Recovery of Nickel from Nickel-Rich Electroplating Effluent and Preparation of Nickel Hypophosphite
Actual nickel-rich electroplating wastewater was used as the study object,and nickel hypophosphate(Ni(H2PO2)2· 6H2O)was prepared by using Ni(OH)2 obtained from its precipitation and recovery as the nickel source.The effects of reaction pH and temperature on the metal precipitation rate,reaction P/Ni ratio and temperature on the reaction rate,yield and purity of nickel hypophosphite synthesis were mainly investigated.The experimental results showed that the precipitation efficiency of metal ions increased with the increase of reaction pH and temperature,and the precipitation rate and Ni loss rate of Fe,Al and Cr reached 98.7％,95.6 96.2 and 3.47％,respectively,at pH 3.6 and reaction temperature of 85 ℃ with 1 mol/L NaOH solution as precipitant.The precipitation rate of Ni was 97.5％at a pH of 8.2 and a reaction temperature of 85 ℃.XRD physical phase analysis showed that P/Ni was an important factor affecting the reaction rate,yield and purity of Ni(H2PO2)2·6H2O synthesis.The recovered Ni(OH)2 was prepared by the neutralization reaction with H3 PO2 at a P/Ni of 2.4 and a reaction temperature of 60℃ to produce Ni(H2PO2)2·6H2O with high purity.
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维普
