Research On Recycling Of Discharged Copper Nitrate Electrolyte

During copper electrolytic refining, as the anode copper electrochemical dissolution, impurity on the anode plate into the electrolyte, and accumulate in the electrolyte, when impurity concentration exceeds a certain extent, may be on the cathode copper deposit, with serious impact on the quality of electrical copper. Therefore, in order to guarantee the quality of cathode copper, must be regularly for purification in the electrolyte.This article first USES the adsorption method,, purifies the electrolytic liquid discharge experiments showed that nitrate system because of the high concentration of nitrate, strong oxidizing, easy damage of extractant and ion exchange resin, the lower extractant and ion exchange resin in the capacity and service life will be destroyed. The evaporation crystallization method is adopted, it will need the nitric acid in the purification liquid copper recovery in the form of crystal, crystal by the recrystallization method after purification standard to compound electrolyte returned to continue to participate in the electrolytic refining of aluminum reduction cells, and a small amount of residual copper impurities and enrichment of the crystallization mother liquor and using iron powder replacement method and chemical precipitation to further purification or collection.After adsorption purification electrolytic liquor. Selection of chelating resin, the control of resin for the200g/L, increasing the initial concentration of solution, adsorption more than20min under the conditions of static adsorption, iron, nickel impurity adsorption rate can reach more than96%, arsenic adsorption rate at about50%. Desorption solution with6%hydrochloric acid solution, copper desorption rate can reach more than90%, impurity desorption rate can reach more than85%. Selects the powdered activated carbon, control the dosage of activated carbon for150g/L, the solution pH=2.5above40min under the conditions of adsorption, iron, nickel, arsenic impurity removing impurity rate can reach more than85%, desorption solution with6%hydrochloric acid solution, desorption rate can reach more than60%.Evaporative cooling crystallization recycling copper nitrate. Electrolytic copper ion initial concentration of447.86g/L, evaporation temperature is90℃, the crystallization process of adding liquid1%solid seed weight, under the condition of low speed mixing, treat two crystallization purifying liquid, total crystallization rate can reach76.1%. Recrystallization of the crystal, crystal purity can be up to99.998%.Iron powder displacement method after purifying crystallization mother liquor. When actual iron powder dosage too much than the calculated value is10%, the pH control in3～4, replacement reaction temperature control at80℃above, more than15min, copper replacement rate can reach87.7%, replacement income copper powder purity can reach93.57%.Sulfide precipitation after purifying crystallization mother liquor. The dosage of sodium sulphide and copper mole ratio is1.5, pH=1～3, more than5min, can selectively to solution of copper ion selective precipitation from other impurities ion, precipitation rate is as high as99.98%above.