| 摘要 |
<p>PROBLEM TO BE SOLVED: To make it possible to separate and recover an Ni-Si based alloy and metallic Sn by adding an SiO2 -contg. material and a reducing agent to a solder-contg. nickel alloy and subjecting the mixture to reduction melting in a a specific temp. range under a strong reduction atmosphere under which Si is stable. SOLUTION: The SiO2 component, such as silica stone, as an Si source and coke, etc., as the reducing agent are added to the solder-contg. nickel alloy and the mixture is sufficiently mixed and is charged into a graphite crucible. This graphite crucible is heated in a temp. range of >=1400 to <=1600 deg.C under the strong reduction atmosphere under which the Si is stable in a high-frequency induction heating furnace to melt and reduce the mixture. At this time, the Si grade in the Ni-Si based alloy is preferably controlled to 15 to 35 wt.%, more preferably 30 to 35 wt.%. When the melting and reducing of the mixture ends, the mixture is held at the prescribed temp. and is then cooled to cause phase sepn. As the result, the Ni-Si based alloy of a low Sn grade and the high-grade Sn are separated and recovered at a high yield. Particularly the Si grade in the Ni-Si based alloy is controlled to 30 to 35 wt.%, by which the Sn grade is confined to about <=3%.</p> |
