VANCOUVER, May 9, 2012 /CNW/ - Search Minerals Inc. ("Search" or the "Company") (TSXV: SMY) and its wholly-owned subsidiary, Alterra Resources Inc., are pleased to announce the completion of metallurgical tests on a bulk sample from the Foxtrot Project to produce a high grade REE product for refining.
Highlights:
A 1250 kg sample of Foxtrot mineralization was prepared from surface channel samples taken at the Foxtrot site. The channel samples were obtained from surface mineralization. The head analysis of the sample sent to SGS Minerals Services is compared to the recently announced indicated and inferred resource numbers for the Foxtrot Project in Table 1 below. The values for the REE's and Y are very close to the reported resource values.
Jim Clucas, President of Search Minerals, stated "The Foxtrot success story continues from outstanding drill results to excellent metallurgical test results. The SGS recommendation to proceed quickly to continuous metallurgical pilot plant in keeping with the remarkable pace of development of this project."
The sample is deemed representative of the Foxtrot Project mineralization for the purposes of metallurgical testing.
Table 1. Indicated and Inferred Resource Values Compared to Channel Sample Analysis
Tonnes | Indicated | Inferred | Channel Sample | |
t | 3,410,000 | 5,850,000 | 1.25 | |
Oxide | Units | Indicated | Inferred | Metallurgical |
Y2O3 | ppm | 1,345 | 1,290 | 1,404 |
La2O3 | ppm | 1,946 | 1,716 | 1,771 |
CeO2 | ppm | 4,138 | 3,657 | 4,372 |
Pr6O11 | ppm | 466 | 414 | 516 |
Nd2O3 | ppm | 1,687 | 1,494 | 1,750 |
Sm2O3 | ppm | 298 | 268 | 338 |
Eu2O3 | ppm | 15 | 13 | 16 |
Gd2O3 | ppm | 234 | 216 | 260 |
Tb4O7 | ppm | 39 | 36 | 43 |
Dy2O3 | ppm | 218 | 208 | 257 |
Ho2O3 | ppm | 42 | 40 | 50 |
Er2O3 | ppm | 116 | 114 | 140 |
Tm2O3 | ppm | 17 | 17 | 20 |
Yb2O3 | ppm | 103 | 106 | 117 |
Lu2O3 | ppm | 15 | 16 | 17 |
ZrO2 | ppm | 13,014 | 13,746 | 21,687 |
Nb2O5 | ppm | 879 | 796 | 1,015 |
LREO | % | 0.85 | 0.75 | 0.87 |
HREO | % | 0.21 | 0.21 | 0.23 |
TREO | % | 1.07 | 0.96 | 1.11 |
Notes:
MINERALOGY STUDIES
A bulk sample obtained from a Fox Harbour channel sample was submitted to the Advanced Mineralogy Facility (AMF) at SGS Minerals Services (Lakefield Site). The sample was stage crushed to K80 of 150 μm and then screened into two size fractions: +38μm and -38μm for the mineralogical study. A micro-riffled sub-sample of each size fraction was submitted for whole rock analyses. Two graphite impregnated polished epoxy grain mounts were prepared from the coarse fraction and one from the fine fraction, and submitted for QEMSCANTM analysis. The mode of QEMSCANTM analyses used for this project were the Particle Mineral Analysis (PMA) and Specific Mineral Search (SMS). The minerals identified in the sample are listed in Table 2.
Table 2 - Mineral List and Formulas
Mineral | Mineral Formula | Mineral | Mineral Formula |
Columbite(Fe) | (Fe,Mn)Nb,Ta2O6 | Plagioclase | (NaSi,CaAl)AlSi2O8 |
Bastnasite | (Ce, La)CO3F | K-Feldspar | KAlSi3O8 |
Synchysite | Ca(Ce,La)(CO3)2F | Biotite | K(Mg,Fe)3(AlSi3O10)(OH)2 |
Monazite | (Ce,La,Pr,Nd,Th,Y)PO4 | Quartz | SiO2 |
Chevkinite | (Ce,La,Ca,Th)4(Fe2+,Mg)(Fe2+,Ti,Fe3+)- (Ti,Fe3+)2(Si2O7)2O8 |
Muscovites/Clays | KAl2(AlSi3O10)(OH)2 |
Fergusonite | (Y,Er,Ce,Fe)NbO4 | Amphibole/ Pyroxene |
(Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6 |
Allanite | (Ca,Ce)2(Fe2,Fe3+)Al2O- (SiO4)(Si2O7)(OH) |
Carbonates | CaCO3 |
Zircon | ZrSiO4 | Fluorite | CaF2 |
Apatite | (Ca,Ce,Y)5(PO4,SiO4)3(F,Cl,OH) | Hematite Ilmenite Magnetite |
Fe2O3 FeTiO3 Fe3O4 |
Mineral Abundance by QEMSCANTM
Data for the modal abundance of the minerals and elemental distribution are based on the PMA. Figure 1 illustrates the normalized mass % of the REE minerals (excluding zircon). It is apparent that allanite is the primary REE phase. The sample is dominated by quartz (35.8%) and K-feldspar (21.0%), moderate amounts of amphibole/pyroxene (13.7%), plagioclase (12.3%), minor Fe-oxides (4.4%), biotite (3.9%) and muscovite/clays (1.6%), and trace amounts of other silicates, carbonates, fluorite, other oxides and sulphides. REE-Zr minerals include mainly allanite (2.6%), zircon (2.5%), chevkinite (0.3%), fergusonite (0.2%), bastnasite/synchysite (0.1%), monazite (0.1%) and rare columbite. Most of the allanite (2.2%) occurs in the +38 μm, but most of zircon (1.5%) in the -38 μm fraction. Note that amphibole and pyroxene are grouped together due to their similar chemistries.
Figure 1 - Normalized Mineral Abundance of REE Minerals
Grain Size Distribution
The D50 or 50% passing value from the cumulative grain size distribution of the fergusonite, bastnasite/synchysite, allanite, monazite, chevkinite, zircon, quartz/feldspars, muscovite, other silicate and oxide minerals are as follows;
• fergusonite is ca. 22 μm; • bastnasite/synchysite is ca. 51 μm; • allanite is ca. 65 μm; • monazite is ca. 24 μm; • chevkinite is ca. 53 μm; • zircon is ca. 24 μm |
• quartz/feldspars is ca. 98 μm; • muscovite is ca. 24 μm; • other silicates is ca. 83 μm; • oxides is ca. 141 μm; • overall particle is ca. 98 μm. |
The grain size data indicates that it should be possible to liberate the REE minerals from the barren gangue minerals using a moderate grind size. This information bodes well for beneficiation of the Foxtrot mineralization.
Mineral Chemistry
Electron microprobe analyses (EMPA) were conducted on chevkinite, allanite, fergusonite, bastnasite and synchysite, zircon and an undefined Si/Y/Ca REE phase.
Elemental Deportment
Elemental deportment was estimated for a number of key elements. The plots for two of the economic elements in the Foxtrot deposit are shown in Figures 2 and 3 (Nd, Dy).
Neodymium Elemental Deportment
The elemental distribution of neodymium is graphically presented in Figure 2. Allanite carries most of the Nd (66.4%), followed by chevkinite (12.7%), monazite (10.1%), bastnasite/synchysite (7.9%) and fergusonite (2.9%).
Figure 2 - Elemental Deportment of Neodymium
Dysprosium Elemental Deportment
The elemental distribution of dysprosium is graphically presented in Figure 5. Allanite and fergusonite carry most of the Dy at 49.3% and 40.5%, respectively, followed by chevkinite (8.8%) and bastnasite (1.4%).
Figure 3 - Elemental Deportment of Dysprosium
Liberation and Association
The liberation and association characteristics of allanite, fergusonite, bastnasite/synchysite, monazite, chevkinite and zircon were examined.
The mineralogical work on the Foxtrot sample set the groundwork for beneficiation studies.
BENEFICIATION OF FOXTROT SAMPLE
Three beneficiation techniques were studied in order to concentrate the REE in the Foxtrot sample. These include Wilfley tabling, magnetic separation and flotation. The Wilfley tabling was used to test amenability to gravity concentration. Magnetic separation (LIMS) was used to reject magnetite from the Wilfley concentrates. Flotation was tested both as a primary method of concentration for the Foxtrot sample and as a scavenging method to recover additional REE from the Wilfley tails. The work presented below is preliminary in nature but shows the promise of these techniques.
Gravity Concentration with the Wilfley Table and Magnetic Separation
A ~100 kg charge was stage ground with the closing screen size of 105 μm. The -105 μm fraction was screened on 75 μm, and 38 μm screens to make 3 fractions. The +75 μm fraction was tabled and the tails re-passed. The test generated 3 fractions: Concentrate, Scavenger Middlings, and Scavenger Tail. The +38 μm fraction was tabled and the tails repassed. The test generated 3 fractions: Concentrate, Scavenger Middlings and Scavenger Tail. The -38 μm fraction was passed through the cyclone to eliminate unnecessary slimes on the table. The cyclone overflow was filtered. The cyclone underflow was passed over the Wilfley Table and the tail was re-passed. The Concentrate, Scavenger Middlings and Scavenger Tailings were submitted for assay. All the table concentrates were passed through Low Intensity Magnetic Separator (LIMS) to separate mainly magnetite. This flowsheet is depicted in Figure 4.
Figure 4 - Gravity (Wilfley Table) and Magnetic Separation Flowsheet for Foxtrot Testing
Table 3 summarizes the results of the gravity and magnetic separation. Using just these two methods, it is possible to recover 71.4% of the Ce, 70.7% of the Nd and 70.7% of the Y into a concentrate containing 22.3% of the original mass. While this is a good first result, flotation was also examined to enhance the overall recoveries.
Table 3 - Summary of the Beneficiation of the Sample of Foxtrot Material using Gravity and Magnetic Separation
Prod. | Weight | Assays, %, g/t | % Distribution | |||||||||||||||
No. | g | % | CeO2 | Nd2O3 | Y2O3 | ZrO2 | Nb2O5 | SiO2 | Al2O3 | Fe2O3 | CeO2 | Nd2O3 | Y2O3 | ZrO2 | Nb2O5 | SiO2 | Al2O3 | Fe2O3 |
1 | 8,713 | 9.53 | 1.50 | 0.58 | 0.39 | 2.15 | 0.24 | 57.8 | 3.70 | 17.3 | 33.8 | 32.2 | 28.5 | 12.0 | 23.5 | 8.12 | 4.88 | 14.6 |
2 | 1,484 | 1.62 | 0.09 | 0.12 | 0.10 | 0.76 | 0.10 | 4.43 | 0.30 | 97.4 | 0.35 | 1.10 | 1.25 | 0.72 | 1.65 | 0.11 | 0.07 | 14.0 |
3 | 167 | 0.18 | 0.25 | 0.12 | 0.10 | 0.76 | 0.10 | 69.9 | 7.67 | 11.4 | 0.11 | 0.12 | 0.14 | 0.08 | 0.19 | 0.19 | 0.19 | 0.18 |
4 | 28,797 | 31.5 | 0.05 | 0.01 | 0.01 | 0.57 | 0.01 | 76.8 | 8.50 | 4.10 | 3.66 | 2.13 | 2.39 | 10.5 | 4.58 | 35.6 | 37.1 | 11.5 |
5 | 5,082 | 5.56 | 1.56 | 0.57 | 0.39 | 3.09 | 0.31 | 58.0 | 4.20 | 15.4 | 20.5 | 18.4 | 16.6 | 10.1 | 17.8 | 4.75 | 3.23 | 7.61 |
6 | 917 | 1.00 | 0.07 | 0.03 | 0.08 | 0.55 | 0.03 | 4.23 | 0.35 | 95.7 | 0.17 | 0.20 | 0.58 | 0.33 | 0.29 | 0.06 | 0.05 | 8.52 |
7 | 329 | 0.36 | 0.10 | 0.03 | 0.08 | 0.55 | 0.03 | 77.4 | 8.06 | 3.78 | 0.08 | 0.07 | 0.21 | 0.12 | 0.10 | 0.41 | 0.40 | 0.12 |
8 | 17,382 | 19.0 | 0.11 | 0.05 | 0.05 | 0.62 | 0.04 | 75.3 | 8.53 | 5.68 | 4.97 | 5.14 | 7.34 | 6.93 | 8.29 | 21.1 | 22.5 | 9.60 |
9 | 6,576 | 7.20 | 1.00 | 0.48 | 0.40 | 8.37 | 0.33 | 61.5 | 5.44 | 9.52 | 17.0 | 20.0 | 21.9 | 35.3 | 24.1 | 6.52 | 5.42 | 6.08 |
10 | 976 | 1.07 | 0.12 | 0.05 | 0.10 | 1.10 | 0.05 | 5.64 | 0.48 | 92.7 | 0.30 | 0.31 | 0.81 | 0.69 | 0.54 | 0.09 | 0.07 | 8.79 |
11 | 34.3 | 0.04 | 0.31 | 0.13 | 0.11 | 3.54 | 0.09 | 70.8 | 8.02 | 6.14 | 0.03 | 0.03 | 0.03 | 0.08 | 0.03 | 0.04 | 0.04 | 0.02 |
12 | 12,914 | 14.1 | 0.31 | 0.12 | 0.09 | 2.20 | 0.06 | 70.8 | 8.04 | 7.43 | 10.3 | 9.55 | 9.55 | 18.2 | 8.21 | 14.7 | 15.7 | 9.33 |
13 | 8,019 | 8.77 | 0.42 | 0.21 | 0.16 | 0.97 | 0.12 | 63.9 | 8.54 | 12.3 | 8.71 | 10.7 | 10.7 | 4.99 | 10.7 | 8.26 | 10.4 | 9.59 |
Calc Head | 91,388 | 100 | 0.42 | 0.17 | 0.13 | 1.71 | 0.10 | 67.9 | 7.22 | 11.3 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
Concentrate 1+5+9 |
20,370 | 22.3 | 1.35 | 0.55 | 0.40 | 4.39 | 0.29 | 59.0 | 4.39 | 14.31 | 71.4 | 70.7 | 67.0 | 57.4 | 65.4 | 19.4 | 13.5 | 28.3 |
Table 4 - Flotation Test Result for Scoping Rougher Test
Prod. | Weight | Assays, %, g/t | % Distribution | |||||||||||||||
No. | g | % | CeO2 | Nd2O3 | Y2O3 | ZrO2 | Nb2O5 | SiO2 | Al2O3 | Fe2O3 | CeO2 | Nd2O3 | Y2O3 | ZrO2 | Nb2O5 | SiO2 | Al2O3 | Fe2O3 |
Rougher Conc. | 536 | 27.4 | 1.14 | 0.52 | 0.35 | 4.71 | 0.27 | 46.1 | 4.66 | 27.4 | 70.5 | 73.6 | 81.7 | 73.3 | 62.7 | 19.0 | 18.0 | 65.8 |
Float Tails | 1,419 | 72.6 | 0.18 | 0.07 | 0.03 | 0.65 | 0.06 | 74.2 | 8.04 | 5.39 | 29.5 | 26.4 | 18.3 | 26.7 | 37.3 | 81.0 | 82.0 | 34.2 |
Flotation Separation
Flotation testing was conducted on a head sample. The flotation was performed as a rougher test with five stages of rougher flotation. Appropriate flotation reagents and test conditions were supplied by SGS for recovery of allanite and fergusonite. The feed particle size was 80% passing 150 μm. The flotation test results are shown in Table 4. Flotation by itself produced a concentrate containing 70.5% of the Ce, 73.6% of the Nd and 81.7% of the Y in a mass pull of 27.4%. These results are slightly better than the results of the gravity and magnetic separation.
As a last step in the beneficiation testing, the Wilfley table tails (3 size fractions) were subjected to flotation to increase the overall recovery of REE's. Note that the cyclone overflow was not floated. The additional rougher flotation concentrate recovered in this manner was added to the gravity and magnetic separation products (Table 3) to generate an overall concentrate. The analysis of this concentrate is shown in Table 5, along with the associated total recoveries. These results should be viewed as indicative of the promise of conventional beneficiation methods to recover the REE minerals from the Foxtrot prospect. There is ample scope to improve the overall recovery (by consideration of the losses to the cyclone overflow - about 10% REE) and the grade (by more selective beneficiation or the incorporation of cleaning steps in the circuit).
Table 5 - Combined Gravity, Magnetic Separation and Flotation Concentrate Product
Concentrate Assay | Recovery (%) | ||
Ce2O3 | % | 0.94 | 83.0 |
Nd2O3 | % | 0.38 | 83.0 |
Y2O3 | % | 0.31 | 83.7 |
ZrO2 | % | 3.71 | 65.9 |
Nb2O5 | % | 0.22 | 81.8 |
La2O3 | g/t | 3968 | 86.2 |
Pr6O11 | g/t | 1160 | 86.6 |
Sm2O3 | g/t | 741 | 84.3 |
Eu2O3 | g/t | 34 | 83.7 |
Gd2O3 | g/t | 559 | 82.7 |
Tb2O3 | g/t | 93 | 82.4 |
Dy2O3 | g/t | 543 | 81.4 |
Ho2O3 | g/t | 105 | 81.6 |
Er2O3 | g/t | 297 | 81.7 |
Tm2O3 | g/t | 42 | 81.9 |
Yb2O3 | g/t | 249 | 81.7 |
Lu2O3 | g/t | 37 | 81.8 |
U3O8 | g/t | 54 | 83.8 |
ThO2 | g/t | 274 | 86.6 |
Hydrometallurgical Extraction of REE's from Foxtrot Concentrate
The gravity concentrate (Table 3) and the combined gravity/flotation concentrate (Table 5) were subjected to acid leaching or acid baking at 200-250 °C followed by water leaching. The results of the testing are summarized in Table 6.
Table 6 - Hydrometallurgical Leaching Studies on Foxtrot Concentrates
Test ID | AL2 | AB4 | WL-AB4 | AB7 | WL-AB7 | AB8 | WL-AB8 | AB9 | WL-AB9 | |
Feed | grav con | grav / flot con | AB4 calcine | grav / flot con | AB7 calcine | grav / flot con | AB8 calcine | grav / flot con | AB9 calcine | |
Time, hr | hr | 6 | 2 | 1 | 1 | 2 | ||||
Temp | °C | 95 | 200 | 250 | 250 | 250 | ||||
H2SO4 | Add kg/t | 1000 | 1000 | 1000 | 750 | 500 | ||||
Free g/L | 91 | 107 | 60 | 90 | 33 | |||||
Extraction, % | ||||||||||
Si | 4 | 1 | 1 | 1 | 1 | |||||
Al | 29 | 17 | 16 | 15 | 14 | |||||
Fe | 35 | 37 | 34 | 34 | 33 | |||||
Mg | 28 | 42 | 41 | 38 | 49 | |||||
Ca | 54 | 45 | 36 | 39 | 33 | |||||
Na | 2 | 2 | 3 | 3 | 2 | |||||
K | 36 | 12 | 22 | 11 | 22 | |||||
Ti | 69 | 74 | 59 | 68 | 53 | |||||
P | 88 | 88 | 54 | 74 | 52 | |||||
Mn | 46 | 43 | 40 | 35 | 39 | |||||
Zr | 1 | 0 | 1 | 1 | 1 | |||||
Nb | 18 | 23 | 16 | 16 | 15 | |||||
La | 97 | 95 | 92 | 93 | 91 | |||||
Ce | 97 | 96 | 93 | 94 | 92 | |||||
Pr | 96 | 96 | 93 | 94 | 92 | |||||
Nd | 94 | 96 | 93 | 94 | 92 | |||||
Sm | 86 | 95 | 93 | 93 | 92 | |||||
Eu | 79 | 94 | 92 | 93 | 92 | |||||
Gd | 74 | 95 | 94 | 94 | 93 | |||||
Tb | 66 | 95 | 93 | 93 | 92 | |||||
Dy | 61 | 94 | 93 | 93 | 92 | |||||
Ho | 58 | 93 | 92 | 92 | 91 | |||||
Er | 54 | 91 | 89 | 89 | 89 | |||||
Tm | 54 | 87 | 85 | 85 | 84 | |||||
Yb | 51 | 80 | 77 | 77 | 77 | |||||
Lu | 45 | 68 | 65 | 65 | 64 | |||||
Y | 64 | 92 | 90 | 91 | 90 | |||||
Sc | 7 | 3 | 2 | 2 | 2 | |||||
U | 22 | 62 | 62 | 60 | 61 | |||||
Th | 80 | 97 | 96 | 97 | 94 |
AL = Atmospheric Leach, AB = Acid Bake, WL = Water Leach, Add = acid added, Cons = acid consumed, Free = free acid in ~10% solids water leach
The metallurgical extractions are excellent. The direct acid leach extractions were somewhat lower and produced slower solid/liquid separations. However, the acid bake and water leach results produced very high extractions (viz. Nd is 91-96%, Tm is 84-87% and Dy is 92-94 %) with modest acid consumptions. Zr and Nb extractions are low. If these elements are to be recovered from Foxtrot mineralization, it may be necessary to re-leach the acid leach residue (possibly with alkali). Table 7 summarizes the leach solution compositions from the screening tests. The solutions are reasonably consistent in the REE values and low in impurity content. These solutions must then be treated for impurity removal and REE recovery as a mixed product for separation and refining.
Table 7 - Solution Assays from Hydrometallurgical Leaching Tests on Foxtrot Concentrates.
Liquor, mg/L | AL2 | WL-AB4 | WL-AB7 | WL-AB8 | WL-AB9 | |
Si | 1190 | 192 | 229 | 223 | 227 | |
Al | 911 | 580 | 578 | 578 | 530 | |
Fe | 4550 | 4060 | 3860 | 3850 | 3750 | |
Mg | 44 | 66 | 63 | 60 | 58 | |
Ca | 3160 | 1680 | 1220 | 1480 | 1120 | |
Na | 61 | 80 | 94 | 100 | 82 | |
K | 911 | 328 | 705 | 308 | 713 | |
Ti | 632 | 428 | 304 | 389 | 300 | |
P | 75 | 34 | 17 | 29 | 16 | |
Mn | 348 | 237 | 216 | 185 | 210 | |
Zr | 18 | 11 | 43 | 39 | 35 | |
Nb | 31 | 39 | 25 | 27 | 24 | |
La | 488 | 430 | 404 | 397 | 400 | |
Ce | 1060 | 947 | 890 | 875 | 887 | |
Pr | 134 | 117 | 110 | 109 | 111 | |
Nd | 482 | 442 | 407 | 406 | 409 | |
Sm | 76 | 75 | 67 | 68 | 69 | |
Eu | 4 | 4 | 4 | 4 | 4 | |
Gd | 54 | 61 | 56 | 56 | 57 | |
Tb | 7 | 10 | 9 | 9 | 8 | |
Dy | 42 | 59 | 52 | 52 | 53 | |
Ho | 8 | 12 | 10 | 10 | 10 | |
Er | 21 | 32 | 28 | 29 | 27 | |
Tm | 3 | 4 | 4 | 4 | 4 | |
Yb | 18 | 24 | 21 | 22 | 21 | |
Lu | 2 | 3 | 3 | 3 | 3 | |
Y | 212 | 293 | 259 | 259 | 259 | |
Sc | 0 | 0 | 0 | 0 | 0 | |
U | 2 | 4 | 4 | 4 | 4 | |
Th | 31 | 29 | 28 | 27 | 27 | |
LEACH SOLUTION PURIFICATION AND RECOVERY OF MIXED REE PRODUCT
The leach solution purification involved simple pH adjustment to pH 3.0. At this pH iron, aluminum, silica, titanium, phosphate, zirconium, niobium and thorium are removed as a mixed hydroxide waste precipitate.
After impurity precipitation, the solids were filtered and analyzed. The remaining solution was then treated with oxalic acid at pH 2.0 to precipitate the REE from solution. The form of the precipitate is as a mixed REE oxalate.
The mixed REE oxalate was filtered and washed and analyzed. The remaining solution was also analyzed.
The pH 3.0 precipitate contained 29.7% Fe, 1.78% Al, 2.51% Si, 2.54% Ti, 0.28% P, 0.30% Zr and 0.18% Nb. The precipitate also contained small amounts of Th and REE. Analysis of the REE in the precipitate and the loss due to co-precipitation is shown in Table 8.
Table 8 - Analysis of the Impurity Precipitate and Calculated Losses of REE.
Element | Feed Solution Analysis (mg/L) |
Filtrate Analysis (mg/L) |
Solid Precipitate Analysis (ppm) |
Amount Precipitated (%) |
La | 455 | 392 | 467 | 0.77 |
Ce | 1000 | 853 | 1280 | 0.96 |
Pr | 121 | 103 | 170 | 1.06 |
Nd | 437 | 374 | 687 | 1.18 |
Sm | 78 | 68.5 | 125 | 1.17 |
Eu | 4 | 3.39 | 6.3 | 1.19 |
Gd | 67 | 55.2 | 86.9 | 1.01 |
Tb | 11 | 8.73 | 14.5 | 1.07 |
Dy | 62 | 51.7 | 86.6 | 1.07 |
Ho | 12 | 9.99 | 16.8 | 1.08 |
Er | 33 | 27.4 | 49.9 | 1.17 |
Tm | 5 | 3.71 | 7.3 | 1.26 |
Yb | 25 | 20.9 | 49.2 | 1.50 |
Lu | 3 | 2.52 | 5.7 | 1.45 |
Y | 295 | 255 | 440 | 1.12 |
U | 4 | 2.59 | 78.2 | 16.4 |
Th | 32 | 1.32 | 2020 | 90.9 |
Note: Y analysis is still pending, but estimated at 1.12 % loss to precipitate (average of Ho and Er). Y solid analysis entered as estimate using Nd analysis of precipitate as reference.
The final oxalate precipitate composition and associated recovery is shown in Table 9.
Table 9 - Mixed Oxalate Precipitate of REE Recovered from Solution: Analysis and Recovery
Element | Oxalate Precipitate Analysis (% or ppm) |
Oxide | Oxalate Precipitate Analysis (% or ppm) |
Recovery from Solution (%) |
|
La | % | 7.8 | La2O3 | 9.15 | 99.96 |
Ce | % | 18.3 | Ce2O3 | 21.43 | 100.0 |
Pr | % | 2.1 | Pr6O11 | 2.54 | 99.97 |
Nd | % | 8.7 | Nd2O3 | 10.15 | 99.98 |
Sm | % | 1.24 | Sm2O3 | 1.44 | 99.94 |
Eu | ppm | 759 | Eu2O3 | 879 | 99.12 |
Gd | ppm | 11600 | Gd2O3 | 13370 | 99.95 |
Tb | ppm | 1840 | Tb2O3 | 2164 | 99.66 |
Dy | ppm | 10600 | Dy2O3 | 12165 | 99.90 |
Ho | ppm | 2020 | Ho2O3 | 2314 | 99.80 |
Er | ppm | 5430 | Er2O3 | 6209 | 99.85 |
Tm | ppm | 735 | Tm2O3 | 839 | 98.92 |
Yb | ppm | 4240 | Yb2O3 | 4828 | 99.90 |
Lu | ppm | 499 | Lu2O3 | 567 | 98.81 |
Y | ppm | 50763 | Y2O3 | 64466 | 99.99 |
U | ppm | 5.5 | U3O8 | 6 | 23.17 |
Th | ppm | 282 | ThO2 | 321 | 97.73 |
LREO | % | 44.70 | |||
HREO | % | 10.78 | |||
TREO | % | 55.48 |
Note: Y analysis not available. Y solid analysis entered as estimate using Nd analysis of precipitate as reference.
SUMMARY
The metallurgical process has been studied from initial recovery of a REE concentrate, through extraction of REE into solution, followed by purification of the solution and precipitation of a mixed REE product. The bench scale testing has been highly successful in producing a concentrate, leaching to high efficiency, precipitating of impurities (with negligible losses of REE) and finally precipitation of the mixed product.
To summarize the results of the testing, the following table (Table 10) calculates the overall recovery the Foxtrot sample to final mixed REE product.
Table 10 - Calculation of Overall Recovery of REE into Final Mixed REE Product
Oxide | Recovery to Concentrate |
Leach Extraction (Test 4) |
Loss to Impurity Precipitate |
Precipitation Efficiency with Oxalate |
Overall Recovery |
(%) | (%) | (%) | (%) | (%) | |
Ce2O3 | 82.98 | 95.89 | 0.96 | 100.00 | 78.80 |
Nd2O3 | 83.04 | 95.64 | 1.18 | 99.98 | 78.47 |
Y2O3 | 83.71 | 92.48 | 1.12 | 99.99 | 76.54 |
La2O3 | 86.21 | 95.29 | 0.77 | 99.96 | 81.49 |
Pr6O11 | 86.56 | 95.79 | 1.06 | 99.97 | 82.01 |
Sm2O3 | 84.32 | 94.70 | 1.17 | 99.94 | 78.88 |
Eu2O3 | 83.73 | 94.28 | 1.19 | 99.12 | 77.31 |
Gd2O3 | 82.65 | 95.30 | 1.01 | 99.95 | 77.93 |
Tb2O3 | 82.38 | 94.69 | 1.07 | 99.66 | 76.91 |
Dy2O3 | 81.36 | 94.21 | 1.07 | 99.90 | 75.76 |
Ho2O3 | 81.59 | 93.31 | 1.08 | 99.80 | 75.15 |
Er2O3 | 81.67 | 90.83 | 1.17 | 99.85 | 73.21 |
Tm2O3 | 81.87 | 86.80 | 1.26 | 98.92 | 69.41 |
Yb2O3 | 81.73 | 79.89 | 1.50 | 99.90 | 64.25 |
Lu2O3 | 81.75 | 67.70 | 1.45 | 98.81 | 53.90 |
Note: Overall Recovery = (Recovery to Concentrate) X (Leach Extraction) X (1-Loss to Impurity Precipitate) X (Precipitation Efficiency with Oxalate)
Exploration Program Update
The Port Hope Simpson REE District is 135 km long and 4 - 12 km wide, consists of 4326 claims in 86 licenses, and occupies 1081 square kilometres. There are a total of 11 REE prospects in the District, including: Rock Rolling Hill, Rattling Bog Hill, Piperstock Hill, Southern Shore, Toots Cove, Pesky Hill, HighREE Island, Foxtrot, Fox Pond, Foxy Lady, and Ocean View. The Foxtrot Project, Fox Pond and Foxy Lady prospects occur in the Fox Harbour mineralized belt. Piperstock Hill, Southern Shore, Toots Cove and Pesky Hill occur in a 13 km mineralized zone known as the HighREE Hills. The Ocean View Prospect occurs in a 3 km mineralized zone known as the Ocean View mineralized belt. The Fox Harbour, Ocean View and HighREE Hills mineralized zones are considered very prospective for both HREE and LREE.
Qualified Person:
Dr. David Dreisinger, Ph.D., P.Eng., is the Company's Vice President, Metallurgy and Qualified Person for the purposes of NI 43-101. Dr. Dreisinger has reviewed and approved the technical disclosure contained in this news release as applicable. The company will endeavour to meet high standards of integrity, transparency, and consistency in reporting technical content, including geological and assay (e.g., REE) data.
About Search:
Search Minerals Inc. (TSXV: SMY) is a TSX Venture Exchange listed company, headquartered in Vancouver, B.C. Search is the discoverer of the Port Hope Simpson REE District, a highly prospective light and heavy REE belt located in southeast Labrador where the company controls a dominant land position in a belt 135km long and up to 12km wide. In addition, Search has a number of other mineral prospects in its portfolio located in Newfoundland and Labrador, including a number of claims in the Strange Lake Complex, where Quest Rare Minerals has an earn-in agreement with the Company; and at the Red Wine Complex, where Great Western Minerals Group has a Joint Venture with the Company.
Furthermore, Search Minerals is the owner of patents relating to the Starved Acid Leaching Technology ("SALT"), a process with the potential to economically recover nickel and cobalt from known deposits currently considered sub economic.
Search Minerals is led by a management team and Board of Directors with a proven track record in the mining industry. The Company has experienced geological and metallurgical teams led by Dr. Randy Miller and Dr. David Dreisinger respectively.
All material information on the Company may be found on its website at www.searchminerals.ca and on SEDAR at sedar.com.
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility of the adequacy or accuracy of this release.
Cautionary Statement:
This news release contains forward-looking statements that are not historical facts. Forward-looking statements involve risks, uncertainties and other factors that could cause actual results, performance, prospects, and opportunities to differ materially from those expressed or implied by such forward- looking statements. Factors that could cause actual results to differ materially from these forward- looking statements include those risks set out in Search's public documents filed on SEDAR at www.sedar.com. Although Search believes that the assumptions and factors used in preparing the forward-looking statements are reasonable, undue reliance should not be placed on these statements, which only apply as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. Except where required by law, Search disclaims any intention or obligation to update or revise any forward-looking statement, whether as a result of new information, future events or otherwise.
PDF available at: http://stream1.newswire.ca/media/2012/05/09/20120509_C6074_DOC_EN_13509.pdf
PDF available at: http://stream1.newswire.ca/media/2012/05/09/20120509_C6074_DOC_EN_13510.pdf
PDF available at: http://stream1.newswire.ca/media/2012/05/09/20120509_C6074_DOC_EN_13511.pdf
PDF available at: http://stream1.newswire.ca/media/2012/05/09/20120509_C6074_DOC_EN_13512.pdf
Jim Clucas
T: 604-688-6180
President & Chief Executive Officer
E: [email protected]
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