Process Mineralogy of Titanomagnetite Ore in the Damiao Deposit, Chengde

The Damiao titanomagnetite deposit on the northern margin of the North China Craton is a typical Fe-Ti-P polymetallic ore with significant deep resource potential. However, the mineralogical factors controlling its beneficiation remain poorly quantified. This study integrates multi-element analysis, chemical phase analysis, XRD, EPMA, and MLA to systematically characterize the ore’s chemistry, mineralogy, element deportment, grain size, dissemination, and liberation. Results show that Fe (25.81% TFe), Ti (6.50% TiO2), and P (0.95% P2O5) are the main valuables. Fe is mainly in magnetite (59.53%), Ti in ilmenite (48.90%) and rutile (33.89%), and P almost entirely in fluorapatite. Magnetite, ilmenite, apatite, and pyrite are coarse-grained and achieve >80% free + rich intergrowths at 60% passing −0.074 mm, while rutile is fine and poorly liberated, representing the key titanium bottleneck. Silicate-bound iron (28.07% of Fe) causes irreversible loss; Ca-gangue (>20%) and chlorite slimes interfere with flotation. A staged flowsheet—primary grinding, magnetic separation, regrinding of rough concentrate, desulfurization, and sequential flotation—is proposed. This work provides a mineralogical basis for process optimization and offers references for similar deposits.