Applied Mineralogy of the Kevitsa Nickel-Copper-PGE Deposit, Sodankylä, Northern Finland

Applied Mineralogy of the Kevitsa Nickel-Copper-PGE Deposit,Sodankylä, Northern Finland

K Kojonen1, J Laukkanen2 and F Gervilla3

ABSTRACTThe Kevitsa Ni-Cu-PGE deposit in northern Finland contains disseminatedNi-Cu-Fe sulfides, and platinum-group minerals (PGM). The 2.05 Ga-oldultramafic-mafic, funnel-shaped intrusion is intruded into avolcanosedimentary sequence. The major ore minerals are pentlandite,hexagonal pyrrhotite and troilite, chalcopyrite, cubanite and magnetite.Pyrrhotite and pentlandite are replaced by pyrite, millerite andheazelwoodite near the surface. Nickeline, maucherite and gersdorffite arelocally abundant. A pilot feed sample of 575 t of the main orebody atKevitsa had average grades 0.45 per cent Cu, 0.36 per cent Ni, 1.85 percent S, 0.33 g/t Pt, 0.34 g/t Pd and 0.19 g/t Au, with 0.06 per cent Nicontained in silicates. Higher PGE contents (2 - 27 ppm) occur in a verticalN-S bearing fault zone. The PGM (n = 6022) mapped in specimens of fourdrill holes, consist of sperrylite 34.7 vol per cent, braggite and cooperite18.5 vol per cent, geversite 17.2 vol per cent, moncheite 14.7 vol per cent,merenskyite 6.7 vol per cent, stibiopalladinite 4.3 vol per cent, sobolevskite1.9 vol per cent, kotulskite 0.7 vol per cent, michenerite 0.6 vol per cent,keithconnite 0.3 vol per cent, rustenburgite 0.1 vol per cent, melonite,froodite, laurite together 0.1 vol per cent and only a few grains ofsudburyite, irarsite, vysotskite, erlichmanite, hongishiite, Pt-Cu-alloys,three undefined Pd and Pt bismuthinides and antimonides and a

Pd-Cu-bearing Pt-Ni-Fe sulfide. Most of the PGM, 62 per cent, areenclosed in silicates, 29 per cent are intergrown with sulfides, nine per centare within sulfides. A portion of the PGE occurs in solid solution insulfides and arsenides. Ni flotation yielded smelter-grade concentratesaveraging 12.2 per cent nickel. The average sulfide Ni recovery is78.8 per cent and total Ni recovery is 65.3 per cent. The average Pt is 10 g/tat 55 per cent recovery, Pd 7.7 g/t at 38 per cent recovery and Au 1.6 g/t atten per cent recovery. Cu concentrates averaged 28.6 per cent Cu with anaverage recovery of 78 per cent and further 11 per cent in the nickelconcentrate. The copper concentrate contains 4 g/t Au at 24 per centrecovery. The average Fe to MgO ratio 17.9 is well above the targetedminimum of 4.5. The pilot results show that the previously used TETA(triethylene tetramine) can be avoided and good quality, smelter-gradeconcentrates can be produced from the Kevitsa ore at economical levels ofrecovery by conventional flotation methods.

INTRODUCTION

The Kevitsa (Keivitsa) Ni-Cu-PGE deposit (Figure 1) inSodankylä commune, Northern Finland, was discovered by theGeological Survey of Finland in the 1960s, but because of lowmetal grades was not classified as an economic ore deposit. In1992, an extensive exploration program was started by theGeological Survey of Finland and 278 holes were drilledtotalling 32 845 metres (Mutanen, 1994). The exploration rightswere sold in January 1996 to Outokumpu Oy who drilled15 holes totalling 2200 metres, and conducted geochemical andgeophysical mapping and metallurgical tests. Outukumpu Oyreturned the Kevitsa mining rights back to the ministry in the endof 1998, because no new higher grade deposits were discoveredduring the three-year exploration period. As a result of the

Ninth International Congress for Applied Mineralogy Brisbane, QLD, 8 - 10 September 2008 605

1. Senior Scientist, Geological Survey of Finland, Bedrock Geologyand Resources, PO Box 96, Espoo 02151, Finland.Email: [email protected]

2. Senior Scientist, Geological Survey of Finland, Mineral Processing,Tutkijankatu 1, Outokumpu 83500, Finland.

3. Professor, Instituto Andaluz de Ciencias de la Tierra (Universidad deGranada – CSIC), and Departamento de Mineralogía y Petrología,Facultad de Ciencias, Granada E-18002, Spain.

FIG 1 - Simplified geological map of the Keivitsa-Satovaara intrusion, redrawn after Mutanen (1997). The symbols shown in the mapare the following: 1 = Cu-Ni-PGE ore, 2 = pelitic and black schist hornfels, 3 = komatiite-related ultramafic rocks, 4 = olivine werhliteand olivine websterite, 5 = gabbro, 6 = granophyre, 7 = mica schists and other pelitic rocks, 8 = black schists, 9 = arkosic quartzite,

10 = chlorite-amphibole rocks, 11 = fault.

exploration work Outokumpu company reported the mineralreserves as 87 Mt @ 0.25 per cent Ni, 0.39 per cent Cu, 0.6 g/tPGM+Au, 0.015 per cent Co, which were not economic to minewith the current metal prices. However, a preliminary plan wassuggested with open pit mining 6 Mt/year. The sulfides wouldhave been processed by flotation to produce copper and nickelconcentrates from which the metals would have beenhydrothermally leached. In 1999, the Geological Survey ofFinland started new geochemical and mineralogical studies alongwith deposit modelling of the previously drilled samples todefine the PGE rich zones or reefs in the Kevitsa intrusion. Newgeochemical analyses were made previously as several metreslong samples analysed cores that showed elevated PGE contentsfrom half a metre samples using MS-ICP method.Simultaneously, XRF-whole rock analyses were made to providehost-rock compositional date that was computed in 3D oredeposit modelling program. This led to the discovery of apreviously unknown PGE-rich zone with ‘pipes’ in the centralpart of the Kevitsa intrusion.

In 2000, the Scandinavian Gold Prospecting company acquiredthe mineral rights of the Kevitsa deposit and started furtherexploration and metallurgical studies of the ore in co-operationwith the Geological Survey of Finland. At present, a mine isunder construction at Kevitsa by the Kevitsa Mining Oy that isscheduled to start production in 2010 (Scandinavian MineralsLtd, 2007). The mining is planned to start as an open pitoperation with mining 5 Mt/year ore, and about 15 Mt/year wallrock (Figure 2). The proven ore reserves are 52 Mt @ 0.295 percent Ni, 0.415 per cent Cu, 0.014 per cent Co, 0.141 ppm Au,0.201ppm Pd, 0.310 ppm Pt; probable ore: 10.6 Mt @ 0.295 percent Ni, 0.492 per cent Cu, 0.015 per cent Co, 0.142 ppm Au,0.171 ppm Pd, 0.267 ppm Pd, totalling 66.8 Mt down to 400 mdepth. The resources to 1000 m depth are (0.1 Ni cut-off):185 Mt @ 0.22 per cent Ni, 0.29 per cent Cu, 0.01 per cent Co,0.09 ppm Au, 0.13 ppm Pd, 0.21 ppm Pt and indicated 90 Mt @0.31 per cent Ni, 0.42 per cent Cu, 0.01 per cent Co, 0.13 ppmAu, 0.19 ppm Pd, 0.30 ppm Pt.

GEOLOGY

The Kevitsa layered intrusion is a funnel-shaped body about6 × 4 km in size, consisting of ultramafic and mafic rocks thatwere intruded 2.05 Ga ago (Huhma et al, 1996) intovolcanosedimentary country rocks of central Finnish Lapland(Figure 1). From bottom to top, this intrusion consists of:

1. a chilled microgabbro margin;

2. a thick ultramafic unit made up of olivinepyroxenitecumulates;

3. a gabbro unit composed of gabbros, ferrogabbros andmagnetite gabbros; and

4. a granophyre unit.

The volcanosedimentary country rocks are komatiiticvolcanogenic rocks within pelitic rocks, which contain abundantgraphite and sulfides in variable amounts (Mutanen, 1997). Boththe intrusive rocks belonging to the Kevitsa intrusion and thevolcanosedimentary rocks were locally hydrothermally altered andmetamorphosed into greenschist-facies conditions (Tyrväinen,1983). The ore present at Kevitsa consists of:

1. low-grade disseminated Fe-Ni-Cu sulfides with low PGE +Au (<1 ppm, regular ore);

2. low-grade disseminated Fe-Ni-Cu sulfides containing zonesof high PGE+Au (>1 ppm) contents; high PGE+Au ore);and

3. Fe-sulfide rich ore type with low Ni and Cu (false ore).

The high PGE+Au ore is located in a N-S striking verticalshear zone in the Keivitsansarvi, in the NE part of the Kevitsaintrusion (Gervilla and Kojonen, 2002). The host rocks of thehigh Ni-Cu-PGE zones (PGE+Au ≥1 ppm) are altered olivineclinopyroxenites and olivine websterites, with narrow layers ofwehrlites and lherzolites. The cumulus minerals are olivineFo75-90,diopside and orthopyroxene. The intercumulus minerals areorthopyroxene, plagioclaseAn60-80, actinolitic amphibole andminor phlogopite, chlorapatite, graphite and sulfides. The rocksare altered and sheared and contain secondary actinoliticamphibole and serpentine with minor chlorite, talc, phlogopite,epidote and calcite. The low PGE + Au ore type (regular) occuras disseminated orebodies (totalling) on both sides of the shearzone, and are less altered. The sulfide minerals are pentlandite,hexagonal pyrrhotite and chalcopyrite, magnetite beingabundantly intergrown with the sulfides. The third ore type(false) consists mostly of iron sulfides, pyrrhotite and pyrite, andhas very low Cu, Ni and PGE. Furthermore, verticalmassive-sulfide veins, up to few cm wide, consisting of Cu-Ni-Fesulfides, have been occasionally observed in the drill cores.

ANALYTICAL METHODS

The selected drill core samples were prepared as polishedsections or polished thin sections with standard preparationmethods. The specimens were studied by polarising microscopyin transmitted and reflected light and photographed. Some of thespecimens were studied by JEOL JSM 5900 LV variable vacuumscanning electron microscope (SEM) and analysed by energydispersive spectrometry (EDS). The gangue and ore mineralswere analysed quantitatively with Cameca SX50 electronmicroprobe using wavelenth dispersive spectrometry (WDS) andboth synthetic and natural microprobe standards. Pyrrhotite typewas studied with magnetite colloid staining method (Bitter,1931) and electron microprobe analyses. A rare phase searchprogram Turbo-Scan installed in Cameca SX 50 was used tolocate automatically the PGM and native gold grains in thespecimens (Johanson and Kojonen,1995). Intergrowths betweenPGM and sulfides or silicates were recorded by BSE-images

606 Brisbane, QLD, 8 - 10 September 2008 Ninth International Congress for Applied Mineralogy

K KOJONEN, J LAUKKANEN and F GERVILLA

FIG 2 - A 3D model made of the Kevitsa disseminated Ni-Cu-PGEorebodies (red) and the planned open pit (green). Compiled by

Jyrki Parkkinen (Walker, 2007).

from each PGM or gold grain (see Appendixes 1 - 4). TracePGE-analyses were made from some sulfides and arsenides usingthe CSIRO-Trace software in Cameca SX50 electron microprobewith 35 kV accelerating voltage, 500 nA current and 600 secondsmeasuring time. PGM concentrates were made by NATIResearch (http://www.natires.com) of selected PGE-rich drillcore samples in two grain size fractions (-37 µm and -80 µm) andprepared as polished sections. These were analysed by MineralLiberation Analyser (MLA) at the Mineral ProcessingLaboratory of GSF. The drill core bulk analyses were made byICP-MS with nickel sulfide collection for PGE and Au, andwhole rock analyses by XRF for the major elements. Theanalyses of Cu, Ni and Co were made with ICP. The products ofthe mineral processing tests were analysed by AAS and ICPMethods.

ORE MINERALOGY

The major sulfide minerals present are pentlandite, pyrite,chalcopyrite, cubanite and hexagonal pyrrhotite. In the upper partof the Keivitsansarvi deposit pyrite, pentlandite, millerite,heazlewoodite and chalcopyrite often show fine graphicalintergrowths. Pyrite is replaced along fractures by pentlandite. TheAs-bearing minerals niccolite, maucherite, and gersdorffite, areabundant in some samples. The oxidic ore minerals includechromite and magnetite. Hexagonal and monoclinic pyrrhotite andtroilite have low Ni contents (0 - 0.87 wt per cent) and pentlanditeexhibits Fe/Ni ratios below 1 (down to 0.7). Coexisting pyritecontains 0.17 - 1.97 at per cent Ni and 0.18 - 2.37 at per cent Co(Gervilla and Kojonen, 2002). The sulfides occur either in theintercumulus spaces of the primary cumulus silicates orintergrown with secondary actinolitic amphibole, serpentine,chlorite and phlogopite. The Ni content in pentlandite correlateswith that of the associated olivine (up to 1.75 wt per cent Ni). ThePGM occur mostly as monomineralic grains <75 µm in sizeincluded in hydrosilicates or attached to the grain boundaries ofsulfides. Only a small portion of PGM grains are included insulfides. The Pt minerals consist of sperrylite, moncheite, braggite,cooperite and geversite, and Pd minerals of merenskyite,michenerite, keithconnite, kotulskite, sobolevskite, vysotskite,stibiopalladinite, Pd-rich melonite, undefined Pd(Bi,Sb,As) and(Cu,Ni,Fe)Pd. Part of the Pd is hosted by pentlandite andarsenides/sulfarsenides in trace concentrations. Irarsite occurslocally with laurite in pentlandite and amphibole. Erlichmanite isintergrown with gersdorffite and sperrylite. The Pt/Pd ratio is onaverage 1.77 (N = 4217) in the Kevitsa pyroxenitic PGE-richzones. Melonite contains significant amounts of Pt, Pd and Bi(Figure 3; Gervilla and Kojonen, 2002); moncheite is poor in Nibut high in Pd and Bi (Figure 4). Moncheite forms near completesolid solution with merenskyite (Figure 4) from nearlystoichiometric PtTe2 to (Pt, Pd) Te2 with Pt/Pd = 1.

Merenskyite is rich in Bi and Ni (Figure 5), and has a Pd/Ptratio close to 1. Merenskyite from the upper part of the pipes isvery rich in Pt approaching the composition of moncheite;however, in the lower part of the central pipe, (drill core 813) it ispoor in Pt (<1.25 wt per cent), and exhibits a complete solidsolution between PdTe2 and (Pd, Ni)Te2 with Pt/Pd = 1.Moncheite shows extensive substitution of Te for Bi: fromstoichiometric composition to 30.5 wt per cent Bi and 40 wt percent Bi, respectively (Figure 5).

A complete solid solution also exists between kotulskite andsobolevskite, although Te is substituted by Bi and Sb (Gervillaand Kojonen, 2002). The distribution of PGM analysed by MLAfrom concentrates made from drill cores taken from differentdepths, is heterogeneous. In the upper part, ie the uppermost 40m of the central pipe sampled (drill core 713), the PGMdistribution (N = 1790 grains) in the fractions +37 to -90 µm is:sperrylite 54.8 vol per cent, geversite 30.5 vol per cent,stibiopalladinite 7.7 vol per cent, sobolevskite 3.4 vol per cent,

braggite and cooperite 1.35 vol per cent, kotulskite 0.7 vol percent, michenerite 0.6 vol per cent and trace moncheite,rustenburgite, froodite, merenskyite, keithconnite and laurite.The samples from the intersection at 85 m (N = 650 grains, drill


APPLIED MINERALOGY OF THE KEVITSA NICKEL-COPPER-PGE DEPOSIT, SODANKYLÄ, NORTHERN FINLAND

FIG 3 - Palladian melonite, Ni-Pd bearing moncheite andPt-Ni bearing merenskyite from Keivitsansarvi plotted in thePtTe2-PdTe2-NiTe2 ternary diagram. R = diamond drill hole.

FIG 4 - Bismuthian moncheite analysed from the Keivitsansarvidrill core specimens. R = diamond drill hole.

FIG 5 - Solid solution between kotulskite and sobolevskite andincomplete solid solution between merenskyite and michenerite

in Kevitsa drill core samples. R = diamond drill hole.

core 695), the PGM assemblage is largely dominated bymoncheite 83.1 vol per cent, cooperite and braggite 7.3 vol percent, merenskyite 4.0 vol per cent, kotulskite 2.2 vol per cent,sperrylite 1.9 vol per cent, michenerite 0.6 per cent, sobolevskiteand rustenburgite 0.3 vol per cent. At greater depth of 310 m(drill core 813, N = 340 grains) the PGM are: merenskyite 57.0vol per cent, sperrylite 38.8 vol per cent, geversite 3.1 vol percent, michenerite 0.4 vol per cent, moncheite 0.3 vol per cent,sobolevskite and stibiopalladinite 0.8 vol per cent each. In adifferent pipe cut at 60 - 72 m (drill core 824, N = 709 grains) thePGM are: braggite 85.2 vol per cent, moncheite 8.6 vol per cent,merenskyite 2.0 vol per cent, keithconnite 1.6 vol per cent,cooperite 1.5 vol per cent, sperrylite 0.8 vol per cent, laurite 0.2vol per cent and kotulskite 0.1 vol per cent.

INTERGROWTHS

Textural observations made from BSE images from polished thinsections show that 54 per cent of the 336 PGM grains occurenclosed in hydrous silicates (amphibole, serpentine or chlorite);38 per cent are in contact with sulfides, only six per cent areincluded in sulfides and two per cent fill late fractures in sulfides(see Appendixes 1 - 4). The PGE-rich zones are hydrothermallyaltered. The base metal sulfides and the PGM are located in theintercumulus spaces intergrown with actinolitic amphibole,serpentine, chlorite, and phologopite.

PGM DISTRIBUTION

The MLA results of PGM concentrates show that size of most ofthe 6022 PGM grains are <37 µm (96.2 per cent) and only somefew grains are 37 - 80 µm (3.8 per cent) in size. From the

measured areas of PGM in all four drill cores, they consist ofsperrylite 34.7 vol per cent, braggite and cooperite 18.5 vol percent, geversite 17.2 vol per cent, moncheite 14.7 vol per cent,merenskyite 6.7 vol per cent, stibiopalladinite 4.3 vol per cent,sobolevskite 1.9 vol per cent, kotulskite 0.7 vol per cent,michenerite 0.6 vol per cent, keithconnite 0.3 vol per cent,rustenburgite 0.1 vol per cent, melonite, froodite and lauritetogether 0.1 vol per cent (Figure 7). Other PGM occurringsporadically in low concentrations are irarsite, vysotskite,erlichmanite, hongshiite, Pd-Cu alloys and three differentunidentified Pd and Pt bismuthides and antimonides, as well as aPd-, Cu-bearing Pt-Ni-Fe sulfide.

TRACE PGE ANALYSES OF SULFIDES ANDARSENIDES

The PGE trace elements in gersdorffite, nickeline, maucherite,pentlandite, mixture of pentlandite and pyrite and chalcopyritewere analysed by Cameca SX50 using the CSIRO-Traceprogram. Rhodium was discovered in gersdorffite up to 454 ppm,platinum in gersdorffite <30 - 277 ppm, nickeline <33 - 36,chalcopyrite <27 - 54 ppm, and a mixture of pyrite andpentlandite <29 - 42 ppm. Palladium was analysed in pentlanditewith contents of 27 - 150 ppm, from nickeline with contents<25 - 342 ppm, from maucherite with contents <25 - 241 ppmand from gersdorffite with contents <15 - 868 ppm (Gervilla andKojonen, 2002).

MINERAL PROCESSING TESTS

An ore sample totalling 575 t was tested in the pilot plant of theMineral Processing Laboratory of the Geological Survey ofFinland in three phases from September 2006 to February 2007.The first two phases were concentrated for the processoptimising and the third phase to improve the results. The samplewas collected from the drill cores with average 0.448 wt per centCu, 0.36 wt per cent Ni, 1.85 wt per cent S, 0.329 g/t Pt,0.336 g/t Pd and 0.186 g/t Au. The ore was milled to 80 per cent<70 µm grain size and further fine milling was done during theprocess. The nickel and copper concentrates were made byflotation and the concentrates had average 12.2 per cent Ni, and28.55 per cent Cu, respectively. These correspond to recoveriesof 78.8 per cent Ni and 89 per cent Cu of the sulfides. Part of theNi remained in the silicates. The Ni concentrate also contained10 g/t Pt and 7.7 g/t Pd with recoveries of 55 per cent and38 per cent, respectively. The copper concentrate contained4 g/t Au with 24 per cent recovery. The Fe:MgO ratio of theconcentrate was 17.9 (Walker, 2007).



FIG 6 - Intergrowth patterns of the PGM in the drill core specimensdiscovered from the Kevitsa drill core specimens, N = 336 PGM

grains.

sobolewskite; 1.90

laurite; 0.04

kotulskite; 0.73

michenerite; 0.58

keithconnite; 0.33

rustenburgite; 0.21

melonite; 0.03

froodite; 0.01merenskyite; 6.71

stibiopalladinite;

4.26

moncheite; 14.71 sperrylite; 34.67

geversite; 17.22

cooperite; 1.43

braggite; 17.16

FIG 7 - PGM vol per cent from specimens of four drill cores of Kevitsa deposits analysed by MLA, N = 6022 grains.

DISCUSSION AND CONCLUSIONS

The PGE mineralogy of the Kevitsa Cu-Ni-PGE sulfide deposithas been studied with optical and modern electron beam methodsto reveal the PGM phases present, their intergrowth patterns,grain sizes and relative abundances in the drill core samples.Furthermore, pilot mineral processing tests have been made atthe mineral processing laboratory of the Geological Survey ofFinland aiming to maximise the recoveries of copper and nickelto produce good quality, smelter-grade concentrates.Unfortunately, this has been made in cost of PGE recoveries. Therecoveries of Ni and Cu are 78.8 per cent and 89 per cent,respectively, whereas the recoveries of Pt and Pd are 55 per centand 38 per cent, respectively. The low recoveries of PGM areprobably due to the fine grain size of the PGM, which wouldneed additional grinding to become liberated from their hostminerals. The fine grain size of the PGM is common in manyPGE deposits worldwide and normally the recovery of the PGEis improved with flash flotation and ultrafine grinding (Xiao andLaplante, 2004; Anyimadu, Rule and Knopjes, 2006; Buys, Ruleand Curry, 2005; Rule, Anyimadu and Anthony, 2007).Scandinavian Minerals Ltd has signed an engineering agreementwith Outotec Oy for detailed engineering work, including openpit modelling, and designs the processing plant.

REFERENCESAnyimadu, A K, Rule, C M and Knopjes, L, 2006. The development of

ultra-fine grinding at Anglo Platinum, in Proceedings InternationalPlatinum Conference ‘Platinum Surges Ahead’, 143-149 (TheSouthern African Institute of Mining and Metallurgy: Johannesburg).

Bitter, F, 1931. Phys Rev, 38:1903Buys, S, Rule, C and Curry, D, 2005. The application of large scale

stirred milling to the retreatment of Merensky reef platinum tailings,in Proceedings 37th Annual Meeting of the Canadian MineralProcessors, Ottawa, 15 p.

Gervilla, F and Kojonen, K, 2002. The platinum-group minerals in theupper section of the Keivitsansarvi Ni-Cu-PGE deposit, northernFinland, Canadian Mineralogist, 40:377-394.

Gervilla, F, Kojonen, K, Parkkinen, J and Välimaa, J, 2004.Platinum-group element mineralogy, geochemistry and 3-Dmodelling of the Keivitsa Ni-Cu-PGE sulfide deposit, northernFinland, Mineral Exploration and Sustainable Development (eds:Eliopoulos et al) pp 583-586, (Millpress: Rotterdam).

Huhma, H, Mutanen, T, Hanski, E, Räsänen, J, Manninen, T, Lehtonen,M, Rastas, P Y and Juopperi, H, 1996. Isotopic evidence forcontrasting sources of the prolonged Palaeoproterozoicmafic-ultramafic magmatism in Central Finnish Lapland, in Programand Abstracts IGCP Project 336 Symposium, Rovaniemi, Finland,33:17 (University of Turku, Finland, Div Geol Mineral, Publ).

Johanson, B and Kojonen, K, 1995. Improved electron probemicroanalysis services at Geological Survey of Finland, Geol SurvCurr Res, 20:181-184.

Mutanen, T, 1994. Keivitsansarven kupari-nikkeli-jalometalliesiintymä,Geological Survey of Finland Report, 61 p, 12 images, 11attachments (in Finnish).

Mutanen, T, 1997. Geology and ore petrology of the Akanvaara andKoitelainen mafic layered intrusions and the Keivitsa-Satovaaralayered complex, northern Finland, Geological Survey of FinlandBulletin, 395.

Rule, C M and Anyimadu, A K, 2007. Flotation cell technology andcircuit design – An Anglo platinum perspective, Anglo Platinum.

Scandinavian Minerals Limited, 2007. Press release, Marketwire, 5 July.Tyrväinen, A, 1983. Pre-quaternary rocks of the Sodankylä and Sattanen

map-sheet areas, Sheet 3713 and 3714, Geological Survey of Finland,Espoo, Finland (in Finnish with English summary).

Walker, P, 2007. Scandinavian minerals, the Kevitsa, Finland, nickelproject: Towards production, Fennoscandian Exploration andMining, Rovaniemi, Finland, November.

Xiao, Z and Laplante, A R, 2004. Characterizing and recovering theplatinum group minerals – A review, Minerals Engineering,17:(9-10):961-979.





(a) Michenerite grain with pentlandite, scale bar 5 µm, BSE image. Ddh 695/80.15 m; (b) Merenskyite in silicate, scale bar 5 µm, BSEimage. Ddh 695/81.80 m; (c) Moncheite with pentlandite, scale bar 5 µm, BSE image. Ddh 695/83.70 m; (d) Moncheite in silicate, scale bar5 µm, BSE image, Ddh 695/81.15 m; (e) Moncheite with chalcopyrite in silicate, scale bar 10 µm, BSE image. Ddh 695/82.30; (f) Braggite

with pentlandite, scale bar 10 µm, BSE image. Ddh 695/84.10 m; (g) Kotulskite in silicate, scale bar 5 µm, BSE image. Ddh 695/83.30 m; (h)Ni-bearing merenskyite grain in silicate, scale bar 5 µm, BSE image, Ddh 695/80.15 m; (i) Moncheite in silicate, scale bar 10 µm, BSE

image. Ddh 695/80.15 m; (j) Moncheite in silicate in, scale bar 10 µm, BSE image. Ddh695/82.30; (k) Merenskyite with pentlandite, scale bar5 µm, BSE image. Ddh 695/82.30 m; (l) Moncheite in silicate, scale bar 5 µm, BSE image. Ddh 695/82.30 m; (m) Merenskyite withchalcopyrite, scale bar 5 µm, BSE image, ddh695/80.15 m; (n) Moncheite it silicate, scale bar 10 µm, BSE image. Ddh 695/82.30;

(o) Kotulskite with pentlandite, scale bar 20 µm, BSE image. Ddh 695/84.10.

APPENDIX 1



(a) Sperrylite within silicate, scale bar 5 µm, BSE image. Ddh 713/18.25 m; (b) Merenskyite with pentlandite, scale bar 5 µm, BSE image.Ddh 713/18.25 m; (c) Sperrylite within silicate, scale bar 5 µm, BSE image. Ddh 713/19.50 m ; (d) Sperrylite and mertieite II with pn, scalebar 10 µm, BSE image. Ddh 713/19.50 m; (e) Stibiopalladinite with pn in silicate, scale bar 5 µm, BSE image. Ddh 713/19.50; (f) Palladianmelonite within silicates, scale bar 10 µm, BSE image. Ddh 713/23.30 m; (g) Pd-Bi-menonite,, stibiopalladinite and pn in silicate, scale bar

10 µm, BSE image. Ddh 713/29.35 m; (h) Pt-Fe alloy, sperrylite and stibiopalladinite within silicate, scale bar 20 µm, BSE image, Ddh715/29.35 m; (i) Sperrylite with pentlandite in silicate, scale bar 20 µm, BSE image. Ddh 713/29.35 m; (j) Moncheite in silicate in, scale bar

5 µm, BSE image. Ddh 713/38.20 m; (k) Kotulskite in sulfide vein, scale bar 5 µm, BSE image. Ddh 713/38.50 m; (l) Moncheite with millerite,scale bar 10 µm, BSE image. Ddh 713/38.50 m; (m) Moncheite in silicates, scale bar 5 µm, BSE image. Ddh 713/39.05 m;

(n) Moncheite in silicate, scale bar 10 µm, BSE image. Ddh 713/39.05 m; (o) Palladian melonite with pentlandite, scale bar 20 µm, BSEimage. Ddh 713/40.70 m.

APPENDIX 2



(a) Sperrylite, michenerite and PdSbS with cpy, scale bar 20 µm, BSE image. Ddh 813/308.20 m; (b) Sperrylite and michenrite with cpy andilmenite, scale bar 20 µm, BSE image. Ddh 813/308.20 m; (c) Michenerite within silicate, scale bar 5 µm, BSE image. Ddh 813/309.20 m;

(d) Michenerite in silicate, scale bar 5 µm, BSE image. Ddh 813/309.20 m; (e) Sperrylite with magnetite and sulfides, scale bar 20 µm, BSEimage. Ddh 813/309.20 m; (f) Kotulskite in silicate, scale bar 5 µm, BSE image. Ddh 813/309.20; (g) Merenskyite within silicate, scale bar5 µm, BSE image. Ddh 813/310.20 m; (h) Merenskyite in silicate, scale bar 5 µm, BSE image. Ddh 813/310.20 m; (i) Merenskyite within

silicate, scale bar 5 µm, BSE image, Ddh 813/310.20 m; (j) Sperrylite with merenskyite in silicate, scale bar 20 µm, BSE image. Ddh813/310.20 m; (k) Merenskyite in silicate in, scale bar 5 µm, BSE image. Ddh 813/310.20 m; (l) Kotulskite within silicate, scale bar 10 µm,

BSE image. Ddh 813/310.90 m; (m) Michenerite in silicate, scale bar 5 µm, BSE image, Ddh 813/310.90 m; (n) Michenerite in silicate,scale bar 5 µm, BSE image. Ddh 813/310.90 m; (o) Sperrylite in silicate, scale bar 50 µm, BSE image. Ddh 813/310.90 m.

APPENDIX 3



(a) Michenerite in silicate, scale bar 5 µm, BSE image. Ddh 824/61.45 m; (b) Michenerite in silicate, scale bar 5 µm, BSE image,Ddh 824/61.45 m; (c) Michenerite with cpy in silicate, scale bar 100 µm, BSE image. Ddh 824/61.45 m ; (d) Michenerite and moncheite

in pn vein, scale bar 10 µm, BSE image. Ddh 824/61.45 m; (e) Braggite with pn, scale bar 100 µm, BSE image. Ddh 824/65.85 m;(f) Keithconnite with cpy, scale bar 5 µm, BSE image. Ddh 824/309.20; (g) Altered braggite in silicate, scale bar 5 µm, BSE image.

Ddh 824/64.40 m; (h) Irarsite with pn, scale bar 5 µm, BSE image. Ddh 824/64.40 m; (i) Altered braggite with pn, scale bar 50 µm, BSEimage. Ddh 824/64.40 m; (j) PdCu in pentlandite-millerite grain, scale bar 200 µm, BSE image. 824/64.40 m; (k) Braggite in pn, scale bar50 µm, BSE image. Ddh 824/64.40 m; (l) Altered braggite with pn and vysotskite silicate, scale bar 20 µm, BSE image. Ddh 824/64.40 m;

(m) Altered braggite with pn and NiS, scale bar 200 µm, BSE image. Ddh 824/64.40 m; (n) Altered braggite with pn, scale bar 50 µm,BSE image. Ddh 824/64.40 m; (o) Keithconnite with pn, scale bar 50 µm, BSE image. Ddh 824/64.40 m.

APPENDIX 4


Documents

Applied Mineralogy of the Kevitsa Nickel-Copper-PGE Deposit, Sodankylä, Northern Finland