Abstract: Aiming at the key technical difficulties such as poor selectivity and low separation efficiency of reagents reaction
in the flotation separation of apatite and dolomite,this study realizes the selective separation of apatite and dolomite
through ultrasonic pretreatment of apatite and dolomite surfaces and the introduction of sodium humate as an inhibitor. The results
of single-mineral test showed that the minerals were ultrasonically pretreated and then subjected to flotation,the flotation
recovery of apatite was increased from 61. 61% to 91. 17%,while the recovery of dolomite was maintained at 0. 5%,which effectively
enlarged the floatability difference between the two,and the artificial mixed-mineral test yielded a recovery of apatite
of 70. 12%,and a low recovery of dolomite as low as 8. 23%,which resulted in a better sorting effect. The analysis based on
the results of adsorption capacity test,Zeta potential test,infrared spectroscopy and SEM-EDS test showed that the ultrasonic
pretreatment could effectively clean the mineral surface and accelerate the dissolution of PO3-
4 and F- on apatite surface and
CO2-
3 on dolomite surface,which exposed more Ca active sites for apatite and more Ca and Mg active sites for dolomite. Due to
the weak adsorption between apatite and sodium humate,most of the newly generated active sites on its surface were occupied
by sodium oleate after pretreatment,and the sodium humate adsorption capacity was low;While sodium humate was strongly adsorbed
on the surface of dolomite through chemical bonding,and the newly generated active sites were occupied by sodium humate,
which inhibited the subsequent adsorption of sodium oleate,and the high efficiency of the two separations was realized.

Key words: ultrasonic pretreatment,sodium humate,apatite,dolomite