Rezerve Bakra I Zlata U Istražno - Eksploatacionom Polju Rtb-A Bor**

INSTITUT ZA RUDARSTVO I METALURGIJU BOR YU ISSN: 1451-0162 KOMITET ZA PODZEMNU EKSPLOATACIJU MINERALNIH SIROVINA UDK: 622

UDK: 622,013:330.1:55.006:553.43(045)=861

Mile Bugarin*, Miroslava Maksimović*, Vesna Ljubojev*

REZERVE BAKRA I ZLATA U ISTRAŽNO - EKSPLOATACIONOM POLJU RTB-A BOR**

Izvod

RTB Bor raspolaže značajnom mineralno-sirovinskom bazom, odnosno rezervama bakra i zlata, koje omogućavaju eksploataciju za više decenija. Istražna-eksploataciona polja RTB-a smeštena su u okviru Borske metalogenetske zone, koja se prostorno i genetski poklapa sa „timočkim magmatskim kompleksom“ (TMK), i obuhvata prostore sledećih rudnih polja; Bor, Cerovo, Majdanpek i Čoka Marin. Ekonomičnost rezervi rude bakra je u funkcionalnoj zavisnost pre svega od cene bakra na LME berzi, potražnje bakarnih proizvoda, svetske proizvodnje bakra i troškova valorizaije rude bakra. Detaljnim istraživanjem nedovoljno istraženih delova ležišta, uvođenjem novih metoda eksploatacije, savremenijih tehničko-tehnoloških metoda u pripremi i preradi bakra, otvara se mogućnost da se veći deo vanbilansnih rezervi prevede u bilansne. Trend visokih cena bakra i zlata, takođe utiće i na smanjenje graničnog sadržaja, što može dovesti do značajnog povećanja rezervi mineralne sirovine. Ključne reči: geološka-ekonomska procena rezervi rude, ležište bakra i zlata Bor, ležište rude, rudno polje, mineralne sirovine, istražno-eksploataciono polje RTB-a Bor.

UVOD

Mineralni resursi istražno-eksploa- velike rezervi rude bakra i zlata unutar taciona polja RTB-a Bor istaržuju se više timočkog magmatskog kompleksa i ste- od jednog veka, a istraživanja u zadnjih čena su bogata iskustva na valorizaciji pedeset godina kao i eksploatacija rude bakra i zlata. Istražno-eksploataciona polja bakra je veoma intezivana. Obezbeđene su RTB-a smeštena su u okviru Borske meta-

* Institut za rudarstvo i metalurgiju Bor ** Ovaj rad je proistekao kao rezultata Projekta TR-37001 „Uticaj rudarskog otpada iz RTB-a Bor na zagađenje vodotokova sa predlogom mera i postupka za smanjenje štetnog dejistva na životnu sredinu“ i 33021 „Razvoj tehnologija flotacijske prerade ruda bakra i plemenitih metala radi postizanja boljih tehnoloških rezultata“, koga finansira Ministarstvo za prosvetu, nauku i tehnološki razvoj Republike Srbije1

Broj 3, 2012. 1 RUDARSKI RADOVI logenetske zone, koja se prostorno i gene- meno nalaze najveće količine bakra u tski poklapa sa „timočkim magmatskim borskom ležištu. Mineralizovani sistem u kompleksom“ (TMK), i obuhvata prostore ovom delu ležišta dug je oko 2 km. Rudna sledećih rudnih polja; Bor, Cerovo, tela centralnog dela ležišta su: rudno telo Majdanpek i Čoka Marin. Ekonomičnost Čoka Dulkan, grupa 5 rudnih tela Tilva eksploatacije rude bakra u funkcionalnoj Mika (1, A, B, C, D), rudno telo E, rudno je zavisnosti od: kapaciteta eksploatacije, telo F, rudno telo Tilva Ronton, rudno telo iskorišćenja metala u preradi, cene metala Šistek, rudno telo Kamenjar, rudno telo G, i troškova valorizacije rude bakra, tako da rudno telo Silifikacija, rudno telo L, rudno borska ruda koja sadrži u proseku od 0,3- telo Tilva Roš, rudno telo P2A, rudno telo 0,6% bakra spada u siromašne rude, ali O, rudno telo Kamenjar 2, rudno telo povoljna cena bakra sa kontrolisanjem Krpe, rudno telo Cementacija, rudno telo troškova eksploatacije prerade i iskorišće- nja kao i razvijene infrastrukture na rud- T, T1. td. nicima, omogućuje rentabilnu proizvodnju U severozapadnom delu Borskog bakra u narednih nekoliko decenija. ležišta bakra poznato je za sada, samo jedno rudno telo – Brezanik a potenci- RUDNO POLJE BOR jalnost je interesantna dalje u pravcu kriveljskog kamena. U jugoistočnom delu Rudno polje Bor, nalazi se istočnom borskog ležišta nalaze se: rudno telo Novo delu Borske metalogenetske zone u pro- okno, rudno telo H, rudno telo J, rudno stornoj i genetskoj vezi sa gornjokrednim telo I, rudno telo M, rudno telo N i rudno magmatskim kompleksima i to; ležišta telo Borski Potok.Skoro sva naznačena bakra i zlata Bor (Tilva Roš sa brojnim rudna tela ležišta u sklopu “Tilva Roš” – rudnim telima koja su uglavnom su izvađena do nivoa kote -40, odakle se izvađena), Borska Reka, Borski Potok. nastavlja rudno ležište Borska Reka. Ležište bakra i zlata Bor – „Tilva Rudno ležište Borska reka - nalazi se Roš“, nalazi se se u centralnom delu istoi- u krajnjim severozapadnim delovima enog rudnog polja Bor. Ležište se nalazi na ležišta Bor, a sl. br. 1. Smešteno je u in- istočnom obodu grada Bor, pruža se SZ-JI u tenzivno hidrotermalno izmenjenim ande- dužini oko 5 km, a u širinu oko 500 m. zitima i njihovim vulkanitima. Prema Osnovna karakteristika borskog ležišta razmerama, porfirsko ležište Borska reka je prisustvo više desetina rudnih tela raspolaže sa preko 1.000.000 tona bakra. različitih razmera i strukturno-teksturnog Prosečni sadržaj bakra kreće se oko tipa orudnjenja, nastalih u periodu gornje 0,55%. Karakteriše ga štokverkno- krede-paleogen, u složenim procesima impregnacioni tip orudnjenja. Njegov strukturno-geološkog uobličavanja TMK. pravac pružanja je SZ-JI, zaleže prema U tom prostoru je dosad indentifikovano 30 zapadu, odnosno, jugozapadu pod uglom rudnih tela, koja su razvrstana u tri grupe: 450-550. Maksimalna dužina rudnog tela je rudna tela severozapadnog, centralnog i 1.410 m. izmerena na K-395. Maksimalna jugoistočnog dela ležišta (slika 1). širina od 635 m. izmerena je na istom Najveći broj rudnih tela nalazi se u nivou, a prosečna je oko 360 m. centralnom delu ležišta, gde se istovre-

Broj 3, 2012. 2 RUDARSKI RADOVI

Sl. 1. Prostorni razmeštaj rudnih tela ležišta Bor

Ležište bakra Veliki Krivelj nalazi se jugozapadu. na udaljenosti oko 4 km severoistočno od Rudno polje Cerovo Bora. Ležište bakra Veliki Krivelj pripada porfir-skim ležištima velikih razmera, Rudno polje Mali Krivelj – Cerovo, karakteriše se štokverkno-impregnacionim nalazi se desetak kilometara severozapadno tipom orudnje-nja i zonalnim rasporedom od Bora, prostire se od Čoke Čuruli i hidrotermal-nih alteracija. Ovo ležište nosi Kriveljskog kamena na jugu, preko samog sva obeležja koja su karakteristična za sela Mali Krivelj do Balačonje na severu, porfirska ležišta, smeštena u vulkanoge- zahvatajući područje izvorišnog dela Božine nim kalko - alkalnim komleksima. reke i područje sliva Cerove reke. U okviru Porfirska mineralizacija bakra je smeštena ovog rudnog polja nalazi se nekoliko ležišta u zoni izgrađenoj od hidroter-malno i pojava mineralizacije bakra, među kojima izmenjenih andezitskih stena, dugoj preko su najznačajnija: ležište Cerovo i ležište 2 km, maksimalne širine oko 700 m (prosečna širine 400 m), koja zaleže ka Kraku-Bugaresku- Cementacija (sl.br.2).

Broj 3, 2012. 3 RUDARSKI RADOVI

Sl. 2. Šematski prikaz rudnih tela u rudnom polju Mali Krivelj - Cerovo

Ležište Cerovo nalazi se na oko 13 ležišta nalazi se železnička stanica i jedan km, vazdušne linije, severozapadno od tunel, (dužina tunela je 300 m), koji je centra Bora, u dolini Cerove reke, između smešten na severnom obodu, kao i brda Šušulajka i Kraku Bugaresku sa železnički most na južnom obodu ležišta. zapadne i jugo-zapadne strane, sa najvišim Ležište bakra Kraku Bugaresku - ce- kotama +667 m i +612 m. i brda Drenova mentacija, nalazi se na oko 13 km, vaz- sa istočne strane, sa najvišom kotom dušnom linijom, severozapadno od Bora, i +739 m. Nivo Cerove reke je na koti na 2 km od najbližeg sela Mali Krivelj. +460 m. Neposredno iznad ležišta nalazi Iznad siromašne porfirske mineralizacije, se trasa regionalne železničke pruge Bor- u reonu Kraku Bugaresku, SZ od Malog Majdanpek (dužina trase koja prolazi Krivelja, obrazovano je ležište sekundarnog iznad ležišta je 800 m), i trasa sulfidnog obogaćenja, Cementacija – Kraku visokonaponskog dalekovoda. Pored Bugaresku. U okviru ležišta Cementacija – navedenih objekata, u prostoru iznad Kraku Bugaresku, U konturi graničnog

Broj 3, 2012. 4 RUDARSKI RADOVI sadržaja bakra 0,2% Cu, izdvajaju se 3 rudna gnajsevima i jurskim krečnjacima. Stene, u tela: Cementacija 1, Cementacija 2-4, i kojima je smeštena rudna mineralizacija, su Cementacija 3, koji predstavljaju delove pod uticajem hidrotermalnih rastvora jednog ležišta, naknadno erozijom razdvo- pretrpele intenzivne izmene. Hidrotermalne jenih. Rudno telo „C2 – C4“ je izdeljeno u alteracije magmatskih stena i kristalastih dva segmenta na bazi distribucije, odnosno škriljaca, koje su u tesnoj vezi sa stvaranjem sadržaja oksidnog bakra, pri čemu segment porfirske mineralizacije bakra, obuhvataju „C4“ predstavlja deo sa povišenim nekoliko facija alteraci: kalijsku-silikatnu sadržajem oksidnog bakra (iznad 10% metasomatozu, sericitizaciju, silifikaciju, procentualnog učešća u ukupnom bakru). hloritizaciju, argilitizaciju. Mineralizacija bakra smeštena je u zoni Rudno telo Tenka nalazi se u izgrađenoj od hidrotermalno izmenjenih severnom obodnom delu severnog revira, stena, dugoj oko 2 km, sa maksimalnom koje je po svojim tektonskim, fizičko- širinom oko 800 m (prosečno oko 600 m), mehaničkim i termodinamičkim uslovima, koja zaleže ka istoku. Ležište je, u bilo pogodno za deponovanje olovo- horizontalnoj projekciji (u konturi graničnog cinkove mineralizacije sa promenljivim sadržaja 0,05% Cu), izduženo u pravcu SZ – sadržajima zlata, srebra, bakra i pirita. Ima JI. U vertikalnoj projekciji je nepravilnog oblik nepravilnog trapeza pruzanja S-J, oblika i zaleže ispod kote +5 m. čija je duža stranica oko 650 m, a kraća od 150 do 250 m. U zapadnom pojasu Tenke Rudno polje Majdanpek lokalizovana je polimetalična sulfidna mineralizacija. Rudno polje Majdanpek nalazi se na severnom delu senonskog rova i TMK. U Rudno polje Vlaole-Jasikovo okviru ovog polja najznačajnija ležišta su: Južni revir, Severni revir. U rudnom polju Vlaole - Jasikovo Ležište Južni revir je najveće ležište u geološkim istraživanjima otkriveno je majdanpečkom rudnom polju i tipično je ležište Čoka Marin sa tri rudna tela - Čoka porfirsko ležište. Duža osa pravca Marin 1, Čoka Marin 2 i Čoka Marin 3. pružanja sever-jug iznosi preko 2km. Ležište Čoka Marin nalazi se vaz- Moćnost (debljina) rudnog tela (osa istok- dušnom linijom na oko 14 km južno od zapad) se kreće od 270 do 350 m (srednje Majdanpeka i na oko 2,5 km od sela 300 m) na višim etažama (+110), da bi se Leskovo, Jasikovo i Vlaole. sa povećanjem dubine redukovala na 250 Ležište Čoka Marin je smešteno unutar do 170 m (nivo –100 m). hidrotermalno izmenjene zone andezita, Porfirsko orudnjenje je deponovano u pravca pružanja SZ-JI. Rudonosna zona hidrotermalno izmenjenim andezitima, duga je oko 2,5 km. Ležište je istraživano gnajsgranitima i gnajsevima amfibolitske istražnim bušotinama dubine između 45 i facije. 600 m, pri čemu su istražena i okunturena Ležište Severni Revir je drugo po tri rudna tela. veličini ležište u majdanpečkom rudnom Rudno telo Čoka Marin 1, u morfoge- polju i u njemu se nalaze: netskom smislu pripada masivno sulfidnom - porfirska rudna tela: „Centralno orudnjenju, sa izraženom mineralizacijom rudno telo“ i „Dolovi-1“; zlata, koju prate štokverkno i štokverkno- - Cu-piritska rudna tela: „Dolovi-2“ i impregnaciona orudnjenjnja. Zlato se javlja „Stari Dušan“. kao samorodno, u vidu individualnih zrna, - polimetalično rudno telo Tenka vezano za minerale jalovine (kvarc i ređe Lokalizovno je u krednim andezitima, barit), ili kao dispergovana metalna faza u delom i u malim intruzijama, granit- sulfidnim mineralima. U okviru masivno

Broj 3, 2012. 5 RUDARSKI RADOVI sulfidne mineralizacije jasno se mogu kosim istražnim bušotinama, po mreži izdvojiti: masivno sulfidni-polimetalični i 50×50 i 50×40m, u periodu od 1983-1999. masivno sulfidni tip orudnjenja. U okviru godine. Ukupno je izbušeno 31 bušotina, masivnosulfidnog-polimetaličnog orudnje- odnosno 12.624 m bušenja. nja zastupljeni su zlato (sadržaji Au >10 g/t) Rudno telo Čoka Marin 3 nalazi se na i sulfidi olova, cinka i bakra (sadržaji Pb, Zn 2,2 km jugoistočno od rudnog tela “Čoka i Cu>1 %), dok se masivno sulfidnom Marin 1”, odnosno 0,7 km južno od rudnog orudnjenju javljaju zlato (sadržaji Au >1,5 tela Čoka Marin 2. Istraživanje rudnog tela g/t), i sulfidi bakra i podređeno olova u cinka izvođeno je sistemom vertikalnih i kosih (sadržaj Cu>1 %, dok su sadržaji Pb i Zn istražnih bušotina, po mreži 50×50 m. <1%). U okviru štokverknog i štokverkno- impregnacionog orudnjenja javlja se zlato sa Istraživanja su izvedena tokom 1989-1999. sadržajem i do 1 g/t, najčešće oko 0,6 g/t, godine. Izbušene su ukupno 8 bušotine, bakar, oko 0,3 %, olovo i cink, oko 0,4 %. odnosno 2.554 m. Rudno telo Čoka Marin 2 nalazi se Tabelarni prikaz bilansnih rudnih rezervi jugoistočno od rudnog tela Čoka Marin 1, eksploatacionog rudnog polja RT-a Bor; na oko 1,5 km. Istraženo je vertikalnim i

Tabela 1. Proračun rezervi „B+C1“ kategorije rudnog tela „Čoka Marin 1“ metodom vertikalnih preseka po klasama kvaliteta u štokverkno-impregnacionom tipu orudnjenja

Srednji Količina Srednji Količina Srednji Količina Srednji Koli- Srednji Količina Srednji Količina Količina sadržaj metala sadržaj metala sadržaj metala sadržaj čina sadržaj metala sadržaj metala Kklasa rude Au Au Ag Ag Cu Cu S S Pb Pb Zn Zn

(t) (g/t) (kg) (g/t) (kg) (%) (t) (%) (t) (%) (t) (%) (t)

A B C D E F G H I J K L M N

0,0-0,5 g/t Au 141.578 0,459 65 5,114 724 0,247 350 5,773 8.174 0,660 934 0,403 571

0,5-1,0 g/t Au 74.720 0,501 37 3,824 286 0,182 137 7,498 5.636 0,163 122 0,194 146

1.0-1.5 g/t Au 58.078 1,178 68 6,830 397 0,592 344 12,783 7.424 0,139 81 0,186 108

Vanbilansne rezerve C1 kategorije tela pre svega po dubini ove rezerve iznose 202.156 t rude sa srednjim sadržajem najvećim delom mogu se prevesti u bilansne Au 0,633 g/t, Ag 14,429 g/t, Cu 0,397%, Zn rezerve. 0,573% i Pb 0,428%. Istraživanjem rudnog

Tabela 2. Geološke rezerve rude bakra i zlata RTB-a

Granični Kategorij Cuox Cu-sulfid Ležište/rudno telo Q (t) Cu (t) Au (kg) Ag (kg) Zn (t) Pb(t) Mo( kg) sadržaj a rezervi (t) (t)

Cerovo 0,20% Cu B+C1 319.377.890 990.392 - - 46.168 275.399 -

Kraku Bugaresku- 0,20% Cu B+C1 70.092.712 208.235 17.887 190.348 6.104 83.983 - - - cementacija

Veliki Krivelj 0,15% Cu B+C1 621.921.288 1.978.514 - - 34.719 151.516 - - 10.135.650

Borska reka 0,30% Cu A+B+C1 556.910.629 3.151.164 - - 114.619 932.080 - - 20.631.532

Južni revir 0,15% Cu A+B+C1 463.127.844 1.465.556 - - 82.156 632.274 - - -

Severni revir 0,10% Cu B+C1 176.356.633 524.789 - - 41.928 305.021 - - -

Tenka3 0,10% Cu C1 17.626.856 48.966 - - 3.307 29.175 - - -

(Tenka1+Tenka2) 0,50% Zn+Pb B+C1 1.435.930 3.176 - - 908 12.988 23.422 6.445 -

Čoka Marin B+C1 673.016 7.531 - - 1.859 17.167 5.771 3.796 -

Broj 3, 2012. 6 RUDARSKI RADOVI

Tabela 3. Bilansne rezerve rude bakra i zlata RTB-a Cu- Granični Kategorija Cuox Ležište/rudno telo Q (t) Cu (t) sulfid Au (kg) Ag (kg) Zn (t) Pb(t) Mo( kg) sadržaj rezervi (t) (t) Cerovo 0,20% Cu B+C1 150.138.317 492.136 - - 20.235 145.809 - Kraku Bugaresku- 0,20% Cu B+C1 45.800.129 141.353 11.121 130.232 130.232 11.121 - - - cementacija Veliki Krivelj 0,15% Cu B+C1 474.291.085 1.533.821 - - 26.343 117.721 - - 7.453.802 Borska reka 0,30% Cu A+B+C1 319.969.179 1.601.091 - - 65.232 517.488 - - 11.447.399 Južni revir 0,15% Cu A+B+C1 246.947.462 834.492 - - 47.184 348.287 - - - Severni revir 0,10% Cu B+C1 138.431.743 423.597 - - 35.332 252.488 - - - Tenka3 0,10% Cu C1 8.073.532 27.085 - - 1.798 12.910 - - - (Tenka1+Tenka2) 0,50% Zn+Pb B+C1 918.398 2.175 - - 600 8.497 16.331 4.474 - Čoka Marin Au B+C1 470.860 6.729 - - 1.731 14.250 4.612 2.930 -

Tabela 4. Vanbilansne rezerve rude bakra i zalata RTB-a Ležište/rudno Granični Kategorija Cuox Cu- Au Q rude (t) Cu (t) Ag (kg) Zn (t) Pb(t) Mo( kg) telo sadržaj rezervi (t) sulfid (t) (kg) Cerovo 0,20% Cu B+C1 169.239.573 498.256 - - 25.933 129.590 - Kraku Bugaresku- 0,20% Cu B+C1 24.292.583 66.882 6.766 60.116 2.262 29.161 - - - cementacija Veliki Krivelj 0,15% Cu B+C1 147.630.203 444.693 - - 8.376 33.795 - - 2.681.848 Borska reka 0,30% Cu A+B+C1 236.941.450 1.550.073 - - 49.387 414.592 - - 9.184.133 Južni revir 0,15% Cu A+B+C1 216.180.382 631.064 - - 34.972 283.987 - - - Severni revir 0,10% Cu B+C1 37.924.890 101.192 - - 6.596 52.533 - - - Tenka3 0,10% Cu C1 9.553.324 21.881 - - 1.509 16.265 - - - (Tenka1+Tenka2) 0,50% Zn+Pb B+C1 517.532 1.001 - - 308 4.491 7.091 1.971 - Čoka Marin B+C1 202.156 802 - - 128 2.917 1.159 866 -

ZAKLJUČAK

RTB Bor raspolaže značajnom Osim istraženih i overenih rezervi bakra mineralno-sirovinskom bazom, odnosno u rudnim telima i ležištima koja nisu u rezervama bakra i zlata, koje omo- eksploataciji pored bilansnih bilansnih gućavaju eksploataciju za više decenija. rezervi u ležištima koja se eksploatišu Ekonomičnost rezervi rude bakra su u postoje potencijalni prostori za dalja funkcionalnoj zavisnost pre svega od cene istraživanja radi pronalaženja dodatnih bakra na LMI berzi, potražnje bakarnih količina rude bakra. Stepen istraženosti u proizvoda, svetske proizvodnje bakra i okviru samih ležišta nije ravnomeran, troškova valorizaije rude bakra. odnosno postoje delovi ležišta koji zahtevaju Prema sadašnjim sagledavanjima pogušćenje mreže istražnih radova, praćenih raspoloživih kapaciteta i infrastrukturno hidrogeološkim, inženjersko-geološkim, raspoloživih mogućnosti svih aktivnih tehnološkim i drugim ispitivanjima. ležišta RTB-a uz dodatna ulaganja od oko Detaljnim istraživanjem nedovoljno 250-300 miliona eura, moguće je povećati istraženih delova ležišta, uvođenjem novih kapacitet proizvodnje katodnog bakra sa metoda eksploatacije, savremenijih tehni- sadašnjih od 25.000,00 tona od oko čko - tehnoloških metoda u pripremi i 60.000,00 tona godišnje i taj kontunuitet preradi bakra, otvara se mogućnost da se održavati oko deset godina, pri čemu treba veći deo vanbilansnih rezervi prevede u još uložiti oko 350 miliona eura investicija bilansne. za narednih deset godina da se taj Deo vanbilansnih rezervi, sa sadašnjom kapacitet održi za dodatnih deset godina. cenom 8000 Eura/t bakra i 45.000 eura/kg

Broj 3, 2012. 7 RUDARSKI RADOVI zlata na svetskoj berzi metala, novom [5] Maksimović M., Marinković M., tehničko-ekonomskom ocenom mogao bi (2011): Elaborat o rezervama ležišta da se prevede u bilansne. Ovakav trend bakra „Južni Revir – Majdanpek, visokih cena bakra i zlata, takođe utiće i na 01.01.2011, Bor, Fond Odeljenja za smanjenje graničnog sadržaja, što može geologiju, IRMBor, dovesti do značajnog povećanja rezervi [6] Maksimović M. (2011): Elaborat o mineralne sirovine. rudnim rezervama Cu, Au, Ag, Pb i Zn, rudnog tela "Čoka Marin 1", 31. 03. LITERATURA 2011., Bor, Fond Odeljenja za geologiju [1] Bugarin M., Slavković G., Maksimović IRMBor, M.: „Vrednovanje korisne sirovine [7] Maksimović M., Marinković M., Čoka Marina, časopis: Rudarski radovi (2010): Elaborat o rezervama ležišta br. 2/2010.; Institut za rudarstvo i bakra Veliki Krivelj, stanje metalurgiju Bor, Zavod za informatiku, 30.06.2010, Bor 2010., Fond Odelje- 2010.; (strana od 17 do 22, srpska nja za geologiju, IRMBor, verzija i od 23 do 28 engleska verzija). [8] Maksimović M., Nikolić K. (2007) [2] Bugarin M., Slavković G., Geološko- Elaborat o rezervama ležišta bakra ekonomska ocena rudnih rezervi, Bor „Kraku Bugaresku-Cementacija, 30.09 2012. 2007; Bor 2007; Fond Zavoda za [3] Janković S., Jelenković J.R., Koželj D, geologiju, IRM Bor, (2002) Borsko ležište bakra i zlata, [9] Maksimović M., Nikolić K. (2007) Institut za bakar Bor, Bor Elaborat o rezervama ležišta bakra [4] Maksimović M., Marinković M., Cerovo, 31.12. 2006 godine; Bor 2007; (2012): Elaborat o rezervama ležišta Fond Zavoda za geologiju, IRM Bor bakra „Severni revir i ležištu [10] Maksimović M. (2005) Elaborat o polimetalične mineralne sirovine (Zn- rezervama ležišta bakra – Bor, (rudna Pb-Cu) Tenka – severni revir kod tela “Brezanik”, “Tilva Roš”, “P2A”), Majdanpeka,, 30.06.2011., Bor, Fond 31.XII 2004 godine; Bor; Fond Zavoda Odeljenja za geologiju, IRMBor, za geologiju

Broj 3, 2012. 8 RUDARSKI RADOVI

MINING AND METALLURGY INSTITUTE BOR YU ISSN: 1451-0162 COMMITTEE OF UNDERGROUND EXPLOITATION OF THE MINERAL DEPOSITS UDK: 622

UDK: 622,013:330.1:55.006:553.43(045)=20

Mile Bugarin*, Miroslava Maksimović*, Vesna Ljubojev*

POTENTIALITY AND BALANCE THE MINERAL RESOURCES OF COPPER AND GOLD IN THE EXPLORATORY – MINING FIELD OF RTB BOR**

Abstract

RTB has the significant mineral-raw materials base or the reserves of copper and gold, which allow the exploitation for several decades. The exploratory-mining fields of RTB are located within the Bor metallogenic zone, which is spatially and genetically coincides with the "Timok Magmatic Com- plex" (TMK), and includes the areas of Bor, Cerovo, Majdanpek and Čoka Marin ore fields. The cost-effectiveness of copper ore reserves are in the functional dependence primarily of the copper price on the LME stock market, copper product demand, world production of copper and costs of copper ore valorization. By detailed explorations the insufficiently explored parts of deposits, introduction the new mining methods, modern technical-technological methods for copper preparation and processing, there is a possibility that the most of off-balance reserves would be transferred into the balance reserves. The trend of high prices of copper and gold also helps the reduction of limit content, which could led to a significant increase in the reserves of mineral resources. Keywords: Geological-economical evaluation of ore reserves, copper and gold deposit Bor, ore deposit, ore field, mineral resources, exploratory-mining field of RTB Bor

INTRODUCTION

Mineral resources of the exploratory- the last fifty years the explorations as well mining field of RTB Bor have been re- as the copper ore are very intensive. Large searched for more than a century, and in reserves of copper and gold ore were pro-

* Mining and Metallurgy Institute Bor, Zeleni bulevar 35, Bor ** This work is the result of the Project TR-37001 “The Effect of Mine Waste from RTB Bor on Pollu- tion of Watercourses with a Proposal of Measures and Procedures to Reduce the Adverse Effects on Environment” and Project TR-33031 “Development of Technologies for Flotation Processing the Copper Ore and Precious Metals to Realize Better Technological Results”, funded by the Min- istry of Education, Science and Technological Development of the Republic of Serbia.

No 3, 2012. 9 MINING ENGINEERING vided within the Timok Magmatic Com- northwest, central and south-eastern part plex and rich experiences were gained in of the deposit (Figure 1). gold and copper evaluation. The explora- The largest number of ore bodies is lo- tory-mining fields of RTB are located cated in the central part of the deposit with within the Bor metallogenic zone, which the largest quantities of copper in the Bor is spatially and genetically coincides with deposit. Mineralized system in this part of the "Timok Magmatic Complex" (TMK), deposit is long about 2 km. Ore bodies of and includes the areas of the following ore the central part of deposit are: the ore fields: Bor Cerovo, Majdanpek and Čoka body Čoka Dulkan, a group of five ore Marin. Economy of copper ore mining is bodies Tilva Mika (1, A, B, C, D), the ore in the functional dependence on: the ca- body E, the ore body F, the ore body Tilva pacity of mining, recovery of metals in Ronton, the ore body Šistek, the ore body treatment, metal prices and costs copper Kamenjar ,the ore body G, the ore body ore evaluation, so that the Bor ore contain- Silifikacija, the ore body L, the ore body ing an average of 0.3 - 0.6 % copper be- Tilva Ros, the ore body P2A, the ore longs to the low-grade ore, but the favor- body O, the ore body Kamenjar 2, the ore able copper price with controlling the op- body Krpe, the ore body Cementacija, the erating costs of processing and recovery ore body T, the ore body T1, etc. as well as developed infrastructure in the In the northwestern part of the Bor mines, enables the cost-effective produc- copper deposit, only one ore body - Brez- tion of copper in the next few decades. anik is known until now, and a potentiality is still interesting in the direction of the ORE FIELD BOR Krivelj Stone. In the southeastern part of The ore field Bor is located in the east- the Bor deposit are : the ore body New ern part of the Bor metallogenic zone in Shaft, the ore body, H, the ore body J, the the spatial and genetic relation with the ore body I, the ore body M, the ore body Upper Cretaceous magmatic complexes as N and the ore body Bor Stream. Almost well as: the copper and gold deposit Bor all indicated ore bodies of the deposit (Tilva Ros with numerous ore bodies that within "Tilva Ros" were mined to the are mostly mined), the Bor River and the level of elevation -40, from here the ore Bor Stream. deposit Bor River is continued. Copper and Gold Deposit Bor - “Tilva Ore Deposit Bor River is located in the Ros” is located in the central part of the extreme northwest parts of the Bor deposit, same named ore field Bor. The deposit is Figure 1. It is located in the intensely hydro- located on the eastern edge of the town of thermally altered andesites and their volcan- Bor, in the NW-SE direction in the length of ics. According to the scales, the porphyritic about 5 km and width of about 500 m. Bor River deposit has more than 1,000,000 The main feature of the Bor deposit is tons of copper. The average copper content the presence of dozens ore bodies of dif- is about 0.55 %. It is characterized by the ferent scales and structural-textural type of stockwork-impregnation type of mineraliza- mineralization, formed in the Upper Cre- tion. Its direction is the NW-SE, dipping to the west, i.e. the southwest at angle of 45o- taceous-Paleogene period, in the complex o processes of structural-geological shaping 55 . Maximum length of the ore body is the TMC. In this area, 30 ore bodies have 1410 m, measured at K-395. Maximum been indentified so far, which are classi- width of 635 m was measured at the same fied into three groups: the ore bodies of level, and the average is about 360 m.

No 3, 2012. 10 MINING ENGINEERING

Fig. 1. Spatial distribution of the ore bodies of the Bor deposit

Copper Deposit Veliki Krivelj is southwest. located at a distance of about 4 km Ore field Cerovo northeast of bor. the copper deposit veliki krivelj belongs to the porphyritic deposits The ore body Mali Krivelj – Cerovo is of large scales, characterized by the located about ten kilometers northwest of stockwork-impregnation type of Bor, extending from Čoke Čuruli and mineralization and zonal distribution of Krivelj Stone in the south, through the hydrothermal alterations. This deposit has village of Mali Krivelj to Balačonje in the all features that are characteristic for the north, including the area of source part of porphyritic deposits, located in the the Božina River and the basin area of the volcanogenic calc-alkaline complexes. Cerova River. Within this ore field, there Porphyritic copper mineralization is are several deposits and occurrence of situated in a zone of hydrothermally copper mineralization, the most important altered andesite rocks, over 2 km long are: the deposit Cerovo and the deposit with maximum width of about 700 m Kraku-Bugaresku-Cementacija (Figure 2). (average width of 400 m), dipping to the

No 3, 2012. 11 MINING ENGINEERING

Fig. 2. Schematic view of the ore bodies in the ore field Mali Krivelj – Cerovo

Deposit Cerovo is located about 13 power line. In addition to these facilities, km by air line, north-west of the center of in the area above the deposit, there is a Bor, in the valley of the Cerova River, railway station and a tunnel (tunnel length between the hill Šušulajka and Kraku is 300 m), located on the northern edge, as Bugaresku to the west and south-west well as the railway bridge on the southern side, with the highest elevations of +667 edge of the deposit. m and +612 m and the hill Drenova to the Copper Deposit Kraku Bugaresku is east, with the highest elevation of +739 m. located about 13 km by air line, north- The Cerova River level is at elevation of west of Bor, and 2 km from the nearest +460 m. Directly, above the deposit, is the village Mali Krivelj. regional railroad tracks Bor-Majdanpek Above the poor mineralization, in the (length of the route that passes over the region Kraku Bugaresku, NW of Mali deposit is 800 m), and the high-voltage Krivelj, the deposit of secondary sulphide

No 3, 2012. 12 MINING ENGINEERING enrichment, Cementacija - Kraku Bugare- - porphyritic ore bodies: "Central ore sku, was formed. Within the deposit Ce- body" and "Dolovi-1", mentacija - Kraku Bugaresku, in a contour - Cu-pyrite ore bodies: "Dolovi-2" and of limit copper content 0.2% Cu, the three "Old Dusan", ore bodies are separated: Cementacija1, - Polymetallic ore body Tenka Cementacija 2-4 and Cementacija 3, It is localized in the Cretaceous ande- which are parts of one deposit, subse- sites, partly also in small intrusions, gran- quently separated by erosion. The ore ite-gneisses and Jurassic limestones. body "C2 - C4" is divided into two seg- Rocks, which include the ore mineraliza- ments based on distribution, i.e. content of tion, have undergone the intensive oxide copper, where the segment "C4" is a changes under the influence of hydro- part of high content of oxide copper thermal solutions. Hydrothermal altera- (above 10% of percentage participation in tions of magmatic rocks and crystalline total copper). schists, which are closely related with the Copper mineralization is situated in formation of porphyritic copper minerali- the zone built of hydrothermally altered zation, include several facies of altera- rocks, about 2 km long with maximum tions: potassium-silicate metasomatism, width of about 800 m (average about 600 sericitization, silicification, chloritization m), dipping to the east. The deposit is in and argillitization. the horizontal projection (in a contour of The ore body Tenka is located in the limit Cu content of 0.05%), elongated in northern peripheral part of the North Min- the direction of NW - SE. In the vertical ing District, which according to its tec- projection, it is irregular in shape and dip- tonic, physical-mechanical and thermody- ping below the level of +5 m. namic conditions, was suitable for dis- posal the lead-zinc mineralization with Ore field Majdanpek variable contents of gold, silver, copper and pyrite. It has a form of irregular trape- The ore field Majdanpek is located in zoid, extending the NS, with longer edge the northern part of the Senonian trench of about 650 m, and shorter edge from 150 and TMC. In this field, the most important to 250 m. In the western zone of Tenka, deposits are: South Mining District and the polymetallic sulfide mineralization is North Mining District. localized. South Mining District the largest deposit in the ore field Majdanpek and it is Ore field Vlaole-Jasikovo typical porphyritic deposit. The longer axis of direction extending from north to The deposit Čoka Marin, discovered in south is more than 2 km. Thickness of the the ore field Vlaole-Jasikovo by geologi- ore body (east-west axis) ranges from 270 cal prospecting works, includes three ore to 350 m (average 300 m) at the upper bodies: Čoka Marin 1, Čoka Marin 2 and benches (+110) and it is reduced with in- Čoka Marin 3. creasing depth from 250 to 170 m (-100 m Deposit Čoka Marin is located about level) . 14 km by air line to the south of Majnda- Porphyritic mineralization was depos- pek and about 2.5 km of the villages ited in hydrothermally altered andesites, Leskovo, Jasikovo and Vlaole. gneiss granites and gneisses of amphiboli- The deposit Čoka Marin is situated tic facies. within the hydrothermal altered zone of North Mining District is the second andensite, extending the NW-SE. The largest deposit in the Majdanpek ore field mineralization zone is about 2.5 km long. and it contains:

No 3, 2012. 13 MINING ENGINEERING

The deposit was explored by prospecting- (Cu content > 1%, until Pbi Zn contents drill holes, depth between 45 and 600 m, <1%). Within the stockwork and stock- where three ore bodies were explored and work impregnation mineralization, the contoured. gold occurs with content up to 1g/t, usu- The ore body Čoka Marin 1, in a ally copper of about 0.6 g/t, lead 0.3% and morphogenetic sense, belongs to the mas- zinc of about 0.4%. sive sulphide mineralization, with signifi- The ore body Čoka Marin 2 is located cant gold mineralization, accompanied to the southeast of the ore body Čoka with stockwork and mineralizations. Gold Marin 1, about 1.5 km. It was explored by occurs as native, in the form of individual the vertical and oblique prospecting drill grains, bonded to the gangue minerals holes per network 50×50 and 50×40m, in (quartz and rarely barite), or as a dispersed the period 1983-1999. Total of 31 drill metal phase in sulphide minerals. Within holes was drilled, i.e. 12,624 m of drilling. the massive sulphide mineralization, the The ore body Čoka Marin 3 is located followings can be clearly distinguished: 2.2 km to the southeast of the ore body massive sulphide-polymetallic and mas- Čoka Marin 1, that is 0.7 km south of the sive sulphide type of mineralization. ore body Čoka Marin 2. Exploration of the Within the massive sulphide-polymetallic ore body by the system of vertical and mineralization, the followings are present: oblique prospecting drill holes per net- gold (Au contents >10g/t) and sulphides work on the 50 x 50 m. Explorations were of lead, zinc and copper (Pb, Zn and Cu carried out during 1989-1999. Total of 8 >1%), while in the massive sulphide min- drill holes was drilled, i.e. 2554 m. eralization, the followings are present: Tabular presentation the balance re- gold (Au contents > 1.5 g/t), and sulphides serves of mineral exploitation the ore of copper and subordinated lead in zinc body RT Bor.

Table 1. Calculation of reserves, B+C1 category, the ore body Čoka Marin 1 by the method of vertical cuts per quality classes in stockwork-impregnation type of mineralization

Mean Metal Aver. Metal Mean Metal Mean Mean Metal Mean Metal Ore Quantity cont. quant. Cont. quant. cont. quant. cont. cont. quant. cont. quant. Class quantity S Au Au Ag Ag Cu Cu S Pb Pb Zn Zn

(t) (g/t) (kg) (g/t) (kg) (%) (t) (%) (t) (%) (t) (%) (t)

A B C D E F G H I J K L M N

0.0-0.5 g/t Au 141,578 0.459 65 5.114 724 0.247 350 5.773 8,174 0.660 934 0.403 571

0.5-1.0 g/t Au 74,720 0.501 37 3.824 286 0.182 137 7.498 5,636 0.163 122 0.194 146

1.0-1.5 g/t Au 58,078 1.178 68 6.830 397 0.592 344 12.783 7,424 0.139 81 0.186 108

The off-balance reserves, C1 category, exploration of the ore body primarily in amount 202,156 t of ore with the average depth, these reserves could be transferred content of Au 0.633 g/t, Ag 14.429 g/t, Cu into the balance reserves. 0.397%, Zn 0.573% and Pb 0.428%. By

No 3, 2012. 14 MINING ENGINEERING

Table 2. Geological reserves of coper and gold ore of RTB Cu- Reserve Q ore Cu Cu-ox Au Ag Zn Pb Mo Deposit/ore body Limit content sulphide category (t) (t) (t) (kg) (kg) (t) (t) ( kg) (t) Cerovo 0.20% Cu B+C1 319,377,890 990,392 - - 46,168 275,399 - Kraku Bugaresku- 0.20% Cu B+C1 70,092,712 208,235 17,887 190,348 6,104 83,983 - - - Cementacija Veliki Krivelj 0.15% Cu B+C1 621,921,288 1,978,514 - - 34,719 151,516 - - 10,135,650

Bor River 0.30% Cu A+B+C1 556,910,629 3,151,164 - - 114,619 932,080 - - 20,631,532 South Mining 0.15% Cu A+B+C1 463,127,844 1,465,556 - - 82,156 632,274 - - - District North Mining 0.10% Cu B+C1 176,356,633 524,789 - - 41,928 305,021 - - - District Tenka3 0.10% Cu C1 17,626,856 48,966 - - 3,307 29,175 - - -

(Tenka1+Tenka2) 0.50% Zn+Pb B+C1 1,435,930 3,176 - - 908 12,988 23,422 6,445 -

Čoka Marin B+C1 673,016 7,531 - - 1,859 17,167 5,771 3,796 - Table 3. Balance reserves of copper and gold ore of RTB Cu- Limit Reserve Cu Cu-ox Au Ag Zn Pb Mo Deposit/ore body Q ore (t) sulphide content category (t) (t) (kg) (kg) (t) (t) ( kg) (t)

Cerovo 0.20% Cu B+C1 150,138,317 492,136 - - 20,235 145,809 -

Kraku Bugaresku- 0.20% Cu B+C1 45,800,129 141,353 11,121 130,232 130,232 11,121 - - - Cementacija

Veliki Krivelj 0.15% Cu B+C1 474,291,085 1,533,821 - - 26,343 117,721 - - 7,453,802

Bor River 0.30% Cu A+B+C1 319,969,179 1,601,091 - - 65,232 517,488 - - 11,447,399

South Mining 0.15% Cu A+B+C1 246,947,462 834,492 - - 47,184 348,287 - - - District North Mining 0.10% Cu B+C1 138,431,743 423,597 - - 35,332 252,488 - - - District

Tenka3 0.10% Cu C1 8,073,532 27,085 - - 1,798 12,910 - - -

(Tenka1+Tenka2) 0.50% Zn+Pb B+C1 918,398 2,175 - - 600 8,497 16,331 4,474 -

Čoka Marin Au B+C1 470,860 6,729 - - 1,731 14,250 4,612 2,930 - Table 4. Off-balance reserves of copper and gold ore of RTB Cu- Limit Reserve Q ore Cu Cu-ox Au Ag Zn Pb Mo Deposit/ore body sulphide content category (t) (t) (t) (kg) (kg) (t) (t) ( kg) (t)

Cerovo 0.20% Cu B+C1 169,239,573 498,256 - - - 25,933 129,590 Kraku Bugaresku- 0.20% Cu B+C1 24,292,583 66,882 6,766 60,116 - - - Cementacija 2,262 29,161

Veliki Krivelj 0.15% Cu B+C1 147,630,203 444,693 - - - - 8,376 33,795 2,681,848 Bor River 0.30% Cu A+B+C1 236,941,450 1,550,073 - - - - 49,387 414,592 9,184,133 South Mining 0.15% Cu A+B+C1 216,180,382 631,064 - - - - - District 34,972 283,987 North Mining 0.10% Cu B+C1 37,924,890 101,192 - - - - - District 6,596 52,533 Tenka3 0.10% Cu C1 9,553,324 21,881 - - - - - 1,509 16,265

(Tenka1+Tenka2) 0.50% Zn+Pb B+C1 517,532 1,001 - - - 308 4,491 7,091 1,971 Čoka Marin B+C1 202,156 802 - - - 128 2,917 1,159 866

CONCLUSION

RTB has the significant mineral-raw dependence primarily of the copper price materials base or the reserves of copper on the LME stock market, copper product and gold, which allow the exploitation for demand, world production of copper and several decades. The cost-effectiveness of costs of copper ore valorization. copper ore reserves are in the functional According to the current perception of

No 3, 2012. 15 MINING ENGINEERING available capacities and infrastructure op- [3] Janković S., Jelenković J.R., Koželj D, tions of all active deposits of RTB with the (2002): The Bor Copper and Gold additional investments of around 250-300 Deposit, Copper Institute Bor, Bor (in million Euros, it is possible to increase the Serbian) production capacity of cathode copper from [4] Maksimović M., Marinković M., the current 25,000.00 tons of about 60000.00 (2012): Detailed Study on Reserves of tons per year and to maintain this continuity the Copper Deposit North Mining for about ten years, with the required in- District and Deposit of Polymetallic vestment of about 350 million Euros over Mineral Resources (Zn-Pb-Cu) Tenka – the next ten years to maintain this capacity North Mining District near Majdanpek, for additional ten years. 30.06.2011, Bor, Fund of Department In addition to the explored and verified of Geology, Mining and Metallurgy reserves of copper in the ore bodies and de- Institute Bor (in Serbian); posits that are not in operation, besides the [5] Maksimović M., Marinković M., (2011): balance reserves in the deposits, which are Detailed Study on Reserves of the mined, there are the potential areas for fur- Copper Deposit South Mining District – ther explorations to find the additional Majdanpek, 01.01.2011, Bor, Fund of quantities of copper ore. The degree of ex- Department of Geology, Mining and ploration within the deposits is not very Metallurgy Institute Bor (in Serbian); smooth, and there are parts of deposits that [6] Maksimović M. (2011): Detailed Study require denser network of prospecting wor- on the Ore Reserves of Cu, Au, Ag, Pb ks, followed by hydrogeological, engineer- and Zn of the Ore Body "Čoka Marin 1", ing-geological, technological and other tests. 31. 03. 2011, Bor, Fund of Department By detailed explorations the insuffi- of Geology, Mining and Metallurgy ciently explored parts of deposits, introduc- Institute Bor (in Serbian); tion the new mining methods, modern tech- [7] Maksimović M., Marinković M., nical-technological methods for copper pre- (2010): Detailed Study on Reserves of paration and processing, there is a possibility the Copper Deposit Veliki Krivelj, that the most of off-balance reserves would 30.06.2010, Bor 2010, Fund of be transferred into the balance reserves. Department of Geology, Mining and A part of off- balance reserves, with the Metallurgy Institute Bor (in Serbian); current price of 8,000 Euro/ t of copper and [8] Maksimović M., Nikolić K., (2007): 45,000 Euro/kg of gold on the world metal Detailed Study on Reserves of the market by the new technical-economic eva- Copper Deposit Kraku Bugaresku-Ce- luation could be transferred into the balance mentacija, 30.09.2007, Bor 2007; Fund reserves. This trend of high prices of copper of Department of Geology, Mining and and gold also helps the reduction of limit Metallurgy Institute Bor (in Serbian); content, which could led to a significant [9] Maksimović M., Nikolić K., (2007): increase in the reserves of mineral resources. Detailed Study on Reserves of the Copper Deposit Cerovo, 31.12.2006, REFERENCES Bor 2007; Fund of Department of [1] Bugarin M., Slavković G., Maksimović Geology, Mining and Metallurgy M.: Evaluation the Useful Raw Materials Institute Bor (in Serbian); of Čoka Marin, Journal Mining [10] Maksimović M. (2005): Detailed Study Engineering, No. 2/2010, Mining and on Reserves of the Copper Deposit Bor, Metallurgy Institute Bor, pp. 23-28; (Ore Bodies “Brezanik”, “Tilva Ros”, [2] Bugarin M., Slavković G., Geological- “P2A”), 31.12.2004, Bor; Fund of economical Evaluation of the Ore Department of Geology, Mining and Reserves, Bor, 2012 (in Serbian); Metallurgy Institute Bor (in Serbian).

No 3, 2012. 16 MINING ENGINEERING