Influence Mechanism Of Bacillus Tropicus On Flotation Separation Of Chalcopyrite And Molybdenite

As a beneficiation reagent,microorganism has always been an important research direction in the field of fine mineral recovery,and the research as a flotation reagent has been reported.Microbial cells contain a large number of macromolecules such as proteins and sugars,which give them the characteristics of selective adsorption with mineral surface and changing the properties of mineral surface.Copper and molybdenum ores often coexist closely,the separation process is becoming more and more complex,and the use of reagents is becoming more and more complex.Almost all flotation reagents are toxic.This paper studies the cultivation and screening of microorganisms and the preparation of inhibitors,and further studies its action mechanism between molybdenite inhibitors and mineral surface in the flotation separation of copper molybdenum ore,which makes it possible to find high-efficiency beneficiation agents without or less pollution to the environment by using microbial technology.In this study,84 strains of bacteria were isolated from acid water and soil of Dexing Copper Mine and soil of an orchard in Ganzhou,Using the method of"culture centrifugation dispersion re centrifugation freeze drying pulverization",the bacteria were made into inhibitors for the flotation of chalcopyrite and other sulfide minerals,and a strain of bacteria with obvious inhibitory effect on molybdenite was screened.Bacillus tropicus was identified by morphological analysis and 16S r DNA sequence analysis.In the single mineral flotation test,it is found that excessive tropical bacillus can inhibit the flotation of chalcopyrite,galena,sphalerite and molybdenite,and the recovery is lower than 40%.When the dosage of tropical Bacillus inhibitor is 10mg/L,p H=9.0,the final chalcopyrite recovery is 74.10%,and the recovery of molybdenite is 20.47%.Through test chalcopyrite and molybdenite and tropical bacillus function before and after the contact Angle and Zeta potential,found in tropical bacillus of chalcopyrite and molybdenite are significant changes in surface properties.A new exothermic peak appeared in the DSC curve of molybdenite after the action of Tropical bacillus,indicating that it changed the surface properties of molybdenite.Under scanning electron microscope,the molybdenum surface was attached with irregular fragments and spores after interacting with tropical bacillus.Under EDS,the content of element C in attached fragments increased from33.87%to 64.69%.Under the detection of infrared spectrum,the-OH absorption peak(3559.6cm^-1)and the stretching vibration absorption peak(1628.6cm^-1)of double bond（-C=C-and-N=N=）were found on the surface of molybdenite treated by Bacillus tropicana.-NO₂ absorption peak(1527.2cm^-1).In conclusion,Bacillus tropicalis can be used as molybdenite inhibitor under certain conditions,mainly by adsorbing spores and extracellular polymers on the surface of molybdenite,making its surface hydrophilic and difficult to float up.The exploration of using it as inhibitor can provide a research method for microorganisms as mineral flotation reagent to realize the development of environmental friendly and green reagent.