| Synthetic mattes of different nickel to copper ratios, containing 20% mass per cent sulfur were slowly cooled from the liquid state to room temperature. The resulting morphology of the matte was examined using optical and scanning electron microscopy. Chemical analysis was performed by use of the electron microprobe. Three phases were observed, Cu2S, Ni 3S2 and a Cu-Ni alloy. The effect of arsenic, up to 1 mass per cent, on the morphology and elemental distribution was studied. It was found that arsenic decreased the size of Cu2S and Cu-Ni gains. Arsenic also contributed towards the formation of cellular morphology and tended to concentrate in the metallic phase. A mechanism is proposed to account for the change in matte morphology when small amounts of arsenic are present in the system. |
