An Investigation into

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1 An Investigation into MINERALOGICAL CHARACTERIZATION OF FOUR TAILINGS SAMPLES prepared for LISHEEN MINE LR MI5002-APR07 May 28, 2007 NOTE: This report refers to the samples as received. The practice of this Company in issuing reports of this nature is to require the recipient not to publish the report or any part thereof without the written consent of. SGS Lakefield Research Limited P.O. Box 4300, 185 Concession Street, Lakefield, Ontario, Canada K0L 2H0 Tel: (705) Fax: (705) Member of the SGS Group (SGS SA)

2 ii Table of Contents Page No. 1. Procedures Mineralogical Results Modal Analyses Assay Reconciliation Silicates Oxides Sulphates Phosphates Carbonates Sulphides Conclusions...6 Appendix 1 Photomicrographs and Carbonate Cement Chemistry 7 Appendix 2 X-Ray Diffraction Results 15 Appendix 3 Chemical Analyses 22

3 iii List of Tables Table 1. List of Samples... iv Table 2. Summary modal analyses by optical/ QEMSCAN TM analysis...2 Table 3. Assay Reconciliation showing Mineralogical vs. Chemical Assay...3 Table 4. Average Semi-Quantitative SEM-EDS Composition of Carbonate/Sulphate Cements5 Table 5. SEM-EDS semi-quantitative Cement Chemistry: TMF Table 6. SEM-EDS semi-quantitative Cement Chemistry: TMF Table 7. SEM-EDS semi-quantitative Cement Chemistry: Beach Tails Surface...12 Table 8. SEM-EDS semi-quantitative Cement Chemistry: Fresh Tails List of Figures Figure 1 TMF-4 photomicrograph (162x)...8 Figure 2 TMF-4 photomicrograph (90x)...8 Figure 3 TMF-15 photomicrograph (553x)...10 Figure 4 TMF-15 photomicrograph (398x)...10 Figure 5 Beach Tails Surface photomicrograph (713x)...12 Figure 6 Fresh Tails 1 photomicrograph (247x)...13 Figure 7 Fresh Tails 1 photomicrograph (439x)...13

4 iv Introduction Four tailings samples (listed in Table 1 below) were submitted to Mineral Technologies for mineralogical examination. The samples were labelled TMF-4, TMF-15, Beach Tails Surface, and Fresh Tails 1. The purpose of the investigation was to determine the bulk mineral assemblage and textural characteristics of the mineral species within the sample. The mineralogical examinations included X-ray diffraction analysis (XRD), optical microscopy, and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). Table 1. List of Samples # Sample 1 TMF-4 2 TMF-15 3 Beach Tails Surface 4 Fresh Tails 1 Rob Pooler, B.Sc. (Hons.) Junior Mineralogist Stephanie Downing, M.Sc. Senior Mineralogist Joe Zhou, M.Sc., P.Geo. Group Leader, Mineral Technologies Experimental work by: Report preparation by: Jennifer Glover, Section Preparation Stephanie Downing, M.Sc., Senior Mineralogist Rob Pooler, B.Sc. (Hons.), Junior Mineralogist Rob Pooler, B.Sc. (Hons.), Junior Mineralogist Stephanie Downing, M.Sc., Senior Mineralogist

5 1 Summary 1. Procedures A representative sub-sample of each as-received air dried sample was pulverized and submitted for X-ray diffraction (XRD) analysis, in order to determine the bulk crystalline mineral assemblage. XRD results are presented in Appendix 2. One polished section and one polished thin section were prepared from a representative subsample of each as-received material. Each polished section was examined optically with a petrographic microscope under incident (reflected) and transmitted light at 50x to 500x magnifications. The mineral assemblage and modal abundance of each sample were determined by compiling both optical data with a particle mapping analysis (PMA) generated by QEMSCAN TM technology (results are presented in Table 2). Weight percentages of minerals were calculated from volume percentage using standard grain densities and documented mineral chemistries. A summary of the major elemental assay of each sample calculated by mineralogical analysis is compared to the chemical assay (whole rock analysis, WRA by borate fusion) of each sample as a method of assay reconciliation (presented in Section 2.2). For each sample, SEM photomicrographs were taken to illustrate relevant textural and association data of the sulphide/carbonate minerals. Photomicrographs of individual samples are presented in Appendix 1. Semi-quantitative EDS spectra were acquired from selected areas representing cements within sulphide-carbonate aggregates, and resultant compositions are presented in Appendix 1.

6 2 2. Mineralogical Results 2.1. Modal Analyses Combined microscopic, SEM-EDS, and QEMSCAN TM examination of the four tailings samples indicate that they are composed primarily of carbonate and sulphide minerals. The carbonate mineral content varies from 38 to 45 wt.% and sulphide mineral content varies from 35 to 44 wt.%. A large proportion of carbonate cements showing variable chemistry also occur interstitial to sulphide-carbonate aggregates (varying from 6.4 to 15.3 wt.%). Minor amounts of silicates (3.3 to 5.4 wt.%) and sulphates (1.6 to 4.8 wt.%) and trace amounts of Fe-Ti oxides (0.2 to 0.6 wt.%) and phosphates (~ 0.1 wt.%) are also present. A summary of the bulk mineralogy of the four tailings samples is presented below in Table 2. Table 2. Summary modal analyses by optical/ QEMSCAN TM analysis Project Lisheen Mine Project (MI5002-APR07) Sample TMF 4 TMF 15 Beach Tails Surface Fresh Tails 1 Min Size (Microns) Max Size (Microns) Average Particle Size Mineral Formula TMF 4 TMF 15 Beach Tails Surface Fresh Tails 1 wt. % wt. % wt. % wt. % Quartz SiO K-Feldspar KAlSi 3 O Plagioclase (Ca, Na)(Si, Al) 4 O Talc Mg 3 Si 4 O 10 (OH) Sericite/Muscovite KAl 2 (Si 3 Al)O 10 (OH,F) Biotite K(Mg,Fe) 3 AlSi 3 O 10 (OH,F) Chlorite (Mg,Al,Fe) 12 [(Si,Al) 8 O 20 ](OH) Amphibole Ca 2 (Mg,Fe) 5 (Si 8 O 22 )(OH) Pyroxene CaMgSi 2 O Kaolinite Al 2 Si 2 O 5 (OH) Calcite CaCO Ankerite Ca(Fe,Mg,Mn)CO Dolomite CaMg(CO 3 ) Siderite FeCO Fe-Oxides Fe 2 O Ti oxides TiO Pyrite/Marcasite FeS Pyrrhotite Fe 1-x S Arsenopyrite FeAsS Galena PbS Sphalerite ZnS Amorphous Carb-Cement *(see Table 4) Gypsum CaSO 4 2(H 2 O) Jarosite KFe 3 (SO 4 ) 2 (OH) Other Carbonates MnCO Barite BaSO Apatite Ca 5 (PO 4 ) 3 (F, OH, Cl) Other Cu-bearing Total

7 Assay Reconciliation In general, reconciliation of calculated mineralogical assay versus direct chemical assay is good, demonstrating confidence in mineralogical results (see Table 3 below). Documented mineral chemistries are used for mineralogical assay reconciliation tables for all minerals; therefore actual mineral chemistries will vary slightly from calculated book values. Also, due to variable cement chemistries, additional analyses would be recommended if more statistically precise composition descriptions are required. Table 3. Assay Reconciliation showing Mineralogical vs. Chemical Assay Sample Assay Reconciliation by QEMSCAN TMF 4 TMF 15 Beach Tails Surface Fresh Tails 1 Min Size (Microns) Max Size (Microns) Mass Size Distribution (%) Avg. Particle Size C (QEMSCAN) C (Chemical) Na (QEMSCAN) Na (Chemical) Mg (QEMSCAN) Mg (Chemical) Al (QEMSCAN) Al (Chemical) Si (QEMSCAN) Si (Chemical) P (QEMSCAN) P (Chemical) S (QEMSCAN) S (Chemical) K (QEMSCAN) K (Chemical) Ca (QEMSCAN) Ca (Chemical) Ti (QEMSCAN) Ti (Chemical) Mn (QEMSCAN) Mn (Chemical) Fe (QEMSCAN) Fe (Chemical) Zn (QEMSCAN) Zn (Chemical) As (QEMSCAN) As (Chemical)

8 Silicates Quartz is the main silicate mineral present in all samples, ranging from 1.1 wt.% to 4.6 wt.% of sample. Quartz typically occurs as liberated grains or as interstitial grains, occurring in particles with feldspars, sulphates and carbonates. Minor amounts of sericite/muscovite (0.4 to 0.6 wt.%), K-Feldspar (0.3 to 1.1 wt.%), biotite (0.1 to 0.2), amphibole (0.4 to 0.6 wt.%) and clays (0.4 to 0.8 wt.%) are also present in all samples. Other silicates that are present in trace proportions (typically < 0.2 wt.% of sample) include plagioclase, talc, chlorite, and pyroxene Oxides Hematite and rutile are the main Fe- and Ti-oxide minerals present in all samples. The oxide minerals typically occur in complex particles in association with silicate, carbonate, sulphide and sulphate minerals Sulphates Sulphates occur as complex coatings and interstitial grains (< 2 µm) within carbonate-sulphide aggregates and carbonate cements. The sulphate chemistry is variable, with gypsum, and jarosite occurring in minor amounts in all tailings. Trace amounts of a Zn-sulphate phase (< 2 wt.%) was also present within the carbonate cements and incorporated within the cements in the modal analyses and cement chemistry. Trace amounts of barite are also found within aggregated carbonate-sulphide particles Phosphates Trace amounts of apatite typically occur as attachments to sulphides or as fine grains within carbonate cements Carbonates Carbonate minerals occur in moderate amounts in all samples. Dolomite is the main carbonate mineral found in all samples (ranging from 37.7 wt.% to 44.3 wt.% of sample). The remaining carbonate is comprised mainly of calcite (5.3 wt.% to 6.1. wt.%), with trace amounts of ankerite (0.03 wt.% to wt.%), siderite (0.01 wt.% to 0.03 wt.%), and rhodochrosite (MnCO 3, 0.01 to 0.04 wt.%).

9 5 Carbonate cements (amorphous, grain size < 1 µm) are also common and are found interstitial to sulphide and carbonate grains within aggregated particles, typically as coatings on pyrite/marcasite grains (see photomicrographs in Appendix 1). Numerous semi-quantitative compositions were taken of carbonate cements from selected aggregates. A summary of the cement composition (averaged from all tailings) is presented in Table 4 below. A more complete summary of semi-quantitative cement compositions for each individual sample is presented in Appendix 1, along with their corresponding photomicrographs. The amorphous cements appear as broad or diffuse peaks on the XRD diffractograms (see Appendix 2). SEM-EDS analyses indicate that the majority of cements are carbonate-rich in composition with high calcium and magnesium values indicative of dolomite compositions. A minor sulphate component is also indicated by the average sulphur content (~ 9 wt.% S) of the cements. A minor fine-grained (< 1 µm) silicate content is also indicated by the Si-Al and K compositions. Thus, SEM-EDS results suggest that the majority of amorphous cements are comprised mainly of carbonates with possible sulphate and silicate components either interstitial or adjacent to areas of analysis. Very fine-grained (submicron, < 1 µm) sulphides (mainly pyrite) were also found encased within the carbonate cements. Table 4. Average Semi-Quantitative SEM-EDS Composition of Carbonate/Sulphate Cements Element Average wt. % Mg 6.22 Al 0.51 Si 1.92 S 8.70 K 0.48 Ca 18.9 Mn 0.07 Fe 7.16 Zn 2.57 C 9.72 O Sulphides Sulphides occur in moderate amounts in all samples. Pyrite/marcasite is the most abundant sulphide mineral present in all samples, comprising 90% to 95% of the sulphide species. Pyrite/marcasite typically occurs within aggregates with carbonates or as liberated grains. Trace amounts of sphalerite, pyrrhotite, galena and arsenopyrite (in decreasing order) are also present.

10 6 3. Conclusions The four tailings samples are composed primarily of carbonates, carbonate bearing cements, and sulphides, with minor proportions of silicates, sulphates, Fe-Ti oxides, and trace amounts of phosphates. For tailings samples TMF-4, TMF-15 and Beach Tails Surface, there is an overall higher proportion of carbonates to sulphides. For the Fresh Tails 1 sample, a slightly lower percentage of carbonate to sulphides is present. The majority of sulphides occurred within aggregates composed of carbonate and carbonate cements. Tailings samples TMF-4, TMF-15 and Fresh Tails 1 showed abundant cements (11.2 to 15.3 wt.%). These carbonate cements typically formed coatings on sulphide grains. These amorphous cements also hosted numerous fine (< 1 µm) pyrite grains. The Beach Tails Surface sample showed a much lower abundance of cements, and was found as fine coatings on sulphide minerals. SEM-EDS analysis of the amorphous cements indicated a predominant dolomite composition with a minor sulphate and silicate component, either as fine-grained inclusions (< 1 µm) or as amorphous mixtures.

11 7 Appendix 1 Photomicrographs and Carbonate Cement Chemistry

grains and amorphous carbonate (with minor sulphate component) cements.

12 8 Photomicrographs- TMF-4 dolomite Pyrite/marcasite Figure 1 TMF-4 photomicrograph (162x) Low magnification back-scattered electron image (BEI) showing an aggregate consisting of pyrite grains (< 30 µm), surrounded and encased by distinct carbonate grains and amorphous carbonate (with minor sulphate component) cements. Pyrite/marcasite carbonates Figure 2 TMF-4 photomicrograph (90x) Low magnification BEI showing a typical aggregate (~500 µm) consisting of pyrite (lighter grains) encased by carbonate grains and cements.

13 9 Table 5. SEM-EDS semi-quantitative Cement Chemistry: TMF-4 TMF 4 Elem. Scribe 1 Scribe 1 Cement-3 Cement-4 Cement-5 wt% Cement-1 Cement-2 on Py on Py (1) on Py (2) Mg Al Si S K Ca Mn Fe As Zn C O

10 Photomicrographs- TMF-15 apatite dolomite mica galena Pyrite/marcasite Carb cements Figure 3 TMF-15 photomicrograph (553x) High magnification BEI showing an

Pyrite hosts a fine inclusion of galena.

14 10 Photomicrographs- TMF-15 apatite dolomite mica galena Pyrite/marcasite Carb cements Figure 3 TMF-15 photomicrograph (553x) High magnification BEI showing an aggregate consisting of pyrite grains (< 30 µm), surrounded and encased by carbonates and carbonate cements. Apatite and mica are also present in the aggregate. Pyrite hosts a fine inclusion of galena. carb/sulphates rimming pyrite Rims of carb/sulphates py/marcasite Figure 4 TMF-15 photomicrograph (398x) High magnification BEI of liberated pyrite showing some discontinuous rims of fine (< 5 µm) carbonate and sulphate compositions from SEM-EDS. These grains appear to be broken off from the larger aggregates.

15 11 Table 6. SEM-EDS semi-quantitative Cement Chemistry: TMF-15 TMF 15 Elem. Scribe 1 Scribe 1 Scribe 2 Scribe 2 Scribe 2 Scribe 2 wt% Carb Cement-1 Sphal Trap-1 Carb Cement-2 Carb Cement-3 Carb Cement-4 Sphal Trap-2 Mg Al Si S K Ca Mn Fe As Zn C O

12 Photomicrographs- Beach Tails Surface dolomite Pyrite/marcasite gypsum galena Figure 5 Beach Tails Surface photomicrograph (713x) High magnification BEI, showing pyrite hosting inclusions of

16 12 Photomicrographs- Beach Tails Surface dolomite Pyrite/marcasite gypsum galena Figure 5 Beach Tails Surface photomicrograph (713x) High magnification BEI, showing pyrite hosting inclusions of galena, and showing discontinuous rims of gypsum and minor carbonate. Table 7. SEM-EDS semi-quantitative Cement Chemistry: Beach Tails Surface Beach Tails Surface Elem. Scribe 3 Scribe 4 Scribe 4 wt% Cement-on Sph-Py Rim on Py Rim on Py (2) Mg Al Si S K Ca Mn Fe As Zn C O

13 Photomicrographs- Fresh Tails 1 py/marcasite dolomite Figure 6 Fresh Tails 1 photomicrograph (247x) Low magnification BEI of a pyrite-carbonate aggregate.

17 13 Photomicrographs- Fresh Tails 1 py/marcasite dolomite Figure 6 Fresh Tails 1 photomicrograph (247x) Low magnification BEI of a pyrite-carbonate aggregate. Note that interstitial to the grains is an amorphous cementlike matrix mainly consisting of carbonate cements, with a minor component of clays (Al-silica) and sulphates. Fine pyrite (< 2 µm) encased in carb cements Carb cements py/marcasite Figure 7 Fresh Tails 1 photomicrograph (439x) High magnification BEI of a liberated pyrite grain showing very corroded grain boundaries indicative of breakdown along the grain edges. This grain shows discontinuous rimming of carbonate cements, hosting fine (< 2 µm) pyrite.

18 14 Table 8. SEM-EDS semi-quantitative Cement Chemistry: Fresh Tails 1 Fresh Tails 1 Elem. Scribe 1 Scribe 1 Scribe 1 Scribe 1 Scribe 2 wt% Cement on Py Cement on Py-2 Py-Carb With Py with Py With Gypsum Gypsum Gypsum Rim Rim Mg Al Si S K Ca Mn Fe As Zn C O

19 15 Appendix 2 X-Ray Diffraction Results

20 16 Summary of Qualitative X-ray Diffraction Results Crystalline Mineral Assemblage (relative proportions based on peak height) Sample Major Moderate Minor Trace TMF 4 dolomite, pyrite quartz, calcite *antigorite, *kaolinite, *apatite, *gypsum *anhydrite, *mica, *sphalerite, *galena, *siderite, *rhodochrosite TMF 15 dolomite, pyrite quartz, calcite *antigorite, *kaolinite, *mica, *anhydrite, *siderite, *galena, *sphalerite, *apatite, *rhodochrosite, *gypsum Beach Tails Surface dolomite, pyrite calcite, quartz *antigorite, *kaolinite, *rhodochrosite, *siderite, *galena, *anhydrite, *mica, *sphalerite, *gypsum Fresh Tails 1 pyrite, dolomite calcite, quartz *antigorite, *kaolinite, *mica, *anhydrite, *gypsum, *galena, *apatite, *siderite, *rhodochrosite, *sphalerite *Tentative identification due to low concentrations, diffraction line overlap or poor crystallinity Instrument: Siemens D5000 diffractometer Scan Conditions: Co radiation, graphite monochromator, 40 kv, 30 ma, Step:0.02, Step time:1s Interpretations: JCPDS / ICDD powder diffraction files. Siemens Search / Match software. Detection Limit: 0.5-2%. Strongly dependent on crystallinity. Interpretations do not reflect the presence of non-crystalline / amorphous compounds. Mineral proportions are based on relative peak heights and may be strongly influenced by crystallinity, structural group or preferred orientations. Interpretations and relative proportions should be accompanied by supporting petrographic and geochemical data (WRA, ICP-OES).

21 17 Mineral Composition Anhydrite CaSO 4 Antigorite Mg 3 Si 2 O 5 (OH) 4 Apatite Ca 5 (PO 4 ) 3 (F,Cl,OH) Calcite CaCO 3 Dolomite CaMg(CO 3 ) 2 Galena PbS Gypsum CaSO 4 2H 2 O Kaolinite Al 2 Si 2 O 5 (OH) 4 Mica K(Mg,Fe)Al 2 Si 3 AlO 10 (OH) 2 Pyrite FeS 2 Quartz SiO 2 Rhodochrosite MnCO 3 Siderite FeCO 3 Sphalerite ZnS Note: Michelle Kelvin, B.Sc. Stephanie Downing, M. Sc. Junior Mineralogist Senior Mineralogist

22 TMF Lin (Counts) Lin (Counts) Theta - Scale TMF 4 - File: APR raw - Type: 2Th/Th locked - Start: End: (C) - Quartz - SiO (*) - Pyrite - FeS (C) - Dolomite - CaMg(CO3) (C) - Calcite - Ca(CO3) (C) - Rhodochrosite - Mn(CO3) (C) - Fluorapatite - Ca5(PO4)3F.94Cl (D) - Anhydrite - CaSO (C) - Muscovite 2M1 - KAl2(AlSi3O10)(OH) (*) - Gypsum - CaSO4 2H2O (N) - Antigorite - Mg3Si2O5(OH) (I) - Sphalerite, syn - ZnS (I) - Galena, syn - PbS (C) - Kaolinite - Al2(Si2O5)(OH)4 18

23 TMF Lin (Counts) Lin (Counts) Theta - Scale TMF 15 - File: APR raw - Type: 2Th/Th locked - Start: End: (C) - Quartz - SiO (*) - Pyrite - FeS (C) - Dolomite - CaMg(CO3) (C) - Calcite - Ca(CO3) (C) - Rhodochrosite - Mn(CO3) (D) - Anhydrite - CaSO (C) - Muscovite 2M1 - KAl2(AlSi3O10)(OH) (N) - Antigorite - Mg3Si2O5(OH) (C) - Gypsum - CaSO4(H2O) (C) - Fluorapatite - Ca5.061(P2.87O11.46)F (I) - Sphalerite, syn - ZnS (I) - Galena, syn - PbS (C) - Kaolinite - Al2(Si2O5)(OH)4 19

24 Beach Tails Surface Lin (Counts) Lin (Counts) Theta - Scale Beach Tails Surface - File: apr raw - Type: 2Th/Th locked - Start: E (C) - Quartz - SiO (*) - Pyrite - FeS (C) - Dolomite - CaMg(CO3) (C) - Calcite - Ca(CO3) (C) - Rhodochrosite - Mn(CO3) (D) - Anhydrite - CaSO (C) - Muscovite 2M1 - KAl2(AlSi3O10)(OH) (N) - Antigorite - Mg3Si2O5(OH) (I) - Sphalerite, syn - ZnS (C) - Gypsum - CaSO4(H2O) (I) - Galena, syn - PbS (C) - Kaolinite - Al2(Si2O5)(OH)4 20

25 Fresh Tails Lin (Counts) Lin (Counts) Theta - Scale Fresh Tails 1 - File: apr raw - Type: 2Th/Th locked - Start: End: (C) - Quartz - SiO (*) - Pyrite - FeS (C) - Dolomite - CaMg(CO3) (C) - Calcite - Ca(CO3) (C) - Rhodochrosite - Mn(CO3) (C) - Fluorapatite, syn - (Ca3.544Na0.304Gd0.152)(Ca5.496Na0.042Gd (D) - Anhydrite - CaSO (C) - Muscovite 2M1 - KAl2(AlSi3O10)(OH) (N) - Antigorite - Mg3Si2O5(OH) (I) - Sphalerite, syn - ZnS (C) - Gypsum - Ca(SO4)(H2O) (I) - Galena, syn - PbS (C) - Kaolinite - Al2(Si2O5)(OH)4 21

26 22 Appendix 3 Chemical Analyses

27 23

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