Research On The Removal Of Impurities From Copper Electrolyte By Co-precipitation

The derivative method is undoubtedly effective for the low impurities of copper electrolyte,but it seems insufficient purified competence,large purification liquid volume,high power consumption,the impurities back to the closed-loop of the smelting process for the high-impurity copper electrolyte.Based on consulting a large number of related literature,the process optimization and co-precipitation mechanism of the high-impurity copper electrolyte by Sb₂O₃,regeneration mechanism and process optimization of Sb₂O₃ were carried out as follows:?1?The purification process was optimized by lab and semi-industrial experiments with Sb₂O₃ to co-precipitate the impurities.The results showed this method had a prefect effect on the purification of copper electrolyte,the solid-liquid ratio was the main influence and the reaction temperature was the second on purification.The removal rates of arsenic,antimony and bismuth reached 45.33%,44.93%and 66.90%respectively,under the optimum conditions of solid-liquid ratio of 10 g/L,reaction time of 90 min,reaction temperature of 85?and stirring speed of300 rmp.The impurities concentrations were lower than the design-value of normal production.Meanwhile,the semi-industrial experiment result of copper electrolyte purification by Sb₂O₃ showed that the effect of purification was stable and basically similar with the result of laboratory experiment,and the solution can be returned directly to the electrolysis process after filtration.?2?The purification residue was characterized by ICP-MS,XRD,SEM-EDS,TG/DTA and laser particle size and the formations of arsenic,antimony and bismuth in copper electrolyte were combined.The results showed the purification mechanism was that the arsenic,antimony and bismuth ions were co-precipitated to form AsSbO₄,SbAsO₅,Sb₂O₄ and BiSbO₄ as the main components of greenish yellow residue,and separated from the copper electrolyte.?3?The regeneration mechanism of Sb₂O₃ from purification residue was analyzed through the thermal decomposition behavior of the purification residue.The deep separation of arsenic,antimony,bismuth,and regeneration of Sb₂O₃ were theoretically feasible with the two-stage roasting process,meanwhile,the phases of arsenic and antimony in the purification residue were separated and concentrated as As₂O₃ and Bi₂O₃,respectively.Which could avoid the problems,such as,long processes,large amounts of reagents consumption and other shortcomings in the process of acid leaching or alkali leaching.?4?The separation of arsenic,antimony,bismuth from the purification residue was carried out by a two-stage roasting process in argon atmosphere?0.10 L/min?through increasing the temperature to promote the decomposition of purification residue.And the deep separation of arsenic,antimony,bismuth,and regeneration of Sb₂O₃ were realized during the first stage roasting at 800°C over 2 h,the second stage roasting at 1200°C over 2 h.The recovery rates of arsenic and antimony reached up to 98.50%,the purification effect with the regeneration Sb₂O₃ was stable and basically same as the effect with raw materials.Meanwhile,the products of roasting process were characterized by ICP-MS,XRD,SEM-EDS,TG/DTA and laser particle size analyzer.The variation of phases of arsenic,antimony and bismuth during separation process and the trend were analyzed,the As₂O₃?g?,Sb₂O₄ were obtained in the first stage roasting through the thermal decomposition of AsSbO₄?<700??and SbAs O₅?800??.The Sb₂O₃?g?,Bi₂O₃ were obtained in the second roasting stage through the thermal decomposition of Sb₂O₄?1150??and BiSbO₄?1200??,then the separation and concentration of arsenic,antimony,bismuth in the purification residue were realized,respectively.