RECOVERY OF 1lANGANESE FROM OXIDIZED ORES .M3 IRONAND PHOSPHORUSFREE SOLUBLE SALTS . By . EMIL PIETZ . A' THESIS . submitted to the faculty of the . SCHOOL OF MINES AND METALLURGY OF THE UNIVERSITY OF MISSOURI . in partial rulfillment of the work required for the . Degree or . MASTER OF SCIENCE IN CHFMICAL ENGINEERING .Rolla, Missouri