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7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
3.7 Available Inormation............................................................................................ ,3.5 8P9" :estor' and %im#lation "es#lts ............................................................. ,3.3 >$%imMet %im#lations and Mass balance calc#lations .......................................
8$ CAPITAL COST ESTIMATE $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ 12
:=is report presents t=e res#lts o an #pdated trade6o st#dy cond#cted by AME&
Americas Ltd to compare t=e relative merits o a %A9 mill6based (t=e alternative)vers#s a 8P9"6based (t=e base case) grinding circ#it conig#ration or t=e &erro&asale project. :=e project considers t=e treatment o ore+ at a rate o *,+,,, tpd+t=ro#g= a processing plant recovering gold and copper val#es.
:=e 8P9" base case =as been developed at easibility (%) level+ it= t=e incl#sion o some o t=e major material =andling capital cost red#ction items identiied in t=e %6stage b#t prior to considering t=e eect o t=e grind siBe target red#ction later implemented. :=e related design deliverables orm t=e basis o t=e operating andcapital cost estimates presented in t=is report. or t=e %A9 alternative+ t=e siBing o t=e commin#tion e@#ipment as revised rom t=e earlier preeasibility (P%) stage
assessment to relect adj#stment made since t=en to t=e poer re@#irement. <asedon t=ese+ t=e major e@#ipment re@#irements ere revised+ along it= t=eir e?pectedoperating and capital cost re@#irements.
:=e res#lts o t=e c#rrent st#dy reconirm t=e concl#sion reac=ed at t=e concl#sion o t=e P%+ namely t=at t=e =ig=er poer eiciency associated it= t=e 8P9" circ#ittranslates into a signiicant inancial advantage compared to t=e %A<&6< circ#it+re@#ired to establis= a %A96based commin#tion circ#it+ despite its =ig=er capitale?pendit#re. :able . is preseinting t=e o#tcome o t=e inancial analysis.
T ); , ' 1 $ 1 E <+% + =* < A % ) , * C + = 6) (* %> ! P "R - B )' 0 $ S A "- B ) ' C *( < *&
:=e positive o#tcome o t=e inancial analysis+ avo#ring t=e 8P9"6based circ#it+ isbro#g=t by an e?pected red#ction o t=e overall commin#tion section operating costsby F,.0,3/t+ or F5*.3M per year+ set against t=e additional capital e?pendit#re o F.-M. 9rinding media and liners cons#mption dierences acco#nt or appro?imately F,.35/t o t=is red#ction =ile poer savings acco#nt or an additional
F,.34/t. :=ese savings are partially oset by smaller increases in labo#r (F,.,7/t)+liners (F,.7/t) and maintenance materials and spares costs (F,.3/t). Additionalconveyors+ eeders and associated civil or's acco#nt or t=e b#l' o t=e capital costdierence beteen t=e to commin#tion circ#it conig#rations.
:=e ris's associated it= t=e adoption o a 8P9"6based commin#tion circ#it aredeemed as manageable and+ to some e?tent+ less da#nting t=an or a circ#it it= %A9mills. Most o t=e ris's associated it= t=e 8P9" circ#it relates to potential materials
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
=andling iss#es and d#st prod#ction. :=ese can be mitigated t=ro#g= ade@#atedesign eat#res. %c=ed#le delays d#e to casting problems+ long lead and installationtimes+ and saety iss#es d#ring maintenance are some o t=e 'non ris's associatedit= a %A96based circ#it t=at o#ld be eliminated by t=e selection o t=e 8P9" ro#te.
:=e 8P9" circ#it is t=ereore reconirmed by t=e c#rrent st#dy #pdate as t=e preerredapproac= or t=e commin#tion circ#it design at &erro &asale.
2$ LIST OF ABBRE#IATIONS AND UNITS
%A9 %emi6A#togeno#s 9rinding
8P9" 8ig= Press#re 9rinding "olls
!PC !et Present Cal#e
I"" Internal "ate o "et#rnP% Preeasibility %t#dy
% easibility %t#dy
% easibility %t#dy pdate
t/d Dry metric tonnes per day
F nited %tates o America Dollar
'G= $iloatt =o#r
'G=/t $iloatt =o#r per tonne
M Million
OPEH Operating e?pendit#re
&APEH &apital e?pendit#re
&%% &losed side setting
%A<&6< %A9 mill+ open6circ#ited pebble cr#s=ing and ball mill conig#ration
P0, %creen apert#re siBe t=ro#g= =ic= 0, o t=e material passes
:0, :ranser siBe (0, passing t=is siBe)
mm millimetre
micron One t=o#sandt= o a millimetre
c/ complete it=
/ nderlo
O/ Overlo
/% ndersiBe
O/% OversiBe
v/v vol#me per vol#me proportion
/ eig=t per eig=t proportion
g/t grams per tonne
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
!/m/m !eton orce per s@#are meter per meter lengt= o 8P9" roll
ts/m7/= tonnes second per c#bic meter per =o#r (speciic t=ro#g=p#t or 8P9")
3$ INTRODUCTION
AME& as irst re@#ested at t=e concl#sion o t=e P%+ by t=e &ompania Minera&asale (&M&)+ to perorm a trade6o st#dy comparing t=e relative merits o t=esealternative grinding circ#it conig#rations+ it= a vie to select t=e most appropriateconig#ration or incl#sion in t=e los=eet o t=e proposed &erro &asale Mill at t=e %stage.
:=e concl#sions o t=is earlier st#dy (doc#ment 3-456!6"E6,7) =aving indicatedt=at a 8P9"6based circ#it o#ld be t=e most economical option to p#rs#e+ it as
implemented or detailing in t=e s#bse@#ent %6stage o t=e st#dy. At t=e end o t=eP%+ t=e dierential capital cost as estimated at some F4*M+ avo#ring t=e %A96based circ#it+ b#t an OPEH savings o F.,0/t as alloing a ast paybac'. :=e P%6level %A9 circ#it &APEH and OPEH ere #sed or t=e base case =ile scoping6levelestimates ere prepared to establis= t=e 8P9"6based relevant costs.
Git= t=e establis=ed 8P9" circ#it OPEH and &APEH+ at %6level+ &M& e?pressed are@#irement to revisit t=e earlier concl#sion by incorporating t=e act#aliBed costs or t=e major inp#ts and consider t=e details made available at %+ vers#s t=e #pdatedval#es pegged or t=e %A96based option+ earlier developed at P%6level. :=is reportpresents t=e res#lts o t=is act#aliBed trade6o st#dy and orms part o t=e &erro
&asale easibility %t#dy.
!o additional relevant data as provided rom t=e ,,- testor' campaigns or siBingt=e %A9 mill circ#it+ besides a conirmation t=at t=e earlier *.- 'G=/t or <MGi asapplied to t=e design ore is apparently a valid average. Only t=e incrementalt=ro#g=p#t demand+ o *, 't/d instead o 3, 't/d in t=e earlier st#dy+ as acco#ntedor in resiBing t=e commin#tion e@#ipment. !evert=eless+ t=e %A9 mill circ#it design isdeemed aggressive+ it= nearly all t=e installed %A9 and ball milling poer re@#ired toprocess t=e re@#ired t=ro#g=p#t+ calling as ell or a relatively coarse transer siBe(:0,) beteen t=e to circ#its only deemed ac=ievable by t=e adoption o a %A<&6<circ#it conig#ration (cr#s=ed pebbles ed to close6circ#ited screen+ it= prod#ctmoving into ball mill). Evidence rom benc=mar'ed data are pointing to a idepossible range o speciic %A9 energy re@#irement at t=e lo Ab indicated or t=edesign ore+ made #p o t=e Jear 63 mine o#tp#t. :=is is p#s=ing or a re@#iredconirmation o t=e %A9 poer re@#irements t=ro#g= pilot planting o a representativesample.
AME& consolidated t=e vario#s so#rces o inormation and prod#ced design criteria+los=eets+ process lo diagrams+ mass balances and easibility level capital andoperating cost estimates or t=e 8P9" alternative (see %ections *+ 4 and t=e
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
Appendices or details)+ as part o t=e % deliverables pac'age. %#c= deliverables+or t=e %A9 alternative ere #pdated rom t=e earlier P% level. :=e comparison isbased on t=e re@#irements to deliver a lotation eed prod#ct at a P0, o 3, Km and anominal rate o *, 't/d it= t=e design ore deined as representative o t=e Jear 63ore type mi?t#re. :=e 3, Km #sed earlier as retained or t=is #pdate+ despite t=eselection o a iner target o , Km late in t=e ,,- easibility %t#dy stage+ since s#c=a selection as applied to t=e %A96based option o#ld =ave called or a o#rt= %A9 millto be added+ and a revision o t=e n#mber+ and a possible conig#rationrearrangement+ o t=e accompanying pebble cr#s=ing and ball milling circ#its. :=is int#rn o#ld =ave re@#ired a complete reassessment o t=e e?pected &APEH cost or t=is option.
:=e aorementioned inormation as #sed to estimate and compare t=e dierentialinancial indicators or t=e to alternative los=eets (see %ection 0).
4$ STUDY OBJECTI#ES SCOPE AND DELI#ERABLES
4$1 O;?'<&*0'
:=e primary objective o t=is st#dy #pdate as to present a balanced and #nbiasedcomparison o t=e relative merits o a 8P9"6based grinding circ#it+ as developed to%6level+ vers#s t=e alternate scenario developed earlier or t=e P% involving aconventional %A<&6< circ#it. :=is comparison is meant to provide conirmation+ it=t=e additional design and costing details and acc#racy provided at t=e concl#sion o t=e %+ to allo decision ma'ers to gain #ll conidence in t=e earlier selection o t=e
grinding circ#it or &erro &asale+ calling or t=e incl#sion o 8P9".
4$2 S<+6' )% B)&&'( L*=*&
:=e scope o t=e st#dy as to generate s#icient design data to allo a basiccomparison o t=e economics o t=e to los=eets. :=e list o deliverables belos#mmariBes t=e scope assigned to AME&.
:=e battery limits or t=is trade6o st#dy are2
• pstream 2 &oarse ore stoc'pile eed conveyor
•
Donstream 2 <all mill cyclone overlos to lotation
:=e "OM cr#s=ing operation is identical or bot= t=e %A<&6< and 8P9" los=eets+it= t=e e?ception o a ider coarse ore stoc'pile stac'ing conveyor+ as re@#ired or t=e 8P9"6based circ#it to deal it= sporadic bypassing o a tertiary cr#s=ing circ#itstream. %imilarly t=e lotation los=eets are identical+ it= bot= grinding circ#itsre@#ested to generate a prod#ct it= a P0, o 3, microns+ at a similar sl#rry densityreac=ing t=e ro#g=ing lotation section+ and at t=e same nominal t=ro#g=p#t capability
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
o *,+,,, t/d. In t=e case o t=e %A96based circ#it+ t=e #tiliBation o t=e availableball mill poer contingency e?isting #nder t=e 8P9"6based option+ is #sed #p topermit a coarsening o t=e transer siBe rom t=e %A9 mills and limit t=eir poer demand.
F * > ( ' 5 $1 - 1 C +%<'6 & ), B , +<@ D * ) > ( )= +( " (* % * %> C* ( < *& A ,& ' ( %) &* 0 '
S A BC- B C * (< *& ! P "R C * (< * &
&oarse Ore %toc'pile &oarse Ore %toc'pile
%A9 Mill Dry %creen %econdaryO/%iBe &r#s=er
/%iBe
%creen O/%iBe 8P9"
Get %creenO/%iBe
/%iBe
&yclones <all Mills &yclones <all Mills/lo /lo
O/lo to lotation O/lo to lotation
In t=e %A<&6< conig#ration+ t=e added pebble cr#s=ing step complementst=e %A9 mill grinding poer in providing compression cr#s=ing o t=e so6called critical siBe material+ =ic= o#ld ot=erise b#ild #p in t=e %A9 mill.:=e cr#s=ed pebble stream does not ret#rn to t=e %A9 mill b#t insteadproceeds to a screening stage to allo or recycling o t=e coarse raction o t=e pebble stream. :=e ine raction proceeds to t=e ball milling circ#it. :=isarrangement allos or a coarser transer siBe to be obtained+ despite apossble tendency or t=e ore to generate a limited @#antity o inis=edprod#ct t=ro#g= %A9 milling only.
5$2 D'*>% B)*
:=e detailed design criteria doc#ments or bot= grinding alternatives =ave
been p#blis=ed separately (3-456!6D&6,, or t=e base case %A<&6<circ#it+ and 3-456!6D&6, or t=e 8P9" alternative). :able 3.6s#mmariBes and compares t=e 'ey design ass#mptions and data or bot=scenarios.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
!ote2. :=e initial base case sim#lations made #se o t=e 0, mm primary cr#s=er prod#ct. Later iterations it= t=e retained 8P9" circ#it in % adopted 3, mm b#t no comparable sim#lationdata or t=e %A<&6< circ#it ere generated.
:=e secondary cr#s=ing circ#it or t=e alternative+ as per t=e pebble cr#s=ingcirc#it #nder t=e base case+ is e?pected to r#n only 03 o t=e time. :ocompensate or t=is loer #tiliBation+ compared to t=e rest o t=eserespective circ#it1s components+ an additional pebble cr#s=er+ s=ared by allt=ree %A9 grinding lines+ =as been incl#ded in t=e %A<&6< design =ile anintermediate cr#s=ed ore stoc'pile =as been incl#ded in t=e 8P9" circ#it
design.
Per :able 3.6+ t=e ball mill or' inde? or t=e 8P9" circ#it is e?pected tobe 3 loer t=an t=at o t=e %A9 mill6based circ#it+ per t=e testor'cond#cted by Polysi#s =ic= s=oed val#es o #p to - (beore adj#stmentor dierential 0, and P0, beteen tests). :=is red#ction is attrib#ted tot=e so6called micro crac'ing eect+ res#lting rom t=e =ig= stressesimparted on t=e material passing t=ro#g= t=e 8P9" rolls.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
All inormation pertaining to t=e %A<&6<+ as t=e base case carried in t=e
Preeasibility %t#dy+ is available in separate doc#ments not d#plicated in t=isreport. G=ere relevant+ t=e %A<&6< data is s=on to allo direct comparisonit= t=e relevant alternate case #nder st#dy.
or t=e 8P9" option+ t=e deliverables prepared #p to t=e point =ere t=edecision as made to decrease t=e lotation eed P0,+ rom t=e prior 3, Kmto t=e revised , Km val#e+ ere t=e basis or t=e estimates.
5$4 !P"R T'&+(@ )% S*=,)&*+% R',&
Drill core samples ere provided to Polysi#s to test t=e amenity o t=e ore to
8P9" cr#s=ing. :=e samples tested by Polysi#s incl#ded a Jear to 3blend composite sample as ell as an additional si? individ#al ore typesamples. :=e objectives o t=e tests ere to generate data re@#ired or e@#ipment siBing+ cost estimates and to assess ris's pertaining to t=evariability o t=e orebody N.
%ome o t=e 'ey metrics and indings rom t=ese tests are2
• Liner ear rates increase it= an increase in eed moist#re content.:=e implication is t=at t=e los=eet design and e@#ipment siBings=o#ld aim at minimiBing 8P9" eed moist#re+ e.g. t=ro#g= longer
et screens to ens#re better drainage.• At a 5 moist#re content t=e A:GAL abrasion test yielded a ear
rate o * g/t or t=e composite sample. :=is is classiied by Polysi#sas a lo to medi#m abrasiveness ore response.
• Meas#red ear rates ere all in t=e medi#m abrasiveness range it=minimal variability beteen t=e individ#al ore types.
• :=e speciic energy inp#t at t=e optim#m grinding orce as .0 'G=/t
• A speciic t=ro#g=p#t (m6dot) o , ts/m7/= as meas#red at t=eoptim#m grinding conditions.
• Loc'ed cycle cr#s=ing tests s=oed t=at t=ere o#ld be no b#ild6#p o
a =arder component in closed circ#it operation d#e to preerentialcr#s=ing o soter constit#ents.
• <ond test res#lts indicate t=at a 8P9" prod#ct o#ld re@#ire - lesspoer in t=e s#bse@#ent ball mill to grind a 6* mm eed don to 3micron compared to a cr#s=er prod#ced 6* mm eed. :=econirmatory Labmill test proced#re yielded a smaller dierence.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
AME& adopted 3 as a reasonably conservative estimate or t=ee?pected poer red#ction.
•
:ests cond#cted on t=e seven samples indicated only minor dierences in process parameters.
Polysi#s cond#cted sim#lations based on t=eir testing o t=e composites andon proprietary scale6#p actors. %ome o t=e 'ey sim#lation o#tp#ts are2
• A tertiary 8P9" circ#it prod#ct o 6* mm can be prod#ced #sing eit=er ive large .* ? .43 m rolls or si? .5 ? .4 m rolls. &ost and ease o operation dictate t=e latter+ i.e. to parallel #nits or eac= o t=e t=reeidentical grinding lines+ it= one 8P9" dedicated to eeding eac= oneo t=e si? ball mills.
• At a nominal rolls speed o .53 m/s t=is conig#ration ill r#n atappro?imately -, o t=e ma?im#m speed providing an estimated *contingency on t=ro#g=p#t.
• At a -, 8P9" #tiliBation and an estimated average circ#lating loado 3 #sing a c#t siBe on t=e et screen o , mm+ t=e nominal eedto eac= 8P9" ill be +0*5 t/=+ re@#iring 7+37, 'G o motor poer+incl#ding mec=anical losses. :=e #se o to +43, 'G variable speeddrives per 8P9" #nit ill allo or minor variability in bot= t=ro#g=p#tand ore =ardness.
5$5 J:S*=M'& S*=,)&*+% )% M) ;),)%<' <),<,)&*+%
:able 3.36 compares 'ey parameters obtained rom sim#lations+ it= anadj#stment or t=e revised *, 't/d t=ro#g=p#t. G=ere t=ere are minor dierences beteen t=e mass balance and sim#lations+ t=e mass balanceres#lts ta'es precedence as t=is is t=e basis or t=e cost estimate.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
T ); , ' 5 $ 5 - 1 S* = , ) &* + % )% M ) B ) , )%<' ! *>. ,* > . &
E,'='%& U%*&
B)'
C)'SABC-B
!P"RO6&*+%
!#mber o %A9 Mills (5,1 ? 51) ea. 7 ,
!#mber o 8P9"1s (.5 ? .4 m) ea. , *
!#mber o cone cr#s=ers ea. 5 0
!#mber o <all Mills (*1 ? 551) ea. * *
Pebble/:ertiary &r#s=ers &irc. Load *3 03
%econdary/Pebble &r#s=ers &%% mm 7 73
Dry %creen <ottom Dec' Apert#re mm 7 53
%ec./Pebble &r#s=ers Prod#ct P0, mm .3 74
%A9 Disc=arge %creen Apert#re mm - !/A
Pebble/ Get %creens Dec' Apert#re mm , ,
8P9" &irc#it &irc#lating Load !/A 3
<all Mill &irc#it eed :0, mm 0.4 3.-
<all Mill %peed critical 40 40
<all Mill <all &=arge v/v 7 0
8$ CAPITAL COST ESTIMATE
:=e capital cost estimate or t=e base case is relecting t=e detailed cost estimateprepared or t=e Preeasibility %t#dy.
or t=e alternate circ#it+ t=e &APEH estimate is t=e o#tcome o t=e % drat stage. Inbot= cases+ t=e major mec=anical e@#ipment is costed rom b#dgetary @#otes+ or inde?ed or dierential siBe rom recent @#otes or similar e@#ipment. Material ta'e6osere eval#ated on t=e basis o t=e plant area topograp=y and t=e general plant layo#tprepared or t=is p#rpose. :=e precision o eac= estimate varies in relation it= t=e levelo st#dy reac=ed it= eit=er one (/63 or P%+ /63 or % drat)
:=e res#lting dierential &APEH estimate is presented in :ables *6 belo. !ote t=atindirect cost elements incl#ding EP&M+ initial ills+ vendor representatives+ and Oner1scost are acco#nted or by a * actor as s=on in :able *6. :=is val#e represents=al o t=e overall 7 bac'6calc#lated rom t=e overall % &APEH estimate+ relecting
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
:able *6 indicates t=at t=e %A96based scenario o#ld re@#ire a &APEH o#tlayF.-M loer t=an t=e estimation prepared or t=e 8P9"6based circ#it. :able *6 alsoindicates t=at a large portion o t=is incremental e?pendit#re is associated it= t=emec=anical components and str#ct#ral steel costs associated it= t=e 8P9"6basedcirc#it+ partly compensated by =ig=er electrical gear costs or t=e %A96based option.
:=e circ#its donstream o t=e ball milling section are pres#med e@#ivalent in t=eir design or bot= conig#rations eval#ated. :=ey only dier in t=e #tiliBed ball millingpoer base.
&apital cost details are presented in Appendi? <.
7$ OPERATIN" COST ESTIMATE
Detailed operating cost calc#lations are presented in Appendi? &. :able 46 belos#mmariBes t=e poer cons#mption elements+ as e?tracted rom t=e e@#ipment list it=load actors assigned to individ#al e@#ipment+ per Appendi? A6 and A6.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
T ); , ' 7 - 1 S 6' < ** < P + ' ( C +% = 6 &* +% <+ % = ' @ . /& + ( '. ''
I& ' =
A ,& ' ( %) &* 0 '
S A B C - B !P " R%A9 Mill 0.0 6
Pebble/%econdary &one &r#s=ers ,.57 ,.*3
8P9" 6 .-
<all Mills .*7 .77
Ancillary E@#ipment .73 .50
T+&), 23$22 17$37
!otes2
. sing indication t=at .3 times t=e net pebble cr#s=er energy (i.e. e?cl#ding poer cons#mption or no6load and transmission losses) e@#ates t=e %A9 mill poer red#ction+ t=e e@#ivalent %A9 only circ#itspeciic poer cons#mption o#ld be -. 'G=/t.
. %peciic poer cons#mption based on test res#lt data indicating .0 'G=/t o 8P9" eed and 33circ#lating load rom et screens =en operated at a c#t6o siBe o , mm.
:able 46 s=os an e?pected red#ction o t=e speciic poer cons#mption o nearly 3or t=e 8P9"6based+ vers#s t=e %A96based circ#it. :=e most signiicant dierence=ig=lig=ted by :able 46 is t=e 3.47 'G=/t poer cons#mption dierence beteen t=eto centerpiece major e@#ipment items (%A9 mill vs. 8P9"). Ancillary e@#ipmentpoer is =ig=er or t=e 8P9" conig#ration as t=is type o circ#it contains moreconveyors and eeders t=an t=e simpler %A<&6< circ#it.
:able 46 belo s#mmariBes all major cost elements or t=e to conig#rations.
T ); , ' 7 - 2 O 6' ( ) &* %> C + & S = = ) (
SABC !P"R D*'('%<'/& /& /& H 0$ SA
Poer .44 .4,7 ,.345 3.9rinding and &r#s=ing Liners ,.*5 ,.7-, 6,.* 654.*9rinding Media .0- ,.437 ,.37* 5.*Operating and "epair %#pplies ,.70 ,.5*4 6,.5- 65*.0
Direct and &ontract Labor ,.,04 ,.4 6,.,7, 675.T+&), 4$235 3$429 $5 19$
Per t=e details on t=e OPEH derivation provided in Appendi? &+ it is noted t=at2
• :=e poer cost as estimated at a price o %F,.,-,/'G= or electricity
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
• :=e cost or spares and maintenance materials or t=e %A96based circ#it is derivedby applying a actor o 5.3 to t=e &APEH elements representing e@#ipment(mec=anical+ electrical)+ piping+ instr#mentation and b#l' elements e?posed to ear or damage (lig=t steel+ pipes/cables and associated rac's and s#pports+ b#ildingall panels). :=e res#lting val#e (F0.3M) is t=e yearly e?penses re@#ired to cover maintenance spares and materials costs+ e?cl#sive o manpoer.
• or t=e 8P9"6based option+ t=e maintenance spares and materials costs erederived rom a irst6principles approac=+ =ere every piece o e@#ipment asbro'en don into its vario#s main elements and a replacement re@#ency and priceas assigned to eac= o t=em. :=e res#lting s#m o all t=ese individ#al amo#nts+pl#s percentages to cover maintenance o b#l' items s#c= as s#pports+ cabling andinstr#mentation (mostly costed as lots in t=e &APEH derivation)+ yields t=e yearlyb#dget o F*.-M indicated. :=e details o t=is derivation are o#nd in doc#ment
3-456!6DE67,.
• Labor costs are based on t=e b#rdened ages indicated by &M&.
:able 46 indicates t=at t=e 8P9" circ#it is e?pected to be - c=eaper to operate andmaintain t=an t=e e@#ivalent %A<&6< base case circ#it. :=is is attrib#ted to t=esigniicant poer cons#mption advantage oered by t=e 8P9" circ#it+ at 0.- 'G=/t+vers#s 3. 'G=/t re@#ired by t=e %A<&6< circ#it+ incl#ding motor eiciency andtransormation/transmission losses.
<esides t=e poer cost+ t=e majority o t=e remaining cost dierential beteen t=ecirc#its lies in t=e dierence beteen ball ear costs o .-F/t or t=e %A96basedcirc#it+ vers#s t=e 8P9"6based circ#it1s ,.43 F/t.
I t=e costs related to t=e maintenance spares and materials+ liners+ &M&1s on andcontract#al manpoer involved in maintenance activities are tallied toget=er as anoverall maintenance cost+ t=e s#ms compared are F,.-*/t and F,.**/t+ or t=e 8P9" vs.%A<&6< circ#its+ respectively.
$ NET PRESENT #ALUE AND PAYBAC: ANALYSIS
:able 0. presents t=e =ig=lig=ts o t=e inancial analysis perormed.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
Detailed cas= lo inormation is presented in Appendi? E. :=e analysis is based on t=eolloing ass#mptions2
• 8al o t=e constr#ction capital e?pendit#re is inc#rred to years prior to t=e irstprod#ction it= t=e rest divided e@#ally beteen t=e year beore prod#ction startsand t=e irst year o prod#ction
• Inlation and or'ing capital dierential eects are ass#med to be negligible• Interest earned or paid on c#m#lative cas=lo is not considered• All o t=e initial capital ill =ave been ritten o by mine clos#re
ig#re 0. presents t=e sensitivity o t=e indicated !PC(3) to c=anges to t=e 8P9"circ#it1s main cost drivers.
F *> ( ' - 1 F * %)% < * ), S '% * &* 0 *& A %) , * + !P " R M ) * % D (* 0 ' (
NP#5H S'%*&*0*&
3,,53,
5,,
73,
7,,
3,
,,
3,
,,
3,
6
67, 63 6, 63 6, 63 , 3 , 3 , 3 7,
#)(*)&*+% +% !P"R ;)' <+& -H
&APEH O/A Maint Liners Energy Maint %pares/Mat
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
:=e 8P9" circ#it oers an estimated ,.0,3 F/t operating cost saving+ compared to t=e
%A<&6< circ#it. 8oever+ t=is is oset by an estimated F.-M in additional capitale?pendit#re re@#ired or t=e 8P9"6based circ#it. :=e comparative inancial analysisindicates an #ndisco#nted cas=lo dierential o F4,.4M+ or F77.,M in avor o t=e8P9" based circ#it at a 3 disco#nt rate. :=e I"" or t=is comparative scenario is.0. :=e simple paybac' period+ i.e. t=e d#ration re@#ired to pay bac' t=e additional&APEH #sing t=e OPEH saving+ is 5.4 years.
On t=is basis+ t=e inancial beneits o adopting a circ#it comprising 8P9" asreplacement to t=e %A9 milling step or developing t=e &erro &asale processing plantdesign criteria =as been reconirmed.
AME& is o t=e opinion t=at t=e intangible opport#nities oered by t=e 8P9" circ#it alsoovers=ado t=e ris's associated it= t=is circ#it+ s#c= as2
• :=e %A9 circ#it is simple and proven. :=e 8P9" circ#it is more comple?+ it=signiicantly more e@#ipment. :=#s+ t=ere is more t=at can go rong t=ro#g=imbalances beteen e@#ipment or circ#it capacities in a 8P9" circ#it.
• :=e et and dry screening sections do not incl#de any bac'#p #nits+ per circ#it.:=e loss o one screen =ile in operation o#ld red#ce t=e t=ro#g=p#t potentialo t=e circ#it.
• %econdary cr#s=ing and 8P9" demands e?cellent tramp metal detection andremoval to protect st#ds. Eective tramp metal detection on slo moving eedersposes many design problems and t=e scale o t=e &erro &asale operation ille?acerbate t=is c=allenge.
• %A9 circ#its can accommodate clayey ore constit#ents easily. &lay in t=e 8P9"circ#it ill ca#se b#ild6#p at material transer points+ c=#te bloc'ages+ conveyor scraper/cleaning iss#es+ red#ced 8P9" t=ro#g=p#t and increased ear d#e toincreased eed moist#re content+ incomplete disagglomeration o la'es+ etc.9eological reports on t=e &erro &asale orebody indicates t=at t=ere are minimalclayey constit#ents in t=e orebody+ alt=o#g= t=e composite prepared or testor'to em#late t=e early mine o#tp#t+ mostly composed o diorite+ =ad almost .3clay6li'e minerals. It s=o#ld be noted t=at even small localiBed incl#sions in t=is
massive orebody co#ld rea' =avoc to t=e 8P9"6based circ#it t=ro#g=p#tcapability.
• A 8P9" circ#it demands additional d#st s#ppression+ containment ande?traction systems. D#st generation represents bot= a cost as ell as potentialenvironmental and =ealt= ris'.
A more complete list o pros and cons as p#blis=ed it= t=e earlier :O% completed att=e preeasibility stage (doc#ment 3-456!6"E6,7).
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
Most o t=e ris's listed or t=e 8P9" circ#it can be controlled at t=e design staget=ro#g= incl#sion o appropriate ris' mitigation meas#res and operating strategies in t=elos=eet.
:=e 8P9"6based circ#it is t=ereore recommended to be t=e preerred commin#tionapproac= carried or t=e easibility st#dy los=eet.
1$ REFERENCES
. <#rc=ardt+ EgbertQ 8ig= Press#re 9rinding+ %creening R 9rindability :ests on a9old/&opper Ore or t=e &erro &asale Project o $inross/<arric' carried o#t at t=ePolysi#s "esearc= &entre inal :est "eportQ 3 >#ne ,,0. (see Appendi? 6 o P%
doc#ment 3-456!6"E6,7)
. &ontract %#pport %ervicesQ inal report to $inross 9old "es#lts o &erro &asaleProposed &ommin#tion &irc#it 8P9" vs. %A<&6< easibility %im#lation %t#dyQ -%eptember ,,0. (see Appendi? 6 o P% doc#ment 3-456!6"E6,7)
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
A PP END I C O PE R A T I N " C O S T ES T I M A T E S
T ); , ' C - 1 S A BC - B " ( *% *% > L * % ' E * 6 = ' % & )% P + ' ( C+% = 6 & *+ % L * &
:=e dra actor represents t=e raction o installed poer being cons#med =en t=e e@#ipment is r#nning normally. :=ecirc#it #tiliBation actor acco#nts or all dontime incl#ding intermittent #sage e.g. s#mp p#mps =ic= is #sed only =en
spillage occ#rs. :ransmission and transormer losses are ass#med to be less or =ig= voltage s#pply.
3-456!6"E67, 8P9" :O% "ev ,.doc P ;9E 7 O 73
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
<all Mill 6 4.-m D ? 7.5m L ( * ? 55 t ) .77 ,.,4, 4-.4 ,.-3 ,.437$753
SABC
%A9 Mill 6 .-m D ? 4.55m L ( 5, ? 5.5 0.0 ,.,53 7-0.3 .- ,.53,<all Mill 6 4.-m D ? 7.5m L ( * ? 55 t ) .*7 ,.,4, 00., ,.-3 ,.07-
1$29
:=e 8P9" based ear cost o ,.* E#ro/tonne as s#pplied by t=e vendor based ontestor' cond#cted and proprietary scale6#p actors calling or a roll lie o *.,,,=o#rs. :=is as adj#sted or an estimated ear lie o 3+7,, =o#rs+ per benc=mar'ingo &erro Cerde1s operations and acco#nting or roll speed and eed moist#redierentials
All ot=er liner ear rates are based on replacement re@#ency benc=mar's.
:=e empirical <ond correlation beteen steel mass loss per 'G= and t=e abrasioninde?+ Ai+ determined d#ring t=e ,,, easibility %t#dy+ as #sed to derive t=egrinding media cons#mption. :o compensate or advances in materials andman#act#ring processes since t=e elaboration o t=e original <ond empiricale@#ations+ a credit o 7, o t=e calc#lated val#e as applied.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)
T ); , ' C - 4 C + = 6 ) (* + % + O 6 ' ( ) &* %> )% M ) *% & '%)%<' S 66 ,* ' C + &
Estimated ann#al maintenance spares and s#pplies cost (FM) 0.3 *.-&APEH e?cl. Eart=or's+ &ivil and Installation costs 415$2 417$ o e@#ipment &APEH e@#ivalent ,.,53 ,.,*3
(F/t) $32 $487
:able &65 s#mmariBes t=e calc#lation o t=e estimated ann#al s#pplies and sparescosts. :=e &APEH applicable to t=e commin#tion section+ e?cl#ding non6earable civilelements (concrete+ eart=moving and constr#ction) ere obtained rom :able <6 or t=e %A96based circ#it. or t=e 8P9"6based circ#it+ t=e val#e obtained rom t=e % isbased on applying a irst6principles approac= to t=e derivation o t=e ann#al b#dget or maintenance spares and materials.
T ); , ' C - 5 C + = 6 ) (* + % + E & *= ) & ' L);+( C + &
• It as ass#med t=at t=e maintenance and metall#rgy cres assigned to t=egrinding area o#ld be appro?imately one t=ird o t=e total plant strengt=.
• Additional metall#rgical =elpers are b#dgeted or t=e 8P9" as t=e or'load ise?pected to increase disproportionately it= t=e additional belt c#ts and gradinganalysis re@#ired or t=e additional conveyors and screens.
• &ontractors costs ere estimated in detail or t=e base case ,,- easibility %t#dyand is estimated at F7.*0 M/a. :=e e@#ivalent ig#re or t=e %A<& circ#it+ at t=e,,- Preeasibility level+ as F7.3 M/a.
7/23/2019 159742-N-RE-302_R0 (Trade Off Study HPGR vs SAG Economic Comparision Casale)