Analysis and Solution
Alkalic Calcium hydroxide is aggressive and the application under humid conditions at temperatures of 100-120OC. Homopolymeric Polyacrylonitrile (DT) is the suitable material for this application. Calcium hydroxide is very easy to deliquescence under humid conditions, which will cause blinding, so PTFE membrane is recommended to this application.
Result
The DT/DT 504 PTFE membrane bag was successfully running for more than 12 months operation. And they do not worry about the penalty from local E.B anymore.