Elevated temperatures of brine solution

Dear All,

I have a complicated problem in our ZLD system: the brine solution temperature is very high - 109 degree Celsius and is not decreasing by vacuum as normal.

The main compositions of brine are calcium sulphates and chlorides and sodium sulphates and chlorides with traces of silica.

Can you advice please what is the expected reason for this issue?

Thanks in advance for your time.

Best Regards