I recently removed the old unused wood stove in my basement. I now want to properly condemn the chimney.
I found this question which answers what to do with the chimney outside, but I am still unsure about this hole in my basement.


Behind the gray brick wall is the concrete wall of my basement. (The brick wall will be removed when I get to remodeling the basement). My first idea was to simply brick and mortar the hole, but is it a good way to do this? And should I remove the cast iron ring?