Case
Study
ELECTRONICS MANUFACTURING
Electrowinning Process to Increase Silver Recovery from Spent Fixer
| Company | NTI, Colorado Division 6035 Galley Road Colorado Springs, CO 80915 |
|---|---|
| Person to Contact | Frank Gorman, Tech. Director Telephone: (719) 574-4905 |
| Product or Service | Circuit Boards |
| Number of Employees | 306 |
| Waste Stream Targeted | Silver Waste |
| Original System | Silver Cementation Process using canisters. Limited the amount of silver recovered. |
| New System (with P2 Modifications) |
Installed an electrowinning (electrolytic recovery) unit prior to the silver cementation canisters. Increased silver recovery from spent fixer to 98% efficiency. Electrowinning is the recovery of the silver content from solution using an electroplating process. Cathodes made of thin starter sheets of the metal being recovered, or stainless steel blanks from which the recovered metal can be stripped, are mounted in an open tank. As the current passes from the anode to the cathode, the metal deposits on the cathode. With electrowinning added in series prior to canister cementation, NTI experienced a longer effective life for the canisters and improved recovery efficiency. |
| Cost Savings | With the cost savings on canister usage and 98% silver recovery, savings are ~$2,000/year. |
| Major Benefits | Minimization of silver discharged. ~$2,000 savings (canister usage and high silver recovery). Improved business image. |
| Obstacles | none |
| Time Since Implementation | 2 years (3/21/95) |
| Source/Supplier | Silver Recovery, Inc. 604 2nd Street Berthoud, CO 80513 |
| Main Reason Implemented | Silver discharge control and recovery value. |
| Key to Success in Making this P2 Modification | Management commitment/support. Operator involvement - sharing of data and information with waste treatment operators. |
Created by Lighthouse Communications Group, LLC.
Edited for use on this site by Ronald Lee Still and posted with
permission of CDPHE.