Skillman Index for Calcium Sulfate scaling

[SeanR]

I came across a reference to the "Skillman Index" for Calcium Sulfate scaling while looking into information on scale inhibitors for sulfate scaling in an evaporator.
I was unable to find anything more than 1 single-line reference to this with my limited resources.
If somebody could give me an idea where to look for information on this or any other info on Calcium Sulfate scale inhibition, it would be appreciated.

Thanks

 

[luissabate]

CaSO4 scalling is unusual because CaCO3 or SiO2 scale fist (in most of the cases), so max. COC (cycles of concentration)are calculeted in CaCO3 or SiO2 basis.
The way CaSO4 scale is inhibited is similar to CaCO3: by means of a polyacrilate or acrilic-co-polymer, and/or a Ca-complexation agent. Some comercial polyacrilates bulletins have specific info about CaSO4 antiscalling performance.
I wish I´d have more info, but this has been enought for me to deal with diferent water cooling towers.
Regards,
Luis

PS
Invitation to spanish spoken fellows

Invitación
Esta es una invitación a participar en la comunidad Aguas y Efluentes.
Está dirigida a los profesionales, técnicos e interesados en el tratamiento de efluentes industriales y aguas residuales urbanas, potabilización, análisis de laboratorio, química del agua y temas relativos al medioambiente.
Saludos,
Lic. Luis Sabaté

http://www.msnusers.com/AguasyEfluentes/

I came across a reference to the "Skillman Index" for Calcium Sulfate scaling while looking into information on scale inhibitors for sulfate scaling in an evaporator.
I was unable to find anything more than 1 single-line reference to this with my limited resources.
If somebody could give me an idea where to look for information on this or any other info on Calcium Sulfate scale inhibition, it would be appreciated.

Thanks

 

[SeanR]

Thanks, Luis.

This is a start in the right direction.

 

[luissabate]

Phosphonates can be usefull for CaSO4 dispersion and scale inhibition, in a similar way polyacrilates work.
Regards,
Luis

 

[wolson]

We are experiencing calcium sulfate scaling in our cooling tower (20,000 usgpm). Our pH is adjusted with sulfuric acid so we don't see calcium carbonate scaling, but our film fill is plugging up after 2 - 3 years. Can anyone suggest how to monitor, predict, and mitigate this problem?

 

[ConsultUS]

Lok for Langelier Index also, I have never heard aobout your "Skilmman index" , please let me know if you learn something.