Canadian Mineralogist. Vol.23, pp. ... canada centre for Mineral and Energt Technologt, 555 Booth Strcet, ottawa, ontario KIA oGI ... demonstrate the credibility of the data obtained and ...... ing Sn recovery since one cannot ascribe all the Sn.
THE CANADIAN MINERALOGIST Journal of the MineralogicalAssociation of Ganada
Part 2
MAY 1985
Volume 23
Canadian Mineralogist (198s) Vol.23, pp. 133-148
ANALYSIS OF TRACE ELEMENTSIN SULFIDES PROTON.MICROPROBE DEPOSITS FROM SOME MASSIVE-SULFIDE LOUIS J. CABRI canadacentrefor Mineral and Energt Technologt,555Booth Strcet,ottawa, ontario KIA oGI JOHN L. CAMPBELL ' Departmentof Physics,Universityof Guelph,Guelph'Ontario NIG 2W1 J.H. GILLES LAFLAMME CanadaCentrefor Mineral and EnergyTechnolog!,555Booth Street,Ottawa,OntarioKIA OGI ROBERT G. LEIGH AND JOHN A. MAXWELL Departmentof Physics,Universityof Guelph,Ontario NIG 2W1J. DOUGLAS SCOTT Kidd CreekMinesLimited, P.O. Box 175,Suite 5000,CommerceCourt, Toronto, OntarioMsL IE7 So[,tMnIne
ABSTRACT We havedeterminedthe amount of Ge, As, Se,Ag, Cd, In, Sn and Sb present in solid solution in m6jor sulfides suchasbornite, chalcopyrite, galena,plrite, pyrrhotite and sphaleritefrom three massive-sulfidedeposits(Kidd Creek, Geco and Mattagarni-Norita) and one carbonate-hosted Pb-Zn-Ag deposit (Nanisivik). The analyses were performed mainly by proton microprobe (down to levels of - 7 to 20 ppm) and were corroborated, for concenfiations above - 200-300 ppm, bY electron microprobe. Silver, selenium and indium concentrations in sulfides from the Kidd Creek depositvary with ore type. In general,galena and chalcopyrite are important Ag carriers, but sphalerite is of secondaryimportance. Occasionally, pyrrhotite and pyrite havealso beenidentified asAg carriers, but an evaluation of their significance requires further work. Tin is an important trace constituentin much of the Kidd Creek chalcopyrite, as is arsenicin much of the pyrite. More accurate material-balancesmay be obtained in future for elements such as silver by combining tlre results of in situ traceelement analysis of all major minerals with quantitative mineralogy.
On a determindla teneuren Ge, As, Se,Ag, Cd, In, Sn et Sb sousforme de solution solide dans les principaux sulfures, tels bornite, chalcopyrire, galbne' pyrite,tpyrrhotine et sphalerite, provenant de trois gisementsi sulfure massif Kidd Creek, Geco, Mattagami-Norita) et d'un gisement Pb-Zn-Ag (Nanisivik), i roche-mErecarbonatde.Lc analysesont 6t6 effectu6esprincipalemetrt par microsonde protonique (seuil minimum - 7 A 20 ppm); celles qui accusaient une concentration sup6rieurei - 200-300 ppm ont 6t6 corrobor€esd la microsondedlectronique.La concentration en argent, sdl6nium ou indium dans les sulfures du gisementde Kidd Creek varie selon le type de minerai. La galbne et la chalcopyrite sont g6ndralement porteurs d'argent importants, tandis que la sphal€riteest d'importance secondaire.Pyrrhotine et pyrite aussiont parfois 6t6 identifi€es comme porteurs d'argent, mais leur dvaluation n6cessiteraune 6tude plus approfondie. A Kidd Creek, l'6tain est un constituant-trace important de la chalcopy' rite, commel'est I'arsenicde la pyrite. Desbilans plus pr€cis des mat6riaux pourraient 6tre obtenus en combinant iLla mindralogiequantitative l'analysein situ ds 6lEments-traces dans les principaux min€raux.
Keywords: trace elements,proton microprobe, MicroPD(E, electronmicroprobe, base-metalsulfides,Ge, As, Se,Ag, Cd, In, Sn, Sb, Kidd Creek,Geco,MattagamiNorita, Nanisivik.
Mots-cl^s: 6l6ments-trace,microsondeprotonique, MicroPD(E, microsonde6lectronique,sulfures desm6taux de base,Ge, As, Se,Ag, Cd, In, Sn, Sb,Kidd Creek,Geco, Mattagami-Norita, Nanisivik.
133
t34
THE CANADIAN MINERALOGIST
INTRoDUCTIoN The proton microprobe (Micro-PIXE technique) was used to determine quantities of trace elements in major sulfide mineralsfrom someCanadiansilverbearingZn-Pb-(Cu) sulfide ores.The work reported here is a follow-up of the encouragingearlier results (Cabri et al. 1984a,b, Harris et al. 1984)with this analytical technique, which is considered a method complementary to already established methods of quantitative mineralogical investigation. The major objectivesof this investigationare (a) to demonstratethe credibility of the data obtained and (b) to illustrate the usefulnessof such data in quantitative mineralogy and mass-balancecalculationsinvolving minor elementsin massive-sulfidedeposits currently in production. All but one sample analyzedcame from massive base-metalsulfide ores,mostly from the Kidd Creek mine, Timmins, Ontario (Walker& Mann ard 1974). Whereasthe major emphasisof this study concerns the identification of the silver carriers, it is also of practical importance to know more preciselythe partitioning of seleniumbecauseof the deleteriouseffect of high concentrationsof seleniumin copper concentrates. SAMPLES
samplesand five drill-core samples,were studied. The samplesare consideredto form a completesuite representativeof run-of-mine typesof ore collected in January, 1983,with mill headsuniformly about 250 ppm Ag for "C" ore and 30 ppm for "A" ore; however,most of the samplesare not preciselylocatedin the mine as they were taken from the rodmill feed belts. Figure I showsthe location of the five diamonddrill-core samplesand the geologyin the vicinity of the bornite zone on the 20@ level. The samplesare classifiedeither as Zn-Pb-Ag-(Cu) "C" ore (massive,bandedand brecciaores,North orebody),Cu(Zn) "A" ore (stringers,both North and South orebodies),bornile zone(South orebody,Thorpe et al. 1976,Pringle & Thorpe 1980)or bornite-zonehalo (mainly massivechalcopyrite).This classification, together with mineralogical descriptions,is followed in Table l. Mottagami-Norita A + 100-mesh fraction of zinc concentrate (14/03/ZnC) from the Mattagami and Norita mines of Mines Noranda Lt6e, near Matagami, Quebec (MacGeehanet al. l98l) was examined mineralogically. Sphaleriteand chalcopyritegrainswereselected for analysis;no silver minerals were found. Geco
Kidd Creek mine Thirty samples, consisting of twenty-five hand
A head sample (-4 mesh) from Noranda's Geco
'/ / / / / , / , . '/ '/ ,/ /"/ r/ sfringer cholcopy?lt€in chlorllic rhyolite
\\
2028X-C
2OOOlcvel
o- 2 0 . l o @ 8 0 t @
Soulh orebody Kidd Crcck mi]l Tlmmins,Onlorlo
leef
g
mcfrc8
\
\\\
\\\
\
\\
Ftc. l. Plan view of 20@ level, south orebody, Kidd creek mine, showing samplelocations.
135
PROTON-MICROPROBE ANALYSIS OF TRACE ELEMENTS IN SULFIDES TABLE
Mineral-oqy:
Number nC" ore
(massive,
1.
RIDD
CREEK MINE
SAMPLES
banaled anal breqcla
ores) gn>asp.
Massive
83-2
Masslve
fine-grained
sp with
py bands.
Sp, py>G>>cp, po>>asp, gn. po anal py.
83-3
l,lassive flne-grained antl trace cp.
sp with
py breccia
py>G>cp, po>asp. Sp, Ag in po, py and G.
83-4
t{assive sp wlth pyrite bleccia.
83-5
Bandeal fine-grained sp and py sith coarse gn in the 9p.
83-7
coarse-glained sP.
83-9
cranuLar
83-10
Fine-gralned sp.
83-Ll
pyri!e breccia masaes with I'ine-grained recrystallized borders of cublc crystals and nlnor gn ln chelty rhyol-ite rith disseninated sp.
Py, c>>gn,
83-13
E'ine-grained pyrlte stltlal sphalerite
Py>sp, G' cp>gn, and cp.
83-14
Coarse-gralned py interstitial sp.
83-l-5
Massive intermediate-grained thln quartz veins.
83-18
I'fne-grained around graln nino! sp.
83-19
Alternately bandedl (5m) fine-grained py and cp rith nlno! ap ln py bands.
Cp>py>c>>sp>po, cas.
83-22
Partly sp cu!
Cp>>py>c, cp.
83-24
Gn veLn in sp and py.
83-25
Massive gn.
nAn ore
trace
Sp>>G>py>cp>casr po, rn po.
83-l
coarae
sp with
nicroscopic
Mineralogy:
macrosqoplc
coarsely
cp and
mino!
pyrlte
wlth
Ag found
in
sp,
and
ln py and G, areas
Py, sp>>G>9n>>po, cas>asp. tt>my?>>dy? in gn.
Large
Py>sp>G>>qn>>cp>cas, asp.
Trace !t
Py>>sp>>G, gn'
bteccia with inlerand trace cp and gn. with
minor
py!j.te
with
pyrlte breccia invaded boundarj.es by cp and
hi-Ag
of
in gn and
po,
Py>>sp>>G, 9nr
cp>po'
asp.
asp.
cas,
Trace Ag in po,
po.
py
cp.
py>>sp>c>gn>caB.
Cp>py>>po, c>sp.
tarnished cp with trace bn and py bands. by fine-grained coarseLy-banded
found
P y , G > > s p > > c p ,g n , p o .
dlssenlnated
breccla
Traqe Ag founal in
py.
nchertn.
in
Trace Ag found
Trace t!
Sp, py>G>>>cp, gn, asP. and trace t! in sp.
cryslalline
gn and py with
pyrite
9n.
fine-.graineal
sp,
Py>sp>>gn, c, found ln gn.
Trace
cas. po,
Trace A9 in po. A9 found
cas>asp.
cn>>py>ep>po>c, cp>asp.
in
py and
Trace Ag-lich
Ag-rich
tt>aly found
tt>dy in
(stringers) py nrosettesn
py>>c>cp, gn>asp.
83-6
I'ine-grained 1@.
83-8
Coarse-grained Erace sp.
83-12
py bleccla Coarse-grained gn. intergranular
83-l-6
py nrosettesn Coarse-gralned to L cm with cp veinlets in fl.ne-grained black (283L0 stope, near bolnite natrix zone).
py>>c>cp>po>asp.
83-1?
granuLar py with Coarsely-dlssemlnated cp stringers ln ctrlorltic rhyolite.
py>>c, cp,
83-21
Fine-grained
Cp>>G>po, py, ln the cp.
83-23
Masslve coarse-grained cp with euhedral aLbite clystaLs to 8 M (L622 L stope).
sp wlth shiny
to
rrcleavabLert py wi.th
banded cp in
with
dark
trace
rhyolite.
Fy>c>>sp>cp>cas,
Trace Ag in py. aep,
po.
py>>c>>gn, sp>po, cp.
Cp>))py,
sp.
c>cbt,
qas.
cas,
Trace etn monazite?
flnely
disseBinated
r36
THE CANADIAN MINERALOGIST
TABLE I Continued zone halo
Bornite 83-20
a3-26
Massive cp margj.nal
S3-27
adjacen! Massive cp lmedliately zonei DDn 2295 Q LO7t.
83-30
st!inger cp ln rhyolite DDH 2299 Q 66.5,.
e r00.s'.
Bornite
t o bn zonei
Trace tt
cp>>c>>stn, asp, sp.
s!rinqer sp. 163!. M
cp-ln-rhyolite coarse-graineal ore wlth trace dlgsenlnated siope, nea! bn zone.
DDH 2295
C p > > G > s p > n k ?P, Y .
!o bn
c p > > G > s c n / k e s ,g P > P Y .
in G.
G>>cp>py.
near bn zone;
zone qp in bn z o n e i D D H 2 2 9 5 @ 1 1 3 ' .
83-28
Strlnger
83-29
Massive cp in bn zone with 2299 Q 54t.
!!ace
Cp>>G>>bn>naw, stndt
py>crl,
Cp>>bn, c>di>col>tn.
bniDDH
and trace
Trace en, crL,
nn. boh, cv,
eu'
boh bornite, asp arsenopy!ite' siLver, Ag natlve Abbreviati.ons used3 ac acanthj.te, .bn colusile, col chalcopy!ite, cp clausthalite, clu cbt codal!ite, bohdanoriczite, cas cassigerite, G gangue' eu eucalrite, enargite' en dyscrasi!e, dl dlgenite, dy cv covetll.te, cr1 calrollite, po naumannite' my miargyri_t-e., nn ni mackinawi!e1 miw mawionite, kesterite, 9n gaLena, kes tn tennantite, stannoidite, stnd py!ite, py s!n stannite, sp sphalerite, iyrr-nofite, tt tetrahedrite
mine in the Manitouwadgemining camp, Thunder Bay mining district of northwesternOntario @riesen et al. 1982)wasprepard for analysisof chalcopyrite, sphalerite, pyrrhotite and pyrite; no silver minerals were observed. Nanisivik Sphal6ritegrains from a hand sampleof ore from the Nanisivik zinc-lead deposit, near the northern tip of Baffin Island, N.W.T. (Clayton & Thorpe 1982,Olson 1984),wereanalyzedbecause$phalerite is known to be a silver carrier in that deposit(McIntyre et al. 1984).
TABLE
2a.
X-RAY LINES
AqLq
(PbrAg) S
Galena Spttalerite
&etaL
SeKo
Polishedsections(3 cm in diameter)wereprepared for all the samples and carefully examined microscopically. Grains of chalcopyrite, galena, pyrite, pyrrhotite and sphalerite,free ofinclusions; wereselectedand sawedfrom the sectionsas2-4 mm cubes.Theseessentiallymonomineraliccubeswere resetin araldite, together with appropriate synthetic standards(Table 2), to make new 2.5-cm-diameter polished sectionsso that all suitable grains of a selectedsulfide were located in one section. The new sectionswere, onceagain, carefully re-examinedwith
line ZoKo
(zn,Ee)s
n te
Ore microscopy
FeKc
CdLa
InLc
(zn,Fe)s
cds
(znrAgrIn)s
C u 4( F e r Z n )5 5 g -
SnLq
Fe (S,Se)
.(znrAgrIn)S
Pyrite Chalcopyri
Sbtq
TECHNTeUES
AND STANDARDS USED E.OR ELECTRON-MICROPROBE ANALYSES X-ray
MINERAL
ANelvrrcel
c u 4 F e 5( s , s e ) I o r F e( S , S e )
me!al
(ZnrAgrln)S
n
Born i te wergneo-1n parentneses) trace-element coDtents and calculated "homogenexty' values (tn lor tttese synthet.ic (Fb,Ag)S3 0.40 wtE A9(0.78), standards are as fol-lolrs! Fe(S,Se): 0.17 !rtt (zn,A9,In)S: Se(0.66) i 0.114 wtB Ag(0.46) ?nd 0.119 ntg In(0.39)i cua(Fe,zn)qsR3 0.I5 wtB zn(0.40)i (Zn,Fe)S had 5.4 wbt Fe. Cu4Feq(S,se)a:0.15 wtA Se(0.55). th6 fol1ow-in-gstandards (Elba), were used foi b-ackgroind corrections: Cu4Fe5SB and PbS, ZnS and (Zn,!'e)S, pyrite Cu5E'eS4.
PROTON-MICROPROBE ANALYSIS OF TRACE ELEMENTS IN SULFIDES TABT.E 2b.
X-R"AY LINES
AND STANDARDS USED EOR MICRO-PXXE X-!ay
l.llneral
AgKo
(Pb,Ag) s
GaIena
li.nes SeKd
(Zn,Fe,Ag,In)S serieg
ChaLcopy!ite and bornite
"
Fe(S,Se) or c u 4 F e 5( s r s e ) 8
rSee
discussion. T!ace-elenent conieotg given standards are beLow TabLe 2a, as q o l r e c t i ons. standards f o r used backgrgund
the ore microscopeand an SEM in order to locate inclusion-free areasfor the proton-microprobe analyses. Electro n-microp ro be onaly ses A Materials Analysis Company (MAC) model 400 electronmicroprobe was usedto obtain the iron content of the sphalerite and the antimony content of the galertaas well asto verify the proton-microprobe results, wherg applicable.For quantities abovethe detectionlevdlsby electronmicroprobe, we were able to either conlirm the proton-microprobe results or to reject them owing to contaminationfrom adventitious inclusionsbelow the surfaceof the polished section. All the analyseswere performed at 25 kV, with exception of the galenaanalyses,which were carried out at 20 kV, according to analytical procedures describedby Cabri & Laflam:ne (L976).The X-ray linesand gtandardsusedare listed in Table 2a. Raw data were rEducedwith a locally modified version of EMPADR VII (Rucklidge & Gaspanini 1969). The standardsweretestedfor homogeneityaccording to the homogeneitytest of Buseck& Goldstein 3.
CALCULATED DAPIIIS
Uatlix eleBeot
Se Se Se Se Se Ag Ag A9 Ag A9 Ag ln In In In Io rcalculated
PbS ZnS (Zn,Fe) S Fes FeS, PbsZng (Zn,Ae) S FeSt fesCuFeS, PbSZoS (znrFe) S FeS2 FeS
f,or
OF X-RAY
al abaorbe! (!n) thicknese
( Z n , F e , A g, 1 n ) S series
Penetlation (!n) alepthr
JI
1050 750 750
49 49 4A
for rel1
these synthetic of as tbe list
(1969),in which a standardis consideredhomogeneous if f/
