I recently did some calcination (500C) on a hydrated powder material in three sets of experiments. The experiments only differ in the moisture content of the calciner i.e. 0, 40 and 80%.

Then I used TG to determine how much the calcination was successful to see if the steam can catalyze the calcination process at high temperature processing!

The results are as attached. My questions are:

1- What is the reason of this decrease in TG mass change for the same material being processed in different moisture conditions?

2- May this decrease in mass change be an advantage in terms of higher pozzolanic activity of the samples after calcination? I mean can steam have positive effect on the materials properties after calcination?