Thong tin khoa hpc cong nghe m o NGHIEN Ctlru Uifi CHON CONG NGHE NO MJN HOP LY N H A M N A N G CAO O N D I N H BOr MO KHI KHAI THAC XUONG SAU CAC MO QUANG SAT Drilling and blasting operation is considered as one of the important technological links in open pit mining activities In the mining technological activities, drilling and blasting operation is more likely to cause the danger in mining process In particularly, drilling and blasting operation affects dramatically mine site, people, equipment and the surrounding buildings by shock wave As a result, for ensuring these purposes in mining process, it is necessary to comply with the national technical regulations on safety in the exploitation of open cast mines TS LLfU V A N T H I / C ThS DLfONG TRUNG JAM kS VO BiNH TRLI-ONG Viin Khoa hoc Cdng nghd /Wo - Vinacomin Bien tip: TS Lwu Van Thuic Tai hlu hit eac mo (trir mc Thach Khe), quang Dac diem dilu kien tu> nhien - ky thuat sat deu dypc phan bo o" cac vung doi niii, dia hinh cdc mo quang s i t phia Blc Vif t Nam phire tap Theo phuong phap thoat nuoc khai 1.1 Dac diem dieu kien tiy nhien cac mo tryo'ng, cac mo dupe chia nhom: quang sat - Nhdm 1; Cac mo khai thac tren mire thoat Cac mo quang sat thupc khu vuc phia Bac Viet Nam c6 dilu ki$n ty nhiSn typng doi phirc nuo'c tu chay nhy; mo sat Sang Thin, Quy Xa, tap, nhieu phay pha, dirt giy Dac dilm dilu kipn Lang Thap, Thanh Ky - Thanh Tan - Typng Son v.v Cac mo dilu kien thoat nude thuan tien, dja hinh chii y i u la doi niii tir thap d i n cao, dja dilu kien thuy van va DCTV khong anh huo'ng hinh biln d l i nhilu, cac khu vuc md thuo'ng nhilu d i n qua trinh khai thac ciia md nam xa trung tam va eae khu vyc dan cy, dilu - Nhdm 2: Cac mo khai thac duoi mire thoat kien giao thong lien lac kho khan, eo sd' ting nuoc tu chay, dae dilm chung ciia cae mo thip kem * Bac diem didu kidn dia chat cdng trinh cac phan bo g i n cac song suoi nhu: mo Na Rua nim g i n song Hiln va song Bing Giang, mo Na md quang sat: Lung nim g i n cac suli thoat nuo'c cua khu vyc, - Dac dilm eua t i n g phii Dp tir: Can cif vao mo Tung Ba dypc phan chia khu vuc dac dilm c i u triie dia chit cua cac mo quang ngan each bo'i suoi Ng6i Nao, md Ngupm Chang sat, ting phu phia tren thuo'ng la d i t De tir hoac nam g i n song Bang Giang, mo Trai Cau Neogen Day la tang d i t yeu anh hyo'ng d i n on canh khai truo'ng e6 suoi Thac Lac chay qua djnh bo mo eung nhy cac khau cua day chuyen Mat khac, da chira quang thuong thuoc loai san xuit nirt ne manh va tang da vol, da hoa phat triln - Dac diem ciia ting da ciing vay quanh via eae hang eastp Vi vay, eae md tren khai thae quing: Ting nham thach chira qu|ng goc 6' cae dupi mii-c thoat nudety chay, lypng nyoc ngim mo, da vay quanh chu yeu la loai: Oa philn chay vao khai truong kha 16'n lam anh huong thach anh-sericit, cat kit quarzit, grabo chira eac d i n qua trinh khai thae Nguon nypc chay vao via quang sat, mcgma-grpnitbiptit, da vpi, da vol khai tryong anh hypng d i n edng tac khai thae, dolomit hoa, da plagipgranit, plagingranitpgnels bao gom: Nhu'ng phan tich tren day cho thiy, da vach, da - Nydc mya: Lypng nypc mua tmng binh hang tru va da kep eo anh huo'ng dang k l den cong nam o khu vue miin niii phia Bae noi e6 cac mo nghe khpan no min, xue boc chpn Ipe va chat qujng sat dao dpng khoang lypng quang sat nguyen khai Dac tinh co ly ciia 2000+2120mm/nam, lypng mya eao nhit dat da cae mc dupe trinh bay trpng bang d?t 200+250mm/ngay, lypng mua cao nhat * B$c diem dieu kidn dja chat thijy van cac mo trcng thang van mua mya din 850+900mm/thang quang sit: KHCNM S6 10/2014 * CNKT LQ THIEN Thong tin khoa hpc cong nghe mo Bang Die tinh chit ca ly cda lit did mdt s6 md quSng sit phia B§c Viit Nam Ten mo LOfii dat da D^t phong hda Ni Lung Di ci>ng 37,3+126,9 4,12+11,47 Dat phong hda NiRva Ngip^m ChSng Di cLPng 82,4+101,4 8,83+18,04 Dat phong hoa Di cirng 28,4+67,67 Khoi luwjg th4 tich Yi (g/cm') sang Than QuyXa Di cirng 61,3+112,29 2,9^11,8 Dat phong hoa 1,73+8,52 KIpTifdc 11 Lang My 0,43+3,16 1,73+2,01 23+32 36»20'+37«3r 71+142 1,76 20°23'+23»34' 0,46-0,59 2,66+3,01 36»36'+37°10' 101+208 1,96 21,66 0,311 2,66+2,74 37-38°47' 49,7+211 16°39'-24°33' 0,17+0,43 2,68+284 34»00' 37''16' 47+136 1,32+2,06 16°14' 22°60' 0,12+0,35 Da cirng 13,0+89,34 3,0 3,03 2,7 27°17' Da Macmamica 86,3+96,12 2,9 30°16' 1,71 21»51' 1,17 2,76 37''23' 196 Da 108,2 10,1 134,6 18,6 2,25+2,51 Dit Oa Trai Cau Life dinh kite (KG/cm'j QuSng ngh^o va da kep Dat Gdc ma sat tp(dd} 2,71+2,83 Dat phong hoa Tung Bi 13 Cuvngdd khang nen 6n (MPa) III TT Dat set, i set - Nuoc ngim Ngudn ny6e ngim gay khd khan cho khai thac quang la ting chira nude d^ voi caebon - pecml ddi nirt ne Lupng nuoc chay vac khai tryong phu thupc vao sau eiia day khai trudng ting chira nypc 1.2 Dac diem dieu kien ky thuat cic mo quang sat Dae trung ve dac dilm ky thuat ciia eae mo qusng sat la' Cac yeu t l ve kich thuoc thong so hinh hpc cua eae mo, cac thong s i cua he thong khai thac (HTKT) va eae khau cong nghe mo Cac mo quang sat chu y i u dypc phan bo a khu vyc phia Blc eua nudeta Cac mo d i u nim d cac viing sau, viing xa, c6 dilu kien khai thae khong thuan Ipi, quy mo khai thac thuong nho, dieu kien khai truong han c h i Dac trung v l cae thdng s6 hinh hpc md cua mpt s i md quang sit t h i hien d bang [1] 2,81 32»46' 314,38 1,72+1,92 15+24=33' 0,387+0,476 bai thai ngp^i va bai thai trpng, sCr dgng cdng nghp khIu theo Idp dCrng Ngoai ra, mpt s i md cd dilu kien tao dac thu chu yeu la Ip via tren be mat dja hinh, than qugng nim ngang, nhy mo Lang Vinh - Lang Cp, Sang Thin, Quy Xa Tai cac mc nay, c6 the ap dgng HTKT ngang, khai thae cucn chieu d l tgn dung khdng gian dn thai trpng Cac thdng so cp ban cija HTKT cua eae md quang s i t nhu: Chieu cao ting h = 5+12m; k i t thiic hiii= 10+20m; chieu rpng mat tang cong tac tir 22+30m; gdc nghieng bp ccng tac tif 22+30° K l hoach khai thac cua mot s6 md quang s i t Hien nay, tai cac mc quang sat eiia nydc ta, hlu nhy da tiin hanh khai thac h i t io|ii quang deluvi, eluvi va phong hda tren b l mat Hlu hit cae mo quang sat deu ed dang tren sydn nui Ct cae mo quang sat, ehu yeu sir dung HTKT dypi moong sau, d i t da t i p trung a phia tren dpc mdt hoae hai bd cong tac, d i t da dupe d l ecn quang tap trung 6' phia dyp'i Trpng thp'i gian n KHCNM s o 10/2014'CNKT LO THIEN Thong tin khoa hpc cong nghe mo Bing Cic chi tieu ca bin vi khai tniong mdt sd md quSng sat TT Chi tieu Kich thu'dc khai tru'dng Dan vi Ni Lung Na Rua Kip Twdic Tien Bg Sing Than Lang My Timg Ba Dai m 905 1174 568 1680 1088 796 520 R6ng m 540 816 281 660 265 368 430 Di0n tich 48,87 95,79 11,2 110,8 2,8 29,3 22,36 +210 -70 +115 -20 +930 +20 +270 2.406 12.402 1.394 23.228 32012 141 1.922 C6t cao day mo TrO lupng quang dja chat 10» t i n bign gidi khai truong Khoi lupng quang nguygn khai 10= t i n 436 11.930 375 21.730 31.372 884 1902 Dat bdc 10»m» 23 173 77.637 4.091 23.509 335 17.735 17.553 H$ so bdc trung binh m>/t 9,5 6,5 3,0 1,1 0,01 3,6 9,2 tai, cac mo deu se phai khai thac xuong sau, bien gioi tren mat du-gc ma rpng, khai thac quang g i c du-ai mipc thoat nu-ffc tu" chay San lu-gng mpt s i mo quang sat du'p'c gio'i thi^u tai bang [3] Cdng nghe nd co d i i u khien nham nang cao on djnh bd* mo B^ dam bao cac mo quang sat du'p'c khai thac theo k i hoach nhu' tren, can chu trpng din cac giai phap d i i m6i cac day chuyen cong nghe Dac biet, vi§c dliu khien ba kit thuc co y nghTa quan trpng doi vo'i mo Ip thien Niu khong c^eu khiin du'p'c hau xung vao ba mo thi se gay Idn sy khong on dinh cua bo' mo, anh hu'O'ng d i n khai thac mo Goc ba kit thuc giam, giam tri> lu'p'ng quang cp t h i lay du'p'c, tang he so boc, d i t da ba md bi biin dang 16'n, dai an toan bj m i t di, diiu kien lam vi$c nguy hiim, vung ching do" nhan tao tang len, chi phi khai thac tang len e giam thiiu cac tac dpng x i u nhu' tren, can ap dung cac phu'cng phap nhu': N i tap man chan hole no tap mat phang Day la phu'cng phap no tap s y t i p trung nang lygng n i thip tai m i i khu vyc bo' mo 3.1 Cong nghe no tao man chan (tao bien trw6>c) Cong nghe no tap man chan la cong nghe no nhim giam chin dpng d i n bci' mo, cong Bang San lugng cic md qu$ng sSt TT Cac md Die kien cdng suit khai thac (1(y tan/nam) 2011-2016 2016+2020 3.300- 3.300 3.300 Lie Cai Mo Quy Xa 000 3.000 Md Lang Cp 100 100 Md Lang Vmh 100 100 100 100 Md Kip T u d c // Yin Bii 100 100 Mo Lang My 100 100 //; Hi 200 200 Md Tung Ba 100 100 Md sang Than 100 100 IV Cao Bing 370 420 Giang Md Na Rua 100 200 Na Lung 150 100 Ngudm Chang 120 120 V Thii Nguyen 820 770 Khu Trai Cau 220 170 Md Tien Bd 600 600 trinh can bao ve, lam giam sdng dap khdng khi, ding da n l se gon hpn hole n l se giii' nguyen dupe eiu triic eua via quang, dd, thuan Ipi eho cdng tac xue boc chpn Ipc KHCNM S 10/2014 • CNKT LQ THIEN Thong tin khoa hoc cong nghe mo Su' dung cac 16 khoan tao bien co dyang kinh d = 90^105mm, cac 16 khoan pha co du'ang kinh ti> 165^200mm Cac 16 khoan tao bien du-gc khoan tru'O'c tien, tru-ac cac 16 n i pha Trong tru'O'ng hgp sau, hang bien du'gc kich n i ding •—Bu&niS th6i tru'oc vu n i chinh vo'i tho'i gian tCf 100 15°ms Rach tao se chan n i tCr hang Mdinj dem khong cho chung phat t n i n vao khii da phia Hang lo khoan bien c6 khoang each giua cac 16 alb = 2m, goc nghieng 15° so vo'i phu'ong thang di^ng kh6ng k i to'i c i u true dit Lo khoan tao bidn (tao khe ban diu) Ld khoan khiu (phi vo dit di) da Thiet bj khoan c i n c6 kha nang khoan diing Hinh Sa dd nd tao bien man chin trudc hifo-ng mat tang vo'i goc nghieng 15°, cho bien n i u dung cot bua thi dh 40-^50% khoang dai an toan nho hen tring Cac 16 khoan hang bien va hang dem khong b Hang lo khoan dem: Cung nhu- hang cuii khoan them di 6a pha mat ting du'O'i va bo' mo cung cua n i ehinh tang cot bua d i tranh phi sau kit thue tai vj tri Cae thong s i n i vao bo' mo sau hang bien tao bien tru'O'c du'gc xae djnh nhu- sau u Hang lo khoan binh thuung: Cac hang 16 - Khoang each giOa cac id bien: Khoang each khoan eo khoang each hang va lo binh giOa cae 16 bien ty le thuan v6i du'o'ng kinh lo thu'O'ng, thu tue nap ca ban khoan va la ham s i cua ty 1$ giu'a dp bin nen NMTB du'gc ap dung d i tang on dinh ting va (5n) va ben keo {5k) Vdi da s i eac loai da mo, ty I? 5n/6k ~ 12/1-i-15/1 Vo'i tu'cng d i i : atb = bo' mo chung tiin tai bien giai Co phu'ang phap NMTB; (11^13)dik, mm ~ Phu'ang phap 1: Tao rach man chan, dpc - M$t dg nap thuoc cac lo bien- Mat nap thuic VLKa du 6^ tach da ma khong pha nat Diiu theo bien thiit k i cua ba mo, ngu'O'i ta khoan va dat du'cc nho" ehu-a lai khoang khong n i tru'O'c mot hang 16 khoan gin vai du'ang giu-a khii thuic va 16 khoan Cung nhu' kinh nho (60-^100mm) - Phu'ang phap 2: N6 tao bien sau dit da hang bien vo'i hang 16 khoan dem c6 ty le chieu da pha tai bien thiit k i Cac 16 khoan hang tgo cao bua nhu-sau [1]: + Dii vdi dat da ci!cng: -^^ ^ 4.o + Dii VO'I dit da mem ^^^•° - Khai no cac l6 khoan tao bien Hang 16 khoan tao bien n i tru'O'e cac lo khoan chinh v6i thai gian tif 100-^150ms Cae 16 n i chinh ap dyng vi sai qua hang de loai trCf rui ro lu'gng ap suit 16'n tac dong vao hang bien cung tho'i gian, va han ehi dja chin no 3.2 No tao mat nhin (tao bien sau) N i tao bi6n (NMTB) la ky thuat n i dieu khiinco SLP dgng 16 khoan du'ang kinh lan vai cae lo khoan tao bien va n i chinh Bing Cic thdng sd khoan nd tao bi&n sau CO nap bua • 51+64 0,91 1,22 0,12+0,37 30 0,5 0,7 0,07 76+69 1,22 1,52 0,19+0,74 37 0,6 0,9 0,12 102+104 1,52 1,83 0,37+1,12 44 0,6 0,9 0,17 127+140 1,83 2,13 1,13+1,49 62 1,0 1,3 0,35 152+165 213 2,74 1,49+2,23 75 1,2 1,6 0,6 87 1,4 1,9 0,7 Co thi no kit hgp tang, n i tang cao han gpi la no tao bien cat tang d i tao ting tren to'i gio'i han Vu n i co phin rieng biet gling nhu' no tao rach man ehin: a Hang tao bi§n de t^o bcf ket thuc: Hang tao 100 1,6 2,1 0,9 125 2,0 2,7 1,4 160 2,4 3,2 20 i KHCNM S6 10/2014'CNKT LO THIEN Khdng nap bua P d, mm a, m W, mP, kg/m d, a, m W, mm m kg/m 200 3,0 4.0 3,0 Thong tin khoa hpc cong nghe mo Bang Cic thdng sd khoan nd cho mdt sd md quSng sit Md Dit da, quing Khoang each Khoang Chieu dii Dw&ng Chieu siu giOia cic 16 cich giu^ cot thudc Chieu dii khoan Chi tieu q khang khoan cac hing Id cot bua them chan ting kg/nil hang khoan W, m a, m b, m Lt, m Lb, m Trai Cau Quang 0,48-0,55 3,50 3,60 3,00 4,50 1,50 1,00 B i t da 0,30+0,32 5,50 5,50 4,50 7,40 3,10 1,50 1,00 Lktm Ngudm Chang Na Lung NaRua Lang Vmh Kip Tudc sang Than Quang 0,32+0,36 3,50 3,50 3,00 2,50 3,50 Dat da 0,28-0,3 5,50 5,50 4,50 7,40 4,10 1,50 Quang 0,5 +0.55 3,00 3,00 3,00 3,30 2,70 1,20 oataa 0,38+0,42 6,00 6,00 5,00 9,00 4,50 1,50 Quang 0,42+0,45 3,50 3,50 3,00 3,70 2,30 1,00 Dltaa 0,38- 0,42 5,50 5,50 4,50 7,00 4,50 1,50 Quang 0,32-0,35 1,60 1,50 1,30 1,90 1,10 0,50 oat da 0,38+0,42 3,50 3,60 3,00 2,70 1,30 1,00 Quang 0,45+0,50 3,00 3,00 2,50 3,26 2,50 0„75 Dat da 0,36- 0,39 4,00 4,00 3,60 9,00 3,00 1,50 Quang 0,42-0,45 1,50 1,50 3,00 2,50 1,00 0,50 Dataa 0,40+ 0,42 3,37 3,37 2,89 5,75 2,98 0,75 bien dupe nap bai opt thuic phan doan budc vdi dpc day d i n Khnang each giua hang bien va cae Id no tpi bang (10+20)dT Cac thdng s i NMTB t h i hien Jniu&nd bang Sp dd NMTB t h i hien tren hinh 3.3 Tinh toin lira chgn cic thdng sd no -Mfini cho mot so mo quang sat Hi#n nay, edng nghe no vi sai phi dien da dupe su dung hipu qua eac cdng trinh nd pha, tren cac mo Ip thien, dac biet chilm uu t h i Ld khoan biin (tao khe ban diu) Ld khoan cac edng trinh no Idn hole edng trinh n l khiu (phi vd dit di) ddi hoi ky thuat cac Hinh Sa dd nd tao bidn Lfu dilm chinh cdng nghe n l vi sai phi dien ddng dien tap va sdng dien tCr B l u ghep dpn la kit hpp dupe nhipng uu dilm cua phuong gian, cho phep thiet ke nd vi sai Id phap gay n l bang dien va day nc, ddng thdi loai khoan, hieu qua pha da tdt, eo hat dong deu, it bp dupe nhOng nhupc d i l m ciia hai phuong d l lai md chan ting, kich thude dong da gpn phap Bp tin c|iy va dp an toan eao, cho Ngpai ra, giam hau xung, chp phep tang quy mp phep thilt ke sp no vi sai linh hoat vol so vu no, giam eh! tieu thude n l , dieu khiln tot lupng khdng h?n c h i , khdng chiu tac dpng cila hupng dieh chuyin eiia dong da, viec phoi hpp KHCNM S 10/2014 * CNKT LO THIEN Thong tin khoa hgc cong nghe mo sir dgng d l dang cac phu kien sp no lam cho viec thiet k l trd* len thuan tien va toi uu va nang cao hieu qua n l so vdi cae phuong phap thdng thudng Cdng nghe no vi sai phi dien irng dung duoc tit ca cae dang nd pha, nhien, nd t h i hien tinh hieu qua cao n l cac bai n l cd so Id khoan Idn, cac edng trinh n l ddi hdi yeu eiu ky thuat eao, cae edng trinh nim vung nguy hiem ve sdng dien tir va ddng dien rd Nam d i n nam 2020 da dupe Thii tupng Chinh phii phe duyet, eac md quang sit se tang cudng khai thac nham tang san lupng, dap img nhu eiu quang s i t cho nganh Thep va nin kinh t l Hien nay, cac md quIng sat dang giai doan chuyen doi tif giai doan khai thac thii cong manh miin sang giai doan khai thac ed trat tu, md' rdng quy mo khai thae, tap trung hda san xuit, diu tu cac thiet bj khai thac hl$n dai va phii hpp vdi dieu kien khai thac cua tirng mo Tren ep so dieu kien tu nhien cac mo sat, kich thudc ting bdc d i t va phan ting khai thac quang, dudng kinh lo khoan, yeu c i u v l chit lupng no min, tinh toan thdng so khoan, n l che cac md sat t h i hi$n bang - Be dam bao cho qua trinh khai thac md duoc an toSn, tan thu toi da tai nguyen va mang lai hieu qua kinh t l eao nhit, cae md eIn chu trpng d i n eac giai phap ky thu|t, tuan thu eac quy trinh, quy pham dp Nha nude ban hanh, dong thai ehii trpng dao tao nguon nhan lue vdi chit lupng cap, edng tac quan tri tai nguyen, ap dgng cae giai phap khai thae va c h i biln than thien voi mdi truong B l i vol eae md quang sit, sir dung n l bdc da ben bd tru, ngoai cae thdng so no tinh toan theo bang 2, tiiy tirng dieu kien eg thi, se sir dung n l tao tiidn trudc hoac bien sau (bang 1) nhIm giam dupe xung luc ciia n l den I n dinh bd mo va cae edng trinh K i t luan Vdi eac md quang sat, su thay d l i tinh chit eo iy, hinh dang md, dilu kien BCCT-DCTV eho thay: - Theo ehilu sau khai thac, dp ben nen ciia d i t da cd ehilu hudng tang, mii'c dp nirt ne giam, ty le Id khean ngam nupc tang, lam tang chi phi va gay khd khan cdng tac khoan, n l - B l khac phuc nhiing khd khan v l dieu kien tu nhien, ky thuat, can sii' dgng cac bien phap cdng nghe khoan, n l tien tiin Sir dgng cac loai may khoan cd tinh eo ddng cao, nang suit phii hpp se khac phge dupe dieu kien lam viec va dia hinh phirc tap va tang cupng chit iupng Id khean, giam ton thit met khoan ^ - Sir dgng cac edng nghe n l nhu thay doi ciu triic cdt thuoc, sir dung hdn hpp thuoc no Ap dung cae bipn phap nap thuoc khdng chig nude sau thao khd, giam chi phi thuoc n i , tang hieu qua cdng tac khoan, n l - Be bao ve bp t i n g md, sii' dung cac bi$n phap nd t|io bien d l man chin khoanh vting tac dpng cga eac khg vue n l khdng iam mit on djnh cila ting, bp mn Id thien - Thep Quy hoach phat triln nganh Thep Vipt jm KHCNM s o 10/2014-CNKT LO THIEN Tai cac md sat Id thien, ap dgng NIVITB o eae ting dupi sau nham han c h i anh hudng a i n on dirih bd md, dam bao an toan cho ngudi va cac thilt bi khai thac hoac dua bd' md vao gidi han kit thuc, eIn thilt phai thii' nghiem, tren eo so dd se hoSn thien cae thdng so NMTB / Tii lieu tham khao: Luu Van Thuc va nnk; "Nghien ciru de xuat cac giai phap cdng nghd ca giai hda khai thac va tuyen hap ly cho cac mo quang sat quy md nhd khu vire phia Bic Viet Nam" Vi$n Khoa hpc Cdng nghe Md - Vinacomin, 2013 Nguyin Thanh Binh va nnk "Nghidn ciru cong nghd pha va dat da va quang tai cac mo Id thidn Viet Nam khai thac dwdi mire thoat nuvc tir chaf Vien Khoa hoc Cdng nghe Me Vinacomin, 2011 Quylt dinh so 124/2006/QB-TTg 30/5/2006 eiia Thu tupng Chinh phii v l viee phe duyet quy hoach tham do, khai thac, ehi biln va su dgng quang s i t d i n nam 2010, dinh hudng d i n nam 2020 H i ST Giac: "No hda hoc: Ly thuyet va thuc hanh" - Nha xuit Khpa hoc va Ky thult Ha Npi, 2010 H i SI Giap:" Khai thac khoing san rin bing phunng phap 16 thien' - Nha xuat ban Giao thdng Van tai, 2009 ... cong manh miin sang giai doan khai thac ed trat tu, md'' rdng quy mo khai thae, tap trung hda san xuit, diu tu cac thiet bj khai thac hl$n dai va phii hpp vdi dieu kien khai thac cua tirng mo Tren... +270 2.406 12.402 1.394 23.228 32012 141 1.922 C6t cao day mo TrO lupng quang dja chat 10» t i n bign gidi khai truong Khoi lupng quang nguygn khai 10= t i n 436 11.930 375 21.730 31.372 884 1902... sat du''p''c gio''i thi^u tai bang [3] Cdng nghe nd co d i i u khien nham nang cao on djnh bd* mo B^ dam bao cac mo quang sat du''p''c khai thac theo k i hoach nhu'' tren, can chu trpng din cac giai