Study On The Resource Utilization Of Converter Dust Containing Zinc

Converter dust is a by-product collected in the converter steelmaking dust removal system.According to the different dust removal processes,it can be divided into dry dust(dry dust)and wet dust(wet dust).The iron content is high.Valuable secondary resources,the traditional way of utilization is to directly return to the smelting system for secondary smelting.In recent years,with the addition of galvanized scrap steel in the converter steelmaking process,the zinc content of the converter dust has increased and it cannot be directly returned to the furnace for smelting.At present,there is no suitable technology for treating converter-containing dust and sludge at home and abroad,and the problem of zinc removal of converter dust and sludge has attracted much attention.This paper proposes a new process plan of "low temperature alkaline roasting-alkali leaching" to reduce the zinc content of converter dust and sludge,focusing on solving the problem of zinc removal of converter dust and sludge.Through this process,zinc-containing leachate and iron-containing leachate can be obtained,and the process of preparing zinc powder by leachate electrowinning and sodium removal of the leachate are systematically studied.The main research contents are as follows:NaOH and converter dust sludge are mixed and roasted.NaOH solution was used for leaching the samples after roasting.The effects of mixing method,roasting conditions and leaching conditions on the zinc removal rate were discussed.Zinc electrowinning experiments were carried out on the leaching solution,and the effects of initial zinc concentration,initial alkali concentration,and electrode plate spacing on zinc purity and zinc yield were discussed.Due to the large amount of NaOH used in the experiment,the residue of leaching slag was more Na,so the leaching slag was desodiumed using CaO.the result shows:(1)The zinc removal rate increases with the increase of alkali ratio.Alkali ratio is the main factor that determines the zinc removal rate.In addition,the mixing method and whether alkali is added to the leaching agent have a great influence on the zinc removal rate.Under the conditions of adding water 0.3g/g,roasting temperature 350?,leaching agent concentration 5mol/L,leaching time 3h,roasting time 1h,solid-liquid ratio 1:50,stirring speed 400rpm,leaching temperature 90?,dry dust removal The zinc rate is 99.28%(alkali ratio 1g/g),and the wet process sludge zinc removal rate is 97.25%(alkali ratio 1.2g/g).(2)The best electrowinning conditions are:initial zinc concentration 15g/L,initial alkali concentration 5mol/L,electrode plate spacing 1cm,zinc yield is 97.99%,zinc purity is 91.72%.(3)When the reaction time of the sodium removal experiment is 7h,the sodium content is 1.98%.Using the whole process experiment,the final sodium content is only 0.47%(dry method dust)and 0.50%(wet method mud).At present,this process can effectively reduce the zinc content of converter dust and sludge,so that it meets the reuse standard,has a broad industrial application prospect,and provides a new method for zinc removal of low zinc converter dust and sludge in the future.