MOT SO GIAI PHAP CONG NGHE NO MIN TREN CAC MO THAN LO THIEN
• - • •
n h a m giam t h i e u a n h hvfdng d e n c a c k h u vi^c k h a i t h a c d o n g thcfi h a m 16 - l o t h i e n
In fact, the open and underground coal co - mining method carried out at one deposit site for increasing production efficiency and decreasing resource losses has been more and more widely applied on the world. The study on the selection of the proper technological solutions for blasting operation and of the mining sequence for ensuring high safety and efficiency is a very essential task
KS. NGUYiN THANH BINH Th.S. D 6 NGQC Tl/dC KS. TA MINH Dtfc VA NNK Vien Khoa hpc Cdng nghe Md - TKV
1. Dat van de
Viec tien hanh khai thac tren ciing mpt khoang sang vdi hai phtfdng phap 16 thien va ham 16 nham nang cao hieu qua va ctfdng dp khai thac cung nhtf tan thu tdi da tai nguyen ngay cang dtfdc ap dung rpng rai tai nhieu ntfdc tren the gidi. Dien hinh ve stf dung cong nghe nay la cac ntfdc CO nganh cong nghiep md phat trien nhtf Nga, My, Tay Ban Nha, Phan Lan, Canada.... Tuy nhien, stf anh htfdng lln nhau trong viec khai thac phdi hdp gitfa hai phtfdng phap ham 16 va Ip thien dien ra trong cung thdi diem va khong gian khai thac la dieu khong tranh khdi. Do vay, cac nha khoa hoc trong ITnh vtfc md tren the gidi v i n tiep tuc nghien etfu de dtfa ra cac giai phap cong nghe htfu hieu nham giam thieu stf anh htfdng lan nhau gitfa hai phtfdng phap khai thac.
6 Viet Nam, do yeu cau ve san Itfdng cung nhtf dac diem phan bd eiia cac via than, mpt sd md khai thac than thupc Tap doan ket thue khai thac Ip
thien chuyen sang khai thac ham 16 hoac khai thac ddng thdi ca hai phtfdng phap tren cung mpt khoang sang theo 66 sau khac nhau trong nhtfng nam tdi. Cac via V I I , VI0, V9, V7 tai md than Nui Beo dtfdi moong Ip thien via 14 va cac via than md ham 16 Khe Cham ll-IV se khac thac ham 16, cac via 12, 11, 10, 9, 8 dtfdi moong Ip thien ciia md Cao Sdn va md Ip thien Khe Cham II.
Hien nay, cac md khai thac than CO nhtfng thuan Ipi cd ban ve cong nghe khai thac, cu the la viec dau ttf mdi nhieu thiet bj khai thac hien dai, ddng bp tren md Ip thien.
Cong tac ed gidi hoa ngay mpt hoan thien va dtfdc ap dung rpng rai trong khai thac ham 16. Nhtfng nhtfng md ap dung phtfdng phap khai thac hdn hdp se gap phai nhtfng khd khan, do la: Cac md than Viet Nam CO dieu kien ttf nhien phtfc tap, nhieu dj thtfdng trong cau true dja chat, dja chat thu9 van, dia chat cong trinh phtfc tap, stf tdn tai cCia eac tiii khf metan, tui ntfdc
luon la eac hiem hoa rinh rap gay ra cac stf cd nguy hiem, anh htfdng cCia nd min md Ip thien den khai thac ham 16.
Ngoai ra, kinh nghiem trong ap dung cong nghe khai thac hdn hdp vdi qui mo Idn eiia eac md cdn rat nhieu han che.
Tren cac md than Ip thien Idn, san Itfdng da't da can nd min ttf 7 -^ 30 trieu mVnam.
Qui mo bai nd ttf vai tan den hang chuc tan thudc nd/vu nd.
Tan sua't nd hang nam tdi hang tram vu, cac vu nd lap di lap lai nhieu lan gay cha'n dpng va lam suy yeu stf lien ket da't da trong khdi. Nhtfng ntft ne va lan truyen trong I6ng da't, vdi stf epng htfdng cCia cac vu nd gay nen nhtfng tiem an khd Itfdng, gay mat an toan, nha't la eac khu vtfc ham 16 dang boat dpng ben dtfdi.
Vi vay, ngay ttf bay gid, viec nghien ctfu stf dung cac bien phap cong nghe hdp ly trong cong tac nd min Ip thien, trinh ttf khai thac phii hdp nham dam bao an toan va hieu qua trong qua trinh khai thac la cong viec het stfc can thiet, cap bach.
KHCNM s o 1+2/2010* CNKT L O THifiN
2. NhUhg ye'u tdanh hUdng lan nhau khi khai thac hdn hdp Ip thien - ham 16.
a. Anh hudng do khai thac Id thien den ham 16
- Ap ltfc len nen eiia cac thiet bi lam viec tren tang nhtf may khoan, may xuc, oto v.v...
- Anh htfdng do cong tac nd min gay ra ma chii yeu la song cha'n dpng cCia cac vu nd lan truyen trong khdi da xudng dtfdng 16 khai thac.
- Anh htfdng do ntfdc tich tu dtfdi day moong khai thac gay nguy cd ngap md ham 16.
Trong cac yeu td anh htfdng ke tren thi anh htfdng do c6ng tac nd min va ntfdc tfch tu trong moong khai thac la nhtfng yeu td gay nguy hiem nha't. Trong trtfdng hdp cac dtfdng 16 khai thac nam dtfdi day moong chtfa ntfdc thi khoang each an toan ttf day moong den cac dtfdng 16 khai thac dtfdc xac dinh nhtf trong trtfdng hpp khai thac ham 16 dtfdi day ao hd, song sudi.
Khoang each gitfa day md Ip thien den dtfdng 16 (H) tuy thupc vao phtfdng phap chen lap va pha boa eo cac gia tri nhtf sau:
Khi ap dung phtfdng phap pha hda: H= 40 x M, m.
Trong do: H - Khoang each gitfa day md den dtfdng 16, m;
M- Chieu day cCia via than khai thac bang phtfdng phap ham 16, m.
Khi ap dur.g phtfdng phap Chen 16: H = 30M.
b. Anh hudng do khai thac ham Id den khai thac Id thien
- Gay ndt ne va sut liin tang, bd md, bai thai Ip thien trong pham vi khai thac ham 16.
- Gay sut lun cac cong trinh nha, xtfdng eiia md Ip thien trong pham vi 16 khai thac.
- Gay 6 nhiem do khi nd thoat ra ttf cac khu vtfc nd min len md Ip thien.
3. Mpt so giai phap cong nghe nham giam cha'n dpng do nd min tren md Ip thien.
Nang Itfdng cCia khdi min tham gia vao viec dap vd da't da xung quanh khdi min cang Idn thi tac dpng chan dpng nd min cang giam. Bdi vay, dieu kien quan trpng de dam bao an toan do chan dpng nd min gay ra la stf dung tdi da nang Itfdng nd de dap vd da't da bang cac bien phap dieu khien nd tien tien.
Trong khuon khd bai bao nay chung toi xin gidi thieu mpt sd bien phap cong nghe nd min mang tfnh eo the ap dung trong dieu kien cac md than Ip thien Viet Nam nham giam thieu tdi da cha'n dpng khi nd min.
3.1. Giam cha'n dpng nd min bIng bien phap sur dung thdi gian vi sai hdp ly.
Hien nay, ta't ca cac md khai thac than Ip thien deu stf dung phtfdng phap nd min vi sai nhieu hang chia thanh nhdm cac khdi thude nd. Day la cong nghe nd min tien tien, ngoai viec cai thien chat Itfdng nd thi phtfdng phap nay lam
giam chan dpng lan truyen trong khdi da't da xung quanh.
Tuy nhien, ngoai viec xac djnh khdi Itfdng thudc nd trong nhom theo nguyen tac 2/3, can thiet phai chpn thdi gian vi sai (khoang cham) t^ dam bao vtfdt thdi gian tdn tai eiia song cha'n dpng, ed nghTa la:
f , > — V F ^ e ° ^ giay hoac k
ttfdng tfng vdi f, >0,0232°'*
Thtfc te thi khoang gia tri thdi gian vi sai cung nhtf nhieu yeu td khac chiu anh htfdng chu yeu ttf tfnh cha't ed ly dat da md. Theo gia tri ciia 66 ctfng am hoc ed the phan thanh 5 nhdm eo gia tri nhtf sau: (9 - 13)10'; (13 - 17).
1 0 ^ (17-20) 10"; (20-23)10';
2310' (kg e/m^). De xac dinh thdi gian vi sai hdp ly ap dung cho dieu kien thtfc te san suat thi ngoai yeu td dieu kien ttf nhien can thiet phai tfnh toan theo dieu kien phan bd ciia mang Itfdi Id khoan, cu the la khoang each thtfc te gitfa cac Id min (a).
Vdi cac loai da't da c6 66 ctfng am hpc khac nhau thi thdi gian vi sai xac dinh theo cong thtfc ciia Giao stf Cergitrue:
, Itf ,giay(1) l2a-52 (ll-1.0Sb)A
l(f
Trong do: a - Khoang each gitfa cac Id khoan, m; p^ - Op ctfng am hoc ciia da't da, Kg/mls.
Ttf ham phu thupc thi=f(a, p^) lap dtfdc 66 thj nhtf hinh 1.
KHCNM S6 1+2/2010* CNKT L O T H I 6 N
1 1
\^
S 10 15 20 25^
O^ cxmg am hpc cGa d^t da. 10*kg/m's
Hinh 1. Suphy thudc ciia khoang cham hgp ly vdo khoang cdeh glQa cac id khoan va dp cdng am hpc cua
dat dd.
3.2. Giam cha'n dong no min bIng giai phap tang mtfc nd va giam khdi Itfdng thudc trong ttfng mtfc.
Khi nd min vi sai vdi qui mo bai nd Idn thi viec giam chan dpng bang giai phap tang mtfc nd trong mpt vu nd bj ban che, ctfdng 66 dja cha'n ehl dtfdc xac djnh d giai doan dau cua vu nd. Trong giai doan tiep theo thi mtfc dp chan dpng hau nhtf phat trien dn djnh deu nhau va chi phu thupc vao khdi Itfdng thude nd trong t i ^ g mtfc (hinh 2). Ctfdng dp xung ltfc nd \)i le thuan vdi nang Itfpng nd trong mpt mtfc, dtfdc
xac djnh theo cong thtfc:
P=(K^Qo)"(2).
Thay the P, phtfdng trinh c6 the viet dtfdi dang:
V.ax= Ko( K,„Qo)" (3)
Trong do: A:^ = —-,
E - Nang Itfdng rieng thudc nd stf dung; EQ- Nang Itfdng thudc nd chuan; n- He sd t^ le.
Ket qua do dtfdc thong qua eac vu nd thtfc te cho thay dao dpng cha'n dpng t^ le nghich vdi binh phtfdng khoang each ttf tam vu nd. Tdc 66 chan dpng tdi da eCia vu mtfc nd xac dinh theo cong thtfc (4):
1,9VS^
R' (4).
Dieu khien cha'n dpng vu nd ra't hieu qua bang dieu chinh khdi ludng thude trong mtfc nd. Tdc 66 djch chuyen eiia dat da dtfdc giam den 30 lan khi giam 10 lan khdi Itfdng thude nd trong mpt mtfc nd.
3.3. Sur dung phtfdng phap nd min thay do! cau true cot thudc
Thong qua eac vu nd thtfc
i8-
1.5
1,0
0.5
y ' ^
r
/r
\ 1
\
2 3
10
So mtfc nd
20 3 0 4 0
Hinh 2. Suphy thudc ciia tdc dp chan ddng vdo sdmiic nd theo khdi lupng khdc nhau ciia tCing miit. 1, 2, 3 tuong Ung khdi
lupng thudc nd Qgld 8000kg, 6000kg vd 4000kg
nghiem, cac nha khoa hpc da cbtfng minh rang viec giam khdi Itfpng thudc nd trong Id min bang bien phap nd min Itfu cpt khong khf trong va day cpt Id khoan (dem khong khi) da cho ket qua kha kha quan ve chat Itfpng nd cung nhtf hieu qua trong viec giam chan dpng nd so vdi viec nap thudc nd cpt thudc lien tue (hinh 3).
Cu the vdi viec stf dung dem khong khi hay phtfdng phap POD (power desk - phtfdng phap Itfu dem khong khi dtfdi day Id khoan) ddi vdi Id khoan c6 dtfdng kinh D = 220 - 250 mm, dat da c6 f = 10 - 12 cho tha'y dtfdng ki'nh cd hat trung binh giam 25 - 30%. Do thudc nd khong tap trung tac dpng trtfc tiep tai khu vtfc khoan them nen nen tang khong bj pha hu9, dp bang ph^ng tdt hdn, tao dieu kien lam viec va tang nang suat cho may xiic, dac biet giam tac dpng dja Chan ttf 15 - 20%. Trong trtfdng hdp dieu kien ttf nhien thuan ldi, neu stf dung bien phap nap min POD ket hdp phan doan tren Id khoan thi c6 the giam tac dpng chan dpng den 30%. Phtfdng phap nd min de cpt khong khi khi thtfc hien cd nhtfng han chd nhtf khd khan trong viec tao khoang trdng cung nhtf tfnh toan chi'nh xac chieu cao cpt khong khf.
KHCNM s o 1+2/2010* CNKT L 6 THIEN
a, b,
-—P
\ Hinh 3. So dd cau true cpt Id
khoan sCrdyng phuong phap nap luu cdt khdng khi
a, Luu cot khdng khi trong lo khoan; b, LUu cot khdng
khi dudi day id ( POD) 1- Thudc nd; 2- Cot khdng khi; 3 - Bua
Bang 1. Tdc dp chan ddng cho phdp ddi vdi cdc nhdm dat da khac nhau
Loai dat da
Oait nuft ne manh, set chua khd rong Da ctfng ntft ne manh
Dat 6a tuong doi dong nhat nhieu khe nOtvaktidrSng Da dong nhat it nijft ne
Da rat ran It khe niit Dp kien co'f 1-3 3 - 5 5 - 9
9 - 1 4 14-20
Tdc dp lan truyen song doc 10^ m/giay
2-3 3-4 4 - 5
5 - 6 6 - 7
Tdc dp djch chuyen cho phep theo nhom da't da,
cm/giay I
6,8 9,5 12,2
14,9 17,8
13,6 19,0 24,4
29,8 35,6
20,3 28,4 36,7
44,6 53,3
IV 34,0 47,5 60,0
74,5 89,0 3.4. Xac djnh qui mo
vu nd hdp ly
Viec xac djnh qui mo vu nd CO y nghTa het stfc quan trpng trong san xua't eiia md Ip thien. Khdi Itfdng mpt lan nd, sd vu nd trong nam anh htfdng den chi phf chung cCia san xua't. Ddi vdi khai thac hdn hdp thi qui mo hdp li vu nd e6n dam bao
an toan cho cong trinh khai gn thac ham 16 phia dtfdi.
a. Xac djnh qui md vu nd dam bao an toan cho cdng trinh
Ban cha't eiia phtfdng phap nay la xac djnh kha nang chju ltfc cCia cong trinh ngam do tac dpng dja cha'n nd min gay ra ttf cong trtfdng khai thac Ip thien thdng qua tdc 66 dich chuyen Vdc cho phep:
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2000
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* * "
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5000
200 150 100 50 Khoang cdeh tC/ tdm n&, m
O 2000 6000 Kh6i Itftpng vu T\6. Kg
1«
Hinh 4. Bieu dd xdc dinh cdc thdng sd vd chdn ddng dam bao todn cho cac cdng trinh bdtri trong dat da md.
cong trinh bao ve den diem
V = K R
,cm/giay (5) Trong dd: Q - Khdi Itfdng thudc nd min Ip thien, kg/vu.
R - Khoang each do thtfc te ttf tam vu nd den dtfdng 16 khai thac, m.
K - He sd phu thupc vao dac diem da't da va cdng nghe nd min. Kinh nghiem nd min tren cac md Ip thien eiia ntfdc ngoai cho tha'y, khi stf dung phtfdng phap nd min vi sai thi he sd K CO gia tri nhd hdn rat nhieu so vdi nd min ttfc thdi, nhd do ma anh htfdng cha'n dpng giam dang ke.
n = 1,5-3 - Chi sd phu thupc vao khoang each ttf
nd. Cac gia tri tdc 66 cha'n dpng cho phep ddi vdi cac ddi ttfdng da't da khac nhau va eac cong trinh can bao ve dtfdc the hien trong bang 1.
Ttf gia trj tdc 66 djch chuyen xac djnh qui mo vu nd cho phep dam bao an toan cho cong trinh ham 16 theo cong thtfc:
e = R'ciu{i-2^hr-\]\'" Mg (Q) De xac djnh nhanh qui md vu nd theo tieu chuan an toan
KHCNM s o 1+2/2010* CNKT L O THlfiN
do anh htfdng eiia cha'n dpng, CO the stf dung bieu 66 (hinh 4) xac djnh eac thong sd ve chan dpng dam bao an toan cho eac cong trinh bd tri trong da't da md.
b. Xac djnh chieu day ngan each an toan giOa day mo 16 thien deh ham Id
Chieu day bao ve gitfa day md Ip thien den cong trinh khai thac ham 16 dtfa tren cd sd cac thong sd ve dieu kien ttf nhien eCia da't da nhtf tdc 66 song dpc, he sd bien dang, he sd Poatson v.v... thdi gian tdn tai ciia cong trinh. Muc tieu eiia phtfdng phap la trong khoang each xac djnh, tien hanh dieu ehlnh qui mo vu nd tren md Ip thien phu hdp, dam bao an toan cho cong trinh ngam.
Chieu day tru bao ve gitfa day md Ip thien den ham 16 dtfpc xac dinh theo bat diing thtfc ciia Giao stf Mocinhes:
H> 1452°
cr[(i+(i-2/.).r-ir
1 + A
-iO,57
m; (7) Trong do: Cp -Tdc 66 eiia song dpc m/giay; // - He sd Poatson, f - He sd bien dang dan hdi cho phep, phu thupc vao chtfc nang stf dung va thdi gian tdn tai ciia cong trinh ngam.
De giiip cho viec xac djnh nhanh khoang each an toan gitfa day md Ip thien den dtfdng 16 can ctf vao cac thong sd ve dieu kien ttf nhien dtfdc
0.25 0.20 200 0.30
0.35 0.40 c
poats
X
v ^ N ^
, ^ S"^
s ^
sN
^s
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ChiSu c l y tru b ) vS di ii day n 6 16 thii n, m
100.0 87.5 75.0 62.5 50.0 37.5 25.0 12.5 rronq trudnq 1 (Vdi E.< 0.0001)
i7.5 60.5 51.5 42.0 34.0 25.0 17.0 8.5 Trong tn/dng II (Vdi £.< 0.0002)
54.5 47.5 40.0 33.5 27.5 20.0 13.5 6.5 Trong trudng III (Vdi £.< 0.0003)
"
300
400 1 500 1 ' 600 'S c
i D> i
s-
1«
2000 4000 6000 8000 Khdi li/dng thuoc n6. Kg
Hinh 5. Bleu ddxdc djnh khoang each an todn tCfddy md Ip thien den dudng Id.
xac dinh dtfa vao ket qua khao sat va thiet bj hd trd c6 the stf dung bieu 66 hinh 5.
4. Ke't luan
- De giam thieu tdi da stf anh htfdng cha'n dpng eiia nd min tren md Ip thien den ham 16 khi stf dung phtfdng phap khai thac hdn hdp can thiet phai nghien etfu va ap dung cac bien phap cong nghe khoan, nd min phu hdp.
- De ap dung cac cong nghe vao thtfc te san xua't ddi hdi phai c6 nhtfng nghien etfu va danh gia mpt each chi'nh xac dieu kien ttf nhien, dac biet la dieu kien dja cha't thu^
van, dja chat cong trinh ciia cac md than trtfdc va trong qua trinh san sua't.
- De khai thac an toan, hieu qua nhtfng khoang sang theo phtfdng phap hdn hdp ham 16 - Ip thien can thiet phai nghien etfu, thtf nghiem Itfa chpn
cdng nghe thfch hdp cho ttfng khoang sang cu the./.
Tai lieu tham khao
1. Phtfdng an xudng sau cac md Ip thien viing Cam Pha. Cong ty Cd phan Ttf van Dau ttf va Cong nghiep Md - TKV. 2003
2. Mosinhes V.N Tac dung pha hu9 va cha'n ddng do nd min trong da md. Nha xuat ban "Nhedra" Moskva 1976.
3. Kutuzov.B.N. - Cong tac pha vd dat da bang nd min trong phdng thf nghiem va ngoai thtfc te. Nha xuat ban"Nhedra" Moskva 1981.
4. Drucovantfi. M.P.
Phtfdng phap dieu khien nd tren md 16 thien. Nha xuat ban
"Nhedra" Moskva 1973.
5 Rzevski V.V- Cac qui trinh khai thac md Ip thien.
Nha xuat ban "Nhedra"
Moskva 1983.
6. Repin. N.A - Cong tac nd min va xiic bdc tren cac md than Ip thien. Nha xuat ban
"Nhedra" Moskva 1978.
KHCNM s o 1+2/2010* CNKT Lp T H I £ N
