Re: [Phys-L] carbon wars

[brian whatcott <betwys1@sbcglobal.net>]

On 10/6/2014 2:37 PM, John Denker wrote in part:
> ///The only process I know of for effective long-term carbon 
> sequestration is the weathering of silicate rocks. This was mentioned 
> a couple of days ago under the heading of "carbon sequestration, or 
> not". On 10/04/2014 01:50 PM, I wrote:
> >     CO2 + CaSiO3 --> ... --> CaCO3     + SiO2
> >     CO2 + wollastonite   --> limestone + sand
> >
> > This happens naturally on a timescale of hundreds of
> > years.
> ///
John's note brought to mind a delightful property of silica sand, when 
moistened with water-glass (sodium metasilicate, Na_2 SiO_3 ) and formed 
to some desired shape such as a foundry casting mold.
When infused with carbon dioxide gas from a bottle (or more slowly from 
the atmosphere) the sand shape turns into what is essentially sandstone.

Brian Whatcott