This is my first time posting, and my first build. I'm trying to build a foundry to melt steel for casting, but mainly for making ingots for knifesmithing. Its a small build, and I was looking for feedback to see if it would work safely, and for any improvements I could cheaply apply.

The build is about 9x8x9 with a lid of 9x9x2. The walls are firebrick held together with angled steel/stainless. A fan from a bounce house attached to a stainless steel pipe would put the air in, and propane would be put into the steel pipe up by the fan, hopefully to avoid possible explosions, if I need to worry about that. A small 8 kg graphite crucible to melt in.
The firebricks:
https://www.amazon.com/gp/aw/d/B000U...EuL&ref=plSrch
The crucible:
https://www.amazon.com/gp/aw/d/B00FB...VAMEYW7E&psc=1
Please let me know what you think!