Sir What is role of CH3OH used for washing of filterate in free lime test Regards Dilip yadav
Ted Krapkat
Hello Dilip,
Normally absolute (water-free) ethanol is used to wash the residue of clinker free of filtrate in the glycol/ethanol free lime test. The reason is that the wash solvent must be free of water so that Ca(OH)2 is not formed by hydration of the clinker minerals during the washing process.
Methanol, or denatured alcohol (methylated spirits) can be used as long as it contains <5% water, however absolute ethanol is the preferred solvent.
Regards,
Ted.
norew
Ted,
We are using the glycol method and we do not directly boil the solution. We are just subjecting it to steam for 30 minutes. Please have your comment.
Ted Krapkat
Hello Norew,
I assume you are using a steam bath to boil the gylcol/alcohol solution. This is okay because the boiling point of the glycerol/ethanol solvent is ~85 deg C while glycerol/methanol is even lower at ~70 deg C. Both will boil quite happily on a steam bath.
However, the advantage of this method is that it is safer. A hot plate or heating mantle would have the inherent risk of a fire if the vessel broke and spilled flammable solvent over the electrics.
Regards,
Ted.