|
ff DIVISION OF RECLAMATION, MINING AND SAFETY
<br />Department of Natural Resources
<br />1313 Sherman St., Room 215
<br />Denver, Colorado 80203
<br />Phone: (303) 866-3567
<br />FAX: (303) 832-8106
<br />?March 14, 2008
<br />5TATE OF COLORADO
<br />RM=I / D
<br />MAR 17 2008
<br />Division of keciamation,
<br />Mining and Safety
<br />COLORADO
<br />D IV IS I ON OF
<br />RECLAMATION
<br />MINING
<br />SAFETY
<br />Bill Ritter, Jr.
<br />Governor
<br />Harris D. Sherman
<br />Harold Luzar Executive Director
<br />-rtl Mine Development, Inc. Ronald W. Cattany
<br />X3319 E 4th Ave. Division Director
<br />Durango, CO 81301 Natural Resource Trustee
<br />Re: Neglected Mine, Permit No. M-1981-165, Technical Revision (TR-3) for New Leaching Process,
<br />Preliminary Adequacy Review Letter, and Extension of Decision Date.
<br />Dear Mr. Luzar,
<br />This office has begun the review of the above-named technical revision, regarding the testing of a new leaching
<br />process at the Neglected Mine. Your submittal, received on February 27, 2008 described a process involving
<br />several chemicals that will be used singly and in combination. I have discussed the revision application with our
<br />staff geochemist in Denver, and our discussion has revolved around issues of quantities and concentrations of
<br />these chemicals, as well as their storage and use, the types of containment, and the proximity to surface and
<br />ground water. Our collective questions and comments appear in the following paragraphs, along with citations
<br />of the pertinent sections of the Hard Rock/Metals Rules, which I encourage you to refer to.
<br />1. The chemicals named in the technical revision include: sodium bromide, sodium chloride, potassium
<br />monopersulfate, potassium persulfate, sodium borohydride, sodium hydroxide, and hydrochloric acid. Review
<br />of the MSDS literature concerning several of these substances reveals their individual inherent hazards and
<br />toxicities. Given the characteristics (such as pH, reactivity, toxicity, corrosivity, flammability) of these
<br />chemicals, it is a misnomer to label this ore processing method as "non toxic." Indeed, poor handling or
<br />inadvertent spills or releases could result in adverse impacts to human health, wildlife, the soil or water, either
<br />onsite or possibly offsite. When considered solely by their toxic producing characteristics and potential effects,
<br />these chemicals should be regarded as designated chemicals, pursuant to Rules 1.1(1) and 1.1(13).
<br />2. The proposed pilot phase of processing the ore with these chemicals will not initially require huge quantities
<br />of these chemicals, but the amounts are nevertheless larger than what an onsite assay lab would require. As an
<br />example, an onsite assay lab may have comparably toxic processing chemicals present, but usually is not
<br />considered to have "designated chemicals" onsite, due to the smaller quantities. In Rule 7.2.6(1) the distinction
<br />is made between the. lesser quantities required for assaying and the larger quantities needed for extractive
<br />metallurgical processing involved with production. Even though this pilot project is not the full-scale extraction
<br />that may be implemented in the future, the amounts needed in the proposed test of this leaching process appear
<br />to be sufficient to adversely affect human health, property or the environment.
<br />3. The technical revision described the storage of the chemicals as being within the mill building. Please
<br />describe the storage conditions and actual containment inside the building.
<br />4. Assuming that 2,000 pounds of ore constitutes a single test run, how many test runs of this.process do you
<br />propose to perform? What is the expected total volume of tailings to be generated by the entire project?
<br />Office of Office of
<br />Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines
|