Study On The Activation And Migration Of Elements In Lead-zinc Mine Tailings Under Different Redox Conditions

The physical and chemical properties,heavy metal content and morphological characteristics of tailings from Dachang lead-zinc polymetallic mining area in Guangxi were analyzed.Through leaching experiments,the migration and release of five elements Cu,Zn,Cd,As and Pb in Lutang lead-zinc tailings in Dachang town,Guangxi were discussed under different redox conditions,different speeds and solid-liquid ratio.By designing dynamic leaching experiment to simulate the migration of heavy metal elements in tailings under different redox conditions,changing different redox conditions,atomic fluorescence and atomic absorption were used to detect and analyze their effects on the migration and release of heavy metals in tailings.Through the morphological analysis of heavy metal elements in tailings,we can preliminarily find out the morphological characteristics,controlled factors,migration and bioavailability of heavy metal elements in tailings,and discuss the effects of leaching experiments on the removal rates of Cu,Zn,Cd,As and Pb,in order to better assist the selection of leaching agents and determine more effective leaching experiments,so as to provide real and effective reference data for future production.The main results of this study include:1.The migration and leaching curves of Zn,Cd,Pb,As and Cu in five different oxidation environments were different in morphology,outflow time,end time and peak value of leaching.But the same is that the increase of oxidant concentration can promote the release and migration of heavy metals.2.Tailings treated with high concentration oxidation and high concentration reduction show acidic environment with pH < 7,while tailings treated with low concentration oxidation show weak alkaline environment with pH > 7.3.The activation and migration of Cu elements in tailings is obviously affected by pH value,that is,high concentration reduction and high concentration oxidation conditions can promote the migration of Cu.The release and migration of Cd is also affected by pH,and acidic conditions promote the migration of Cd.There is a competitive adsorption relationship between Zn and Cd,but there is still a significant difference between them.Pb and As elements are affected by reduction conditions,which can effectively promote the release and migration of Pb and As elements,while the effect of oxidation conditions is relatively small,but the oxidation environment is common in nature,and the environmental pollution can not be ignored.4.The oxidizing environment can effectively promote the release and migration ability of each element.The higher the oxidant concentration,the more each element migrates;the liquid-solid ratio for the best release and migration of each element is different,and the most suitable solid-liquid ratio for Zn element is 1:3 The most suitable solid-liquid ratio for Cd element is 1:3,the most suitable solid-liquid ratio for Pb element is 1:3,the most suitable solid-liquid ratio for Cu element is 1:5,and the most suitable solid-liquid ratio for As element is 1 :6.