Abstract: Using fluorapatite and dolomite as research objects,this study investigated the selective effect of the novel inhibitor fulvic acid on flotation separation between the two minerals in a sodium oleate collector system through pure mineral micro-flotation tests combined with Zeta potential,contact angle,and Fourier-transform infrared spectroscopy (FTIR) analyses. The results showed that without inhibitors,both fluorapatite and dolomite exhibited high floatability under sodium oleate action, making their separation difficult. However,under weakly acidic conditions with appropriate fulvic acid addition,fluorapatite was strongly inhibited while maintaining higher floatability for dolomite. Optimal separation was achieved at pulp pH of 5,with fulvic acid of 15 mg / L and sodium oleate of 60 mg / L, yielding a concentrate with P2O5 grade of 33. 86% and recovery of 92. 36% from artificial binary mixed ores,demonstrating excellent selective separation. Further study revealed that fulvic acid competitively chemically adsorbed with sodium oleate on fluorapatite surfaces,selectively reducing surface hydrophobicity and significantly decreasing floatability,thereby enabling effective separation from dolomite. 

Key words: flotation,depressant,filvic acid,fluorapatite,dolomite ,