^ ^ KHOA HOC VA CONG NGHE MO TAC DONG CUA CAC YEU TO KINH IE , KY THUAT VA MOI TRlTONG DEN TIEN TRINH DAU TIT KHAI THAC MO LO THIEN ThS NGUYEN ANH TUAN, KS LE TH] MY Hy\NH Trw&ng Dai hgc DHo Dja chit[.]
^ KHOA HOC VA CONG NGHE MO ^ TAC DONG CUA CAC YEU TO KINH I E , KY THUAT VA MOI TRlTONG DEN TIEN TRINH DAU TIT KHAI THAC MO LO THIEN ThS NGUYEN ANH TUAN, KS LE TH] MY Hy\NH Trw&ng Dai hgc DHo-Dja chit K hai thac Id thien la mdt hoat ddng cdng nghe nhIm thu hdi khoang san cd ich tu' Idng d i t bang cac cdng trinh md tidn hanh ngoai trdi theo mot trinh ty xac djnh Hoat ddng cdng nghe bao gdm cac khau co ban: d i u tu' xay dung co ban va md md; khai thac md va td chu'c trung hoa chit lugng quang trude tuydn; c h i biin va tuyin khoang san Nhu vay, mdi khau cdng nghe tren d i u lam tang them gia tri cua khoang san va ddng thdi cung cd cac tac ddng khac tdi mdi trudng sinh thai Cac tac ddng rd rang nhit cua khai thac Id thien tdi mdi trudng lam biin ddi dja mao va canh quan khu vuc; chidm dung nhidu dien tfch d i t dai lam khai trudng va bai thai thdi gian dai; lam d nhilm nude va dit dai quanh md; phat thai nhidu ddc va bui vao mdi trudng; gay dn va rung Cac tac hai tren va nhung he luy tdi mdi trudng hoat ddng khai thac md la khdng t h i tranh khdi Cac giai phap cdng nghe ky thuat qua trinh khai thac dugc nhilu nha khoa hoc va ngoai nganh mo Id thien nghien cuu, d l xuit va u'ng dung, da cd nhung tac ddng tich cue va dang ke viec han c h i su tac ddng va suy giam mdi trudng xung quanh md va sau qua trinh khai thac Trong pham vi nghien cu'u nay, nhdm tac gfa phan tich su tac ddng cua cac y l u td kinh t l , ky thuat va mdi trudng tdi quy md d i u tu va thdi gian khai thac va hieu qua cua md Id thien Y§u td kinh t l tac dong tO"! quy mo d i u tu", khai thac dif an mo 16 thien Tai nguyen khoang san cua nude ta rit da dang, cd gin 5.000 md va dilm quang vdi 60 loai khoang san khac Ngoai mot sd khoang san nhu than, titan, s i t va bauxite, cac khoang san cdn lai cd triln vpng kha nhung chung v i n chua dugc diu tu khai thac tuong xu'ng vdi tilm nang tru: lugng va su-c manh cua nin kinh t l nude CONG NGHIEP MO SO - Anh hudng quan trpng tdi hoat ddng cua nganh khai thac md Id thien la gia nguyen, nhien vat lieu va nhan cdng biin ddi d mdt pham vi Idn thdi gian tiin hanh du an md, cung rihu nhu ciu v l quang cua cac nganh cdng nghiep khac Vi du, tu giua nam 2008 d i n cudi nam, gia trung binh mdi quy cua nhdm niem y i t tren san LME (London Metal Exchange) m i t mdt phin ba, gia ddng mit mdt nua, gia chi va gia niken bj giam hai phin ba, sau dd phuc hdi va dao ddng manh Ben canh dd, nganh md Id thien ndi rieng cang dugc CO gidi hoa a mu'c cao vdi sd lugng can bd ky thuat c i n thilt d l van hanh quan ly va khai thac md yeu c i u cd trinh dp cao va t i m nhin san xuit va quan iy Tu' dd cho thiy, cac hoat ddng khai thac md Id thien rit nhay cam vdi tac ddng va thay ddi cua cac y l u td kinh td-ky thuat ndi chung Vdi su b i i n ddng manh gia cua cac loai khoang san tren t h i gidi ddng thdi tac ddng tdi gia trj ham lugng quang cdng nghiep nhd nhit dugc dua vao khai thac dam bao md Id thien khai thac cd lai Vi t h i cac gia tri ham lugng la thdng sd kinh t l ky thuat giup phan biet dau la d i t da va dau la khoang san cd ich (quang) Tuy nhien, cac gia trj ham lugng cung bj tac ddng va chi phdi r i t Idn bdi cac y l u td kinh tl-ky thuat thdi gian khai thac nhit djnh (theo tu'ng nam, tham chi la theo tu-ng thang) Cac y l u td ky thuat-td chipc co* ban tac dong ial quy mo d i u tu', khai thac 16 thien Cac md hinh td chu'c cdng tac khai thac cac md Id thien nhu "md", "md-tuyin", "md-tuyln-luyen" cang phd biin d nude ta nhu c i u phat triln cua nganh cdng nghiep md va tinh nang ddng cua thj trudng khoang san Trong dilu kien nin kinh tl-c6ng nghiep nang ddng cac y l u td ky thuattd chuc khai thac se tac ddng rit Idn tdi hieu qua hoat ddng cua du an khai thac Id thien, dilu m KHOA HOC VA CONG NGHE MO ddng nghTa vdi tinh hieu qua va hgp ly cua mdt phuong an kinh tl-ky thuat md dugc lua chpn va day la thach thu-c Idn ddi vdi cac nha khai thac, quan ly khai thac va xa hdi •; 2.1 Loi nhuan tac dong den th&i gian thiec hien dy an mo lo thien Theo quan dilm gia tri Igi cua md la nhuan tdi uu tuong u'ng vdi ham muc tieu NPV (Net Present Value) Idn nhit cung vdi cac dilu kien rang budc v l san lugng nguyen khai cua md, nang suit cua cdng tac c h i biin va luyen kim theo yeu ciu Khi dd, hieu qua kinh t l cua du an khai thac md dugc danh gia bIng chT tieu NPV la tdng cua hieu cac ddng tiin mat thu va chi cac nam hoat ddng cua ddi du an quy v l thdi dilm danh gia, theo bilu thuc (1) va khdi lugng quang khai thac vdi gia trj ham lugng bien xac djnh theo nguyen t i e tren t h i hien tren bang [4] NPV: T 1=1 (1 + r) d ' m Dilu kien rang budc: Qmi^M; Qci^C; Qn^R vdi i=1, ,T Lgi nhuan hang nam cua md dugc xac djnh theo bilu thu-c (2): L,=[(P-s).Q,-Qe,c-Q^,m],d (2) Trong dd: P - Gia ban quang, d/t; s - Chi phi dich vg cho mdt t i n quang, d/t; Qc - Khdi lugng qugng c h i biin nam (nghiln-tuyin), tin; Qn - Khdi lugng san phIm (kim loai) thu hdi nam thu" (i) sau luyen kim, tin/nam; T - Tudi tho cua md, nam; Qd - Khdi lugng quang tinh chd biin nam thu* (i), tIn/nam; c - Chi phi c h i biin quang tinh, d/t; Qmr Khdi lugng quang nguyen khai thac Id thien hang nam, tin; m - Gia khai thac mdt t i n quang, d/t; Qri - Khdi lugng kim loai thu hdi nam thu- (i), tIn/nam; M - Kha nang san lugng quang nguyen khai cua md hang nam, tin; C - Cdng suit nghilntuyin cua nha may c h i biin nam, tIn/nam; R Cdng suit hang nam cua nha may luyen kim, tIn/nam; r - Gia trj chilt khiu vdn; NPVj - Gia tri hien tai rong cua du an tinh tdi nam thu" (i), d; m - Gia khai thac mdt t i n quang nguyen khai, d/t Bang Bang tinh gia tri lai nhuan cua mo (Lr) theo su biin ddng cua cac chi so ccf ban tidn hanh du an md Id thien ' Nam khai thac, T i T • Ham luo'ng bien HLB, % HL trung binh, % Qm, tan Qc, tan Qr, tan Lr,d NPV, d gHLBI giBi Qm1 Qci Qn Lr1 gHLB2 gTB2 Qm2 Qc2 Qr2 Lr2 NPVi NPVa gHLBI giBi Qmi Qci Qn Lri NPVi gHLBN giBT LrT Tdng >*.NPV TD TE H Ham so gia tri hien tai rong NPV cua md theo thdi gian khai thac (T) Tir cac gia tri cua Bang a tren ta xay dung dugc ham sd tich luy luu lugng tai chinh theo thdi gian (ABCDE) la ham sd bilu thj gia tri Igi nhuan cua mo Id thien quy v l thdi dilm danh gia (NPV) QmT QcT QrT EQm EQc IQr NPVT NPV theo thdi gian dugc bilu didn theo Id trinh d i u tu va khai thac md Id thien a hinh H.1 Tren dd thj, hoanh dd la thdi gian tiin hanh du an khai thac Id thien, tung dd la gia tri tich tu luu luong tai chinh hay NPV Dudng cung AB thd hien giai doan d i u tu khai thac, nhO'ng hang muc cdng trinh md dang dugc lip dat, md chua dat cdng suit thilt k l va chua cd Igi nhuan O dilm B, hoanh dp TB, tung dp V, chi va thu can bIng Tung dp V la vdn ban d i u cua du an, day la vdn tdi thilu d l thuc hien dugc du an d i u tu khai thac md Id u'ng vdi cac md hinh md khac Dudng cung BC t h i hien giai doan hoan vdn cua du' an Nhung hang muc da dugc lip dat hit hay g i n hit, md da dat hay b i t d i u dat cdng suit thilt k l Nhd md khai thac khoang san nguyen khai theo thilt k l dd gia trj Igi nhuan tich luy cua md tang len, md chi it han la thu D i l m hoanh dp C gpi CONG NGHIEP MO SO - ' pyp!^ KHOA HOC VA CONG NGHE MO la thdi han hoan vdn, nghTa la luc chu dau tu da thu lai hit nhung khoan tai chinh chi d l thuc hien du an Thdi han hoan vdn la mot dilm rit quan trpng vi c i n so sanh so bd nh&ng du an vdi nhau, du an nao cd thdi han hoan vdn ngin nhit la du an se cd uu dilm han Dudng cung CD t h i hien giai doan sinh Igi nhuan cua du an khai thac md Id thien Nhung hang muc da dugc l i p dat h i t hay g i n hit Md chi cd chi phi van hanh Dao ham cua ham sd Id trinh giam theo thdi gian tdi thdi dilm TD Luc dd tich tu luu lugng tai chfnh dat tdi da bilu thj bdi dilm D Hieu qua cua md Id thien luc t h i hien bIng hieu sd chi phi va doanh thu cua md d cac nam khai thac cd tinh tdi cac y l u td anh hudng: Luc ban diu doanh nghiep md chi v l bao tri nhd; Sau dd, chi phi bao tri tang vi nhung thilt bj trd nen cu cin dugc sua chua hay thay thd, ngoai md phai tiin hanh cac hoat ddng bao ve va phdng chdng d nhiem mdi trudng thien nhien cang Idn; Q giai doan khai thac sau cua md tru lugng g i n can, ngoai viec bao tri va thay t h i thilt bj va phdng chdng d nhilm, xi nghiep phai bit d i u k i t thuc khai thac va hoan thd mdi trudng Dudng cung DE t h i hien giai doan cudi cung cua hoat dong khai thac md tru lugng khoang san bit diu can kiet Thu hoach cua xi nghiep kem han la chi phi hoan thd nen tich tu luu lugng tai chinh giam Hoanh dp T thd hien thdi dilm xi nghiep tra lai mat bIng da dugc tai thilt Tung dp L t h i hien tdng sd lai cua md sinh tu' hoat ddng khai thac D l ddi phd tinh trang dd xi nghiep khai thac md thudng lap sin mdt tai khoan tich tu mdt phin cua l l khai thac md hay cdn d giai doan cd luu lugng tai chinh tang thilt k l thi chu dau tu se cd quylt dinh dilu chinh va bd sung va quylt djnh thuc hien du an tren ca sd cac chi tieu kinh t l ky thuat mang lai Igi nhuan Idn nhit cho md thdi gian tdi uu Quy md d i u tu khai thac cua du an md la djnh gia ban d i u cua ham lugng va tru lugng quang cdng nghiep va vdn d i u tu c i n thilt Mge dich la quylt djnh cd nen tham dd dia chit them d l thilt lap mot phuang an khai thac hay khdng Lfdc lugng dua tren nhung md tuang tu dang dugc khai thac tren t h i gidi Ty suit Igi nhuan (E) khdng chinh xac, sai sd khoang chung 40-^50 % Du an d i u tu va thilt k l ca sd va thilt k l ky thuat thi cdng dugc cac nha tu v i n thilt k l tinh clipn chi tilt cac chi sd kinh t l ky thuat nhung ty suit (E) d giai doan chinh xac khoang 20^30 % Viec nghien cuu va phan tich du an diu tu, thiet k l CO sd va danh gia tac ddng mdi cac phuang an khai thac md Id thien nlu se giup dilu chinh, bd sung cho du an va tao ca sd khoa hpc dan tdi quylt djnh thuc hien hay khdng thuc hien du an Gia tri ty suit Igi nhuan E chinh xac tdi 10-15 % nlu dugc phan tich va cho kit qua lgi nhuan cua md dang tin cay thi md se dugc thuc hien Mot du an khai thac md thudng keo dai hang chuc nam, tham chi han nCra t h i ky vi t h i md hoan toan cd kha nang dilu chinh va bd sung du an cd them thdng tin chi tilt d nhung giai doan khai thac md nhit djnh V i n d l la cac giai doan khai thac md c i n dugc hoach dinh va djnh hudng thilt k l cai tao va bd sung giai doan lap du an diu tu khai thac md MNTV So vdi phuang phap tinh ty sd Igi nhuan tu' nhung luu lugng tai chinh mdi giai doan cua du an thi phuang phap tinh tu' tich tu luu lugng tai chinh chi cin ddn nhung tri sd V, L, TB, C, TD va T nen san tran nhung bidn ddi ngin han cua gia khoang san, dd, ty sd Igi nhuan dugc tinh mot each thuc t l hon va chinh xac han 2.2 Lya chon quy mo dau tw khai thac dy an mo 16 thien hap ly Isighien cu'u chi tilt mdt du an Idn huy ddng nhidu chuyen gia mdt thdi gian lau, cd tdi hai ba nam, va rit tdn kem, r=0,5-2 % gia tri cua du an va mot du an thi tfnh bIng nghin ty ddng D l tranh tiin hanh vd ich, cdng trinh nghien cuu dd ngudi ta chia du an d i u tu va khai thac md lam ba giai doan: xac djnh quy md d i u tu khai thac cua du an, lap du an d i u tu bao gdm ca danh gia tac ddng mdi trudng tiin hanh song song, thilt k l ca sd va thilt k l ky thuat thi cdng Sau mdi giai doan tu v i n CONG NGHIEP MO SO - H.2 Sa dd so sanh cac phuang an Id trinh diu tu xay dung ca ban va khai thac du an an md Id thien Ham sd tich tu luu lugng tai chinh theo thdi gian NPV (H.2), bilu dien Id trinh d i u tu va khai thac md dat lai la thip nhit, Idn nhit Tren bilu dd, hoanh dp T t h i hien thdi dilm md hoan tra mat bang dugc hoan thd Tung dp t h i hien tdng sd lai CNM KHOA HOC VA CONG NGHE MO cua xi nghiep md sinh tu" hoat ddng khai thac md Gia trj: V, L, TB, C, TD va T nen san tran, tu-c la nhung biin ddi ngin han cua gia khoang san tren thj trudng dugc coi la dn djnh, tu- dd ty sd Igi nhuan dugc tinh mdt each thuc td va chinh xac han Nlu gpi ham sd Id trinh cua md chu d i u tu lap dudng II va Id trinh danh gia thim djnh cua ca quan nha nude dua danh gia bilu thi bdi dudng bilu thj Khi xu t h i cac dudng bilu thj [d trinh cua hai ben gin gidng thi co quan thim dinh cd thi tilp tuc nghien cu'u va quylt djnh thdng qua du Nhung nlu dudng bilu thj ciia du an md d i u tu khac vdi dudng bilu thj cua ban nghien cu'u thi cd t h i cd mot hai tinh hudng bilu hien bIng hai dudng bilu thj II va III Khac biet bilu hien du an khdng thuc t l va tdi uu v l thdi gian d i u tu xay dung cdng trinh, khai thac, ddng ciia md va phuc hdi mdi trudng md Su bit hgp ly dan d i n cac nguy ca du an md khdng t h i thuc hien dugc cac cam kit diu cua du an v l mdi trudng va sau qua trinh khai thac tinh kha thi va hieu qua cua du an Thuc t l cd hai phuang an Id trinh diu tu xay dung CO ban va khai thac cua du an cd t h i xay ra: • Dudng cong II so vdi dudng cd mdt sd dac dilm sau: vdn d i u t u V it han; thdi gian hoan vdn C ngin hon; dao ham d cac dudng cung BC va CD Idn hon; khdng cd dudng cung DE hay dudng cung dd nhd hon; lai t h i hien gia tri NPV la L Idn han (lai t h i hien tich tu luu lugng tai chinh cua md); ty sd Igi nhuan ciia du an cao hon • Dudng cong III so vdi dudng I cd mdt sd dac dilm sau: vdn diu tu V nhilu han; thdi gian hoan vdn C lau han; dao ham d cac dudng cung BC va CD nhd hon; dao ham cua dudng cung DE Idn han; lai t h i hien bdi tich tu tai chinh L nhd han; ty sd Igi nhuan cua du an thip hon Nhu vay, tu" nhung phan tich tren ta thiy thuc t l cd nhilu du an md ke khai lap du an d i u tu khdng chinh xac (Idn hon hay nhd han) so vdi cac gia tri thilt bj, cdng nghe su dung, cdng trinh md du kiln xay dung, chi phi bao ve an toan-ve sinh lao dong, y t l va bao ve mdi trudng, hoan thd mat bIng khdng phu hgp vdi gia tri thuc t l du an khai thac da lap Cac ylu t6 sir dung va phuc hdi dit tac dong to'i quy mo diu tu' khai thac Dac dilm cua khai thac Id thien la phai chilm dung mot dien tich d i t dai kha Idn md khai trudng, lam bai thai va xay dung cac cdng trinh phu trg phuc vu cho khai thac md Trong hoat ddng khai thac khoang san thi khai thac Id thien la cd tac ddng manh me nhit tdi mdi trudng, dac biet la mdi trudng dit: chilm dung nhilu d i t dai, lam thay ddi dja hinh, dja mao va canh quan khu vg'c, dan d i n thu hep ru-ng d i u ngudn, xam pham d i t ndng lam nghiep, Bdi vay xu hudng chung la chpn mot quy trinh cdng nglie khai thac md lam d l viec chilm dung d i t vao thdi gian mudn hon, va viec hoan pliuc cin phai thuc hien ddng thdi vdi qua trinh phat triln cdng trinh Danh gia hieu qua si> dung dit cua md Id thien ta su dung chi sd: hieu qua su dung dit (Id) va dugc xac djnh theo bilu thu'c (3) [1 ]: T+t NPV- X C j a : j=T+1 Id = - (3) T+t k=1 Trong dd: NPV - Gia tri hien tai rdng cua du an, ty ddng (theo du an); T - Thdi gian hoat ddng du an, nam; t - Thdi gian phuc hdi mdi trudng sau khai thac, nam; Cj - Chi phf phuc hdi mdi trudng cac nam, (j = T+1, , T+t); aj - He sd chilt khiu: , , , , , ai= ; r - Ty suat chiet khau vdn dau tu; Gk (1 + ry Lgi nhuan thu hdi tu' dien tich d i t ma du an sii dung cac djch vu ma d i t mang lai d thdi dilm tinh toan (trdng trpt, canh tac, du ljch, ) ty ddng/nam; ak- He sd chiet khau: a^ \k-1 vai (1 + r)'' (k= 1, ,T+t) Thay gia tri NPV d bilu thu'c (1) vao (3) dd ta xac djnh chf sd sii dung d i t Id (4): T , d ^ T+t h ^(1 + r)' jiti T+t -I k=i (1 + r) 'jury ^ ' Vi thi, qua trinh khai thac md Id thien c i n bdc Idp dit thuc vat nam tren tuyIn cdng tac md va tuyIn thai cung nhu tren khu vuc xay dung Tuy theo kha nang xuc bdc, van tai va nhu c i u sii dung cin nhanh chdng van chuyin Idp d i t tdi khu vuc hoan thd nhIm bao ve d i t bdc phu va giam chi phi phuc hdi, cai tao d i t dat muc dich su dung nhit djnh D l danh gia dugc tinh hieu qua cua cdng tac phuc mdi trudng, chi sd phuc hdi d i t [1] dugc dua vao tinh toan va dugc xac djnh theo bilu thu'c (5) (5) lr Trong do: Gm - Gia trj cua d i t dai sau phgc hdi, du bao theo gia ca thj trudng tai thdi dilm tinh toan; ty ddng/dien tich du an; Gp- Tdng chi phi cho viec phuc hdi, cai tao d i t d l dat dugc muc dich sii dung tren, ty ddng/dien tfch du an; Gc - Gia tri CONG NGHIEP MO SO 6-2010 CNM KHOA HOCVA CONG NGHE MO nguyen thuy cua d i t trude md md, d thdi dilm tinh (theo djnh gia ciia Nha nude), ty ddng/ha Chi sd Ip cd t h i Idn han hay nhd han theo kha nang phuc hdi, quy md phuc hdi, muc dich su dung cung nhu vj tri cua vung d i t phuc hdi sau khai thac He sd giup DTM cac du an khai thac md Id thien cd dilu kien danh gia v l quy hoach sii dung dit sau du an khai thac H.3 Phuang an khai thac theo khu vuc doi vdi md cd dien tfch phan bd Idn [2] Vf du vdi dac dilm dilu kien t h i nam cua than khoang sang phan bd nIm ngang thf md hoan toan cd t h i tiin hanh khai thac theo khu vuc, sii dung bai thai va bai thai tam Trat tu khai thac phan chia cac khu vuc dugc t h i hien d hfnh phuang an hoan thd nhu hinh H.4 Msttar^ \Jip& n^n l^ng nUl ne H.4 Phuang phap trdng cay cai tao ba ddc va hoan thd mat tang sau ket thuc khai thac Kit luan va kiln nghj Vdi tilm nang va triln vpng v l tai nguyen khoang san quang va phi quang cua Viet Nam cung nhu cac tac dong cd hai tdi mdi trudng cua CONG NGHIEP MO SO - cac du an md Id thien, nhdm tac gia tiin hanh phan tich va khao sat va lam rd cac mdi quan he va su tac ddng cua cac y l u td kinh t l , ky thuat va mdi trudng md tdi quy md d i u tu khai thac khac Tu' ca sd ly luan tren, nhdm tac gia d l xuit cac bien phap quan ly md, danh gia hieu qua du an d i u tu xay dung md 16 thien va td chu'c khai thac cu t h i nhIm tang hieu qua d i u tu, qua trinh khai thac va bao ve mdi trudng md 16 thien cd t h i thuc hien theo hudng sau: ap dung cdng nghe khai thac su dung bai thai khai thac khdng nhiing ddi vdi than quang nIm ngang va ddc thoai ma cdn ddi vdi nhung than quang nIm xien dja hinh ddi ddc; ap dung cdng nghe khai thac theo giai doan cd thdi gian tdn tai khoang 8-^12 nam dam bao cho md hoat ddng hieu qua phu hgp vdi dieu kien kinh t l thj trudng hien nay, ddng thdi kit hgp vdi viec su dung bai thai tam, tao dilu kien d l han c h i dien tich dit bj chilm dung ddng thdi; hinh bai thai tren mdt dien tich dii Idn, phdi hgp ddng thdi qua trinh hinh bai thai va qua trinh hoan thd tren bai thai va cac khu vuc da k i t thuc khai thac.n TAI LIEU THAM KHAO Hd ST Giao va nnk (2010) Bao ve mdi trudng khai thac md 16 thien NXB Tu- diln Bach Khoa Nguyen Anh Tuin (2007) Nghien cu'u ap dung cong nghe khai thac hgp ly cho cac md da set d Viet Nam nhIm dam bao san xuit an toan va bao ve mdi trudng Hoi nghj KHKT Md toan qudc lin thu XVIll, Hdi KHCN Md Viet Nam, Sa Pa, tr156-161 Nguyen Anh Tuin, "Vin d l ham lugng bien va can bien qua trinh khai thac cac md quang Ip thien" Tap chi CNM, Sd nam 2009, tr 49-51 Ngwai bien tap: Ho Sy Giao SUMMARY er's author introduces some study ^ results of estimating the impacts of economytechnology-environment factors on investment process in open pit mining C6 the but ngu'di khdi que hu'dng, nhuTig khong the but que hu'dng khoi ngudi / D Paxost Tien la thii kiem du'dc bang md hoi nUdc mat, nhung lai tan bien chi nhay mat Colette VTH smi tam ... du an khai thac da lap Cac ylu t6 sir dung va phuc hdi dit tac dong to''i quy mo diu tu'' khai thac Dac dilm cua khai thac Id thien la phai chilm dung mot dien tich d i t dai kha Idn md khai trudng,... cua vung d i t phuc hdi sau khai thac He sd giup DTM cac du an khai thac md Id thien cd dilu kien danh gia v l quy hoach sii dung dit sau du an khai thac H.3 Phuang an khai thac theo khu vuc doi... chu''c khai thac cu t h i nhIm tang hieu qua d i u tu, qua trinh khai thac va bao ve mdi trudng md 16 thien cd t h i thuc hien theo hudng sau: ap dung cdng nghe khai thac su dung bai thai khai