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The first order ternary interaction parameters of bismuth in molten copper containing either iron, arsenic or antimony have been evaluated using a pseudo equilibrium process at temperatures between 1398 K and 1473 K. The isopiestic distribution technique developed in this investigation yielded the following results: εFeBi=[(1.11x10⁶)/T]- 754 εAsBi=[(4.4x10⁴)/T]-24 εSbBi=-11 These results, coupled with other activity data, have been used to calculate the isoactivity curves for each constituent in the copper rich corner of each ternary system. The basis for the ternary interactions associated with εFeBi, εAsBi and εSbBi are also discussed.

The equilibrium distribution measurements of As, Sb and Bi between molten copper and white metal and molten copper and matte were conducted to evaluate the activity coefficients of these impurity elements in copper smelting matte. The experimental results were analyzed through comparison and reconciliation with data in the literature. The following equations, based on a liquid standard state, were obtained for ᵞAs, ᵞSb and ᵞBi in white metal coexisting with copper phase at 1,150-1,200°C. Ln ᵞAs = -2.49 + 0.186 NAs; Ln ᵞSb = -1.23 + 23.5 NSb; Ln ᵞBi = 3.01 + 14.0 NBi where Ni represents the mole fraction of the element Bi in white metal. Analysis of the data demonstrated that a major factor in removing As, Sb and Bi in matte during smelting involves careful control of the sulfur pressure, ie. matte's sulfur content, the optimum matte composition's being those that approach the Cu₂S-FeS pseudo binary.

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This research was undertaken to study the suitable physico-chemical conditions for the selective recovery of gold and silver from simulated thiosulfate leach liquors containing copper, gold or silver, ammonia and thiosulfate using three anion exchange resins. In particular, the effect of chemical variables such as thiosulfate, cupric ion and ammonia concentrations and the solution potential of the system on the batch loading of silver and gold onto the resins have been investigated in detail. Pourbaix diagrams have been constructed to understand the stability of this complex system under various Eh and pH conditions. The experimental results indicate that IRA-400 resin has the highest capacity for both silver and gold compared to IRA-68 and IRA-94. All the three resins investigated are not selective to silver and gold over copper. The elution studies using ammonium thiosulfate solutions have revealed that selective elution of silver from copper is not possible, while some selectivity can be achieved between gold and copper. (Abstract shortened with permission of author.)