Editing Openai/6941cb52-a9c8-8002-b0a9-66ac5c3b6011 (section)

====== 6. Metals Purification (Spin Chamber Focus) ======
* '''Physical Mechanism''': Induction heating (eddy currents, 2,700°F) melts metals; centrifugal spin (100-500 RPM, 0.5-5 G) stratifies by density (heavy metals outward, light slag inward); electro-migration (1-5 A/cm² DC) moves ions (e.g., copper to cathode, silicon to anode via quasi-electrolysis); Lorentz forces (0.5-2 T magnetic fields) stir/dampen flow for precision. Wire extrusion uses electromagnetic pinch (0.8-1.5 T coil) to stabilize stream.
* '''Components''':
* '''Induction Coils''': Copper windings ($200-$500, 2-5 kW) for melting.
* '''Spin Chamber''': Rotating vessel (200-500 RPM, motor $500) with DC electrodes (graphite, $50-$100, anode ring/center, cathode die/wall).
* '''Magnetic System''': Neodymium coils/magnets ($500-$1K, 0.5-2 T) for stirring/braking.
* '''Extrusion Die''': Ceramic (alumina/zirconia, $200, conical with embedded coils) for wire pull (1-2 mm, 0.5-2 m/min).
* '''Outer Shell''': Non-ferrous, non-conducting, high-temp material like alumina ceramic (Al2O3, melting point ~2,050°C, thermal conductivity <30 W/m·K, electrical resistivity >10^14 Ω·m) or zirconia (ZrO2, ~2,700°C, similar properties). These ceramics are ideal—non-reactive with molten metals, withstand 1,000-1,500°C operations, and insulate induction fields. Alternatives: Silicon nitride (Si3N4, ~1,900°C, non-wetting) or silicon carbide (SiC, ~2,700°C, but semi-conducting—avoid if full insulation needed). Shell thickness: 5-10 cm for structural integrity, with cooling channels (water, $200).
* '''Ideas for Optimization''': Variable fields (pulsed 3-10 T) for targeted migration; integrate with asteroid extrusion (conical heads on probes). Boosts purity from 97-98% to 99.9-99.999% in one pass.
* '''End Goal/Varied Applications''': Purify 20 tons/day (5-15 min/10 kg), extrude wire for welding/printing; Earth: High-quality brackets ($20-$50); asteroids: Iron-nickel wire for habitats. Ideologically, "purification" as refining waste's essence.
* '''Time/Cost''': 5-15 min/batch; $2K-$3K module.