Aluminothermic Ferroniobium Reduction (2D)

This 2D companion strips the ferroniobium smelting process down to a crucible cross-section driven by an actual energy balance instead of a scripted animation loop. Choosing the aluminum excess and the iron-oxide additive fraction sets how much heat the thermite reaction can release versus how much thermal mass has to be warmed by it, which in turn sets the peak temperature, how fast the self-propagating reaction front eats through the unreacted charge, and — through a temperature-dependent separation efficiency — how much of the niobium actually ends up in the ferroniobium button rather than trapped in the slag cap or lost to vaporization. Run it cold (low excess Al, no iron oxide) to see a slow, oxygen-starved burn with poor separation, or push both sliders up to see how a too-hot melt trades slag fluidity for niobium loss.