2013-04-19_REVISION - M1990057

• Permit No: M1990057
• IBM Index Class Name: REVISION
• Doc Date: 4/19/2013
• Doc Name: 110‎(d)‎ PERMIT APPLICATION
• Media Type: D
• Archive: No

The Leadville Mill
4.6 ORE BUYING ACCEPTANCE CRITERIA
4.6.1 GENERAL INFORMATION
M1990-057
EXHIBIT C — MILL PLAN
Page 4 -21
UMC's Ore Buying Program is designed to fill mill capacity with high quality ores. Ore
must meet specific metallurgical criteria.
• Ores must be amenable to conventional mill concentration methods
• Ores will be tested for grade, and deleterious substances prior to being
accepted. If ores are not acceptable, no purchase contract will be offered to
the supplier.
• Initial sample testing will require a 30 -501b sample that is representative of
the ore to be mined and shipped. This will be crushed, blended and fire
assayed for precious metal values and a 40- element ICP analysis performed
for other metals and contaminants. Assays and analyses will be reviewed to
determine if the material meets the ore criteria and a report will be sent to
the supplier.
• If tests show ore does not meet purchase criteria, no further work will be
performed.
• If ore meets purchase criteria, metallurgical tests will be performed to
determine process and general amenability to the Mill. A metallurgical report
will be prepared and sent to the supplier, advising whether the ore is suitable
for processing.
• UMC will reserve the right to modify these requirements at any time.
4.6.2 ORE BASELINE ANALYSIS LIMITS
Sampling tests are completed for each sample of custom ore brought to the Mill. An
elemental scan (4 acid digestion ICP analyses) determines elemental concentration
on a range of metal and non - metals in the sample. Certain ores may be rejected
based on metallurgical or environmental constraints.
Version 1.0 April 2013