Study On Appliancation And Mechanism Of MES In The Flotation Of Scheelite

The application of MES to the flotation of phosphate proved its possibilities as a new collector in the flotation of calcium minerals.In the flotation of scheelite,two problems were the low recovery in roughing flotation process and the consumption of collectors by Ca2+and Mg2+ions in the pulp,which could be solved effectively to a certain extent by MES due to its high surface activity and resistance of calcium and magnesium ions.In addition,the price of MES is lower than traditional collectors,which shows its potential value in the flotation of scheelite. In this thesis,single mineral flotation tests,pratical ore flotation tests,surface tension of the collectors and foam performance studies,mineral surface wettability studies,Zeta potential measurements,infrared spectrum analysis were carried out to study the application and mechanism of MES in the flotation of scheelite.Single mineral flotation tests indicated that:when the mass proportion between733and MES was4:1,scheelite、fluorite and calcite showed remarkable floatability differences with the cooperation of the inhibitor-water glass.After MES was added into733,its anti-hard water capacity was significantly improved that it can hardly be affected by Ca2+and Mg2+ions in the pulp.Surface tension of the collectors and foam performance studies showed that:the addition of MES could reduce the CMC values of733,improve its foamability and enhance the stability of the foam.Mineral surface wettability studies demonstrated that:the combination of733and MES could enhance the hydrophobicity of the three minerals’surfaces significantly.When the mixed collectors was combined with water glass,the surface of scheelite still remained excellent hydrophobicity,meanwhile hydrophobic of fluorite’and calcite’surfaces was weak.Zeta potential measurements revealed that:the combination of733and MES had stronger adsorption on scheelite and fluorite than the collector733alone,while the former and the latter had the same adsorption strength on calcite.The mixed collectors and water glass had competitive adsorption on the surfaces of the minerals.On the surface of scheelite,the mixed collectors had a competitive advantage.The results of infrared spectrum analysis showed that:chemical adsorption occurred on the surface of sheelite when733and MES were used as collectors respectively.The adsorption could be even stronger when they were used together.But the mixed collectors had a relatively weaker adsorption on both fluorite and calcite. When the mixed collectors was combined with water glass,the mixed collectors still had strong chemical adsorption on the surface of scheelite with the adsorption of water glass being weaker.While on the surfaces of fluorite and calcite,the mixted collectors had weaker adsoption and there was no significant decrease to the adsorption of water glass.Using mixed collectors of OXB(733is the main component) and MES,desirable results could be achieved in roughing flotation process in the lab at room temperature.From the raw ore in which the grade of WO3was0.57%, the scheelite concentrates with the grade of WO3being65.76%and recovery being66.04%were finally obtained.