Bulk Flotation—Separation Technique Study For Scheelite And Fluorite

Scheelite-fluorite paragenic ore has a large quantity with great exploitation potential in China,however,it is very difficult to separate scheelite from fluorite,and the traditional recovery processing is that recovery for scheelite is preferential to fluorite's,thus resulting in the large dosage of inhibitor.When inhibited intensively,the fluorite is very hard to be activated,and waste water of tailings is hard to be treated.Aiming at the disadvantages of traditional processing,and under the proper conditions of agent regime and processing,the bulk rough concentrate of scheelite and fluorite is obtained by bulk flotation.Selective desorption technique of the agent adsorbing on the mineral surface is utilized to achieve the separation of scheelite and fluorite,and finally to get fluorite and scheelite concentrate.On the basis of chemical calculation of flotation solvent,electrokinetic potential test of mineral surface,mineral and flotation agent infrared spectrometry and agent adsorption amount tests,the action mechanism of floatation agent and the mineral surface are studied in this paper.The single mineral tests show that scheelite and fluorite are well collected by anionic collecting agent sodium oleate with similar flotation behaviors,which is the basis of bulk flotation of scheelite and fluorite to get bulk flotation concentrate.By the co-action of single agent CR,oxalic acid,and water glass for the two single mineral flotation concentrate,it has a limited influence on the floatability of flotation concentrate.Under the co-action of CR and water glass,the floatability of scheelite concentrate is intensively inhibited,but it has a lower influence on fluorite floatation concentrate.When the oxalic acid and water glass are added,the floatability of the two minerals floatation concentrate is both inhibited.The bulk mineral hand-tests indicate that when Na₂CO₃'s PH value is adjusted to about 9 and the dosage of sodium oleate is2.5x10^-4mol/l,bulk floatation is well achieved.With some certain CR and water glass,bulk floatation concentrate of scheelite and fluorite can be separated;the grade of fluorite concentrate is about 95%,its recovery is approximately 85%;accordingly,the grade of scheelite concentrate is about 50%,and the recovery is more than 90%.For the mineral which includes about 7.5%of CaF₂,0.42%of WO₃,gangue mineral mainly contenting quartz,carbonate and garnet,laboratory tests for the bulk floatation separation of scheelite and fluorite are carried out.By pulp mixing with Na₂CO₃,using modified water glass as the inhibitor,ZY as the collector,roughing tests are implemented.Through the close-circuit tests with once scavenging and thrice concentration,the bulk concentrate index indicates that the grade of fluorspar is 78.33%and its recovery is 92.29%,the scheelite's are 1.27%and 91.46%accordingly;when adding CR and water glass,we make separation tests for the bulk concentrate.With thrice concentration separation,the separation index announces that the grade of fluorite concentration is 95.13%,the recovery is 81.72%,and the sheelite's are3.49%and 85.82%accordingly.Electrokinetic potential and infrared spectrometry tests show that sodium oleate has chemical adsorption on the surface of scheelite and fluorite.Desorption amount of sodium oleate tests manifest that when adding CR,the collecting agent adsorbed by the two mineral surfaces both are desorbed by different degrees,but the desorption amount of the collecting agent on the surface of scheelite is apparently more than fluorite's,which is good for the selective absorption of the inhibitor water glass.The tests for adsorption amount of water glass indicate that water glass adsorption amount on the surface of scheelite is more than fluorite's.When adding CR and water glass,they enhance the floatability difference between scheelite and fluorite,finally resulting in the separation of the two minerals.