Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

Pyrometallurgy: Roasting, Smelting, Refining & Electrowinning

  • To participate in the 911Metallurgist Forums, be sure to JOINLOGIN
  • Use Add New Topic to ask a New Question/Discussion about Pyrometallurgy and Electrometallurgy.
  • OR Select a Topic that Interests you.
  • Use Add Reply = to Reply/Participate in a Topic/Discussion (most frequent).
    Using Add Reply allows you to Attach Images or PDF files and provide a more complete input.
  • Use Add Comment = to comment on someone else’s Reply in an already active Topic/Discussion.

Recycle metal PCB by hydrometallurgy process (1 reply)

A
Amir
7 years ago
Amir 7 years ago

 

I recycle metal (gold. Silver and palladium) from pcb by hydrometallurgy process.

Before i dismantled component  from pcb with  air hummer. But now i decided chemically by  organic solution  like  alkane sulfonic acid and glycol ether  selectively dissolve solder. And then use electrowinning to separate solder from solution .  Given that reduction potential of tin and lead closer together.

Is it possible  to separate tin and lead  by electrowinning?

How is doing this?

 

David
7 years ago
David 7 years ago

Amir, this may help (not perfectly) ...but have a read to https://www.911metallurgist.com/blog/electrolytic-method-recovery-lead-scrap-batteries page 14 talks on Tin separation of Lead.

Fortunately, tin is one of the easiest elements to remove from lead. During melting of the cathodes, tin will report to the dross on top of the molten lead and will be removed as the dross is skimmed prior to casting the lead in the desired form for market.

While sulfuric acid was not a suitable leachant for the dissolution of metals from PCBs, hydrochloric acid selectively dissolved tin.

A report I saw says crushed PCBs were leached in HNO3 to dissolve the metallic values in leaching reactor under the controlled experimental conditions.

It is seen that the recovery of copper increased with an increase in the concentration of HNO3 and time. Where, the minimum copper recovery with 2M, 4M and 6M HNO3 in 10 minutes was 23.21%, 63.76% and 90.46%, the maximum copper leaching was found to be 63.92%, 90.67%, and 99.99% respectively in 75 min. The leaching reaction was found very fast for all the metals except tin. The total Fe and Ni was leached within 10 minutes whereas 38% Pb leached in 40 minutes. Lead present in the PCBs as solder material, which is the mixture of Pb and Sn. The formation of tin complex on the surface of lead may prevent the dissolution of lead with nitric acid. The leaching of Sn was very poor with nitric acid even at elevated temperature and acid concentration (6M). A mixture of salts as tin complex appears with residue during the leaching. Nitric acid dissolves tin readily and forms hydrated stannic oxide, SnO2 often called metastannic acid (H2SnO3).

REF: Leaching Studies for the Recovery of Metals from the Waste Printed Circuit Boards (PCBs) by Jha, Manis Kumar by The Minerals, Metals and Materials Society, Jan 1, 2010

Use the Social Share Bar on the Left. Tell everyone you can about https://www.911metallurgist.com/metallurgy/ It's FREE & GOOD.

Please join and login to participate and leave a comment.