SweetPDZ Zeolite geopolymer first try... Promising Dec 23, 2017 16:12:39 GMT -8 lucian likes this
Post by Karl playing with geopolymers on Dec 23, 2017 16:12:39 GMT -8
Zeolites are relatively soft, but with a hardness around 4.5 to hard for mortar and pestle.
Natural materials are never pure.
The commercially sold zeolites here have a purity from slightly above 80% to more than 90%.
Lets assume the worst case for Sweet PDZ then slightly more than 15% are other minerals which may not be dissolvable.
I have no problems to sufficiently dissolve 0.5 - 1.0 granules in a 3/1 ratio to a thick paste,
which can take quite a lot water to form a still relatively thick gel.
A possible strategy would be to attack first the larger zeolite particles with a 1/1 or even more concentrated ratio,
keep it hot in a water bath and later add finer particles and more water.
1) If using all zeolite as both binder and aggregate (as opposed to other aggregates) and using finest fraction as binder, and sodium hydroxide NaOH as alkali gelation agent, I need 7% or more of my total dry ingredient weight to be lye, and if doing 3:1 zeolite:lye binder that would dictate 21% of the total zeolite and lye weight for my mix, including the "aggregate portion" would be the amount of Zeolite to use as binder, and with 4:1 it would be 28% of total dry ingredient weight that becomes the "binder portion" of the zeolite... Am I understanding your ratio recommendations properly as applies to my choice of materials for this next experiment?
7% lye of the total dry mass with zeolite in a 3/1 ratio gives 28% binder.
With respect to geopolymers and especially LTGS you need to use the word binder more carefully.
2) I really like the idea of making a thin enough binder to use in a couple of ways... A more pasty one like mayonnaise, that could be spread with a rubber spatula onto surfaces as a refractory surface sealer/rigidizer/lining for ceramic wool and rock wool, as well as used like epoxy in layered build ups with cheese cloth, burlap, or similar materials, and another like a thin gravy that one could saturate mineral wool, and then be mostly removed by centrifuging most of it off to leave a thin geopolymer coating over the mineral wool structure... Is any of this possible with a pure Clinoptilolite zeolite binder? I presume if it is, highly micronized particles for the binder portion would be fairly critical.
The binder is an usually alkaline liquid or gel, which binds and hardens other incredients.
The binder is usually a mixture of waterglass and lye, but in the case of LTGS it is an alkaline gel of dissolved minerals.
Binder may also refer to a mixture of waterglass, lye and a reactive mineral which binds the inert aggregate.
The viscosity of the final mixture can be adjusted with water, but higher amounts of water may require more lye.
Your idea is possible.
Zeolites are already highly reactive.
3) Is acid activation useful at all with a pure zeolite binder? (make it more hollow/porous/reactive before alkali addition?) (I have phosphoric and acetic acid laying around to experiment with)
An acid treatment cannot improve that.
The Red devil TSP substitute is sodium metasilicate.
4) I have a 4 lb bag of the sodium metasilicate "red devil tsp90" phosphate free TSP substitute as a source of water glass... Did not use this in my original mix... A solution if I t WAS however, soaked into half of the scrap that I put into the wood stove, just to see how it would soak into the already "sintered" piece, before I put it in the wood stove. (600g/litre solution). How would I use this solution in any of these Clinoptilolite mixes? Could I use it as the water I add at some stage/s of mixing the binder?
A 33% solution of it can be used as a binder for zeolite powder.
It will harden pure zeolite at ambient temperatures within a relatively short time.