[Cob] Rice Hull Ash

[Scott Van Kirk]

I would be very interested in your results.  I was told by some people who 
looked into this that most rice hull
ash available in the US useless as a pozzolan because it was burned too 
hot.  This crystalizes the silica in the rice
hulls and drystalized silica is non-reactive. What you want is a lower 
burn temperature which gives you amorphous silica.
Please let me know how it goes.  If it goes well, I would also love to 
find out your friends source.

-Scott


On Thu, 27 Nov 2003 20:59:57 -0500, Quinn <quinn1 at mindspring.com> wrote:

> Don't know why this didn't make it to the list the other day:
>>
>> New subject-
>> a local builder in my area gave me some rice hull ash ( made from
>> burning the waste rice hulls) which is used as a pozzolan with lime to
>> harden/strengthen it to a strong cement.  I was surprised it was jet
>> black in color, and extremely fine dust. am looking forward to fooling
>> with it to add to lime putty.  My friend did say it turns lime dark gray
>> and looks like cement, so that is a downer, but  am excited to test it
>> for various natural building uses.
>>