⚙️ Blast Furnace: Countercurrent Iron Reduction (2D)

This 2D companion strips the 3D blast-furnace plant down to the reaction that actually makes iron: hot blast air burning coke at the tuyeres to generate CO-rich gas, which rises countercurrent to the descending ore burden and reduces it, layer by layer, from Fe₂O₃ toward metallic iron. Every ore chunk tracks its own reduction degree as a function of how far it has descended and the furnace's current CO utilization — itself a formula of blast temperature and blast rate — so pushing the sliders changes hearth temperature, CO efficiency and hot-metal output the way a real furnace campaign would.