Silver distribution between copper and copper selenide and the effect of impurities

Silver is frequently a by-product of the copper industry. Most of this silv er is found in solid solution in the copper anode, but a small portion-usua lly less than 1% of the total silver-is associated with the copper selenide (Cu2Se) phase in the copper anode. The distribution ratio of silver betwee n the copper-rich matrix phase and the copper selenide-rich phase was studi ed in the temperature range 1130-1223 degrees C. The two liquid phases were equilibrated, rapidly quenched and subsequently analysed by use of an elec tron microprobe. The effects of silver content, temperature and nickel, gol d, platinum and palladium additions an the silver distribution ratio were s tudied. The solubility of silver in the copper selenide-rich phase could be described by the equation %Ag-(Cu2Se) = -0.89 + 9 x 10(-4) T (degrees C) The distribution of silver was not affected significantly by the presence o f nickel, gold, platinum or palladium. For a given silver content the impur ity distribution ratios at 1177 degrees C were %Ni-(Cu)/%Ni-(Cu2Se) = 1.84 + 39.87 [%Ni-(Cu)] %Au-(Cu)/%Au-(Cu2Se) = 1.58 + 5.72 [%Au-(Cu)] %Pt-(Cu)/%Pt-(Cu2Se) = 0.05 + 3.47 [%Pt-(Cu)] %Pd-(Cu)/%Pd-(Cu2Se) = -1.44 + 48.12 [%Pd-(Cu)].