Rare Element Resources
Bear Lodge Project
Canadian NI 43-101 Technical Report
October 9
th
, 2014
10135-200-46 - Rev. 0
13-39
Figure 13.14 - PP1 Precipitation efficiency vs. Oxalic Acid Dosage (g/L feed solution).
Excess oxalates were not recycled.
(SGS Lakefield, 2014
)
Thorium precipitation was close to 100% regardless of oxalic acid dosage and
uranium precipitation was below 5% throughout the campaign. Oxalic acid selectivity
against base metals was proven during this campaign. Base metals precipitation
efficiencies were close to zero for most of them. Occasionally, low precipitation
efficiency was observed due to the lack of oxalic acid recycling (crystal pump failure)
or blocked pipes and unscheduled pilot plant maintenance.
(SGS Lakefield, 2014)
Oxalates were effectively recycled in PP6 and PP7 campaigns to lower the fresh
reagent requirement. The reagent consumption in PP6 and PP7 campaigns was
36% to 59% lower than PP5. Oxalates were not recycled in the PP5 campaign. In
0
10
20
30
40
50
60
70
80
90
100
La Ce Pr Nd Sm Eu Gd Tb Dy Ho Y Er Tm Yb Lu Th U
Precipitation (%)
161 g/L Oxalic Acid
157 g/L Oxalic Acid
136 g/L Oxalic Acid
118 g/L Oxalic Acid
85 g/L Oxalic Acid
74 g/L Oxalic Acid
0
10
20
30
40
50
60
70
80
90
100
0
50
100
150
200
REE Precipitation (%)
Oxalic Acid Dosage (g/L)
Campaign ID
PP5
PP6
PP6
PP7
PP7
COMP B COMP C COMP A COMP E COMP D
PL Run + Downtime h
109
51
60
38
72
Precipitation Feed
L/h*
2.01
2.10
2.15
1.89
2.11
Pre-Leach Feed
kg/h*
0.52
0.60
0.71
0.44
0.62
Reagent
H
2
C
2
O
4
H
2
C
2
O
4
H
2
C
2
O
4
H
2
C
2
O
4
H
2
C
2
O
4
Reagent usage
kg/h*
0.15
0.07
0.11
0.08
0.12
Consumption
g/L**
76.2
34.9
51.1
40.7
55.1
Consumption
kg/t***
296
121
155
175
189
* rates are averages fromentire campaign; normalized to PL Run + Dow n Time
** g of reagent @ 100% per liter of precipitation feed
*** kg of reagent @ 100% per tonne of dry composite
Table 13.21
-
Reagent consumption in oxalate precipitation circuit
