Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
13-46
that acid levels in the feed were high initially (90-100 g/L HCl), but drop down to 41
g/L by Cycle 9. The situation improved and acid in the feed rose back to 60 - 70 g/L
HCl for the remainder of the pilot operations.
Acid addition to the leach circuit affects free acid availability in the feed to the
distillation column. Changes in acidity of PLS are also affected by changes in oxalic
acid addition or a drop in Fe III ions assays in the leach solution.
(SGS Lakefield, 2014)
Table 13.26 shows the composition of REEs (average = 0.21%TREE) in the
crystallized oxalates out of the distillation bottom liquor. Recycling oxalates improves
overall recovery of REEs depending on the mass of solids recycled.
Cycle La Ce Pr
Nd Sm Eu Gd Tb Dy Ho Y Er
Tm Yb Lu Sc Th U TREE
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
g/t
2 977 1230 114 350 40.6 8.40 20.3 0.80 5.30 1.20 23.0 1.90 0.60 1.50 0.80 <25 6.50 6.10 2775
3 1400 1800 173 521 63.6 14.0 30.2 3.70 12.0 2.20 49.0 3.90 1.10 2.80 1.10 <25 13.3 15.3 4078
4 3570 3050 291 695 66.0 12.6 28.7 3.60 15.4 2.50 140 7.10 1.10 5.90 1.00 <25 4.70 27.3 7890
6 1000 688 62.5 169 19.4 4.20 10.6 1.00 3.40 0.60 20.0 1.10 <0.3 0.70 <0.5 <25 7.60 7.20 1981
7 802 492 38.3 92.5 6.60 1.90 3.70 <0.5 0.90 0.70 16.0 <0.5 0.6 <0.5 0.6 <25 1.00 6.30 1457
9 578 358 37.6 119 15.8 3.60 8.50 0.60 2.60 0.30 13.0 0.80 <0.3 0.60 <0.5 <25 6.00 15.4 1139
10 235 113 8.00 22.0 2.10 0.50 1.90 <0.5 1.20 0.30 <10 0.50 <0.3 0.60 <0.5 <25 0.70 10.0 396
11 581 421 30.3 79.0 9.00 2.30 5.30 1.20 2.10 1.00 11.0 1.40 0.80 1.00 0.7 <25 3.80 22.6 1147
12 243 151 9.50 27.0 2.00 0.90 2.00 5.00 2.70 0.60 10.0 1.20 0.30 0.90 0.5 <25 2.00 6.40 457
13 538 322 31.6 81.0 7.10 1.50 4.00 <0.5 1.90 0.40 19.0 1.00 <0.3 0.80 <0.5 <25 0.90 6.00 1010
14 170 104 10.1 28.0 3.80 1.00 2.30 <0.5 1.10 0.40 <10 0.60 <0.3 0.60 <0.5 <25 1.70 3.30 333
15 626 335 27.4 63.0 5.80 2.00 4.40 1.20 2.10 1.20 14.0 1.50 1.10 1.70 1.10 <25 2.00 6.90 1088
16 3300 1600 102 225 13.0 2.40 9.00 5.00 3.60 0.80 44.0 2.30 0.40 1.80 0.50 <25 2.30 42.2 5310
17 315 110 5.8 13.0 1.00 0.30 1.00 5.00 0.60 0.30 10.0 0.50 0.30 0.50 0.50 <25 0.50 3.60 464
AVERAGE
1213 818 67.6 175 17.1 3.89 9.40 2.64 3.92 1.07 28.8 1.87 0.73 1.57 0.86 33 4.02 15.55 2109
MIN 170 104 5.80 13.0 1.00 0.30 1.00 <0.50 0.60 0.30 <10.0 <0.50 <0.30 <0.50 <0.50 <25 0.50 3.30 333
MAX 3570 3050 291 695 66.0 14.0 30.2 5.00 15.4 2.50 140 7.10 1.10 5.90 1.10 25 13.3 42.2 7890
REVSTD 105% 112% 120% 117% 121% 112% 105% 92% 112% 78% 125% 103% 60% 102% 36% 0% 95% 87% 105%
Table 13.26 - Composition of Oxalate Crystals Recovered from Distillation Residual
Solution (Recycled)
