Study On The Performance And Mechanism Of Flotation Separation Of Scheelite And Calcium Bearing Gangue Mineral With Organic Depressants

China is rich of scheelite resource,but it is generally characterized by low grade and complication of mineral composition.In particular,scheelite and calcium-bearing gangue minerals such as calcite and fluorite have similar surface physicochemical properties and complex solution chemical behaviors,making their separation more difficult.This paper was based on the practical problems of flotation separation of scheelite and calcium-bearing minerals,which led to low crude concentrate grades,high cost of heating and low selection efficiency.The research on the performance and mechanism of mineral flotation was of great significance to the energy saving and consumption reduction of scheelite and the reduction of environmental pollution.In this paper,the flotation separation of scheelite from fluorite and calcite was discussed using single mineral flotation test.With the help of analytical testing methods such as surface potential data,contact angle,infrared spectrum,and XPS of minerals and molecular dynamics simulations,the internal mechanism and action mechanism of the flotation separation of various minerals,and based on this,a rough separation test of a low-grade scheelite was carried out.The main conclusions obtained in this paper are as follows:?1?The results of the single mineral flotation test showed that:The effects of organic depressants with different functional groups on the flotation behavior of single minerals were investigated.Their ability to inhibit gangue minerals ranged from high to low:Organic phosphine>Tannin extract>CMC>Sodium humate>Citric acid>EDTA,and DP has the best selectivity among organic phosphine depressants.?2?The measurement results of the surface potential data of minerals showed that these three organic depressants changed the fluorite and calcite The surface potentials affect the potentials of fluorite and calcite from high to low:DP>EP>AP.The change of contact angle with and without the reaction with depressants showed that the organic phosphine depressant can selectively enhance the hydrophilicity of fluorite and calcite to reduce the floatability of fluorite and calcite.Through the comparison of the size of the contact angle,the degree of inhibition of the fluorite and calcite floatability of the inhibitor from high to low was:DP>EP>AP.The results of infrared spectroscopy showed that new phosphine-based absorption peaks appeared on the surfaces of fluorite and calcite,while no new absorption peaks appeared on the surface of scheelite.XPS analysis showed that the combination of DP and Ca spectra after the interaction of DP with fluorite and calcite indicates that DP has chemical interaction in the form of Ca PO³⁺on the surface of fluorite and calcite,and Ca spectrum with FX-6 after DP The small change in binding energy indicated that DP can be selectively adsorbed on the surface of calcite and fluorite,and hinders the re-adsorption of FX-6 to gangue minerals.After DP simulation,the adsorption energy of DP to fluorite,calcite and white tungsten is-948.39 kcal/mol,-1336.57 kcal/mol,-110.24 kcal/mol,indicating that the adsorption energy of DP and calcite is the strongest,fluorite second,the adsorption capacity of scheelite is the weakest,which is consistent with the single mineral flotation results.?3?In view of the complex symbiosis of the actual scheelite and the difficulty in improving the rough grade,the actual mineral flotation test was carried out on the low-grade scheelite with WO₃grade of 0.13%in the raw ore.In the depressants screening process,one roughing separation process was used.Compared with the traditional depressant water glass crude concentrate WO₃grade of 2.64%,the organic depressant DP makes scheelite on the premise of ensuring the recovery rate of scheelite rough separation.The grade in the rough selection stage has increased by about 1.8 percentage points,but the amount used is one hundred of the amount of water glass used.In the roughing separation process,sodium carbonate was used to adjust the p H of the pulp,DP and FX-6 were used respectively depressant and collector.After an open circuit test of one roughing,one scavenging and the combination of roughing concentrate and sweep concentrate.Finally,WO₃grade4.04%,WO₃recovery rate of 84.21%scheelite roughing concentrate was obtained.It has created conditions for the subsequent the heating selection section of high-grade scheelite concentrate grade and cost reduction.