Magnetic separation of lunar soils

The authors report measurements of the distribution by magnetic susceptibility of anorthite, ilmenite, pyroxene, and metallic iron separated from the minus 1-mm size fraction of five lunar samples using a Frantz isodynamic separator. Low-iron content, pure anorthite was separated from the feebly paramagnetic fractions of an immature anorthistic highland soil. The concentration of anorthite is not affected by soil maturity, but recovery is. A concentrate containing 30% ilmenite and 15% pyroxene was separated from the intermediate susceptibility fractions of both immature and submature high-Ti mare basalts. Both concentration and recovery of ilmenite are affected by soil maturity. Metallic iron was separated from the highest magnetic susceptibility fractions of all soils. The concentration and recovery of iron is shown to increase with soil maturity