

I have found that the microwave allows me to reduce or eliminate the water from acid activated EPK clay mixes being activated with vinegar and/or my phosphoric acid source, lime and scale remover concentrate.

This should allow me to take advantage of the concentrated chemical attack of starting with dry ingredients, and be controllable like starting with dry ingredients.

The first mix I tried to do this way, I concentrated down from a thin paste, 45g of EP Kaolin, 45g of vinegar, and 9 g of First Street Lime and Scale, which I believe to be roughly 30% phosphoric acid.

I then added 45g lye to the thick paste which immediately went super thin, and then foamed up with the water boiling off in about 30seconds (luckily didn’t overflow the plastic tub, leaving a thick, gritty paste to which I added water, as it had reached this state in less than a minute while I carried the steaming plastic tub in a metal pan outside and ran back in to get water.

I called this batch “Lost Boy”

I was going to make it a 1:1 ltgs binder and just added the copious amount of KOH too quickly. If I try that one again it will be with less lye and added slowly a bit at a time.

I will be testing mixes in this thread with some of all of the binder and aggregate portions activated with acids.

[coastalrocketeer]

Re-reading Karl’s acid activated geopolymers thread, I am making a mix with a binder of 92.5g EP Kaolin, and 7.5g Bentonite. I have activated the binder with 50g of 5% vinegar, 3g of Lime and Scale
Acid activator additions:
45+2g H2O = 47g H2O
5g acetic acid
1g phosphoric acid

Added Bentonite to tub, Added about 1/4 of vinegar and added L&S... mixed to get a paste then alternated between small amounts of EPK and more vinegar until about half the EPK and all vinegar added, then added water and remaining EPK until all EPK gone, using 53 grams of water to bring to a thick slip consistency... thinner than mayonnaise... perhaps a thickish gravy.

Then I dried the product in a cottage cheese tub in the microwave, stirring periodically (not sure stirring is even necessary)
then I decided to add 10g of MoraLeaf P&K (basically MKP)

I added it and added 100g water, mixed it in and microwaved until dry again.

Added 15g 92% KOH flakes + 120g H2O, + 10G LWG to get a easily sitrrable, but thick paste consistency.

I am now considering my aggregate portion... looking at perhaps a mix of my coarse zeolite powder and more acid activated kaolin, plus a few percent Rockwool, and 400g/L solid water glass content for this batch. If anyone has any suggestions (@karl) or modifications to my mix let me know! :-)

[coastalrocketeer]

Went with 150g sweetPDZ zeolite powder, 30g nepheline syenite a270, 20g Custer feldspar, and 10g shredded Rockwool...

After mixing in 15g 92% KOH flakes to the dried out acid activated P&K enriched binder clay chunks, it took 120g H20 and 10 G 400g/liquid water glass to get a workable consistency for aggregate addition. ...

I then added enough 400g/L waterglass to make a thick but workable mix with the aggregate added... (30g)

I think the Zeolite is quite porous, so am thinking I should add 10g of cement at the end before molding, and beginning curing.

(Edit... adding no accelerator this time... but am including 10g shredded Rockwool batt insulation.

[coastalrocketeer]

The mix made enough to fill one 230ml “mold box” with an extra 1:5th left over, so to test the addition of 10g Portland cement, I added 2g PC to the remainder and packed it into the corner of a second box.


The one with PC added was notably harder than the main mix, PK-1, after 150F toaster oven curing overnight, and over about 2 days of continued “heated curing” after which the cement containing PK-1B sample was removed to room temp curing at 60-70F, and PK-1 got a couple of days in the regular oven at 170F, with my other samples curing.



Top side of PK-1B ^^^




Mold sides of PK-1B ^^^


Mold side of PK-1... demolded and drying ambient, still rather moist at this time.^^^


 PK-1  Lid side ^^^

[coastalrocketeer]

It will take some time for them to dry fully, at which time I will test strength, heat tolerance, and insulative value, before and after torch testing, and higher heat curing

[Jura]

I have nothing to add as to the topic.

I just wanted to ensure you I'm following this topic with a huge interest.

[coastalrocketeer]

I am trying a bunch of different mixes with different binder materials, activation methods, and aggregates.

Working to develop a system of documenting my experimentation properly.

Since I don’t have the level of understanding that Karl’s got... the sort of knowledge, experience, and intuitive sense of “what is likely to work well” chemical makeup wise, and “how much water is the right amount” and so on, I find myself not remembering exactly how many 25g doses of water I added at the end, to get the consistency to allow a workable mix after aggregate addition. Optimally I would be adding all of this water at the end of the binder dissolution stage, so knowing these amounts before hand is the goal.

And I scratch my head at all the possibilities presented here in these many threads on various methods and materials. There are tons of possibilities just with the 5 acids and alkalines, 4 clays, 2 stone flours, zeolite, and 3 aggregate type materials I have.

I also find myself being at times too impatient with trying to unmold and examine my test bricks. Many times the drying of the top surface fools me as to the maturity of lower, moister layers. This tends to be worst with mixes that have little to no shrinkage.

My other thread is called “Kaolin Geopolymer Experiments” and a list of the feedstocks I have obtained, and some data about them I’ve collected there start it off. Some mixes will be documented there.

[coastalrocketeer]

Tried to get better dissolution with heat, but made the mistake of a cigarette break while the zeolite “waterglass substitute” for the ABE mixes was simmering at 120F... came back 10 minutes later to “hard taffy” again... so another hour spent adding water and breaking down chunks with my knife.

The idea with this mix, was for it to be mostly EPK clay with 15% Bentonite for increased porosity based on water demand/drying, acid activated with 5% acetic and 5% phosphoric acids. For Waterglass, since Karl had said that Zeolite could be used as a waterglass substitute, I decided to try substituting zeolite solids for waterglass in the mix.

I measured clays...
30g Bentonite
170g Edgar Plastic Kaolin

Put the Bentonite in a bowl and added 30g of First Street Lime and Scale remover concentrate (approximately 30% phosphoric acid)
And stirred them together, then added vingar and EPK alternating until all the EPK, and 200g of vinegar were mixed in.

Placed that mix on the stove on simmer, stirring periodically while I worked on the zeolite.

I measured 50g KOH, and 150g zeolite powder. My KOH is 92%, and thick flakes... so not optimum for mixing with powders easily. I put the KOH in a sauce pan and added in the first 25g of zeolite powder to cover it all, and then added 25g of H2O. It sputtered a bit but not too bad. I added some more zeolite and more water, until I had all the zeolite in and it was just liquid enough to be easily stirrable. Then I took a smoke break, and found out I should have stayed with it. It was super hard, like room temperature taffy. I added water 25g at a time and it took half an hour just to get the taffy off the pan into chunks, and then an hour and a half of adding water and stirring the mix to get all the chunks redissolved.

I added water until I had 150g of zeolite in 300g of water to hopefully be equivalent to 300g/L of waterglass... it was thin gravy/slip consistency at this point.

I mixed the clay with a high shear mixer (old electric kitchen mixer paddle in a drill) to get the drier and wetter parts evenly mixed. It was a thick paste.

I added the “zeolite gravy” liquid to the paste and as I mixed it thickened rapidly to a much thicker consistency, but thixotropic, so it would become liquid when the mixer was whipping through it.

I added 100g H2O, and blended, then 4 sheets of Scott single ply tissue in 50g of 400 or 500 g/l Sodium Metasilicate waterglass solution (forgot to write down what I added to 500ml of H2O). The last addition seemed to thin it as much as the previous 100g of H2O, interestingly.

Then I weighed 300 G each of Zeolite powder and fine blasting abrasive coal slag. Mixed those in, and then mixed in 40g Rockwool. At this point the mix was like an adobe clay.

I split the overall mix into two equal portions by weight, and used the drill mixer to incorporate 10G Portland cement into one, and 10G hydrated lime into the other, as accelerators, and pressed them into molds with my fingers. Very much an Adobe brick making consistency.

Placed them on a shelf and went to bed.

The total mix made about 800ml of uncured mix so each half filled all of one mold box, and most of a second.

[coastalrocketeer]

Samples ABE-1-PC, and ABE-1-HL (-X’s are the excess after first mold)


Appearances of each after molding, after 12 hours ambient curing at 65F.  No noticeable hardening yet.





The Hydrated Lime one was a bit softer/easier to work with at molding.

I may have used so much acid (10g/100 of clay, 5 each phosphoric and acetic) as to have upset the potential for geopolymerization... we will see.