Just a clarification.
I don't know if or how much MgO would leach out of papercrete as it
drains. I was not trying to imply that I knew it would leach out.
That is a question I was trying to figure out through my reading and
research. I have not found anything to give me a hint to what the
answer might be.
I suspect that at least trace amounts would leach out. It could be
more than trace amounts too. Whether the actual amount is
significant enough to affect the performance of papercrete or if it
is enough to be potentially harmful to the environment is unknown.
At least it's unknown to me.
There is the possibility that someone could capture and recycle the
water runoff during production to alleviate most of these concerns if
it is found to be a problem.
Another possibility is that paper fibers may be effective at
filtering the water runoff well enough that very little MgO would
leach out. I do not know if that would happen or not.
I know that Magnisium is an important nutrient for humans:
http://www.feinberg.northwestern.edu/nutrition/factsheets/magnesium.ht
ml
It's good for you in small amounts, but you can get too much of a
good thing. The above link lists an upper recommended limit of
350mg/day max for adults. TAKEN INTERNALLY.
I'm not sure if MgO is considered similar to the nutrient form of
Magnesium. They may be completely different substances and act
differently inside the body. I also don't know how much MgO a
typical worker might be exposed to while handling the material. I
don't think many of us go around eating our papercrete, at least
intentionally, though many of us have had a chunk fly up in the face
during mixing. bleaaaaaaaaaaaaah.
The above link does seem to imply that ground Pumpkin seeds might be
an interesting papercrete additive to experiment with. They contain
a lot of magnesium. Of course, using whole seeds would be a bad idea
unless you want Pumpkin vines growing out of your blocks?
So many questions, so few answers, but I'm learning.
--- In papercreters@yahoogroups.com, sire@... wrote:
>
> SG and Ernie, excellent information.
>
> The issue that SG mentions of the MgO leaching out of papercrete as
it drains would seem to be serious. Because of its small particle
size and slow solubility rate, I suspect this would be a problem,
unless it would bond with or get caught in the paper fibers. On the
other hand, if a way can be found for the water to not drain out of
the mix, then the MgO would absorb the remaining water much more than
Portland.
>
> As I understand it the need for a lot of water is in the mix is so
that the paper can be mulched up by a mixing blade. What if the
paper were already shredded and added after the mix was relatively
stabilized?
>
> Neal
>
> -------------- Original message --------------
> From: "slurryguy" <slurryguy@...>
> I've never used it, but I admit I'm learning since the posting. lol.
>
> I doubt if this answers the specific questions posed, but it
probably
> will answer many of the unasked questions about it from others in
the
> group. These first 2 links come from the self proclaimed inventor.
> (of course I've found other references dating back to Stanislas
Sorel
> in 1867, so I don't know if I recognize this dude as the inventor.)
> The cool thing about this link is where it comes from...
TASMANIA...
> that alone makes the link cool. hehehe
>
> http://www.tececo.com/history.magnesium_cements.php
> http://www.tececo.com/history.magnesium_hydraulic_cements.php
>
> Another source:
>
> http://www.greenhomebuilding.com/pdf/MgO-GENERAL.pdf
>
> I'm trying to figure out how much of the MgO will leach out of
> papercrete as it drains. If too much leaches out it won't be a good
> thing to use regardless of cost.
>
> It looks like MgO also plays well with other stuff, e.g. pozzolans,
> like fly ash.
>
> --- In papercreters@yahoogroups.com, "Ernie Phelps" <eepjr24@>
> wrote:
> >
> > --- In papercreters@yahoogroups.com, "xserenity" <xserenity@>
wrote:
> > >
> > > I have done some cordwood with cob/paper concrete mixes for
> using
> > > as morter and surfacing. There is a lot of negative issues with
> > > concrete, and I am wondering if anyone has tried using MGO
> instead
> > > of portland cement ?
> >
> > I'll be honest and say I had not heard of MgO before you
mentioned
> it
> > here. I like the idea and here are the pros and cons as I see it:
> >
> > PRO:
> > 1. Mixes well with Cellulose based materials.
> > 2. Very mold, fire and water resistant.
> > 3. Somewhat better for the environment than portland.
> > 4. Available both as a mix and as pre-made panels.
> >
> > CON:
> > 1. Very expensive compared to portland ($2 per lb vs $.75 per lb).
> > 2. Untested within the papercrete arena (not a big problem as it
has
> > been thoroughly tested with a large variety of aggregates).
> >
> > I am sure there are more points on both sides, that is what a
search
> > and some light reading got me. Anyone out there got some
experience
> > with it? Or good links for non-biased evaluations?
> >
> > - Ernie
> >
>
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