I want some insight from expert on the separation of copper (1.6wt%) from lead and tin alloys. Is there any method to reduce concentration of copper below 0.006wt%?
Dear Abdul Khaliq
As far I can deduce from the respective phase diagrams (Pb -Cu and Sn - Cu) the Cu-solid solubility in Pb and Sn is very low, at least smaller than 1.6 wt% Cu. By very slowly and repeatedly moving a melted zone through a bar of the Pb or Sn alloy from which Cu has to be removed, most of the Cu-atoms will eventually be gathered in one end of the mentioned bar by virtue of the fact that Cu solubility in the liquid is larger than in the solid phase. The experimental parameters (rate of the moving melt region, temperatures, vacuum pressures and number of repetitions) of this approach will depend on the melting technique adopted. However, the lower limit attainable by this repeated melting technique is determined by the respective solid solubilities as given by the study of the respective phase diagrams.
Dear Van,
I appreciate your brief reply. I do agree with this technique. My client has tonnes of waste that he want to process. He has certain limitations with this current set-up. Is there any chances of cascade mould castings? Overall, I do understand the method you narrated as such techniques are also used to produce ultra-refine aluminium as well.
Or other possible approach is to add third element and produce immiscible phase. I thinking of exploring thermodynamic approach to predict stability at various pO2, temperatures and reactive elements additions.
Lets see.....
Cheers
Abdul
Dear Abdul Khaliq,
I agree that zone refining as indicated in my above answer cannot cope with such large amounts of waste. The approach of creating immiscible Cu-containing phases has certainly to be explored. It may be worthwile to envisage the electochemical route, as Cu and Pb/Sn hold quite different positions in the standard electrochemical series.
I also agree with the electrochemical separation. This will be easier and cost effective.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Inorganic Materials
- Metals
- Alloys
- Steel