technical report on the nechalacho deposit, thor lake project ...

Table 14-4: Comparison of Niobium, Tantalum and Zirconium Analyses
Comparison of Method to Mean of All Analyses
Standard Lab Method N Nb Ta Zr
STD-L ALS MS81 188 100% 99% 101%
STD-L ALS MS81H 19 101% 100% 101%
STD-L Acme Method 4A 98 103% 91% 103%
STD-L ALS XRF 43 104% 73% 106%
Average in ppm 1,383 144 9,750
STD-M ALS MS81 153 103% 98% 66%
STD-M ALS MS81H 87 101% 96% 95%
STD-M Acme Method 4A 121 109% 90% 106%
STD-M ALS XRF 46 109% 88% 115%
Average in ppm 2,196 227 14,087
STD-H ALS MS81 112 100% 100% 66%
STD-H ALS MS81H 99 98% 96% 111%
STD-H Acme Method 4A 224 98% 95% 111%
STD-H ALS XRF 21 98% 98% 120%
Average in ppm 2,676 301 17,234
STD-H2 ALS MS81 285 96% 36% 29%
STD-H2 ALS MS81H 182 95% 124% 100%
STD-H2 Acme Method 4A 38 93% 99% 80%
STD-H2 ALS XRF 220 94% 124% 100%
Average in ppm 4,132 313 34,323
Note: cases with analytical limits removed
The results indicate the following:
• For the low grade standard (STD-L), all methods (Acme and ALS) give similar results for
Nb and Zr, but XRF appears to give anomalously low results for Ta. The cause of this is
not known. Standard STD-M is similar.
• For higher grade Zr samples (>1%), MS81 does not give correct results due to analysis
upper limits, however, for Nb and Ta (with the exception of standard H2/S-04-09) the
results are satisfactory.
• Except for standard H2/S-04-09, Zr values are 6% to 20% higher with XRF than the
average of all analyses from all labs.
In addition, XRF10 analyses generally show very low standard deviations.
Technical Report 43-101 – March 13, 2011 Page 14-6
Prepared by Avalon Rare Metals Inc.