The acid consumption tests are being conducted by independent consultant Mountain States R&D International, Inc. of Tucson, Arizona under the supervision of Dr. Ronald J. Roman of Leach, Inc., Tucson, Arizona. Dr. Roman has reviewed and approved the technical information disclosed above in this news release and is an independent consultant who is a Qualified Person (QP) as defined by National Instrument (NI) 43-101. Dr. Roman has verified the data underlying the test results by designing the test procedure, supervising the test work, obtaining all the analytical data over the life of the experiment and performing the calculations presented above.
Submerged leach tests details
Submerged leach testing employs a protocol similar to column leach testing but modified to more closely reflect conditions during in-situ leaching. These tests were designed to be repeatable, and to evaluate the response of mineralization to in-situ leaching at different flow rates and acid concentrations.
To date, five of the 13 tests have been completed and the results are presented in Table 2 below. The remaining eight tests are still under active leaching and are expected to conclude in the next 30 to 60 days. The five tests completed are from the Lower Abrigo rock formation.
Higher acid concentrations (e.g. column 9) and/or longer leach times (e.g. column 13) generated higher recoveries, indicating 100% acid soluble copper is recoverable given sufficient time, acid concentration and economics.
Table 2. Results from submerged leach tests on the Lower Abrigo formation.---------------------------------------------------------------------------- Head Grade(1) Recovery, % Cu % -------------- --------- Flow Acid Acid Cu Cu acid rate(2), content(3), Days Cu acid Consumption(5)Column total soluble lph/m2 gpl acid leached(4) soluble lbs/lbs----------------------------------------------------------------------------9 0.31 0.23 22 15 61 95 19----------------------------------------------------------------------------10 0.33 0.26 37 10 49 85 12.6----------------------------------------------------------------------------11 0.28 0.21 22 10 61 87 17.3----------------------------------------------------------------------------12 0.29 0.21 22 5 61 82 9.7----------------------------------------------------------------------------13 0.28 0.20 11 5 99 92 12.6----------------------------------------------------------------------------1. Calculated head grade2. Flow rate in litres per hour per cross-sectional square metre3. Acid concentration in grams per litre of free acid4. Days leached includes one or two days of post leach rinsing but does not include the extended post leach rinsing period5. Acid consumption in pounds of acid consumed per pound of copper recovered
The submerged leach tests are being conducted by independent laboratory SGS Metcon of Tucson, Arizona under the supervision of Dr. Ronald J. Roman, an independent consultant who is a Qualified Person as defined by NI 43-101. Dr. Roman has reviewed and approved the technical information disclosed in this news release. Dr. Roman has verified the data underlying the test results by designing the test procedure, supervising the test work, obtaining all the analytical data over the life of the experiment and performing the calculations presented above.
