H Sir Md TirdNG

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CNM KHOA HOC VA CONG

N G H £

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XAC NHAN DIEU KIEN AN T O A N V A CONG T A C C H U A N Bj

DE Md LAI TirdNG ^{C H A N}

SAU Sir CO CHAY TRONG MO HAM LO

ThS. Le TRUNG T U Y § ' N , KS. N G U Y I N T U X N ANH Trung tim An toin Md • Vi$n KHCN M6

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i^n nay, hi^n tu-p'ng chay mo xay ra tgi mpt s6 mo than ma nguydn nhan dyp-c nhan djnh la do hi^n tu-p'ng ty chay cua than. Khi xay ra chay, d6i vdi nhu'ng dam chay nho nam trong t i m ki§m scat thi vi$c kh6ng c h l dam chay bang cac phu-ong phap chOa chay thong thu-dng nhu" su* dgng binh chij-a chay, phun nirdc. , ddi vdi dam chay Idn nam ngoai tam kikvn scat thi phu-ong phap khdng ch6 de each ly dam chay vdi ben ngoai blng each xay tu-dng chin blng gach, bao cat, bom ngap nirde, bom nita hoac chit ehdng chay nhlm ngan ngya kha nang t i l p xuc cua dam chay vdi ngudn cung elp oxy. Khi dam chay da du-p-c d i p tat viec md cac tiFdng chin de tilp tuc qua trinh khai thac la mot v l n dd chu'a dipo'c quan tam, nhlt la ve y l u t6 an toan. Chinh vl vay, trong khuon khd bai vilt nay d l cap d i n cac bien phap va phu'ong an 6k md tirdng chan sau khi dam chay da du'O'c dap t i t 6k mo tiep tyc hogt dOng khai thac.

1. Thanh phln khong khf trong tifdng c h i n Thong thu'O'ng, trong dam chay xay ra trong mo him 16, thanh phIn khong khi trong tydng chin du'O'c xac dinh va quan trie thong qua vi#c phan tich cac mlu khf trong tu-dng chin. Phan tich mau khi trong tudng chin tai Via 24 Cong ty than H6ng Thai khi xay ra chay mo va ham lyp'ng khdng khi nhy y§u clu trong QCKT thi hien trong Bang 1 [1], [2].

Bang 1.

Ngay 21.02.2010 22.02.2010 08.03.2010 Theo QCKT

Ham lu'gng khi CO, %

0.0386 0.0377 0.0305 0.0017

CH4, % 1.2 0.3 0.4 1

CO2, % 0.82

0.4 0.8 0.5

O2. % 15.6

17 17 20

Qua bang s6 Ii0u n6u trdn cho thiy, vi^c md lai tydng chin khi chya xac djnh du-p-c tinh trgng dam chay cQng nhy thanh phIn khdng khf phfa trong tu'dng chan tilm I n nhilu v l n d l phai xem x6t.

Vl$c xult hi$n mOt lu-p-ng khi dOc c6 t h i gay nguy hilm cho nhu'ng ngu-di difp-c giao nhi^m vu thyc hi^n thao tac. Vdi lu-p-ng khf CH4 tfch ty phia trong tu'dng chin khi thoat ra ngoai blu khdng khf mo cung la mOt hilm hpa c l n thilt phai d l phong vl nguy co chay n l khf.

2. Md l^i tu'O'ng c h i n sau chay d l tilp tuc khai thac

K l hoach md lai tu'dng chin sau khi dam chay da t i t 6k t i l p tyc khai thac c l n phai du'gc xem xet ky lu-dng d l dipa ra quylt djnh nen ma tu'dng chin vao thdi d i l m nao la hp'p ly. Day la mOt boat dOng h i t syc nguy hilm ma kit qua kha nang dam chay se bung chay trd lai ngay sau khi c6 lulng khdng khf cung cap oxy di vao khu vyc dyp'c md lai. Do d6 vide md tu'dng chan phai tuan thu cac trinh ty d$t ra.

2.1. Cic yeu to dutyc xem xet truKK khi ma l^i m^t khu v{pc da bjt kin

C6 nhilu y l u td phai du'O'c xem xet tru-dc khi 96 ging md lai mdt khu vyc chay da du'O'c dap tat.

v l n d l nay c l n phai dyp'c xem xdt ky lu-dng cua ngu'di ehju trach nhidm cao nhlt cung nhu- nhom cac can bO c6ng nhan vi^n c6 nhilu kinh nghi§m^.

Trong s6 cac y l u t l phai dyp'c lam ro trydc khi mo lai tydng chin nhy: da dat du thdi gian k l tir ngay xay dyng tydng chin cho ngay md lai tu-dng chan hay chya? Cac y l u to chu y l u chi phli va anh hydng tdi thdi gian trdn ra sao? Cac ylu t l chi phli va anh hydng tdi thdi gian tren phai bao gim:

• Do kin cua tydng chin va khu vyc du-gc bjt kin, dieu quan trong nhlt la tydng chan va khu vyc bjt kfn khong bj ro ri khi;

• Anh hydng cua ap suit khf quyen tai khu vyc;

CONG NGHIEP MO SO 2-2012

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KHOA HOC VA

C O N G N G H I

MO CNM

• Dac tinh cua vat lieu chay va vj tri cua via than nam phia tren;

• Pham vi va cu-dng do cua khu vyc bj chay ban dlu;

<• Vj tri cua cac tu'dng chin doi vdi thong gid md;

• Kich thu-dc cua khu vyc bjt kin.

•:• cac thanh phln cua cac khi trong khu vyc bj chay.

2.2. Yeu cau dat ra cua viec m& tw&ng chin trey lai

Viec md tu'dng chin cln phai xem x6t ky cang, va dua ra cac yeu clu d l thyc hidn md tirdng chin phai:

•:• xac djnh tl le phln tram CO trong khu vyc chay la bao nhieu? Dilu nay rit quan trpng vl nd la mot trong nhdng dlu hiou dam chay dang boat dong hay ngi^ng boat dong.

• Ndng do oxy hoac metan la bao nhi§u la an toan d l khi md tipdng chin? Khi mOt khu vyc bj chay nIm hoan toan trong via than cd nhilu khi (metan) thi ti le phln tram cua khi metan trong khu vyc kin se tang len, trong khi ty le phln tram cua oxy se giam xulng.Ty le ho-p ly la liFong oxy trong khong khi se bj hip thy va lam cho gidi han de chay cua khi metan (tren 15 % CH4) giam xulng.

Khi CO rIt nhilu sy hip thy lam cho t^ le phln tram oxy dat tdi gidi ban tren la 12,4 % kit hop vdi gidi han tren cua CH4 thi qua trinh chay trd lai khong thi xay ra.

Trong mot khu vyc ma khi metan khong thoat ra, mot hon hgp de chay, cd t h i se khong bao gid phat sinh, vl lu'gng oxy se giam xulng eon 12,4 % tru-dc khi s i lu'gng gia tang khf metan dat 6,5 %.

va khi ham lu'gng khf metan da tang tren 15 % hoac lu'gng oxy giam xulng du'di 12,4 %, nguy co cua mot vy nd khf xult phat tO trong khong khf se khong xay ra [3].

Nhu- vi dy tren du-a ra ham lu'gng oxy trong tudng chin la 15.6 % va ham lirgng oxy t l i thilu cho phep theo quy chuIn ky thuat la 20.0 % theo do, lu-gng oxy thilu hyt se la 4.4 %. Lu'gng oxy thilu hyt nay cd t h i da bj hip thy trong via than hoac tham gia vao phan dng chay... td do cd t h i thIy ring dam chay vln dang t i n tai" [1].

Theo ly thuylt v l n l hdn hgp khong khf-khi CH4, ham lu'gng CH4 gidi ban td 5-15 %; O2 gidi ban td 12.4-20.95 % thi xay ra phan dng chay cua me tan. Dilu kien gay n l cua hori hgp khf dygc minh hoa blng tam giac hon hgp no (H.I) [4].

• Sy xult hien khf CO2 trong khu vyc chay co anh hu-dng gl? Lu'gng khf CO2 ed anh hydng rIt nho tren dam chay, nhu'ng nd la mot y l u t l 6k du'gc xem xet trong viec xac djnh lieu khu vyc nay cd xay ra n l hay khdng.

• Khi nao la an toan d l md lai mpt khu vyc bj chay? Khi ham lugng CO trong cac khu vyc bj chay tu-ong dyong ham lu'gng CO binh thudng cua mo (theo Quy chuIn ky thuat); nhi^t dO cua khu vyc bjt kfn blng vdi nhi^t dO trong mo d dilu ki^n blnh thydng cd t h i du'gc nhan djnh ring dam chay khdng cdn boat dOng. Ngoai ra, ed t h i sd dyng chl so dam chay Graham [1] dya trSn gia tri ham lu'gng cac khf do dac d l danh gia hi$n trang phia trong tu'dng chin.

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2.3. Cac cong viec phai dwg>c thirc hien trw&c khi mvlai cac twcmg chan

cac cdng viec chuIn bj phai du'gc thyc hien tripdc khi md lai cac tirdng chin cln thyc hi$n theo cac bu'dc sau:

• Lap k l hoach day du chi tilt dipgc chuan bj, thing nhlt vdi cac ben tham gia.

• Dpi thong gid d p edu cua mo dirge giao thyc hi$n nhidm vy tren.

• Do nhlot do, khf CH4, CO, CO2 tai khu vyc da bjt kin (trong va ngoai tu'dng chin) dam bao ham lygng khf nam trong mdc cho phep theo Quy chuIn ky thuat.

• Thong gid cln phai du'gc tfnh toan phu hgp d l dam bao gid saeh khdng di vao khu vyc pha hoa va hoa loang lugng khdng khf CO, CO2 dat yeu clu Quy chuan ky thuat.

CONG NGHIEP MO SO 2 - 2 0 1 2

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KHOA HOC VA CONG N G H | MO

• Dilu chinh thdng gid cln thilt dygc thyc hi$n d l dam bao ring mpt s i lugng du khdng khi se du-gc dua vao, khi thai di qua khu vyc bjt kin se khong di qua bit ky nguin danh Ida tilm I n nao.

•:• Khdng khi td cac khu vyc chay md ra, khf thai nen dugc thoat ra theo cac doan dydng Id ngln nhlt d l thoat ra ngoai b l mat.

•:• Dudng Id cd khi thai td khu vyc bjt kin di ra phai du'gc kilm tra xem cd dlu hi$u ndng l§n hoac nguySn nhan ed phat sinh ra tia Ida, tat ca cac thilt bj di^n tai khu vyc du'dng Id do phai ddng hogt dpng.

•:• cac quat thdng gid d l cung elp cho khu vyc md tu'dng chin phai du'gc elp di#n td nguIn di0n dat d lulng gid sach.

•:• Tit ca cac thilt bj sd dyng trong vi^e md tudng chin phai la loai phdng n l .

V Cln phai lien tyc giam sat cac khu vyc bj chay trong khi md khu vyc bjt kin d l xac djnh nguy CO chay trd lai.

•:• Cac khu vyc giap ranh vdi tu'dng chin phai dugc phu bui da.

• Tit ca cac dudng dan vao khu vyc chay phai dugc rao chin.

• Chl ed s i lugng t l i thilu cdng nhan cln thilt mdi dugc cho phep dudi md.

• Phai ehuln bj dly du dudng day thdng tin lien lac giOa cac vi tri cua tirdng chin, cac nguon khdng khi sach va phdng kilm soat trung tam.

Sau khi da xac nhan cac dilu kien chuan bj neu tren, cdng tac md tudng chin dugc tiln hanh nhu sau:

• Xac nhan cac dilu kien:

+ Khdng phat hien ham lugng CO;

+ Ham lugng O2 giam din mdc 1 hoac 2 %;

+ Nhiet do trong tudng chin tuong ty nhi^t dO dudng Id xung quanh;

+ Khdng phat hien cac mui la;

+ Ham lugng CO2 khdng thay d l i .

•:• Khi tudng chin dugc md, phai lam mOt tudng chin tam (cd b l tri cua) phfa ngoai tudng chin cln md d l d l phdng khdng khf tu ngoai di vao khoang khdng khf phfa trong tudng chin.

Trong qua trinh md tudng chin, dpi d p cuu mo phai do dac ham lugng khi ben trong tudng chin.

• Sau khi xac nhan khdng cd nguy hilm, tilp tuc md tudng chin, tudng chin tam se dugc di chuyin din v l phia tudng chin e l djnh dugc md.

Khf trong khoang khdng dugc md dugc thao ra ngoai theo mdc do md cua tren tudng chin tam.

• N I U trong qua trinh md tudng chin phat hi^n viec chay trd lai phai lap tuc ngung vi$c md tudng chin, ddng cua tren tudng chin tam. Gia c6 lai tudng chin cd djnh va thyc hien cac bidn phap bjt kin tudng chin.

3. Kit lu$n

Vi$e md lai tudng chin sau khi da khic phuc dygc sy e l chay mo la cdng tac h i t sue quan trpng d l md cd t h i tiln hanh san xult binh thudng trd lai.

Trong khudn k h i bai vilt nay, d l xult mpt s6 cac ylu t l dugc xem x6t trude khi md lai mdt khu vyc da bjt kfn blng tudng chin, cac ySu cau dat ra cua vi$c md tudng chin trd lai va cac cdng vi$c phai dugc thyc hi$n trude khi md lai cac tudng chin d l dam bao an toan.l!!

TAI LliU THAM^{K H A O}

1. L6 Trung Tuyin va nnk. Danh gia tinh hinh dam chay dya trdn ti6u chi v l khi. Hpi nghi KHKT Mo toan quic nam 2011. 08/2011.

2. B | Cdng Thuong. Quy ehuln ky thuat quIc gia v l an toan trong khai thac than him Id. Nha xult ban Lao dong. Ha NOi. Nam 2011. Trang 43, 56.

3. R. Morris, T. Atkinson. The reopening of a previously sealed fire area. Mining Science and Technology, 5 (1987) 247-262, 247 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netheriands.

4. Trin Tu Ba va nnk. Bao cao ting kit Dk tai xac djnh dO chua khf. 2000.

Ngudl bien tip: Ddo Die Tao

SUMMARY

The paper shows some results of confirming the safety conditions and preparing works to open prevent wall after the mine fire in the underground coal exploitation.

Mff VIA KHOANG SANG THAN..

(Ti^p theo trang 14)

3. Tai lieu thu thap tCr cac Cdng ty than Nui Beo.

Ha Lam. Vi§n KHCN md.

NgudI biSn t$p: V6 Trgng Hung