NGHIEN CUU LUA CHON THIET Bl XUC BOC - VAN TAI HOP LY Cho cac mo sat lo thien co dieu kien dja chat phuc tap
I Basing on the analyzed mining conditions at the open pit liron ore mines in Vietnam including geological,, i I hydrogeological and engineering geoteehnical conditions, .]
\ the paper suggests the suitable selection of the loading [ t and hauling equipment such as excavators, hydraulic back • L- hoe shovels and specific trucks for removing soft rock, ]
hard rock and iron ore s well. The paper also providesJ^
technical and economic analysis for each selection.
ThS. LUU VAN THJC KS. DJONG TRUNG TAM Vien Khoa hgc Cong nghe Mo-TKV
1. Dac diem khai thac cua cac md
Dae diem chung cCia cac md quang sat cau tao dang via khai thac Id thien nudc ta ed dieu kien kie'n tao cung nhu dia chat thuy van, dja chat edng trinh phufc tap. Ca'u tao dja tang cac md gdm:
- Tang phCi phia tren thudc loai tang da't ye'u: Cac md nhu Thach Khe, Trai Cau, Na Rua v.v... cd tang phCi la da't da de tCf, cat, set, cat pha set va nedgen. Dae diem chung cCia tang da't yeu d cac md la cd chieu day de'n vai chuc met, dac biet md Thach Khe cd chieu day thay ddi tCf 26+227m. Tang da't yeu d cac md cd do am cao (15-^36%), trgng lugng the tfch tCf 1,7 -^2,0 ta'n/m^ he sd xdp thay ddi tCf 0,37+1,1, gidi ban ben nen nhd, phd bien tCf
(?„= 0,06-1,32 kg/cm^, gdc ndi ma sat d trang thai ty niiien nhd, tCf 6^-32°, Iyc dinh ke't nhd, tCf 0,4+1,7 kg/cml
- Tang ehCfa quang thudc loai tang da cCfng: Tang nay gdm eac loai da nhu Gabro, da vdi, da sCfng v.v... Dac diem chung cCia cac loai nham thach tang nay cd do kien cd Idn, f = 9+11, trgng lugng the
tfch Idn, tCf d = 2,7+3,1 t a n W , do phan khd'i Idn, trong dja tang hinh thanh cae hang kastg. Quang khai thac cd do kien cd Idn, f = 11+15, do phan khd'i Idn, ft nCit ne, trgng lygng the tfch Idn, d = 3,7+4,4 tan/ml
Cac nham thach vay quanh than quang thudng cd cac hang kastg, day la ye'u td tao dieu kien cho nude ngam chay vao khai trudng Idn hgn so vdi cac md than Id thien. Theo cac tai lieu dia chat, nhieu md cd luu lugng nudc chay vao khai trudng Idn nhU: Thach Khe, Na Rua, Tung Ba v.v...
Md Thach Khe cd luu lugng nudc chay vao dy kie'n khoang 3,1 trieu m^/ngay.dem (khi dat de'n do sau -400m), md Na Rua cd lyu lugng nudc chay vao tCf 95^169.10^
m^/ngay.dem. Cac ye'u td dja chat thuy van, dja chat cdng trinh tren da anh hydng Idn den viec lya chgn ddng bd thie't bj cung nhy cdng nghe khai thac cua cac md. De nang cao hieu qua khai thac va dam bao an toan eho eac md quang sat Id thien cd dieu kien dia chat phCfc tap, can thie't phai lya chgn ddng bd thie't bj khai thac hgp ly.
2. Nghien ciru lya chon
thiet bj xuc boc - van tai hdp ly cho cac md quang sat
2.1. Lua chon thiet bj xuc bdc
Trong ddng bd thie't bj khai thac thi thie't bj xue bdc thydng dugc lya chgn dau tien va dyde coi la thie't bi ehu ye'u cCia day chuyen cdng nghe vi nd chiem den 60% gia thanh san pham. Thie't bj xue dygc lya chgn tren eg sd:
+ Qui md san xua't (san lygng quang, khd'i lugng da't bdc).
+ Dieu kien md dja chat (chieu day, san trang cua than quang va da bdc, kfch thydc va hinh dang khoang sang, dja hinh md, tfnh chat cd ly ciia da't da).
+ Cae ye'u td ky thuat cdng nghe md.
+ Gia thanh khai thac 1 tan san pham.
Dd'i vdi cac md ed dieu kien dja chat thuy van, dja chat cdng trinh phCfc tap nhu Thach Khe, Trai Cau, Na Rua v.v..., viec lya chgn thiet bj xuc bdc hgp ly' ed vai trd quan trgng de'n kha nang hoan thanh san lygng cung nhy dam bao an toan trong qua trinh san xuat.
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Thong tin khoa hoc cong nghe m o
Kinh nghiem ciia cac nha khoa hgc md deu nhan djnh rang: Thie't bi xuc bdc bang may xuc thuy Iyc dugc yu tien lya chgn cho cae md ed dieu kien thuy van, dja chat cdng trinh phCfc tap, nen da't ye'u, via mdng, ca'u true phCfe tap, khai thac chgn lgc, nhifng ngi khd khan ve ngudn dien, de ngap lut khi cd mua bao.
Ddi vdi eae tang da't ye'u, ap lye CLia may xCic len nen tang cd y nghTa quan trgng khi lya chon loai may xuc. ap lye len nen may dCfng dugc xac dinh theo bieu thCfc sau:
A^ = Qv
26,(/, +0,35/2,)'
kg/cm^ (1) Q„ = (Q,, + Q,,).Ku,
kg (2) Trong dd: b,<- Chieu rdng ciia ban xich, m; 1^- Chieu dai phan xich nam ngang, m; h^- Chieu cao eiia xfeh, m; Qi^- Trong lugng cua may xuc khi lam viec, kg; Q^^- Trgng lugng ban than cua may xuc, kg;
Qag- Trgng lugng cua dat da trong gau, kg; Kah- He sd anh hydng ciia tai trgng ddng khi xuc, Kah= 1,05H-1,1.
Vdi dung tich gau nhU nhau, thi may xuc tay gau cd trgng lugng Idn gap 2,19+2,6 lan may xuc thuy Iyc, tUdng
Cfng ap Iyc len nen cung gap 1,46+2,3 lan. May xCic thuy Iyc cd kha nang di chuyen vdi tdc do tCf 2-^4,9km/h, trong khi dd cac may xue tay gau chay dien tdc do di chuyen thap tCf 0,42-^0,55km/h. Kha nang xuc dudi mCfc may dCfng cCia may xuc thuy Iyc gau ngygc cd tfnh yu viet hgn ban so vdi may xue tay gau. Cae dae tinh ky thuat tren cua may xue thuy Iyc gau ngugc phu hgp vdi dieu kien khai thac d cac md cd tang da't ye'u vdi do ben nen nhd, day md ludn lay ldi (md Thach Khe, Na Rua, Tung Ba, Trai Cau v.v...) cung nhu cdng tac dao sau day md va khai thac quang (hinh 1 va 2).
Hinh 1. So do quy dao lam viec cua may xuc thuy lut gau ngugc
Hinh 2. May xuc thuy luc gau ngugc xuc tang dai yeu tai mo
sat Thach Khe-Ha Tfnh Lua chon dung tfch gau xuc.Thiet bj xCic bdc duge lya chgn chu ye'u theo qui md san lygng va kfch thudc hinh hgc md. Day la mdt trong nhifng dieu kien quan trgng khi xac dinh dung tfch gau xuc. Khi ap dung cdng nghe kha'u theo Idp dCfng, bd cdng tac md gdm mdt hoac mdt sd nhdm tang va tren mdt nhdm tang cd the bd tri may xuc bang mdt sd so dd eg ban khau dudi theo 1 hydng nhy sau:
a. Truang hgp 1: Trong nhdm tang, tren mdi tang deu cd may xuc lam viec:
Trydng hgp nay tren mdi tang bd tri 1 may xCic lam viec theo ludng xuc dgc tang (hinh 3a). Khi may xuc tren tang xuc he't chieu rdng dai kha'u tygng ung vdi khoang each djch chuyen ngang can thie't ciia tuyen cdng tac trong 1 nam thi sd may xue cd the bd tri tren nhdm tang thCf i ciia ddi bdc da't da la:
af
\ n
" ^ ^ • . • • • 1 ^
I'J'.Ul'J'l'L'iLi;i'J'-LL'JLi;L'J'i!L'JU!l'J'i!lJLL!l'i:.l!L'lm
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.'JliiL'JLIllJUl JH!L'JLl!i'JU
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C M ; -' p r n u i m n r niUI'JLUl'JLi Ld I'JID I'J L J lT."UT:H.'rJIU I'J! L'i'j:
TrnururrnTm
: rj'j: i J ui L'I m I'J LI! i J HI fi'.\i L'J'JJ fjiu I' i LIU'JLLII
Hinh 3. Sa dd cong nghe xuc bdc dai da tren bd eong tae
a. Mdi may xuc tren 1 tang va xuc duoi nhau vdi luong xuc dgc tang; b. Mdi nhom tang cd 2 may xuc - vd/ luong xuc doc tang; c. mdi nhom tang cd 1 may xuc
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N,.= -^-^
n .L
chiec (3)
Sd may xCic can thie't de xCic da't da tren toan bd edng tac cua md dyde tfnh nhy sau:
^x = Z ^ - ' chiec (4)
1=1
Trong dd: Lu, L^i - Tydng ufng la chieu dai trung binh tuye'n cdng tac va chieu dai bloc xuc ciia nhdm tang thCf i, m; m- Sd nhdm tang tren bd cdng tac, n,- Sd tang cdng tac tren nhdm tang.
Sd may xuc tinh theo (4) phai Idn hdn hoac bang sd may xuc can thie't de hoan thanh ke hoach bdc da cua md iV' •
N>N'^ ^ - ^ - ^ • " - • ^ - • ^ - , c h i e c (5)
a a
Qn= ^ T - T ; ,m/nam (6) Trong dd: A - San lygng quang nguyen khai cua md, tan/nam; Vj- Tdc do xud'ng sau, m/n; M- Chieu day trung binh than quang, m; Lq- Chieu dai trung binh than quang, m; K^^ - He sd bdc san xua't, m^/t;
Qn- Nang sua't nam cCia may xuc, m%am; E- Dung tich gau xuc, m^; K,g - He so sCf dung thdi gian ca cCia may xuc; K^d - He sd xue day gau; Nca- So ca lam viee trong nam; Tea- thdi gian lam viec trong ca, gid; K^n- He sd anh hydng cdng nghe trong qua trinh xCic; Tck- Thdi gian chu ky xue, s.
TCr eac cdng thufc tren cho phep xac djnh dung tfch gau ciia may xue nhy sau:
£ = - m J
36Q0N^,.T^^.K^,.K,^.K^„.Y^^
-,m^(7)
Gia SLf vdi cae ye'u td khac khdng ddi, dung tfch gau xuc trong trudng hgp nay phu thudc vao chieu dai than quang, chieu dai bloc may xuc va trgng lugng rieng cua quang:
- Khi: 4, -^ min thi N^, -^ max do dd E ^ min - Khi: L^. -> max thi N^- ->• min do dd £ -> max Do vay, dung tieh gau xue hgp ly cCia md khi bd tri ke't eau bd cdng tae trong trudng hgp nay phai nam trgng gdi ban: E^i^ <E < E^^a^ Ke't qua tfnh toan
iLfa chgn dung tfch gau xuc cho mdt sd md quang sat the hien tren bang 1.
Bang 1 cho thay vdi chieu dai tuye'n edng tac nhu nhau, may xuc da't da mem ye'u cd dung tich gau nhd hgn so vdi thie't bj xCic da't da eCfng nd mln va quang. Khi lya chgn thiet bj xuc da't da va quang, trydng hgp vdi cung dung tich gau nhu nhau, de dam bao Iyc xuc Idn nha't, may xuc quang can lya chgn loai cd chieu dai tay gau ngan hon so vdi may xuc da't da.
b. Trudng hap 2: Tren moi nhdm tang bo' tri 2 may xuc lam viec (hinh 3b)
Trong trydng hgp nay, gia sCf chieu dai tuyen cdng tac tren ta't ca cac tang bang nhau va sd tang tren cac nhdm bang nhau, hay la khdi lygng md tren cac nhdm tang bang nhau, sd may xuc can thie't hoan thanh khdi lygng da bdc la: N^ = 2m.
Khi dd dung tfch gau td'i thieu can thie't ciia may xuc sii" dung la: '"'''
E^ Vs-L^r^rYr^sx-Tck-Kr
,rvr (8) c. Trudng hgp 3: Tren mdi nhdm tang bo tri 1 may xuc lam viec (hinh 3c)
Trong trudng hgp nay, dung tfch gau td'i thieu can thie't cCia may xuc cd gia trj Idn nhat va dygc xac dinh theo cdng thCfc:
.m"
(9) Nhu vay, cd the cd 3 trydng hgp eg ban tfnh toan lya chgn dung tfch gau cCia may xuc de xCic bdc dat da tuong Cfng vdi 3 sg dd cdng nghe chinh nhy tren. Trong 3 trudng hgp tren thi viec bd tri thie't bj theo trydng hgp 1 la phufc tap nha't, nang sua't thap nha't, cdn trydng hgp 3 la dgn gian nha't, nang sua't cao nhat, nhung ddi hdi may xuc cd dung tfch gau Idn nha't.KHCNM S6 8/2010* CNKT L 6 T H I £ N
Thong tin khoa hoc cong nghe m o
Bang 1. Dung tfch gau xue hop ly phu hop vdi chieu dai bide xue va K.,
Lxi (m)
200 250 300 350 400
Mo Thach Khe Cac mo Quang sat khae K., (m'/T)
2,0 4 5 6 7
Dung tich qau xuc (m^) Da't
da mem
ye'u 3,7 4,6 5,5 6,4 7,3
Oat da cifng
va quSng 5,4 6,7 8,0 9,4 10,8
Da't da cifng va quSng
3,5 4,4 5,2 6,2 7,1
4,4 5,5 6,6 7,7 8,9
5,3 6,6 8,0 9,3 10,5
6,2 7,7 9,3 10,8 12,5
Bang 2. Tai trgng xe haply ddi vdi loai dat da ye'u
Dung tich gau
may xuc (m=) Dung
tich thung xe (m^)
Tai trong 6 to'(tan)
2
6,9
15 2,5
8,6
15- 18
3,0
10,3
18- 20
3,5
12
20- 25
4,0
13,7
25- 27
4,5
15,4
28- 32
5,2
17,8
37 6,7
23
40- 45
Bang 3. Tai trgng xe hop ly ddi vdi loai dai da cung va quang
Dung tich gau may xuc (m^) Tai trong 6 to chd da't da (tan) Tai trong 6 to chd quang
(tan)
3,5
28
35 4
3 2 4 0
4, 5 3 6 4 5
5,2
40
50 6,7
53
66 8
6 3 8 0
10
80
100 12
95
120
2.2. Lya chon thiet bj van tai
Can cCf vao dieu kien dja hinh, tfnh chat eg ly da't da va quy md khai thac cCia cac md quang sat Id thien nude ta, tha'y rang: Thiet bj van tai help ly dd'i vdi cac md la d td. Uu diem cua dtd phu hdp vdi eae md cd cau tao than quang phCfe tap, kfch thudc khai trudng chat hep, khai thae chgn, dja hinh phCfc tap.
Viec lya chgn tai trgng d td dUdc xac djnh theo cac ye'u td nhu: Dung tieh gau xue, cung do van tai, trgng lUdng rieng cua loai vat lieu chuyen chd va sd gau xCic day thung xe.
a. Lua chgn tai trgng d td theo cung do van tai va dung tich gau xuc
Quan he giua dung tfch thung dtd (Vo) va dung tfch gau xCic cua may xCic (E) phu thudc vao khoang each van tai xac djnh theo bleu thCfc sau:
^0
-- (4,5E + a)\lL (10)
tan
Trong dd: E- Dung tfch gau xuc, m^; a- He sd phu thuoc vao dung tfch gau cua may xue (a = 3 khi E > 4m^ a = 2 khi E <4 m^); L- Khoang each van tai, km.
Phugng an nay cho phep xac dinh nhanh tai trgng d td khi bie't cung do van tai va dung tfch gau xCic. Tuy nhien, nhUdc diem cd ban cua phUdng phap nay chUa tfnh den ye'u td trgng lugng rieng cua da't da hay khoang san van ehuyen.
b. Lua chgn tai trgng 6 td hgp ly theo trgng lugng rieng cCia vat lieu chuyen chd va trgng lugng rieng bieu kie'n cua 6 td.
De khae phuc nhuge diem cua phygng phap tren, dya tren eg sd sd gau xuc day hgp ly ddi vdi rnoi d td tCf 4-^6, tuy thuoc vao loai dat da va quang se lya chgn dugc tai trgng d td hgp ly.
- Boi vdi cac tang dat yeu (cat, set, cat pha, dat phu de tCf v.v...) cd trgng lugng rieng ciia vat lieu /<— { — - ggi !a trgng lugng rieng bieu kie'n cua d td) thi sd gau xuc day d to:
xe: K
n„.E.K..gau, hay dung tfch thung
K, m (11)
- Doi vdi dat da tang chUa quang (no min) va quang sat cd trgng lugng rieng cCia vat lieu thi:
So gau xCic day o to n
KHCNM SO 8/2010* CNKT L O THifeN
gau, hay tai trong d td q^= ———^ , tan (12) Dd'i vdi tang da't ye'u, can cCf vao bieu thCfc (11), khi ng = 4, he sd xue day gau K^a = 0,9, he sd len chat thung d td K, = 1,05, dung tich thung xe va tai trgng d td dd'i vdi Igai da't da ye'u dygc xac djnh thee
bang 2.
Dd'i vdi tang da ehCfa quang (nd min) va quang sat can cCf vao bieu thCfc (12), khi ng = 5, he sd xCic day gau vdi da't da K,a = 0,85 vdi quang K^a = 0,75, trgng lugng rieng da't da = 2,7 ilm' va quang = 4,1 t/m^ he sd nd rdi da't da K^ = 1,45 va quang K^ = 1,55, tai trgng d td dd'i vdi loai da't da cCfng va quang xac dinh theo bang 3.
Qua bang 2 va 3 cho tha'y khi van chuyen da't da mem ye'u, tai trgng d td can chgn nhd hgn so vdi da't da cCfng phai khoan nd mln. Dieu nay hoan toan phu hgp vdi cac md cd dieu kien dja chat thuy van va dia chat edng trinh phCfc tap. Khi tang da't da ye'u do dd ben nen nhd, ne'u chgn d td cd tai trgng va ap Iyc len nen Idn se nhanh chdng pha buy dudng van tai, dtd bj sa lay, lam giam nang suat cCia td hgp thie't bj xuc bde-van tai.
Do quang sat ed trgng lugng rieng va he sd nd rdi ldn hgn so vdi da't da cCfng phai khoan nd min, vdi eung dieu kien van tai khdi lugng quang va da cung nhu nhau thi d td van tai quang cd tai trgng Idn hdn so vdi van tai da't da cCfng. Tuy nhien, san lugng quang hang nam thudng nhd hgn da't da, nen viec lya chgn tai trgng d td cdn phu thude khd'i lugng van tai hang nam cua eac md.
- Dd'i vdi cae md ed dieu kien dja chat cdng trinh phCfc tap, khd'i lugng van tai hang nam gdm: Da't da mem yeu, da't da cCfng nd min va quang. Can cu'vao san lugng cua tCfng loai se lya chgn sd td hdp thie't bj xuc bde-van tai hgp ly. Sd may xuc va d td can thiet de hoan thanh san lygng md dygc xac dinh nhusau:
Sd td hgp hoan thanh san lygng:
^..> =
Q '
To hap(13)
Sd dtd phuc vu cho 1 may xuc la:
r.,
(14)
"o/ = ~-. chiec
«7
Tdng sd dtd can thie't hoan thanh san lugng: NQJ = N,hj.noj, chie'e (15)
(j = 1, 2, 3 tygng Cfng vdi da't da mem ye'u, da cufng nd mln, quang).
3. Ket luan:
Lya chgn ddng bd thie't bj xue bdc, van tai la khau quan trgng dd'i vdi cac md Id thien ndi chung va cae md quang sat cd dieu kien dia chat thuy van, dja chat edng trinh phCfc tap ndi rieng. De nang cao hieu qua khai thac dd'i vdi cac md quang sat cd dieu kien dia chat phCfc tap, can phai lya chgn ddng bd thie't bj phu hgp vdi dac tfnh eg ly cua tCfng loai da't da mem ye'u, da cufng nd min va quang.
Nhung ke't qua tinh toan tren day ed the la tai lieu tham khao cho cac md khi lUa chgn ddng bd thie't bj khai thac./.
Tai lieu tham khao:
1. Bao cao dja chat ke't qua tham dd ty' my md sat Thach Khe - Nghe TTnh, Lien doan Dja chat 4 - Ooan 402, nam 1985.
2. Bao cao tham dd md sat Tung Ba - xa Tung Ba - huyen Vi Xuyen - tinh Ha Giang. Lien doan Intergeo - 2008.
3. Dy an dau tu md khai thac va tuyen quang sat md Thach Khe Ha TTnh. Vien Gipromda - 2007.
4. Dy an dau ty khai thac Id thien md sat Na Rua - Cdng ty Co phan Gang thep Cao Bang. Vien Khoa hgc Cdng nghe Md- TKV, Ha Ndi-2009.
5. Hd ST Giao va nnk "Khai thac khoang san ran bang phygng phap Id thien". Ha Nd i - 2009.
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