Simulation Of Characteristic Pollutants In Flue Gas Of Imported Secondary Copper And Aluminum Smelting

Secondary copper and secondary aluminum are important raw material guarantees to support the development of China's recycled non-ferrous metal industry.However,due to the complex sources of waste copper and aluminum,it is easy to mix with various organic pollutants such as waste plastics,which will lead to the increase of dioxin and heavy metal emissions in the smelting process.At the same time,the current recycled copper and aluminum quasi system is still not perfect,and the relevant basic research is weak,especially the research on inclusions and their pollution characteristics are insufficient,which can not effectively support the adjustment of imported waste catalogue and the formulation of relevant environmental management standards and specifications.Therefore,accelerating the research on the pollution characteristics of recycled copper and aluminum can provide supporting date for the effective prevention and control of pollution emissions in China's recycled copper and aluminum industry,as well as.It also theoretically supports the actual industrial operation and environmental protection departments to carry out environmental management.In this paper,the inclusion content and pollutant discharge nodes of imported copper scrap aluminum raw materials are determined by means of data investigation and field investigation.On this basis,the generation characteristics of heavy metals and dioxins in the regeneration process of copper scrap and aluminum scrap are studied by laboratory simulation.The main results are as follows:?1?The content range of imported waste copper raw materials in China is as follows:copper wire:0.16?0.65%;copper processed material:0.27?1.03%;copper rice:0.15?0.75%.The content of inclusions in China's imported scrap aluminum raw materials ranges from 0.06 to 0.69%.?2?The tube furnace simulates the production characteristics of dioxins in the scrap copper smelting process.It is found that the concentration of PCDD/Fs in flue gas decreases with the increase of temperature when the smelting temperature of scrap copper is 900-1300?,and increases with the increase of inclusion ratio from 0 to 1%.The concentration rule of PCDD/Fs generated by different raw materials is as follows:copper meter<copper processing material<No.1 enameled wire<No.2 enameled wire;and the concentration of PCDD/Fs in No.2 enameled wire is much higher than that of other raw materials.?3?Simulating the production characteristics of heavy metals during copper scrap smelting,the concentration of Cr,Ni,Cu,Zn and Pb in flue gas increases with the increase of temperature when the temperature is 900?1300?,especially the concentration of Cr and Zn;the concentration of Cr,Ni,Cu,Zn and Pb in heavy metal increases with the increase of inclusion content from 0 to 1%;the concentration of Cr,Ni,Cu,Zn and Pb in heavy metal increases with the increase of smelting temperature of different raw materials.In general,the most heavy metals are released from copper processing materials.?4?Simulate the formation characteristics of dioxins during scrap aluminum smelting.When the temperature is increased from 500?to 900?,the concentration of PCDD/Fs increases first and then decreases;the effects of different chlorination additives on PCDD/Fs are as follows:C₂Cl₆>KCl>Na Cl>NH₄Cl;the concentration of PCDD/Fs increases with the inclusion ratio 0 to 1%,especially when the inclusion ratio is 1%.?5?Simulate the production characteristics of heavy metals during scrap aluminum smelting.When the temperature increases from 500?to 900?,the concentration of heavy metals in flue gas increases,and the increase of Cu and Zn is the most obvious;the influence of additives on heavy metals is different.But for Ni and Pb,the influence of four chlorinated additives on them is not significant,and the influence on Cu,Zn and Cr concentration is very different.For Zn,the concentration is C₂Cl₆>Na Cl>NH₄Cl>KCl.For Cu,C₂Cl₆>Na Cl>NH₄Cl>KCl.The concentration of Cr is C₂Cl₆>Na Cl>KCl>NH₄Cl;with the increase of inclusion ratio from 0 to 1%,the concentration of Zn and Cu in flue gas decreases with the increase of inclusion ratio,while Cr and Ni show the opposite law.The content of inclusions has little effect on Pb concentration.?6?Based on the above research,the 0.5%restriction on the content of inclusions in imported scrap copper and scrap aluminum raw materials is proposed for the newly-reproduced standards of"recycled copper raw materials"and"recycled cast aluminum alloy raw materials".The content of powders with a particle size of not more than 2 mm in the scrap aluminum raw material has a limit of 1‰.