Recovery of lead from battery scrap

• US 3,940,265 A
• Filed: 06/25/1975
• Issued: 02/24/1976
• Est. Priority Date: 06/25/1975
• Status: Expired due to Term

• Current Assignee: The United States of America as represented by the Secretary of the Interior
• Original Assignee: The United States of America as represented by the Secretary of the Interior
• Inventors: Wilson, Donald A.
• Primary Examiner(s): Andrews, M. J.
• Application Number:
  US05/589,999
• Time in Patent Office: 244 Days
• Field of Search: 75/77, 75/120
• US Class Current: 75/432
• CPC Class Codes: C22B 13/02 by dry processes
• CPC Class Codes: C22B 13/045 Recovery from waste materials
• CPC Class Codes: C22B 5/10 by solid carbonaceous reducing agents
• CPC Class Codes: C22B 7/001 Dry processes
• CPC Class Codes: Y02P 10/20 Recycling

Abstract

Lead is recovered from battery scrap by means of a process comprising (1) reacting the scrap with a slurry of calcium hydroxide to form a product comprising PbO and CaSO₄.2H₂ O, (2) filtering and drying the reaction product and (3) reacting the product with a mixture of carbon and a KCl-NaCl flux at elevated temperature to flux the calcium sulfate and reduce the lead oxide to metallic lead.

Claims

1. A process for recovery of lead from lead battery scrap comprising (1) reacting the scrap with an aqueous slurry of calcium hydroxide to form a product comprising lead oxide and calcium sulfate, (2) filtering and drying the reaction product and (3) reacting the product with a mixture of carbon and a KCl-NaCl flux at a temperature of about 605°

to 700°

C to flux the calcium sulfate and reduce the lead oxide to metallic lead.

2. The process of claim 1 in which the carbon consists essentially of charcoal in the form of a powder.

3. The process of claim 1 in which the KCl and NaCl in the flux are added in proportions suitable for formation of a KCl-CaSO₄ -NaCl eutectic mixture.