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Thong tin khoa hpc cong nghe mo •fp KET QUA NGHIEN CITU CHE TAO VA AP DUNG KiP VI SAI PHI DIEN AN TOAN TRONG KHAI THAC VIA DOC VADAO LO tai cac mo ham 16 vung Quang Ninh In 2010, Institute of Mining S[.]

Thong tin khoa hpc cong nghe mo •fp KET QUA NGHIEN CITU CHE TAO VA AP DUNG KiP VI SAI PHI DIEN AN TOAN TRONG KHAI THAC VIA DOC VADAO LO tai cac mo ham 16 vung Quang Ninh In 2010, Institute of Mining Science and Technology (IMSAT) had been assigned to carry out the theme "Study on the pilot application of the mining and diiving technology using ttie domestic explosion-proof non - etectncai delay detonators" and the theme "Study on the manufacture of the safety underground nan - etectncai delay detonators and its application v\iith the tong borehole blasting technology at underground coal mines in Quang Ninh coal basin" The key aim of two above themes is to study on the pilot manufacture of the safety non - etectncai delay detonators in Vietnam for its application with the long borehole blasting technology to increase the efficiency in slope coal seam mining and dnving works Theo k i t qua t i n g hpp trOtupng va dgc dilm diiu kidn dva chit - ky thugt md tgi cde khodng sdng than dupe khai thac bing phuang phdp h i m Id vung Quang Ninh Vipn Khoa hoe Cdng nghp Mo Vinacomin thue hipn nam 2011, tru' lupng than tai ode khu vpc via doc (a > 45°) tinh sdu nhit d i n mire -400 khoang 470 tridu t i n Trong dd phin trir lupng via ddy, d i e (m > 3,5, a > 45°) khoang 248 tripu t i n , chilm 53%, cdn Igi la phin trO' lupng via die e i chieu day tir mdng din trung binh B l khai thdc via die, nhung nam vira qua cdc md h i m Id viing Quang Ninh da dua vdo dp dpng mpt s i sa dd cing nghd g i m : sa d i cdng nghd khai thde l i dpc via phdn ting kit hpp sii' dpng l i khoan dudng kinh Idn (PSO), sa d i cing nghd khai thac buing (buing thupng chdo, buing cup, buing neo), so d i cing nghd khai thac sir dpng ddn ehing (ddn ehing cirng, ddn ehing mim), sa d i cing nghp TS NGUYEN ANH TUAN TS BAo HONG QUANG ThS IRAN MINH TI6N Vi0n Khoa hoc COng ngh$ Md - Vinacomin khai thde cit ddi theo hudng d i e ea gidl hda bdng t i hpp 2ANSH, sa d i cdng nghp khai thdc chia Idp ngang nghieng (hoac chia Idp bdng) vd so d i cdng nghe khai thdc Id dpe via phdn ting Tir nam 2003, Tap dodn Cdng nghidp Than - Khoang sdn Vidt Nam (Vinacomin) da cd chu tm'ang hgn ehi dp dung cde sa d i cdng nghp khai thdc budng khd kilm sodt edng tdo an todn Cae so edng nghp khai thde sii' dpng ddn ehing cirng vd mim dang dirng lai d mde dp thii' nghiem khd khan d diiu kipn dp dpng; so d i cdng nghd khai thdc cpt ddi theo hudng die ca gidi hda bing t i hpp 2ANSH ddi hdi diiu kidn dia chit via phai i n dinh, tru lupng tgp trung ndn mdi chi dp dpng tai cdc md him Id ed trO' lupng via mdng die Idn nhu Mao Khd vd Hing Thdi Nhu vgy hipn d l khai thdc via d i e cde md h i m Id viing Qudng Ninh chii y i u dp dung so d i cing nghd khai thdc chia Idp ngang nghieng (hodc chia Idp bang) va so d i edng nghp khai thac Id dpc via phdn ting tinh thich irng cao eua eac so d i cdng nghd dieu kipn d|a chit phuc tap vung Qudng Ninh San lupng than khai thdc theo cae cing nghd ddng gdp tu 10 -^ 15% (khoang 2,5 + 3,0 tridu tan) ting san lupng than khai thdc bang phuang phap him Id hang ndm cua Vinacomin Tuy nhien, cac so d i cdng nghe khai thdc edn mpt s i ton tgi nhu: cing suit Id cha edn thip, phi biln tu 50.000 * 60.000 tIn/ndm khai thde hai phdn ting ding thdi d i i vdi cdng nghp khai thdc chia Idp ngang nghieng vd tu' 25.000 + 35.000 tin/nam khai thac hai phdn t i n g ding thdi vdi cing nghp khai thde Id dpc via phdn ting; chi phi met Id chuin bi eao tu' 20+35m/1000 t i n than khai thdc d i i vdi cing nghd khai thde chia Idp ngang nghieng va tir 28 + 40m/1000 t i n than khai thac vdl cing KHCNM S 1/2013' CNKT H X M L O w Th6ng tin khoa hqc cong ngh$ m6 nghp khai thdc Id dpc via phdn ting Nguydn nhdn co bdn d i n din ehi tieu met Id chuin bi cao la cing tde khai thdc tai cdc Id ehp tren sir dpng gidi phdp n i cdc l i khoan ngin (til da 3,5m) ndn chilu cao phdn ting ede sa d i edng nghp khai thde chia Idp ngang nghidng vd Id dpe via phdn ting bj hgn ehi, p h i biln tu + 8m d i u n i l mgng n i Idu vd phire tgp, kich thude ed hgt sau ede l i n n i khing ddu hcdc Idn han kich thude ydu c l u eiia phuang tidn vdn tai, hd s i sir dung l i khdng d i n g d i u vd thip, thudng chi dgt 75 * 80% Cdc t i n tgi trdn dd Idm tdng thdi gian hodn thdnh mdt chu kji ddo Id, hgn c h i t i c d i ddo Id vd ndng suit lao Trong cdng tde dao Id, nhu c l u tang sdn lupng khai thde nen s i lupng mdt Id ddo hdng nam tai cac md h i m Id vung Quang Nmh cung khdng ngung tang trudng Tir ndm 2000 den s i lupng mdt l i dao mdi tai cac md him Id tdng tir 77.111m/nam len 381.756 m/nam (gip khoang Iln) Trong dd so lupng met Id ddo dd chiem tir 25% + 30% De dat duac kit qua nhu tren, ede md ham Id viing Quang Ninh da dp dung ea hai logi hinh cdng nghp dao Id thii cdng vd ea gidi Tuy nhien, met Id dao theo loai hinh cdng nghp dao Id bang co gidi hda chilm ty Id khdng dang k l tdng s i met lo dao dupe hang nam (theo cdc bao cao khoi lupng md hai nam g i n day nhit ciia Vinacomin thi s i lupng met Id dupe ddo bang may ndm 2010 id 1.477m tren t i n g s i 345.371m l i dao, nam 2011 la 1.240m tren ting s i 381.756m Id dao) Thue te tren cho thiy, edng nghe ddo Id tgi cdc md ham Id ehu y i u la thiJ edng vdi phuang phdp ddo phd guang bang khoan n i si> dgng kip vl sai didn Qua theo d i i thuc t l n i mm bang kip vl sai • dien tai edc guang dao Id cho thiy mpt so tdn tgi thudng xay nhu hien tupng cdm B l khic phpc cdc t i n tgi eiia kip vi sai didn, nhirng ndm gin ddy cdc nude nhu Ba Lan, Slovakia, v.v da nghidn ciru, san xuit kip n i vi sai phi didn an todn vd sir dung d l kich n i khii thuic n i l i khoan ddi khai thdc via d i e bdng so d i cdng nghd khai thde l i dpe via phan ting vdi chilu cao giua cdc phdn ting len d i n 30 m Vide sir dpng kip vi sai phi dien da nang eao dupe hipu qua no ddy ddn tin hipu n i eiia kip cd dp b i n cao, d i dai day ddn khdng gidi hpn, edng tdc diu n i i dan gian Kip vi sai phi dipn an todn vd thuic n i ed sire edng phd cao eung dupe dp dung d l dao ede dudng Id da tai cdc md h i m l i quang hope than tgi edc nude tren vd dd gdp phin nang eao t i e dp ddo Id, ndng suit vd an toan lao ding ding dgt thip Xuit phdt t u ode khd khdn qud trinh khai thdc via die, ddo Id nude vd kinh nghidm su dgng kip vi sai phi didn an todn cua nude ngodi, ndm 2010, Vipn Khoa hpe Cing nghd Md dd dupe Bp Cing Thuang vd Tdp dodn Cing nghipp Than - Khodng san Vipt Nam giao thpc hidn d l tdi "Nghien ciru dp dgng thir nghipm cing nghd khai thde vd iJao Id sir dpng kip n i vi KHCNM S 1/2013* CNKT H X M L sai phi didn phdng n i c h i tgo nude" vd d l tdi "Nghidn eiru sdn xuit kip n i vi sai phi didn an todn h i m Id vd dp dpng cdng nghd n i l i khoan ddi edc m i him Id viing Qudng Ninh" Mgc tidu chlnh eua hai d l tdi ndu trdn Id nghidn ciru san xuit thu nghidm kip n i vi sai phi didn an todn tgi ede nhd mdy ehi tgo vdt lidu n i nude d l dp dgng cing nghd n i 15 khoan ddi nhim ndng cao hidu qud ddo Id vd khai thdc via d i e Trdn ca sd kinh nghidm nghidn ciru, e h i tgo kip n i vl sai phi didn sir dung eho cde md Id thidn, kip n i vi sai didn an todn cho cdc md him Id nude vd ydu c l u v l kJ thudt vd an todn eua kip n i vi sai phi didn sir dung mil trudng ed vd bgi n i , Vidn Khoa hpc Cing nghd M i d i phoi hpp vai Cdng ty TNHH MTV Hda chit 21 - B i Quic phdng (Nha may Z121) nghien ciru c h i tgo cdng kip n i vi sai phi dipn an todn him 16 KVPA8B vdi s i lupng 20.000 chile Sau c h i tgo, kip da dupe thu' nhiiu dpt tgi phdng thi nghipm eua Nhd may Z121, Trung tam An todn Md, Trung tdm Vgt lidu n i Cing nghidp (Vipn Khoa hpc Cing nghp Mo) theo edc ehi tidu nhu; eudng dp n i , thdi gian vi sai, dp bin day d i n tin hipu n i , kha nang n i an toan m i i tordng cd n i n g dp mdtan ± 0,3%, v v Cac k i t qua thu cho thiy cac tinh ndng d i u dgt ydu clu, kip ed t h l sir dgng an toan mdi trudng cd mdtan vdi eac uu dilm vupt trdi so vdi kip vi sai dipn v l d i bin vd chilu ddi eua day ddn tin hidu n i Dpc tinh eiia kip vi sai phi Thong tin khoa hpc cdng nghe m d Bdng Bic tinh kf thuit kip vi sai phi diin an toin (KVPA8B) TT Thdng so kf thuit Don vi Triad Ghi chd Diy dan tin hi^u n6 Budng kinh ngodi mm 3,0 Tic dp din r i m/s £1700 Bp bin kdo cua ddy KG Chidu ddi ddy m - Mdu sdc ddy Mdu sdc nhdn kip vd mdc chO' J // Kip no Vdt lidu ldm vd kip ilS + 300 Di - Da cam - ding Mo Chidu ddi vo kip mm 52*62 Dudng kinh ngodi kip mm max 7,1 Cudng dp n i Dp ben mil ghdp midng kip Kha ndng chiu nude S i kip vl sai Thdi gian vi sai HInhl Kipvisaiphidi^nantoin • Id KVPA8B ^ ham dipn an todn him Id dupe gidi thieu tgi bang TO' kit qua nghien cdu cua d l tdi, nam 2010, Vidn Khoa hpc Cdng nghd Md da d l xuit, thllt k l dp dung cdng nghp ddo Id dd si> dgng kip n i vi sai phi dipn an toan him l i Bo tlln chi tgo kip n i vi sai phi didn an todn nude chdm, ndn Vipn Khoa hpc Cdng nghp Md si8 KG gid 2,0 10 ms 25 + 400 w dgng kip vi sai didn, ehi khdc v l so d i d i u n i i mgng n i , phg kidn n i , mdy n i (so d i mgng n i dde trung dupe md ta trdn hinh 2) Kit qua dp dgng thif nghipm kip vl sai phi dipn tgi mpt s i md him Id Quang Ninh nhu Quang Hanh, Nam Miu, Bong Vdng, Hdn Gai, Bdng Bic, vv eho thay ede ehi tidu nhu tic d i ddo 16 dgt tir 60 + 65 m/thdng (tang tir 1,2 + 1,3 iln so vdi ddo Id sir dpng kip vi sai dipn), ndng suit lao dpng dat 0,06 + 0,08 m/cdng (tdng tu 1,2 +1,6 Iln so vdi ddo Id sii' dung kip vl sai dipn), cde ehi phi khdc (thuic no, kip n i , vv) gin nhu khing thay dii so vdi cdng nghd da ap dyng trudc day tai md Tong hpp kit qua dp dgng thO" nghiem eho thiy toe d i dao Id, nang sgit lao ding tang dp dgng kip vi sai phi didn Id thdi gian dig nil mang n i giam tu 60% + 70% so vdi sir dung kip dien nen njt ngan dupe thai gian hoan thdnh chu ky, he sd su dgng Id cao dgt tir 90% + 95%, khdng cdn hien tupng cam, chit luang phd vd d i t dd t i t (dd qua cd chi edn 5%) nen dd gdp phin ndng cao ndng suit xuc bdc, van tai COng tu' kit qua nghien euu Hinh Sa diu noi mang nosu dung kip vi sai phi diin cong eiia d l tdi, nam 2011, Vien Khoa hoc Cdng nghe Md da tac dio Id di ciing vdl cac md da xin phep phii hap vdi Cdng ty than Bdng Vdng triin khai lgp va dupe Cgc Ky thugt An todn va Mdi trudng - Bp Cdng phuang an dp dung thir Thuang, Vinacomin eho phep nghiem giai phap n i ap dgng cing nghd ddo Id dd 16 khoan dai bang kip vi sai phi SU' dgng kip n i vi sal phi dien didn an todn sa d i cdng thudng, diing cho cae dudng nghe khai thdc l i dpc via phdn Id da khing cd mdtan tang eho dieu kipn via 7B khu Cdng nghe ddo Id dd sir dgng Bdng Vang Danh - Cing ty kip vi sai phi dipn dupe thuc than Bong Ving Phuang an hipn giong nhu cing nghp su' da d\r(?c Vinacomin eho phep dp KHCNM SO 1/2013« CNKT H A M LO Thong tin khoa hpc cong ngh$ m W" dgng thir nghipm thpc t l tgi suit lao ding cdn thip cdng van s i 2795A/lnacomln-KCL Nguydn nhdn chlnh Id hgn c h i ciia phuang tidn n i dd ndu ngdy 30/5/2012 Khu vpc dp dgng tgi via 7B d phin trdn Khi dp dgng gidl khu Bdng Vang Danh cd diiu phdp n i cde l i khoan kipn dia chit ky thudt md nhu ddi SU' dgng kip vi sal phi didn sau: chilu day via thay d i i tu' an todn, cdc thing s i eua sa 3,1 + 3,5m, trung blnh 3,4m, d i cing nghd vd phuang phdp mirc dd biln ding v l chilu ddy ching glO' dupe giO nguydn via Vm = 18%; gdc d i e via thay nhu hidn trgng, chi thay d i i v l d i i tir 50° + 65°, trung binh 58°, chilu ddi l i khoan vd phuang mirc dp biln dpng v l gdc d i e tidn n i , phuang thirc ngp via Vec = 16% Via thupc loal i n cing tde khogn n i hg tr in dinh trung binh v l chiiu ddy vd so vdi gidi phdp n i gdc die Vdch trpe tllp Id cde cdc l5 khoan ngin bing kip vi Idp sdt k i t xen Iln b i t kit, sai didn H i chilu khoan n i chilu ddy vdch trpe tllp thay hg trin bing l i khoan ddi d i i tu' 6,0+11m, eudng d i su dgng kip vi sal phi didn khdng ndn trung binh, 5n = 613 dupe m i ta trdn hinh kG/cm^, trpng lupng t h l tich Gidi phdp n i l i trung binh, y = 2,65 g/em' khoan ddi bing kip vi sai phi Vach ca ban Id Idp tjpt kit xen dipn an todn dd dupe dp dpng ldn eat kit, chilu day tir 12+20m, tgi phdn ting 'i'102 va phdn cudng dp khdng nen trung ting +96 via 7B Tinh d i n ngdy binh, 6n = 1150 kG/cm^, trpng 27/8/2012 sau han mit thdng dd lupng t h l tieh trung blnh, thpc hidn dupe 23 chu ky khai y = 2,64 g/em° Tni true tllp Id thdc tgi phdn ting +102 vd 15 Idp bpt k i t cau tgo phan Idp chu ky khai thdc tgi phdn ting day Khu vpc dupe x i p vdo md +96 vdi s i lupng kip vi sai phi logi I v l metan vdi dp thodt dipn an todn dd su dgng Id 408 0,15 m'/tln/ngdy - dem chile Trong ede ehu ky khai Trif lupng dia chit huy d i n g thdc, tn> cing tdc khoan l i vdo khai thac Id 163.700 t i n vd ngp n i min, cdc cing tdc cin Khu vg'C dp dgng thu lgi dupe thpc hidn tuang nhu nghipm dd dwtyc Cdng ty than Bong Vdng chuin b| theo sa d i cing nghd khai thdc Id dpc via phdn t i n g vdi khoang cdch giira edc phdn ting tir + 10m Cdng tdc khai thdc dd dp dung tgi mpt s i phan t i n g thuic khu vpc thu nghidm Id hg tri n than bdng n i cdc l i khoan ngin (tii da 3,5 m) si> dung kip VI sai didn, ching giO' tdng eudng guang khai thdc b i n g gid thiiy lpc di dpng cd t i n tgi Id t rin than khing sdp d i tridt d l d i n d i n t i n thit than cao, sdn lupng khai thac vd ndng KHCNM sii 1/2013' CNKT HXM L cing nghd khai thde Id dpc via phdn ting n i cdc l i khoan ngin bing kip vi sai didn dang dp dgng Cdng tdc khoan l5 dupe thpc hidn bing mdy khoan ndn e l m tay logi ZQS35/1.6 eiia Trung Quic, choing khoan logi x o l n ruit gd cd chilu ddi 2m, mOi khoan cd dudng kinh i|>42 Trong cde chu ky ddu chi thpc hidn khoan vd n i ede l i khoan ddi din 6,0m, nhidn hidu qud n i thip, t r i n than khdng sdp d i tridt d l , cdc chu ky tllp theo dd diiu chinh vd thpc hidn vide khoan vd n i cdc l i khoan ddi tir 3.6 + 6,0m kit hpp vdi cdc l i khoan ngin tir 1,5 + 3,5m ndn hidu qua n i da dutqrc ndng cao, trin than sgp d i tridt d l Qua theo d i i eho thiy thllt bj khoan IS khoan ddi tuang d i i thieh hpp vdi khing gian hpp cua guong khai thac Id dpc via phdn ting Tuy nhidn, logi mdy khoan ndy vdn cdn nhiiu nhifpc dilm nhir chi khoan dupe IS khoan cd chilu sdu t i i da Id 6,0m, djnh hudng gdc khoan khd khdn, nhdn Ipc phge vu cing tdc khoan nhiiu (3 ngudi), thdi gian khoan HATCHTO-A Hinh Hd chiiu khoan n6 trin Thdng tin khoa hoc cong nghe m o ehi^m ty 1$ lo-n mpt ehu ky khai thae, v.v Bk nang eao han nij'a hieu qua khai thae Id dpe via phan t4ng, no e^e 16 khoan dai bang kip vi sai phi di$n an to^n, Cong ty than B6ng Vong ein xem xet 6ku Xur thiit bj khoan eo kha ndng khoan cac Id khoan chilu d^i lan han, mu'c dp ca giai cao han a l tang chieu cao phan ting giam thai gian khoan Doi vai khau n^p min, ngp bang thu cong nen thd'i gian thi/e hien thu-dng chilm ti> 12 -^ 30% thd'i gian cua ca san xuat, song qua theo doi tgi thye t l ed t h l khing dinh ring viec nap bang phu'ang phap thu edng su* dgng g^y n l i hoan to^n thye hien du-p'c eac Id khoan dai Phu'ang tien de xuat ap dgng d l ^ n h v{ thdi thuoc Id khoan la day nhya cung da phat huy tot kha nang djnh vj thdi thuoe lo khoan dai Trong viec nap min, cae ben eung da thu- nghiem hai hinh thuc la nap lien tue va nap phan doan cac Id khoan dai Qua theo ddi tgi thyc t l thi hieu qua no bing eua hinh thire nap lien tue thap han, diln hinh la tai chu ky khai thac diu tien tgi Id dpe vFa phdn tang +102 eac lo du-p'c nap theo hinh thu-e tren, tran than da khdng sap dd tript d l , phai khoan no bo sung, eac chu ky t i i p theo nap theo hinh thirc phan dogn thi hieu qua nd tang len rd ret tran than da sap d l tript de Khd khan cdng tae la viee nap thulc no va bua thyc hien bang thu cdng se d i n d i n cac han c h i v l chilu dai l6 khoan (tu- kinh nghipm thyc t l cho thay chi cd t h l ngp thu cdng eac Id khoan cd w BSng So sdnh cic chf ti6u kinh tS kp thu$t So IWQ'ng TT f e n chi tieu Khi ip dung kip vi sai phi dl^n an toin Den vf C h i l u dSy via trung binh m Gdc d i e via trung binh C h i l u cao phan t i n g m e 10 T/ngSy ddm 100 114 140 T/thSng 2.500 2800 3600 T/nSm 28.000 San lu-png than kiiai thSc (tfnh cho hai phdn ting) San lu-ang than khai thSc (tinh cho hai phSn ting) C6ng suat khai thSc (tinh cho hai phSn tanq khai thdc) Ndng suat lao dOng c6ng nhSn Id cha C h i l u ddi l5 Lu'png thude nd mdt Id 10 So kip n6 mdt 16 11 Loai thuoc no 12 Phu'ang phdp ngp 13 ThiJ ty n l 32.000 40 000 2,4 m 2,0 + 3,0 3,0 + 6,0 kg 1,8 1,2 + 2,0 +2 cai Kg/1000T KIp/IOOOT 16 Chi phi kip phi dien Kip/1 OOOT 17 Chi phf lu-ffi thdp Kg/1000T 18 Ton that than theo cdng nghS 68 T/cdng 14 Chi phi t h u l c no 15 Chi p h i k i p d i ^ n chilu dai khoang + 10m thdi gian ngp eho mdt Id cd chieu dai 6,0m dd keo del tir 15 + 30 phut) Ngodi ra, vipe gia cing bua dupe thpc hipn thii cing nen cDng khd t i n thdi gian, ding thdi bua cd kich cd, dp ldn nen khdng diu Vi vgy thdi gian tdi, Cdng ty ein xem xdt nghien ciru d i u tu ede thllt b| Idm bua kilu tay quay hogc sir dgng cdc may Idm ggch ngdi d l gig cing bua D i i vdi khdu d i u nii mgng ho, thdi gian thpc hipn chi keo ddi tir + phut, trung binh khoang phiit cae phuang tidn d i u n i i da dupe c h i tgo 3,4 % 3,0 3.4 AH1 NTLT Li6n tuc Phdn doan TPC thpi Vi sal 152 165,5 107,6 29 18 348 - 708 33,0 154 99 649,3 571,6 21,0 26,7 san vd phuang phap dau dan gian Niu so vdi thdi gian diu n i l SU" dung kip vi sai dien an todn diiu kipn s i luang kip bang thi thai gian dau nii sir dung kip vi sai phi dipn an todn giam tir 30 + 50% Tuy edn mpt s i khd khan cdng tac khoan no, song, cing nghp da dat dupe eac chi tieu theo yeu c l u dgt Viee thpc hidn giai phap khoan n i Id khoan dai bang kip vl sai phi dien an todn da gliip trin than sap tuang ddi tript de, eho phep ndng eao he s i (Xem tiip i Irang 23) KHCNM S6 1/20I3* CNKT HAM LO ... 21,0 26,7 san vd phuang phap dau dan gian Niu so vdi thdi gian diu n i l SU" dung kip vi sai dien an todn diiu kipn s i luang kip bang thi thai gian dau nii sir dung kip vi sai phi dipn an todn... nghe khai thdc l i dpc via phdn Id da khing cd mdtan tang eho dieu kipn via 7B khu Cdng nghe ddo Id dd sir dgng Bdng Vang Danh - Cing ty kip vi sai phi dipn dupe thuc than Bong Ving Phuang an hipn... Bk nang eao han nij''a hieu qua khai thae Id dpe via phan t4ng, no e^e 16 khoan dai bang kip vi sai phi di$n an to^n, Cong ty than B6ng Vong ein xem xet 6ku Xur thiit bj khoan eo kha ndng khoan

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