Improvements in Wastwater Treatment at the Leadville Mine Drainage Tunnel

New Mexico State University; Las Cruces NM.
June 2002

Report #47 - Conclusions -

This research produced numerous conclusions on low temperature studies, remediation studies, and on magnetic separation studies. The report documents these findings. Schematics of modes of magnetic treatment, a magnetic separator, and a proposed pilot treatment plant for the Leadville Mine Drainage Tunnel (LMDT) plus an electron micrograph of separator matrix material are found in the report. Major points of the study may be summarized as follows:

1. We have established that the use of magnetites to remove heavy metal contaminants is effective regardless of the mode of application. The relative order of efficiency is in-situ > preformed (laboratory prepared) > commercial (activated) > commercial (unactivated).

2. The binding of heavy metals to magnetites may be able to be enhanced with the selective use of organic chelators. The aspects requires further examination before its practicality can be established.

3. The use of remnant field magnets to perform magnetic separations has been firmly established. These fields appear stable over month-long time periods and the use of inexpensive stainless steel wool matrices is warranted.

4. Separation of 5 micron size particles is effective using these remnant field magnetic separators. Both loading and unloading of the magnetic separator can be controlled by flow velocity and gas sparging, respectively.

This study has provided ample evidence for the use of a novel method for the remediation of heavy metals from a waste stream that requires inexpensive materials and equipment. Because the wastes generated from this approach are less, more compact and robust with respect to leaching (earlier studies), the disposal costs associated with this technique should be reduced as well. Based on the studies described in this report, we feel that taking this work to a small test facility is now both feasible and appropriate.

CONTACT US

For more information about the DWPR program, contact Kevin Price at: Bureau of Reclamation, D-8230, PO Box 25007, Denver CO 80225; phone (303) 445-2260; or e-mail a message to kprice@do.usbr.gov.