I was trying to calcine some CaCO3 (Calcium Carbonate), but ended up with Calcium Hydroxide. To test if I had Calcium Carbonate I added it to some vinegar, no gas was produced. I then mixed in a small amount of the powder with a large amount of water and passed CO2 through it, and it became a milky white which led me to believe I have Calcium Hydroxide. I also tried added the final powder to water, which did not heat up. I heated up my CaCO3 in a laboratory furnace (Electric) at roughly 920°C for 30 minutes which left me with my current product. Do I need to have a nitrogen/argon gas purge of some sort?? Any ideas are appreciated! Thanks!