Study On Alkaline Separation Of Lead And Antimony From Flotation Tailings Of Copper Anode Slime Deselenium Slag

The flotation tailings of copper smelting anode slime deselenium slag?abbreviated as tailings?are by-products of copper anode slime treated by combined process of beneficiation and metallurgy,which contain many valuable elements such as lead,antimony,bismuth,tellurium and silver.About 1400-1800 tons of tailings are produced annually by copper smelting,which has a certain value of recovering valuable elements.In this paper,the alkaline separation and extraction of lead and antimony,which are the two most abundant elements in tailings,are carried out in order to achieve the reasonable recovery of valuable elements such as lead and antimony in tailings and lay a foundation for the enrichment and extraction of other valuable elements.The experimental raw materials in this paper are flotation tailings with 21.36%lead and 14.37%antimony.Firstly,the elements and phase of the tailings are analyzed,and the leaching theory of lead and antimony in alkaline system is analyzed.Based on this theory,leaching of lead and antimony from tailings in alkaline system was studied.The main research contents include:?1?The leaching of lead with NaOH as leaching reagent was studied.The effects of NaOH concentration,liquid-solid ratio,reaction temperature and reaction time on leaching rate were investigated.The optimum leaching conditions were obtained as follows:liquid-solid ratio 10:1,NaOH dosage 180 g/L,reaction temperature 90 C,reaction time 1 h.The leaching rate of lead is stable at about 82%.In order to improve the leaching rate of lead,high temperature carbon reduction was used to pretreat the tailings because of the complexity of the elements and phase of the tailings,and the effects of carbon powder addition,roasting time and roasting temperature on the leaching rate of lead were investigated.The leaching rate of lead could be stabilized at about 97%after carbon reduction.At the same time,the leaching liquor was separated by precipitation with sodium sulfide.When the amount of sodium sulfide was 16 g/L and the reaction time was 20 minutes,the precipitation rate of lead reached 99.63%.?2?The leaching of antimony with Na₂S+NaOH as leaching reagent was studied.The effects of Na₂S concentration,NaOH concentration,liquid-solid ratio,reaction temperature and reaction time on the leaching rate of antimony were investigated.The optimum leaching conditions were obtained as follows:liquid-solid ratio 10:1,Na₂S content 160 g/L,NaOH content 50 g/L,reaction temperature 90 C,reaction time 1 h.The rate is stable at about 81%.The precipitation and separation of antimony from antimony leaching solution by hydrogen peroxide oxidation method were studied.The study shows that the alkaline leaching system is feasible in treating the flotation tailings of Selenium-removal slag.The study has great practical significance for improving the flotation tailings processing technology of Selenium-removal slag.