Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 – Rev. 0
11-7
Fusion digestions show improved accuracy and precision for REE analyses over
analytical methods using 4 acids. Fusion digestions are “total” digestions that are
more destructive to the sample matrix than variants of 4-acid digestions. Four-acid
digestions are also considered by the industry to be “total” digestions. However, this
is not necessarily so, as some resistate mineral phases which contain REE are not
truly digested in their entirety. Fusions are far better at destroying these resistate
mineral matrices and releasing REE contained therein. The analyses from the 4-acid
digestions display poorer accuracy and precision as a result of the less effective
digestion and incomplete digestion of the resistate phases, thus the 4-acid data were
not used for certification of the standards.
Standards RE09007X and RE01001X-RE1004X were certified using lithium
metaborate fusions with ICP-OES finish.
11.4.4 Determination of Certified Values
The means and standard deviations were calculated for all of the analytical data for
each standard material.
11.5 2007-2008 Assay Quality Control
Rare Element enacted a quality control program in 2007 concurrently with the change
of analytical laboratories from ALS Chemex to Activation Laboratories. The program
included the assay of blank samples to monitor possible contamination, assays of
internal standards provided by Actlabs, and assay of analytical duplicate samples.
The quality control program was expanded in the 2008 drilling sample assays to
include more blank and duplicate samples.
11.6 2009-2013 Assay Quality Control
At the request of Rare Element, Dr. Jeffrey Jaacks of Geochemical Applications
International Inc. (GAII) conducted a review of the results for the quality assurance
and quality control (QA/QC) program used in rare earth element assaying for the Bear
Lodge exploration drill programs conducted during 2009 and 2012-2013 at Activation
Laboratories and drill programs conducted during 2010-2011 at ALS Laboratories.
Quality control data reviewed herein include standards, blanks, preparation (crush),
and analytical (pulp) duplicate results, as well as the 2010-2013 check analysis
program results.
