SAMPLE PREPARATION AND ANALYTICAL METHODS GEOCHEMISTRY, EXPLORATION AND MINING

Transcription

1 SAMPLE PREPARATION AND ANALYTICAL METHODS GEOCHEMISTRY, EXPLORATION AND MINING

2 SAMPLE PREPARATION Rock samples The objective of a precise sample preparation scheme is to produce a representative and meaningful test sample (regularly about g) from a large bulk sample. The grain size of the prepared sample must be so fine that the element of interest (or host mineral) can be properly liberated from the bulk matrix and distributed in the pulp to produce a homogeneous distribution sufficiently representative for preceding analytical s. This is particularly important for low-concentration ores (e.g. Au and PGE s) where the number of mineral particles producing ore concentration is always low. Different minerals behave differently during pulverisation most (brittle) minerals will easily break down to small particles while some (e.g. native gold) will just change their shape if proper sample preparation s are not used (see also Figure 2). It is commonly accepted that poor sample preparation is, next to poor sampling, the largest source of bias in an exploration or resource evaluation project. Sample preparation s should therefore be selected as carefully as the actual analytical s. Drying Drill cores are always dried no matter what the earlier sample preparation history is (Method 0). Exceptionally wet and large samples (RC-, chip-samples etc.) require longer drying in elevated temperature (Method 4). Crushing The standard scheme consists of direct one stage fine crushing using a special type jaw crushers (nominal particle size > 70 % < 2 mm), precision riffle splitting (Method 3) and pulverising the split subsample of 00 50g. This is a suitable if crushed reject is needed for future work. The use of this is meaningful to maximum size of 2000 g samples, because if more than 3-4 splittings are required the representativity of the split subsample can not be assured. If larger than 2000 g samples are prepared using this procedure an extra pre - crushing (Method 30) is invoiced. For samples containing visible gold and/or for unusually big or heterogeneous samples, (max. 4 kg) we recommend standard crushing to 5-0mm (Method 30) and followed by pulverising the entire test sample (Methods 50) using Essa LM5 mills. If crushed reject is required for future work the crushed material can be split to two (e.g. -2 kg) splits (riffle splitting Method 35) the other for storage and the other for pulverising (Method 50). Pulverising Pulverising will always cause unavoidable contamination of wear metals at trace level from the grinding surfaces. This contamination may vary depending on material of the bowl, hardness of the sample material, pulverising time etc. The pulverising must be selected to best serve the requirements of the client. Some examples of bowl materials used at LABTIUM and expected contamination: - carbon steel (< 0.2 % Fe, no base metals) - hardened steel (< 0.2 % Fe, low Mn, Ni, Cu, Cr, Co) - chrome steel (up to 200 ppm Cr, < 0.2 % Fe, traces Mn, Cu, Co)

3 - tungsten carbide (W, Co) - agate (Si) To minimise cross-contamination, cleaning of pulverising bowls between samples (pulverising with barren quartzite) is included in the price in all pulverising s. The pulverisers and jaw crushers are cleaned with compressed air and brushes between every sample. The standard scheme consists of direct one stage fine crushing using a special type jaw crushers ((Method 3) nominal particle size > 70 % < 2 mm, precision riffle splitting (Method 35) and pulverising the split subsample of 00 50g (Method 40). For samples containing visible gold and/or for unusually big or heterogeneous samples, (max. 4 kg) we recommend standard crushing (Method 30) and followed by pulverising the entire test sample (Methods 50, hardened steel bowl) using Essa LM5 mills, avoiding any sample splitting which may deteriorate representativity of large samples. The pulverising takes place in large bowl and provides a large homogenised test sample for representative subsampling directly from the bowl without any further sample handling. The grinding action in LM5 is based on impact and hence smearing of gold particles (which are a problem with ring and disc mills) on bowl surfaces is minimised, which is an addition advantage of the technique. The Method 50 is also suitable for pulverising RC (reverse circulation) samples and for percussion drill chip-samples, making crushing and splitting unnecessary. If sample size exceeds 4 kg the sample must be pulverised by separate millings and homogenised before subsampling to analytical sample. In this case additional charge is invoiced for each kg exceeding 4 kg. For high precision whole rock analysis tungsten carbide pulverising must be used.

4 Rock samples Sample preparation schemas Standard sample preparation of rock samples (max 2000g) Total sample preparation of rock samples (max 3500g) ROCK SAMPLE DRILL CORE RC-SAMPLE CHIP SAMPLE ROCK SAMPLE DRILL CORE RC-SAMPLE CHIP SAMPLE Storing half of original sample Splitting by sawing Splitting by sawing Storing half of original sample Drying at 0 o C Drying at 0 o C code 0 code 0 Jaw crushing (max 2.0 kg). Fine jaw crusher. Nominal > 70 % < 2 mm Jaw crushing Coarse jaw crushing. code 3 code 30 Storing coarse reject Subsampling by riffle splitting code 35 Pulverising the entire sample. (max 3,5 kg); LM5 mill; hardened steel bowl. Nominal > 90 % < 00 µm Quartzite cleaning after every samples Storing pulp code 50 Pulverising the split subsample Ring mill; carbon steel bowl Subsampling from the bowl (00-50g) Nominal > 90 % < 00 microns (or by mat-rolling if requested Quartzite cleaning after every sample ( code 36) code 40 Test sample in vial (00 50 g) Test sample in vial (00 50 g) Additionally riffle splitting (35) can be included after crushing to retain 50% of the crushed reject. However coarse crushing (30) has to be replaced by fine crushing (3)

5 Rock samples Sample preparation s Preparation Method Description Maximum Drying in forced air ovens In stainless steel/aluminium trays Drying at 0 o C 4000 g 0 Drying at < 40 o C 4000 g Sorting and drying of exceptionally large or wet samples at > 00 o C (e.g. RC -or chip samples) 8000 g 4 Crushing by jaw crusher Standard coarse crushing the whole sample using Mn-steel jaws 4000 g 30 Fine crushing the whole sample using Mnsteel jaws to nominal > 70 % < 2 mm 2000 g 3 Pulverising in ring mill Quartzite cleaner included Grain size of the pulp > 90 % < 00 µm Pulverising the split sample in carbon steel bowl Pulverising the split sample in tungsten carbide bowl (petrological samples) 50 g g 43 Pulverising the entire sample in hardened steel bowl (LM5) (e.g. Drill cores, RC - or chip samples) 3500 g 50 Pulverising the entire sample in continuous flow chrome steel bowl, splitting by rotary splitter included (e.g. RC-, chip or feasibility samples). 20 kg 5 Cutting of drill cores and rock samples Sawing to two equal halves by diamond saw, returning the other half to original core case, packing the other half to plastic bags or aluminium trays for further processing Core-logging facilities can be leased in Sodankylä for exclusive use on daily basis.

6 Preparation Method Description Maximum Miscellaneous Sample Preparation Separate splitting /subsampling by riffle splitter (max 5 splittings) to g subsample g 35 Separate homogenisation / subsampling by mat-rolling to g subsample g 36 Separate splitting / subsampling by rotary splitter g 37 Wet sieving to 00 µm, (QC for pulverising) and weighing the +00 µm 200 g 28 Compositing / homogenising large pulps in rotary mixer 50 kg Soil and sediment samples Sample preparation s For soil samples (e.g. till), we recommend drying at 0 C (Method 0) and sieving to < 0.06 mm fraction (Method 24). If mercury or other volatile components are to be determined, lower drying temperatures must be used. High drying temperatures may also cause oxidation of some minerals. Other sieve fractions (< 0.25, < 0.25, < 0.5 mm) can be used upon client s request. When requesting sieving, please indicate the fraction to be analysed. For some purposes, the entire soil sample (weathered bedrock) or a coarse sieved fraction of the sample can also be crushed and/or pulverised. Preparation Method Description Maximum Drying in permeable bags* in forced air ovens Drying at 0 o C 2000 g 0 Drying at 40 o C 2000 g Sieving with nylon sieves Sieving to < 0.06 mm fraction 000 g 24 Sieving to a fraction selected by the client 000 g 27 Pulverising in ring mill Pulverising the split sample in carbon steel bowl 50 g 40

7 SAMPLE ANALYSIS Base metal assays To obtain the best quality and cost-efficiency in a particular geological project it is important to decide the strategy of analysis by selecting the appropriate analytical s (element suit, digestion / pretreatment, detection limits, optimum measurement area etc.) to fit the objectives of the project. Selecting a wrong may end up in attaining optimised results in wrong concentration levels and introducing problems in laboratory (contamination, additional sample dilutions) which may deteriorate accuracy and precision. Methods The specialists of laboratory will also assist you in selecting the optimised s of analysis for your project. For geochemical exploration for the base metals, we recommend aqua regia digestion of the sample and multielement analysis by ICP-OES (Method 5P). The package can be upgraded by ICP-MS- analysis to include larger set of elements and lower detection limits (Method 5PM). Although aqua regia is a powerful leaching agent, it still produces a partial dissolution for many elements. The dissolution of silicates and refractory minerals (e.g. baryte, chromite and other spinelles, zircon, cassiterite, tourmaline) varies depending on various factors. Most of the sulphide and oxide minerals (ore forming minerals) are, however, dissolved. The data will also give information on alteration and weathering of rock and till samples. Method 50P is an economic choice when only ore forming base elements are of importance. The is suitable for mineralised samples with moderate grades. There are limitations in the solubility of Ag and Pb at high concentrations, and samples expected to contain more than 5 % of sulphur should be analysed for sulphur using an alternative (e.g. by combustion technique, S-analyser, Method 80L). Refractory ore minerals (e.g. chromite, magnetite, ilmenite, columbite, cassiterite etc.), high-grade base metal ores (e.g. Ni ores) and concentrates can also be analysed using alkaline peroxide fusion and multielement analysis by ICP-OES (720P). When high quality assays of base metals is required more representative subsamples and traditional highprecision procedures either by ICP-OES (54P) as a multi-element package or by FAAS (54A) using single element s can be used. Single-element (or selected multi-element) assays using a total analysis by sodium peroxide fusion is carried out using the 72P. Results close to total are obtained also for major elements (except Si). Methods 720P and 72P can be applied also to mineral samples and concentrates. Multi-acid total digestions and XRF (see additional assays)

8 Geochemical exploration analyses (non-mineralised samples) Decomposition pretreatment Determination Sample Elements Detection limit (ppm) Aqua Regia Digestion The basic package of 5P using ICP-OES can be upgraded by ICP-MS analyses to package 5PM ICP-OES 0.5 g Ag Al As B Ba Be Ca Cd Co Cr Cu Fe K La Li Mg Mn Mo Na Ni P Pb S Sb Sc Sr Ti V Y Zn Zr P 3 elements ICP-MS Ag Be Bi Ce In Mo Sb Se Te Th U W Yb PM Combined 40 elements

9 Ore grade analyses Decomposition pretreatment Determination Sample Elements Detection limit (ppm) Aqua Regia Digestion ICP-OES 0.5 g Ag As Cd Co Cr Cu Fe Mn Mo Ni Pb S Sb Zn P 4 elements Decomposition pretreatment Determination Sample Elements Detection limit (%) Sodium peroxide fusion ICP-OES 0.20 g Al As Ca Co Cr Cu Fe K Mg Mn Mo Ni P Pb S Sb Ti V Zn P 9 elements Check also total digestions and XRF-analyses) and sulphide selective leaches for Ni-ores (additional assays).

10 One element assays Decomposition pretreatment Determination Sample Elements Detection limit (%) Aqua Regia Digestion FAAS.0 g Ag As Cd Co Cu Ni Pb Zn ppm ppm 54A ICP-OES.0 g Ag As Cd Co Cu Ni Pb S Zn ppm ppm 54P (Package of 8 elements) Sodium peroxide fusion ICP-OES 0.2 g Al As B Ba Be Ca Co Cr Cu Fe K La Li Mg Mn Mo Nb Ni P Pb S Sb Sc Sr Ta Ti U V Y Zn P Analyses of processed samples (concentrates and other metallurgical products etc.) on request.

11 Precious metal assays To obtain the best quality and cost-efficiency in a particular geological project it is important to decide the strategy of analysis by selecting the appropriate analytical s (element suit, digestion / pretreatment, detection limits, optimum measurement area etc.) to fit the objectives of the project. To help this selection a description of different strategic levels of analysis applied at is given. Selecting a wrong may end up in attaining optimised results in wrong concentration levels and introducing problems in laboratory (contamination, additional sample dilutions) which may deteriorate accuracy and precision. Methods In gold and PGE-exploration, both the careful selection of sample preparation and the choice of analytical (including the of analytical sample) are critical. Figure 2 shows the effect of the grain size of nugget gold on sample for obtaining acceptable precision in gold analysis. We recommend carrying out a pilot study with selected, typical samples of the specified mineralization at an early stage of a large resource evaluation program. The mode of occurrence of gold can be studied using the so-called diagnostic leach and screen fire assay. Replicate analyses of samples can be carried out to study which of the available analytical techniques (and subsample ) will give acceptable precision (e.g. < 5 %) for reliable resource evaluation. Based on this data, a scheme of sample preparation and analysis can be selected for optimum accuracy and precision. A tailored QA/QC-protocol for the project can be planned. The study will also provide information to be used as baseline data for more thorough metallurgical tests. Sample Diameter of gold sphere (mm) 0. g 2 g g Figure 2. Minimum subsample required to contain the expected 20 particles of gold as a function of gold particle size at 4 ppm Au grade (Figure 3 in: Clifton et al. 969, Sample Size and Meaningful Gold Analysis, U.S.Geol. Surv. Prof Pap. 625-C,7pp.). 20 g g g g g 0.5 Different pretreatment and preconcentration /separation s are available (aqua regia digestion, fire assay, cyanide leach) combined with different s of determination (FAAS; GFAAS; ICP-MS; ICP-OES; gravimetric), each having its benefits and limitations. Our specialists will assist in the selection of a suitable analytical. In the geochemical exploration for the precious metals (Au, Pd and Pt), we recommend aqua regia leach, followed by pre-concentration by Hg co-precipitation and analysis by GFAAS (Methods 520U and 52U; 5 g

12 subsample) (Kontas et al.990). Sub-ppb detection limits can be attained for Au and Pd giving meaningful anomaly contrasts. Alternatively a larger sample of 20 g can be used (Method 522U). The s are applicable to non-mineralised samples (till, weathered bedrock, stream sediments, humus, rock). The use of pathfinder elements in geochemical prospecting particularly for gold is known to give more information of element dispersion in secondary environments and assist in the classification of the type of mineralization. Many studies have been carried out at LABTIUM to study the element associations connected to gold mineralizations (e.g. Nurmi et al.99, Eilu 999). Nurmi et al. concluded that the most important elements in exploration for Precambrian mesothermal gold deposits are: Au, Te, Bi, As, Ag, W and Se. Figure 3 shows the most important pathfinder elements connected to 4 Finnish and selected Australian and Canadian mesothermal gold deposits represented as enrichment factors relative to basalt. LABTIUM offers for gold exploration a unique packing including Au, Bi, Sb, Se and Te (520U) with ultra low detection limits. This set can be complemented by Methods 5P or 5PM. Another option is a multielement package using ICP-OES and ICP-MS analysis (55PM). This package will give totally 42 elements including Au, Pd and Pt with ultra-trace level detection limits. Note that these s are not suitable for mineralised samples. 60 Number of deposits Au Te S As W Bi Ag Se Sb B Mo Cu U Hg Pb Sn Cr Co Tl Ni Zn Enrichment relative to basalt > Figure 3. Frequency and contrast of concentrations (relative to background) of elements enriched in mesothermal gold deposits (Nurmi et al.99). Method 52U or 522U is recommended for low level Au-analyses. The Method 522U, using a 20 g subsample, is best suited for prospecting or for preliminary ore assay. In some cases, depending on the mineralogy of the sample, the aqua regia leach may give slightly lower recoveries for Au as compared with fire assay (Juvonen & Kontas 999). Information on high graphite content, which interferes in the aqua regia leach procedure, should be conveyed to the laboratory. Also dissolution of some PGE-minerals is not complete to aqua regia.

13 Ore grade assays of gold and the platinum metals are performed by a high-precision classical Pb fire assay using either 25 g or 50 g subsamples (704/705), combined with alternative finishes (FAAS, ICP- OES, gravimetric). If only Au (or Pd/Pt) is to be analysed, we recommend the Method 704A (or 705A) where Au is determined by FAAS. If, however, Au, Pd and Pt are to be analysed we recommend the Method 704P (or 705P). When Rh content is required, Method 708P (or 708A) can be applied. Combined with 705A (Au) Au, Pd, Pt and Rh can be analysed. Request for a quotation. Special precautions need to be taken if samples contain appreciable amounts of graphite, S, As, Te, Se, Ni, Cu. For sample with high concentrations of these metals smaller subsample may have to be used deviating from the original request. Gravimetric determination after the fire assay (705G) gives the best precision and accuracy for high-grade ( ppm) gold samples and low-level concentrates. For high-level concentrates use the 700G. When all six of the PGE are to be analysed, the of choice is the NiS fire assay (74M). Our includes Te coprecipitation for better Au recovery (Juvonen et al. 994). Detection limits at the ppb range are obtained by our ICP-MS determination. Osmium is an optional element in this and should be specified in the request for analysis. The routine sample is 5 g, but alternative sample s can be used. As a routine for cyanide soluble gold we recommend 236A which involves the use of PAL000 machine. The enables the simultaneous pulverizing and cyanide leach of crushed rock samples, percussion samples or soil samples. A 0,500 kg subsample can be used. The leaching is very effective due to aggressive leaching conditions which promote the liberation and breaking of gold nuggets. Graphite, organic matter (humus) and sulphides interfere in the cyanide leach, lowering the recovery of gold. The concentration of cyanide soluble free gold may also be evaluated using the sodium cyanide leach. The traditional 3 hour tumbling with the LeachWELL accelerator (235A). A large, representative subsample (0.5 kg) can be used. Combined with pulverising of total sample (sample preparation Method 50) the is the best possible routine in the case of coarse-grained gold for grade control and resource evaluation samples (e.g. RC-samples, chip samples). The results attained by this partial extraction are comparable to technical CIP- and CIL- extraction techniques and are of benefit in the metallurgical testing of the mineralisation. The is not suitable when the total content of gold is needed. Additional s for gold analysis include screen fire assays for coarse grained gold, diagnostic leaches to evaluate mode of occurrence of gold in different mineralogical phases and analysis of the total gold, which includes cyanide leach and analysis of the tailing (and head, if requested) sample by fire assay. The most suitable analysis for silver is by acid digestion with aqua regia and finish with FAAS (5A/54A) or ICP-OES (50P/54P; see base metals). However, there are potential limitations in the solubility of Ag in high concentrations (Ag > 00ppm). Fire Assay and gravimetric finish (705G) with a more representative sample and better precision can be used for ore grade samples (Ag > 50ppm). In addition metallic silver can be analysed with cyanidation s 235A and 236A as gold.

14 Concentration ranges of different analytical s used at for Au-analysis Au ppb 0.ppb ppb 0ppb 00ppb.0ppm 0 ppm 00ppm 000ppm % 0 % 52U U /705U Reagent contamination /705P /705A /705/700G 000 Concentrates 235/225A M Optimum range of concentration Min/max range of concentration PAL000 for simultaneous pulverising and cyanide leach of 0,5 kg subsample

15 Precious metal assays Geochemical analyses (non-mineralised samples) Decomposition pretreatment Determination Sample Elements Detection limit (ppm) Aqua Regia Leach Hg-coprecipitation GFAAS 5 g* Au Bi Sb Se Te 0.5ppb 2ppb 5ppb 5ppb 2ppb 520U 5 g* Au Pd Te 0.5ppb 0.5ppb 2ppb 52U Aqua Regia digestion ICP-OES and ICP-MS 5 g Ag Al As Au B Ba Be Bi Ca Cd Co Cr Cu Fe K La Li Mg Mn Mo Na Ni P Pb Pd Pt S Sb Sc Se Sn Sr Te Ti Th Tl U V W Y Zn Zr 5 0.5ppb 5 0,5 5ppb ppb 0.5ppb 20 2ppb 0,5 5ppb 0. 2ppb 0,0 5ppb PM 42 elements Analyses of Au, Pd and Pt at sub-ppb levels in organic samples (vegetation, humus etc.) based on quotation.

16 Assay analyses Decomposition pretreatment Determination Sample Elements Detection limit (ppm) Aqua Regia Leach Hg-coprecipitation (Preroasting Included) GFAAS 20 g Au Pd Pt Te U Pb-Fire Assay FAAS 25 g Au Pd Pt A 50 g Au Pd Pt A 50 g Rh 708A ICP-OES 25 g Au Pd Pt 0 ppb 0 ppb 0 ppb 704P 50 g Au Pd Pt 5 ppb 5 ppb 5 ppb 705P 50 g Pd Pt Rh 5 ppb 5 ppb 5 ppb 708P NiS-Fire Assay Te-coprecipitation ICP-MS 5 g Au Pd Pt Rh Ir Ru (Os 0.5 ppb ppb 0. ppb ppb 0. ppb 2 ppb ppb) 74M Optional PAL000-analysis. Pulverizing of <2mm sample and Cyanide Leach FAAS 0.5 kg Au Ag Cu A Cyanide Leach 3 h accelerated FAAS 0.5 kg Au Ag A

17 For the analyses of high grade ores and low-level concentrates ( > 50 ppm 000 ppm) we recommend Pb-Fire Assay with gravimetric finish. Analyses of Ag see also Base Metals (s 50/54P). Pb-Fire Assay Gravimetric 50 g Au Ag 2 ppm 5 ppm 705G Special analyses for gold Concentrates Pb-Fire Assay (sample varies 5-30 g) with gravimetric finish. Includes sample preparation and representative subsampling using precision riffle splitter. Concentration range ppm 700G Screen Fire Assay for coarse gold Sieving of a 0.5 kg subsample with a 25 µm (20 mesh) sieve. Weighing each fraction. Fire assay ( Method 705A ) of the entire + 25 µm fraction. Duplicate Fire assay ( Method 705A ) of - 25 µm fraction. Calculation of ed concentrations of gold (total and fractions). Total gold Cyanide leach of a 0.5 kg subsample ( Method 235A or 236A ). Washing, neutralising and homogenising the tailing. Duplicate Fire Assay ( Method 705A ) of the tailing. Party and umpire assays

18 Additional assays When the ore forming mineral is exceptional or when total concentrations for geochemical or petrological studies (trace levels of elements) are required, please contact the laboratory for assistance in selecting the best possible digestion/ pretreatment for your purpose (e.g. total digestion Method 307P/M, XRF Method 75X; see Whole Rock Analysis;). The XRF technique is also a versatile tool in the analysis of the base metals (Method 75X). For more information on the XRF technique see the section on Petrological Analyses. In addition to classical geochemical s, a selection of selective leaches (using water extraction, ammonium acetate, pyrophosphate etc.) combined with ICP-MS-analysis is also available for geochemical exploration of buried ore deposits. The set of elements is comparable to 5MP or 55MP. Elements in specific mineral phases of the sample can also be determined, such as Ni in the sulphide phase or elements in the carbonate phase of the sample. Special s are available e.g. for the determination of mercury, total sulphur and carbon (Combustion; Method 80L) or sulphur and carbon mineral phases. Volatiles Decomposition pretreatment Determination Sample Elements Detection limit Combustion technique Hg -Analyzer 0. g Hg ppm 822L Ignition Gravimetric g Loss on ignition at 000 o C % 83G Combustion technique S/C-Analyzer 0.2 g S C % % 80L 8L Determination of carbonate carbon and non-carbonate carbon Combustion technique Treatment with HCl C-Analyzer g C-tot. C-carb. C-noncarb. 00 ppm L 86L

19 Base metals in sulphides Decomposition pretreatment Determination Sample Elements Detection limit Ammonium Citrate- H 2O 2 - leach ICP-OES 0.5 g Cu Ni Co Fe S 0 ppm 0 ppm 0 ppm 00 ppm 50 ppm 240P Bromine-Methanolleach FAAS 0,5 g Cu Ni Co Fe 5 ppm 250P Comparison of the leaching efficiency of different digestion s in the analysis of ultramafic rock samples with varying contents of sulphide- and silicate-ni Ni (ppm) Ammonium citrate+h2o2-leach Ascorbic acid+h2o2-leach Digestion w ith 7M nitric acid Aqua regia digestion Peroxide fusion Bromine+methanol A B C D E F G H I J K Other parameters Specific gravity Gas pycnometer SG 0,0g/cm 3 90G Magnetization Satmagan Fe 3O 4 0,0% 95G

20 Petrological analyses Whole rock analyses are carried out using high precision s applying state-of the-art instrumentation (XRF, ICP-OES, ICP-MS). Major, minor and many trace elements are determined by XRF. Determinations are made on pressed powder pellets (Method 75X). The XRF analysis can be supplemented by determination of the rare earth elements (Method 307M, package B) and other trace elements by ICP-MS and/or ICP-OES after the total digestion of the sample (package A). PGE at low concentration levels (Method 74M) can be included for petrological studies. Carbon (Method 8L) and loss on ignition (Method 83G) are recommended for complete whole rock analysis. Individual determinations, which are often required in whole rock analysis, such as iron (II), fluoride, H 2 O + and H 2 O -, are also available. The XRF is applicable to rocks and soil samples, such as sand, gravel, till and sediments. Technical products and ash of similar composition can also be analysed. The prerequisite for applicability of the XRF is that the chemical composition of the sample remains unchanged during the fine grinding (< 0 µm) as the pressed powder pellet is prepared. Samples containing > 20 % S cannot be analysed by this.

21 Whole rock analysis Decomposition pretreatment Determination Sample Elements Detection limit (ppm) Pressed powder pellets Determination of carbon is also recommended (Method 8L). XRF 7.0 g Al As Ba Bi Ca Ce Cl Cr Cu Fe Ga K La Mg Mn Mo Na Nb Ni P Pb Rb S Sb Sc Si Sn Sr Th Ti U V Y Zn Zr X Precious metals Decomposition pretreatment Determination Sample Elements Detection limit (ppb) NiS-Fire Assay Te-coprecipitation ICP-MS 5 g Au Pd Pt Rh Ir Ru (Os ) 74M Optional

22 Rare earth and other trace elements Decomposition pretreatment Determination Sample Elements Detection limit (ppm) HF-HClO 4-digestion ICP-MS Package A 0.2 g As Ba Be Bi Cd Co Cr Cu Li Mo Ni Pb Rb Sb Sn Sr Ti Tl V Zn P/M Package B 0.2 g Ce Dy Er Eu Gd Ho La Lu Nd Pr Sm Sc Tb Th Tm U Y Yb

23 Individual determinations for whole rock analysis Decomposition pretreatment Determination Sample Elements Detection limit (%) Ignition Gravimetric g Loss on ignition 000 o C 83G Combustion technique H 2O analyzer 0.5 g Moisture Cryst.water 85L Acid digestion Titrimetric 0.5 g Fe T HF - H 2SO 4 NaOH-fusion Potentiometric 0. g F - 725I

24 SAMPLE MANAGEMENT AND STORAGE Systematic and well-organised sample archiving is not always thought to be included in the quality management of an exploration project. Good archiving helps the future retrieval of samples for e.g. feasibility testing and replicate or umpire analysis. During future audits of the project, well organised archiving is one of the fundamental issues. At special attention is paid on labelling and storing of all materials. The laboratory samples are placed in plastic ampoules and stored in impact resistant styrofoam cases. Pulps and /or rejects are stored in sealed plastic bags in pallets. All the packing materials except for pallets are included in the prices. The cost for long term storage of drill cores, rejects (906) and pulps (907) can be negotiated. Sample batch reception includes checking the sample numbering, sorting etc. and packing materials. If the client does not want the rejects and pulps to be returned a waste management levy is invoiced (902). The disposal of hazardous materials is invoiced on costs (903). If sample batches are arriving in the laboratory highly unorganised the laboratory is forced to invoice also the reorganising of the field samples. Also if the sample bags or containers are damaged, the replacement of the samples to new containers has to be invoiced. Reception of the batch of samples 90 Waste management levy 902 Disposal of hazardous wastes 903 Organising highly disorganised samples 904 Replacing of samples to new containers 905 Storage of rejects/ drill cores after 3 moths from reporting 906 Storage of pulps after moths from reporting 907

25 ACCREDITATION Ltd. (formerly The Geolaboratory of the Geological Survey of Finland), is an accreditaded testing laboratory. The accreditation according to ISO/IEC 7025 was received originally in 994 from the Finnish Accreditation Service FINAS at the MIKES (The Centre for Metrology and Accreditation). The accreditation code of is FINAS T025. The up-to-date scope of the accreditation can be found in and then FINAS service. The FINAS accredited bodies may state in their reports and certificates that they are accredited by FINAS, which is a signatory of the EA (European co-operation for Accreditation), ILAC (International Laboratory Accreditation Cooperation or IAF (International Accreditation Forum Inc.; recognition agreement. Thus a global acceptance and recognition of the accreditation and quality system of Ltd is achieved. Ltd is continuously participating in independent, international proficiency tests in the mineral sector run by e.g. Geostats Pty Ltd, Australia and the GeoPT sponsored by the International Association of Geoanalysts (IAG). These tests are used to evaluate the performance and validity of our s in comparison to other international mineral testing laboratories. The reports are available to clients on request. Lars-Martin Westerberg Quality Manager Oy / Betonimiehenkuja 4 FIN Espoo FINLAND/ Tel:

26 Oy/Ab/Ltd. Business ID tel firstname.lastname@labtium.fi Contact: Heikki Niskavaara Business area director. Exploration and Mining Espoo Laboratory manager Hanna Kahelin tel (Betonimiehenkuja 4) P.O.Box ESPOO Kuopio Laboratory manager Lea Hämäläinen tel (Neulaniementie 5) P.O.Box KUOPIO Rovaniemi Laboratory manager Juha Virtasalo tel (Raidetie ) (96900 SAARENKYLÄ) P.O.Box ROVANIEMI