Study On The Technology Of Comprehensive Recovery And Utilization Of Waste Vanadium Catalyst

Every year a lot of waste vanadium catalysts are produced from the sulphuric acidindustry, which contains not only a certain amount of vanadium but also a lot of potassiumand silicon. Therefore, they have important recovery values. In this work, the leachingtechnology of waste vanadium catalysts was studied and the optimum conditions ofpreparation process of vanadium pentoxide, potassium sulfate and liquid sodium silicatefrom the waste vanadium catalysts were obtained. The economic benefit and environmentalanalysis during the production process were taken. From the results of this study, thefollowing conclusions can be obtained:(1) The optimum reduction conditions of water extraction are as follow: theliquid-solid ratio is2:1, reaction time is120min, reaction temperature is80℃. Under theseconditions, the extraction rate of V2O5and K2O can reach50.9%and71.2%respectively.The results of XRD characterizations indicate that the potassium compounds in thewaste vanadium catalysts can be leached by water immersion, but most of silicon andaluminum compounds are still in the filter cake.(2) The optimum reduction conditions of acid leaching are as follow: the sulfuric acidsolution concentration is8%, liquid-solid ratio is2:1, reaction time is90min, reactiontemperature is90℃. Under these conditions, the extraction rate of V2O5and K2O can reach93.5%and96.6%respectively. The results of XRD characterizations indicate thatalmost all of the potassium and aluminum compounds in the waste vanadium catalysts canbe leached by acid leaching, but the silicon compounds are still in the filter cake.(3) We study and make sure the proper preparation process conditions of vanadiumpentoxide, potassium sulfate and liquid sodium silicate. Under the optimum conditions, themain technical indicators of products can meet the corresponding standards. The recoveryrate of V2O5, K2O and Si2O is over92.0%,94.1%and97.6%, respectively.(4) Economic benefit analysis shows that it has a good economic benefit tocomprehensive recovery and utilization of the useful components from waste vanadiumcatalyst. The environmental conditions analysis shows that the production process forvanadium pentoxide, potassium sulfate and liquid sodium silicate is clean and non-polluted.