[martyn11post]

Hi,

I've been analysing some waste material, for a project, which consists mainly of silicon and calcium carbonate.

I have been using sodium hydroxide to remove the silicon as sodium silicate, except I have been forming Sodium carbonate and calcium hydroxide as well.

I believe the reaction usually proceeds as Ca(OH)2 + Na2CO3 → CaCO3 + 2 NaOH except I'm seeing the reverse of this reaction, which I believe should be thermodynamically unfavourable. 

The reaction is not proceeding to completion, analysis was by XRD

Is this reaction reversible? And what are the conditions which would bush the equilibrium to the left?


Many thanks,
Martyn