Sharing my steel automation setup in case other people are unsure of where to start with it. This particular instance supports 64 HU/t and 24 KU/t, and can be built with steel-level tech and without having built any machines yet (if you don’t have a compressor yet you can replace the dense invar box with something weaker like a bronze or steel box).
Two bronze boilers supply 96 Steam/t (24 KU/t) to a steel crucible which receives iron one at a time. I used a steel crucible to make it heat up slower and not melt down while waiting for the iron to become steel, but you could also use a clay crucible and pre-fill it with some steel to increase thermal mass. The number of molds is tuned to the heat output of the burning box, so increase them if you use a stronger box. There’s no auto shut-off in the screenshot, but you could easily add one.
(Will post the back in the next post since I can’t post multiple images)