بهينه سازي ليچينگ آهن از لجن كنورتور ذوب آهن اصفهان

چكيده انگليسي :

AbstractSignificant amount of solid wastes in form of dust and sludge is generated whit steel andiron production and quantity of these wastes increase yearly Dispose of these wastes orrecycling of them is one of the important issues in iron and steel industries Usual methodfor dispose these wastes is dumping them near the factory But nowadays this dusts andsludge is classified as hazardous material in most of industrial countries Because they havetoxic elements such as heavy metals So they should be disposed in certain place This dothe dispose expensive otherwise steelmaking dusts contain useful recourse such as iron calcium zinc lead and etc that can recover and reuse them Valuable metals lost if thewastes dispose Environmental problems related to disposal of sludge and also high potentialof that to recover iron regarded to high iron content of it make recovery and separation ofiron from sludge as a necessity The aim of this work is investigating the leaching of Iron from converter sludge of ZOBAHAN and optimization of effective parameter on it to recover maximum of Iron In this research leaching of iron from BOF sludge whit sulfuric acid was investigated Primary experiments was done to determine the suitable acid and investigate effect ofadditions and the optimization experiments was done to study effective parameter onleaching and determine the optimum conditions Experiments were carried out in containerwith the capacity of 0 5 lit by stirrer at atmospheric pressure Primary experiments was doneby using sulphuric nitric and chloridric acid Also the effect of adding the sodium chlorideand sodium solphate on iron recovery in the leach system was studied The results of primaryexperiments showed that sulphuric acid is the best choice for leaching 30 min after startingthe experiment recovery of Fe in sulphuric acid chloridric acid and nitric acid system was85 71 and 39 respectively Also it was seen that additions has no effect on the leaching Recovery of Iron was 60 for using the sodium chloride and 69 for using the sodiumsulphate At the next step the effect of acid concentration solid percent temperature andtime was studied by using the center composite design Ranges that proposed for theparameters is 1 3 mol lit for acid concentration solid percent from 10 to 20 temperaturefrom 70 to 90 C and the time from 30 to 90 minuet To determine the optimum condition 30experiments have been done Results of the experimental data were analyzed by analysis ofvariance ANOVA and the most appropriate model with a confidence level of 95 wasused The suitable model for responses of iron recovery was quadratic Results showed thatthe parameters of acid concentration and solid percent had the most effect on Iron recoveryefficiencies Increasing the acid concentration and solid percent increase and decrease theFe recovery respectively Temperature and time have low effect on Fe recovery Maximumrecovery was obtained in 2 95 mol lit acid concentration 10 17 solid percent 89 C and 80minute In this conditions the recovery of iron exceed to 88 95 Kinetic experiments was done to determine the leaching model and computing the activationenergy Experiment was done with constant conditions at 45 60 75 and 90 C Results showedthat leaching reaction follow the shrinking core model SCM and ash diffusion controlledthe reaction Activation energy was earned 55 31 KJ mol Multi steps experiments was done to increase the recovery of iron from solid residual ofleaching and reduce the leaching residual Comulative recovery of iron for first to third stepwas 61 85 77 14 and 91 10 respectively The comulative residual of first to third stepwas 60 31 48 15 and 24 80 respectively Key words Acidic leaching Recovery of iron Zob Ahan Waste

محموديان، ابراهيم

بهينه سازي ليچينگ آهن از لجن كنورتور ذوب آهن اصفهان

ليچينگ اسيدي , بازيابي آهن , پسماند