| The gold leaching rate of two-stage calcine is about 84%in Tong guan Gold Smelting Co.,Ltd,the tailings contains gold about10g·t-1.Aiming at the problems of the high gold in it caused by secondary package and combining with the research status of treatment the wrapped gold by iron oxide with Sulfuric acid curing-water leaching,TG-DSC change of two-stage calcine in the process of Sulfuric acid curing,micro-structure changes before and after curing and the curing conditions affect on the cyanide leaching gold of the water leaching residue and Sodium cyanide consumption that were studied.In addition,the process condition of prepared ferrous oxalate was studied using aqueous extracts of curing material as an iron source.The sulfuric curing mechanism of two-stage calcine shows that the process of generated hydrated sulfate mainly occurs from 127.8 to 249.1?,its micro-structure changes from porous honeycomb before curing into loose crystal plate after curing.Iron removal rate in the curing material is up to 91.69%by water leaching under the conditions of 75%sulfuric acid with 1.6 excessive coefficient at 200?for 90 min.The cyanide gold leaching rate in water leaching tailing reaches 95.54%,which is increased by nearly 11%than direct cyanide leaching,the gold grade in leaching tailing is decreased from 9.10g·t-1before direct cyanide leaching to 6.0g·t-1,the consumption of sodium cyanide also reduced nearly half.Iron powder as used reducing agent,Fe3+and Cu2+can be removed from the leaching water,metals as zinc,magnesium,et can be removed from the restore liquid using dodecyl benzenesulfonic and sulfonated glyceri,the purified ferrous sulfate solution is recrystallized three times,ferrous sulfate with AR can be obtained.The ferrous sulfate as raw material,The preparation ferrous oxalate results show that?-Fe2C2O4with columnar about 9.79um is prepared under the optimum condition of ferrous sulfate concentration 280g·L-1,ferrous sulfate flow velocity 90m L·min-1,oxalic acid concentration 100g·L-1,reaction temperature 30?,purification temperature 90?,aging time 7h,polypropylene pyrrolidone amount 20%.Ferrous oxalate can be decomposed and prepared Fe2O3in air at 240?,and Fe O in N2at 390?.This study solves the problem of cyanide tailing containing high gold of two calcine,new ways of comprehensive utilization iron resources prepared a variety of chemical products has be opened up,the result has broad market prospect. |
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