forge metal, perfect one's skill
煅 centers on applying intense heat to transform something: literally forging metal, and metaphorically refining or perfecting a skill through disciplined practice.
煅 combines 火 (fire) with 段, which likely contributes the sound and the idea of working or shaping something step by step. The exact historical development is uncertain, but the modern form suggests forging with fire.
Fire 火 on the left and 段 on the right: picture a blacksmith using fire to work metal step by step, forging it into a perfect tool.
For タン, imagine a tan blacksmith working at the forge: tan -> タン, and the fire tans his skin as he perfects his skill.