Research On Flotation Separation Of Scheelite And Apatite And Its Mechanism

The scheelite resources are rich in our country,but most exist "lean,fine,miscellaneous" problem,which brings great difficulties to the scheelite flotation separation,belong to the refractory ores or extremely refractory ores.Against the problem that scheelite and gangue mineral containing calcium apatite paragenesis,this article studied the effect of different types of collectors and adjusting agents on scheelite and apatite flotability,at the same time,combined with the artificial mixed mineral and actual ore separation tests,studied the flotation separation of scheelite and apatite under different conditions.Finally,through mineral crystal chemistry,flotation solution chemical calculation,expanded DLVO theory and dynamic potential,SEM,ICP and other detection methods,action mechanism between agents and minerals were discussed.Flotation tests showed that the fatty acid,sulfonic acid and hydroxyl oxime acids collectors had different degrees of collecting effect on scheelite and apatite,and sodium carbonate had different activation or inhibition effects on scheelite and apatite seperately under the above three kinds of collector systems.For scheelite,in sodium oleate and benzene armour hydroxyl oxime acid systems,sodium carbonate enhanced scheelite flotability.In sodium dodecyl sulfate system,sodium carbonate basically had no effect on scheelite flotability.In sodium dodecylbenzene sulfonic acid and Salicylhydroxamic acid systems,sodium carbonate reduced the flotability of scheelite.For apatite,in sodium oleate and benzene armour hydroxyl oxime acid systems,sodium carbonate enhanced apatite flotability.In salicylic hydroxyl oxime acid system,the flotability of apatite was weakly affected by sodium carbonate.In sodium dodecyl sulfate and sodium dodecyl benzene sulfonic acid systems,sodium carbonate reduced the flotability of apatite.In sodium oleate system,organic inhibitors,phosphate inhibitors and sodium silicate had differernt degrees of effects on the flotability of scheelite and apatite.Salicylic acid hydroxyl oxime is a highly selective collector,sodium pyrophosphate was a good selective inhibitor,but both of them were unable to achieve the effective separation of scheelite and apatite.There was interaction effect between scheelite and apatite.Using a single adjustment agent or inhibitor could not achieve their separation.Therefore,in sodium oleate system,"Na2CO3 + Cu2+ +sodium silicate" composite inhibitor was studied in the scheelite and apatite flotation separation,which found that only under the reagent regime of sodium silicate and Cu2+being dosed simultaneously,the composite inhibitor could effectively selectively inhibit apatite,so as to realize the flotation separation of scheelite and apatite.In order to optimize the flotation separation of this method,furtherly,the effect of "salicylic acid hydroxyl oxime + sodium oleate" combination collector on flotation separation was explored,which found that compared with first adding sodium oleate,first adding salicylic hydroyl oxime acid the scheelite recovery of artificial mixed mineral flotation concentrate was higher,but lower in the grade.Mineral crystal chemistry study showed that the active site having function with the collector on the surface of scheelite and apatite was Ca2+,so the relative density of Ca2+ is closely related to the good or bad of mineral flotability.Flotation solution chemical calculation showed that the effective component function with mineral surface in sodium oleate H(OI)2-ion,the optimal pH value is 8.3 or so,appropriate pH range is 6.5?11.5;the way of the active ingredients in salicylic hydroxyl oxime acid and benzene hydroxyl oxime acid function with the mineral surface was the coadsorption of molecules and ions;sodium pyrophosphate,sodium tripolyphosphate,sodium hexametaphosphate three phosphate polymers could complexing the Ca2+ on the surface of scheelite and apatite,reducing the active sites on mineral surface function with reagent,so had inhibitory effect on mineral.The Ca2+ complexing capability of the three phosphate polymers is consistent with their inhibition capability,the sequence from big to small is:sodium pyrophosphate>sodium tripolyphosphate>sodium hexametaphosphate.The effective components in sodium silicate function with mineral surface was SiO(OH)3-,the effective pH range is 9?12.5.the paticles interaction research showed that the reunion phenomenon was serious in the scheelite and apatite's fine particles,the reunion between coarse particle effect was not obvious,adopting the method of "Na2CO3+sodium silicate +Cu2+" combination reagent could reduce this kind of reunion phenomenon,so as to realize the separation of scheelite and apatite.That "Na2CO3 + Cu2+ + sodium silicate" could better realize the scheelite and apatite flotation separation showed that the mechanism of Cu2+ changed the way of sodium silicate function with mineral surface,more as a kind of bridge link with sodium silicate and the anion on the surface of minerals achieving inhibition function,it also provided the active site space for sodium carbonate activating the scheelite.The above research results have practical guiding effect on flotation separation of apatite type scheelite.