Study On The Flotation Mechanism Of Combined Collectors For Galena

Galena is the main form of lead resources in our country.With the exploitation and utilization of lead resources,high-quality lead ore is consumed.Meanwhile the phenomenon of ore poverty and impurity has been gradually emerging.Some factories,colleges and research institutions have carried out a sea of research in the flotation of lead-zinc sulfide ore,and made great progress.The use of combined reagents is one of the main directions of the researches,which has also been introduced in actual production.However,most of the studies are in the stage of the regime of agent,and the basic theoretical research remains still relatively weak.Besides,the synergistic mechanism of combined collectors has not been clearly demonstrated,so further research need be conducted.In this paper,the factors,such as the feeding size,types and dosages of p H adjustors,inhibitors,collectors,types and ratios of combined collectors and so on,were investigated in the process of flotation of galena to hunt for the most prior test conditions.Simultaneously,a series of technical mean,for instance contact angle measurement,adsorption capacity measurement,infrared spectroscopy measurement,etc.were utilized to analyze reasonably the operation mechanism of the combined collectors on galena flotation.Which provides theoretical guidance for the development and use of new collectors..The main conclusions are as follows:The flotation recovery of galena pure mineral can be obviously affected by particles size,the type and the value of p H adjuster,the type and dosage of inhibitors,collectors,and combined collectors and its ratios,and the best flotation conditions are that particle grade is between 0.043to 0.074 mm,concentration of collector is 80 mg/L,and the p H value is 9.0.Yet,the flotation recovery of galena in different system with various types of p H adjustor at the same p H value are significantly different.In terms of the overall indictors:lime>sodium hydroxide>sodium carbonate,but under high alkali conditions（p H≥10）,the effect of sodium carbonate is significantly better than lime and sodium hydroxide.Zinc sulphate can inhibit the flotation of galena in the system of butyl xanthate,ammonium dibutyl dithiophosphate and sodium diethyldithiocarbamate,and the extent affected is:butyl xanthate>ammonium dibutyl dithiophosphate>sodium diethyldithiocarbamate.Under the circumstance that the total concentration of the collector remains unchanged,the flotation effect of the combined collector is better than that of a single collector,and the recovery can be increased by an average of 6.3%.The best combined collector type is butyl xanthate and sodium diethyldithiocarbamate with the ratio of 2:1.In the contact angle measurement,the recovery of galena is proportional to the size of the contact angle of its surface,that is to say,the larger the contact angle is,the higher the recovery is.The contact angle of the raw ore is 54.40°,and the contact angle of galena after the action of butyl xanthate+sodium diethyldithiocarbamate can be reached to 76.39°,which is consistent with flotation result.The contact angle of the raw ore powder determined by the weighing method is a little high.The adsorption capacity measurement reveals a fact that when the concentration of a single collector is 80 mg/L,0.3786 mg of butyl xanthate,0.1966 mg of ammonium dibutyl dithiophosphate,and 0.193 mg of sodium diethyldithiocarbamate adsorbs on the surface of per gram of galena,respectively,and the recovery is proportional to the adsorption capacity;when the total concentration of the combined collector is 80 mg/L with the ratio of 1:1,（1）butyl xanthate+ammonium dibutyl dithiophosphat,0.312 mg of butyl xanthate and 0.0866 mg of ammonium dibutyl dithiophosphat adsorbs on the surface of galena per gram.（2）butyl xanthate+sodium diethyldithiocarbamate,0.2268 mg of butyl xanthate and 0.326 mg sodium diethyldithiocarbamate adsorbs on the surface of galena per gram.（3）ammonium dibutyl dithiophosphat+sodium diethyldithiocarbamate,0.08 mg of ammonium dibutyl dithiophosphat and 0.3266 mg of sodium diethyldithiocarbamate adsorbs on the surface of galena per gram.In infrared spectroscopy measurement,the peaks caused by the functional groups and stretching vibration of bonds of the collector on the mineral surface can be found,meanwhile the peak at 753 cm^-1 in the fingerprint area is the characteristic peak of S-Pb bond of chemisorptions of collector on the surface of galena.In addition,in the infrared spectrum of the combined collector,new peaks except spontaneous generation cannot be found.Combined with the ultraviolet spectrum,it is proved that when butyl xanthate,ammonium dibutyl dithiophosphate,and sodium diethyldithiocarbamate were used with two combinations respectively,there is no new peak being break and reorganization of the chemical bond,which is the only the chemical adsorption of the respective agents.Moreover,agents can promote mutual adsorption,in other words,ammonium dibutyl dithiophosphat can promote the adsorption of butyl xanthate and sodium diethyldithiocarbamate on the surface of galena,and butyl xanthate and sodium diethyldithiocarbamate can mutually promote the adsorption of each other on the surface of galena.