NI43-101Pre-Feasibility Study Report - page 156

Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
, 2014
10135-200-46 – Rev. 0
host. Average core recovery in the oxidized zone was improved significantly during
the 2009 drilling program to better than 80%, owing to consultation with Clint Johnson
of Western Mud Services, the Godbe Drilling mud engineer, and a consequent
change in the mud formula for drilling in the oxidized zone. Through 2009 core
recovery in the transitional and un-oxidized carbonatite zones was generally ≥ 90% to
100%. In 2010, 2011, and 2012 Godbe Drilling continued to focus on improving
recoveries in the oxide zone. During these drilling campaigns, recoveries of FMR
dikes and veins averaged 80% in the oxide zone and 88% in the oxide-carbonate
zone. Recoveries of carbonatite/silicocarbonatite dikes and veins (transitional and
sulfide zones) averaged 94%. In 2011, when a higher proportion of stockwork was
drilled, particularly in the area of Bull Hill West, recoveries of stockwork FMR in the
oxide and oxide-carbonate zones averaged 83%. Recoveries in 2012 were variable,
but similar to those achieved previously. Average 2012 drill hole recoveries for the
stockwork-dominated zone west of Bull Hill ranged between 69% and 93% per hole,
and averaged 81% for the area, while Whitetail Ridge recoveries ranged between
77% and 94% per hole and averaged 86% for the area. Analysis of relative
recoveries in the different resource areas and oxidation zones is ongoing. Recoveries
using HQ diameter core for the 2013 drilling at Whitetail Ridge ranged from 79 – 92%
and averaged 87.1 percent.
The recovery issues with FMR in HQ core suggested the use of PQ core for bulk
sampling of FMR and oxide-carbonate material for metallurgical testing. Friable FMR
zones generally maintain integrity much better in PQ than in HQ core, owing to the
larger diameter of the PQ core. The higher volume of material contained in PQ-size
core appears to better absorb the torque of bit rotation, with consequently less
material lost to “plucking” of FMR veins and stockwork on the core surface. While this
was the case for PQ core drilling conducted through 2012, recoveries were somewhat
poorer and exhibited more variation in the 2013 Bull Hill high-grade infill program.
Core recoveries in this program averaged 86.8% and ranged between 77 and 92
Minimal material was returned to the surface in a small subset of intervals from all drill
holes in the FMR material, owing to extreme friability and loss of material in voids,
possibly related to zones of structural disruption, fracturing related to stockwork
mineralization, or voids related to dissolution of matrix carbonate. Local analytical
bias resulting from poor recoveries in the FMR zones is likely and is under
investigation. A case can be made for under-representation of grade in areas with
poor recoveries, as well-mineralized but poorly consolidated material might be
washed away during the drilling process. ORE suggests that this might be the most
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