NIOSHTIC-2 Publications Search

Process for recovering silver, copper, and stainless steel from silver brazed stainless steel sections.

Dunning-BW Jr.; Chambers-DH
U.S. Pat. 4,090,935 1978 May; :1-8
An electrolytic refining process is used for recovering ag, cu, and stainless steel from stainless steel honeycomb sections from military aircraft brazed with ag-base alloys. The brazed sections consist of ag 5-30, cu 2-15 wt pct, and the balance stainless steel. Thus, ag-brazed stainless steel aileron sections were sheared, shredded, and screened. The anode basket was filled with +30 mesh pieces. The electrolytic refining cell contained the anode basket, which was enclosed by a cylindrical sheet stainless steel cathode. The cell contained an electrolyte solution of copper nitrate and silver nitrate. The refining was carried out at 30 a d.C. and 0.1- 5.0 V. The anode basket was rotated at 0.5-5 Rpm. The deposited ag was scraped, washed, dried, and magnetically separated from possible stainless steel fines. The resulting ag was 95-99 pct pure and was further purified. The stainless steel in the anode basket was washed and dried. The copper nitrate solution was used as the electrolyte in a refining cell, and cu was deposited on the cathode. The anode mud consisted of stainless steel and possibly pd and ag.
Publication Date
Document Type
PA; Patent
Fiscal Year
Identifying No.
PAT 4,090,935
NIOSH Division
Source Name
U.S. Pat. 4,090,935
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division