Oxygen-Enriched Jarosite Slag Enhanced Volatilization Smelting And Final Slag Leaching Toxicity Studies

Jarosite slag is an industrial waste residue produced in the process of zinc hydrometallurgy.At present,due to the lack of mature and efficient technology for the treatment of jarosite slag at home and abroad,a large amount of jarosite slag is accumulated,which not only affects the ecological environment,but also leads to The backlog of valuable metal resources.Therefore,how to recycle the ferrite slag is of great significance.In this paper,jarosite slag is taken as the research object,and its properties are analyzed and studied.The jarosite slag was treated with oxygen-enriched volatilization smelting process.The effects of different smelting process conditions on the lead and zinc volatilization rate on the silver content and slag reduction in the smelting final slag were investigated,and the leaching toxicity characteristics of the smelting final slag were characterized.The following conclusions:（1）Most of the metals in the thermal decomposition products of jarosite slag are mainly in the form of sulfates,and the order of the four metal decomposition reactions of sulfates is:Fe₂（SO₄）₃>Cu SO₄>Zn SO₄>Pb SO₄.The results of TG-DSC thermal analysis and th ermodynamic calculation of jarosite slag thermal decomposition proc ess are basically consistent,and the main components of jarosite de composition products are Fe₂（SO₄）₃,Na₂SO₄and Fe₂O₃;（2）The research on the oxygen-enriched volatilization smelting process of jarosite slag has achieved good results,which can realize the recovery of valuable metals and the reduction of slag at the same time.Under the optimal process conditions of reaction temperature of 1250℃,reaction time of 90min,carbon content of 10wt%,and oxygen-enriched concentration of 40%vol,the final smelting slag contains silver 11.58g t^-1,lead and zinc volatilization rates were 99.66%and 99.88%,respectively.（3）Oxygen-enriched volatilization smelting of jarosite slag is used to obtain final smelting slag and iron-rich phase.The main phase composition of iron-rich phase is metallic Fe phase and iron sulfide phase.The final smelting slag is mainly composed of Fe-Si-O,Fe-Na-Si-O,Fe-Ca-Na-Si-O phase composition;during the smelting process,the sticky slag phase has a single composition,which is Fe-Na-Si-O phase,and its slag formation is insufficient,which makes the slag-metal separation difficult.（4）The main toxic ions of jarosite slag leaching are Cd,Zn,and Pb.The concentrations of Cd,Zn,and Pb in the jarosite slag leaching solution are 38.81 times,10.38 times,and 1.54 times,respectively,of the TCLP international standard limit.（5）The concentration of Cd,Zn,Pb,Cu,and As in the leaching solution of jarosite slag oxygen-enriched volatilization final slag are all lower than the TCLP international standard limit;the concentration of Cd,Zn,Pb,Cu,and As in the self-slag leaching solution is low In TCLP international standard limit and"GB5085.3-2007"domestic standard limit.