KHOA HOC VA CONG NGHE MO
UNC DUNG SANG
TRONG S 0 DO N G H I E N
ThS. N G U Y I N NGpC PHU, KS. PHAM THANH HAI
Trwdng D^l hgc Md-Dja chit
1. Gidi thi^u
Nghiln Id qud trinh giam kich thudc hgt qudng nhdm giai ph6ng ede khodng vdt e6 ich vd ehuln bj lieu cho ede qud trinh tuyln. Mdc du dd ed nhung bude tiln mgnh me trong thilt k l cdc mdy nghiln v l kich thudc, cong suit vd tuli thp nhung so d l nghiln vln gan nhu khdng thay d l i . Trong thyc t l tuyln qugng t h i gidi cd bin phuang dn sa d l nghiln ca ban:
•:• Mdy nghiln thanh d l nghiln thd Idm vi$c trong vdng hd vd may nghiln bi d l nghiln mjn Idm viec trong v6ng kin d giai dogn hai;
•:• Nghiln ca hai giai dogn bdng may nghiln bi lam viec trong vdng kin;
•:• Nghiln mpt giai dogn bdng mdy nghiln bi lam viec trong v6ng kin;
• May nghiln bdn tu nghien d giai dogn mpt vd mdy nghiln bi d giai dogn II Idm viec trong vdng kin.
Thuc tiln cho thly cdc may nghiln hogt dpng it hieu qua va tieu thy lugng dien rlt Idn, ude tinh 10-20 kwh/t vat lieu nghiln, do xdc suit va dgp giua vat nghiln va vdt lieu nghien khong cao. qud trinh nghiln van tilp dien vdi nhung hgt da dgt cd hgt yeu clu do vdy chung phai dugc dua ra khdi mdy nghiln cdng nhanh cdng t i t O l giam thilu cae hieu ung tieu cue cua qud trinh nghiln, cdc may phan d p dugc su dyng phi biln d l giam thilu tgo mun va ndng cao ndng suit nghiln do dd hinh thdnh cdc sa d l nghiln khdc nhau.
Trong thuc t l tuyln khodng, cdc mdy phdn d p dugc su dung rlt rpng rdi trong cdc so d l nghiln nhdm myc dich ho trg cdc mdy nghiln vd kilm soat san phlm nghiln. Tu bdng tram ndm nay khi thilt k l sg d l nghiln thi cdc mdy phdn d p nhu rupt xoln hoac xiel6n dugc coi Id lua chpn t i t ylu.
Cac logi may phdn d p eg ban bao gIm mdy phan elp thuy luc cd ung dung hgn chl, mdy phdn d p rupt xoln vdi ung dyng dang giam dan do sy cing kinh. muc dp mdi mdn cao, ndng suit ban chl, hieu qua phdn d p thlp va phi biln hgn ca Id may phdn d p xicldn. Xicldn dugc phdt triln tO
nhdng ndm 1940 vd ngay tu d l u dd thay thi toSn bd cdc mdy phdn d p ruOt xoln trong giai (Jo?n nahiln mjn vd dang dan thay t h i todn bO cac phSn cap ruOt xodn trong cdc xudng tuyln hi$n d^i, Xicldn cd ndng suit cao. khdng cd bd phdn cliuyin ddng, cd t h i phdn d p thd cung nhu mjn, de tiiich ung vdi thay d l i cua d l u vdo. Nhugc dilm Idn nhlt cua xicldn Id ddi hdi cdc bam cdt cdng su§t Idn vd t i c dO mdn Idn.
Nhin Chung cdc mdy phdn d p cd cdc uu diem noi trOi vd rd rdng nhu d u tgo don gian, nang suSt cao, chi phi d l u tu vd chi phi san xult tuong doi thlp. Mdy phdn d p cd t h i Idm vi^c vdi bCin tir kfia tho tdi rlt mjn vdi hdm lugng pha rdn cao. Tuy
nhidn cdc mdy phdn d p cd nhung nhugc dilm sau: (1) mdy phdn d p khdng chi phdn chia theo ca hgt md cdn theo ti trgng. Do vdy cdc hgt khoang ndng ban cd xu t h i di vao san pham eat va quay Igi may nghiln dan tdi qud nghiln. He qua la dan tdi mIt mdt lugng Idn cdc khodng vgt cd ich dual dgng mijn vd gdy khd khdn cho qud trinh khi) nude. (2) biJn trdn cua may phdn d p thudng co do lodng cao. gdy khd khdn cho cdc qua trinh tuyln tilp theo. (3) Hi$u suit phdn d p thlp nen cln tai trpng tuIn hodn cao d l giam thdi gian luu cue san phlm trong mdy nghiln. DCi da c6 gdng hoan thien cdng ngh$ thi cdc xicldn phdn d p cung khong cho hidu suit vugt qud 60 % trong khi Igi tgo tai trong tuIn hodn l§n tdi 200-^300 %. nhilu khi tdi 500 % H$ qua Id t h i tich mdy nghiln Idn. lugng vat liew phdn d p tdng I6n rd r^t. tdng lugng dien tieu thu.
Nhung nhugc dilm tren cd t h i khdc phuc dum nlu nhu si> dyng sdng trong cdc so d l nghiin Tr§n thyc t l thi sdng dd dugc ung dyng trong sc do nghien tu khd Idu vi dy: sdng cung trong so di nghien qudng chua cdc khoang vdt nang. sant phdng 6k Igc cgn, sgn va sgi thyc vat lan tron|
qudng. Cho tdi nay khdng cd nhilu nghien cCfudf cdp tdi kha ndng ung dung sang trong sa di nghiln d l thay t h i cdc mdy phdn d p . Tuy ring u'l dilm cua sdng so vdi mdy phdn d p da dugc di
C O N G NGHIEP MO SO 2 - 2 0 1 2
KHOAHOCVACONGNGH£M6 3P tu lau nhung cung ehi g i n day ngudi ta mdi
I cap d i n kha ndng thay t h i may phdn d p bdng ang trong cae sa d l nghiln vdng kin.
Viec thay t h i cdc may phdn d p bdng mdy sdng ong sa d l nghien x u l t phdt t u nhung ludn d i l m hinh sau: (1) Qud trinh sdng phdn chia vdt Ii0u chl leo ed hgt va khdng phy thuOe vdo khIi lugng eng eua cac hgt qugng. (2) Higu s u i t sdng c6 t h i at gia tri r l t cao, vi dy 80-^90 %. (3) Cdng ngh$
h i tgo sang vd mat ludi sdng thay d l i nhanh hong cho phep co t h i ed nhung thilt k l t l i uu vd hu hgp. (4) Nhung nhugc d i l m ca ban cua mdy ban e l p chinh la cac d i l u kien tien quylt d l dua ang vao su dyng nhdm myc dich cai thi^n hi^u ua sa d l nghiln vd c h i t lugng qud trinh giai hong. (5) Qua trinh nghiln ed chi phi cao vd anh udng Idn tdi cac qud trinh sau do vgy mpi ca hpi idng cao hieu qua cua qud trinh nghiln c l n phai luge xem xet ky ludng. (6) V i n d l Idn n h l t eua
|ua trinh nghiln Id qud nghiln vd he qua Id m I t nat khi tuyln, chi phi t h u l c t u y l n tdng cao vd s y
;h6 khan trong qud trinh khu nude biJn qudng mjn.
2. Mot nghien c u u v l kha nang u n g dung lang trong so* dd n g h i l n
Nam 1925. E. W. Davis da lam cdc thi nghidm
;o sanh kha ndng s u dung sdng va phdn d p rupt :odn trong sa do nghiln vdng kin va da cd k i t luan ang so vdi s u dyng phdn d p rupt xodn Idm mdy )han elp, sang c h i n ddng cho phep dgt nang s u i t ighiln cao han va giam rd ret hien tugng qua ighiln. Tuy nhien quan niem p h i b i l n khi dd Id
>ang chin dpng khong cd hieu qua kinh t l so vdi nay phdn elp.
Nam 1945, E. Reed Albert nghien cuu vd cho I n g ehi phi nghiln ed t h i giam n l u su dyng sdng am thilt bj phan d p [3]. Tuy nhien s y phdt triln nanh me eua xicldn thdi gian dd lam lu md cdc ighien cuu nay.
Nam 1968 Hukki vd Allenius tiln hdnh nghien cuu la cho ring d l ndng cao ndng suit vd giam chi phi lang lugng nghiln thi chia khda la phai ndng cao tinh
;hinh xac eua qud trinh phdn d p tuc Id higu suit 3han elp [5, 6]. Dk ndng cao hieu suit nghiln vd jiam qua nghiln thi chi ed sang mdi dap ung dugc /eu c l u nay. Cae hgn c h l v l c l u tgo, gid thdnh che ao va ehi phi van hanh sang khi dd da khdng cho )hep sang dugc coi Id thilt bj phdn e l p kinh t l . Khi Jo chl ed sang chin dpng ed t i n s l t h l p do vdy sang :hua chung to dugc uu t h i eua minh.
Tuy vdy sang cung ed nhung nhugc d i l m ca )an khi phan chia vgt lieu mjn la ndng s u i t rieng hip, ehi phi san x u l t cao, dge biet la chi phi ludi
;ang, t i e ludi sang la hien tugng thudng xuyen,
ddc biet nghiem trpng vdi ede logi sdng tinh va sdng cd t i n s l c h i n dpng t h l p . Su phat triln mgnh me cua KHCN, trong dd phai k l tdi cac t i l n bp ddng k l trong c h l tgo thilt bj cdng nghiep da cho phdp khdc phyc cdc nhugc diem tren khd de dang bdng vi0e su dyng cdc logi sdng c6 tan s l cao.
3. Mgt s d logi sdng cd kha nang SCP dung trong so> dd n g h i l n
Sdng Hukki Id mOt logi sdng lai tgp giua sang vd mdy phdn d p . cho phdp cd hi^u s u i t phdn d p cao han [10]. Sdng c h i n dOng dien tu vd sdng cOng hudng didn t u cd t i n s l t u 2500^3600 v/ph cd t h i tde dyng trye t i l p len mat ludi. Nhd c h i n dOng cao t i n giam t h i l u hi^n tugng bjt mdt ludi va lam tdng hi^u s u i t sdng. Sdng cpng hudng dien t u cd c l u tgo dan gian, khdng cdn ddng ca dien, true quay vd dai truyen, cho phep de d i l u chinh bien dp dao dOng cua sang. T i n s l dao dpng cao cho phep sdng dugc cdc vdt ligu r l t mjn, it t i e sang. Day la logi sdng ed nhilu t i l m nang nhung kh6 khan Idn nhlt Id tinh khong tieu ehuln eua ede ca d u c h i n ddng dign t u cung nhu d n phai ed cac 16 xo dac biet cd t u l i thp cao.
Easy acoo^e t>«twe*-i d9cks
Untterjfc^Q COleCt«on p-^no unckv f>aoh Cd 6 » c « « ^ (>»ckrft
UrKlorstza O^s>mzo
H.I. Sang Hukki.
H.2. Sing cdng hudng dien tw
Sang Pansep cd nguyen tde hogt ddng gilng nhu bdng tai d u tgo t d nhCfng tam ludi kich thudc lo tu 45H-600 pm. Sdng cd ndng suit cao do cd t h i phdn
CONGNGHIIPMOS02-2012
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elp ea cac ludi d tren vd ludi dudi sdng. Sdng ndy CO thi dugc su dyng d l tdeh cdc hgt th6 trong bun tran eua may phdn cdp trong so d l nghiln vd thu hIi than CO dp tro thlp tu xicl6n khu mun [11].
Sang Derrick elp lidu da dilm la sdng chin dong quy dao thing e6 cao tin tu 1800 v/ph nhu sang L48-96MS-3 va tdi 3600-vph nhu sdng K48- 96MS-3. Dge dilm rieng bidt eua logi sdng ndy Id he thing d p lipu da dilm cho phdp ndng cao hi^u suit tach cae elp bun min vd nude. Nhd d u tgo dac biet ma sang c6 cac uu dilm nli trdi rihu kit d u ehde chin vd dp bin cao, giam thilu tie ludi, hieu suit sang cao tdi 90 % hode ban, mdi mdn mat ludi thlp do su dyng ludi polyurethane, ehi phi dipn thap, d l dang bao dudng, sua chua vd hieu qua kinh t l khd I n tugng.
t l i da cOa sdng. TCiy theo ydu d u ndng suit mS ci t h i su dyng td 24-5 ludi sdng. Ludi s^nj polyurethane cd tuli thg cao tu 4 thdng tdi Inam ludi cd kich thudc l6 ludi 6,3 mm tdi 75 pm, va he s l di$n tich hdu ich tu 3U45 %. Ludi eo^thldu'ac ghdp tu hai phln vd giua chung ed thi trang b\
thIm hd thing khuly dao bun bdng tia nude m nhdm tdeh hi$u qua hgt mjn ra khdi hgt qud cd
H.3. Sa dd nguyen tic sing Pansep.
Sang Derrick Stack Sizer™ Id sang chin dpng cao tin dugc su dung khd nhilu gin ddy trong cdc xudng tuyln khodng tren t h i gidi, khoang 200 sang [2]. Day e6 t h i coi Id xu t h i chip nhgn su dung sang chin dpng cao t i n trong tuyln khodng n6i Chung va trong sa do nghiln ndi rieng.
Sang c6 5 ludi vdi dilm elp li^u rpng 1,2 m vd ed ludi sang 1,5 m vd trong hlu hit cdc trudng hgp cac ludi sang dugc trang bj gilng nhau dd dam bao ed hgt eua san phlm dudi ludi. Tuy nhien cung co t h i su dyng l5 ludi sdng khdc nhau nlu cln phdn chia ra nhilu d p hgt Mli sdng dugc trang bj hai mdtg chin dpng eg didn cao tin tao cae chin dpng deu nhau vdi bidn dO nhd dli vdi toan bp cac ludi sang. Moi mdta cdng suit 2 kW, hoan toan kin vd khdng cd bp phgn chuyin dpng hoac b6i tron ben ngodi. Chin dpng quy dgo thing dugc tgo ra do hai mdtg gilng nhau quay ngugc chilu cho phep ndng cao ndng suit vd hi$u suit eua sang. Chin ddng quy dgo thing nhanh chong va hieu qua dua vdt ligu tren cd ra khoi ludi sang va do vay Idm tdng dien tich ludi cho d p lieu mdi. Chl dp chin dpng dugc tinh todn vd chi djnh trong tung trudng hgp cy t h i nhdm dgt hi$u qua
CONG NGHIEP MO SO 2 - 2 0 1 2
H.4. Sing Demck Stack Sizer
Tic dd d p lidu dugc coi Id mpt trong cac ylu Ic quan trpng nhlt doi vdi sang vdt li^u mjn. Cap liei qud muc se din din hi^u suit thap vd qua nghi^li dilu tit ylu. Do vdy t i c dp d p lidu phai tli uu va hi?!
nay dugc khuyin nghj xdc dinh bdng nghien m thyc nghigm trong dieu kign cdng nghigp. Day cungli nhugc dilm hidn tgi cua cac sdng sieu mjn do chifi cd du ca sd du lidu nghidn cuu thyc tl.^ Cac ha qudng mjn di qua ludi nhd nude vgn chuyin do va mdt dd bun trong d p lidu ddng vai trd quan Irons Thyc nghidm cho thly bun qudng cd hdm lugng phi rdn tu 15^20 % theo t h i tich Id thich hgp nhlt Hie suit tdeh cdc hgt mjn khdng phy thupe nhilu vao trpng cua cdc hgt qudng vd ddy Id ddc dilm vu'^tfi cua sdng so vdi mdy phdn d p . Ddi khi cung co tti su dyng bun loang hgn vdi ham lugng pha rln 10^1
% theo t h i tich d l ndng cao higu suit sang.
Nhdng thay doi eg ban khi thay t h i xiclon ban sdng trong sg d l vdng kin Id: tdng nan|siii nghien, giam tai trgng tudn hoan nen c6 thi tan d p li$u d l u vdo vd ndng suit nghiln noi chun!
giam chi phi vdt nghiln. giam chi phi nang W nghiln tren t i n san phlm nghiln. giam s y f nghiln cdc khodng vgt cd ich. giai phing khoir vdt cd Ich t i t hgn. giam chi phi thudc tuylnl g'^
KHOA HOC VA
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3U thu dien do e6 t h i elp li^u ty chay vdo sdng la kh6ng cln cac may bam elp lieu dp lye cao, ing thu hoi khoang vat co ich, de khu nude san him tinh va du6i thai, giam chi phi san xult chung 0 cae e6ng dogn tilp theo d l dang ban, ndng udt cap han, kilm soat t i t ban cd hgt Idn trong an phlm nghiln culi cung do cdc hgt nay ed xu l l bi mIt vao du6i thai (hgt cd d > 0,2 mm) vd iam 6 nhiem moi trudng [3, 4].
4. Mot sd k i t qua ung dung thuc t l cua sang 'ong SO" dd nghiln
Tai mo quang dong Cia Minera Condestable, lam My [7] khi thay t h i xicldn bdng sdng cao tin )errick Stack Sizer cho phep tdng ndng suit
uang dlu 34 % tu 171 t/h Idn 222 t/h, giam tai ong tuIn hodn tu 204 % xudng cdn 96 % vd tdng leu suit phan elp tu 63 % len 85 %. San phlm ghiln ed kich thudc ddng d l u ban so vdi khi ighiln kin vdi xicldn. Sdng Stack Sizer hogt dpng flu dan, khdng gap trye trgc. Kilm sodt hdm j-gng pha rdn trong d p lieu vdo sdng dugc coi Id long s l quan trpng nhlt. Theo bdo cdo thi thdi lan khIu hao vln eh? la 1,4 thdng.
Kit qua tai xudng tuyln chi kem El Broeal, Peru ho thly e6 thi tdng ddng k l nang suit, tdng thu ill kim logi va giam tieu hao nang lugng nghiln vd lieu qua phan d p t i t ban. Trude dd. xudng tuyln :l Broeal su dyng 4 mdy nghiln thanh, 4 mdy ighiln bi lam viec trong vdng kin vdi tai trpng tuIn loan cao tdi 400 %. Khodng vdt cd ich ndng ban fa tgp nen cd xu t h i di vdo cdt 6k quay Igi may ighiln do vdy hdm lugng chi trong cdt tdng tdi 15 'o trong khi eua quang d l u chl khoang 2,4 %. Tgo nun qua muc vd mIt mat khoang san trong qud rinh tuyln ndi la vln d l ndi com. Sang dugc coi Id
|iai phap lya chpn tdi uu 6k thay t h i xicldn. Sau hi thay t h i xicldn blng hai sdng chin ddng cao In 5 ludi vdi kich thudc lo ludi 230 pm, El Broeal ang nang suit xudng tdng 10 %, thyc thu ehi tdng 1 % va tai trpng tudn hoan chua it ban 2 % ehi tuc 3 thlp han so vdi qugng d l u . Do tai trpng tuIn loan thlp, chl la 97 % nen khdng cln van hdnh 2 nay nghiln nlu ndng suit qudng dlu khdng dli.
/hi phi thulc tuyln giam rd ret vd vln dlu tu dy in khIu hao hit trong vdng 3 tuln.
Tilp dd. El Broeal quylt djnh tdng cdng suit luang dlu tu 138 t/h len 245 t/h vd Idp dgt them 3 ang, ting cdng Id 5 sdng. Nang suit theo qudng l u tang 75 % nhung ting ehi phi dien cua xudng l i p han so vdi khi dung xicldn phdn d p . Tai trgng j l n hoan dugc giu d muc 60 % va hdm lugng lun trong d p lieu vdo may tuyln ndi giam tu 18 % uong cdn 10 % do vdy lam tang ddng k l thyc thu
kim logi. Khi dd hai mdy nghien bi giai dogn hai dugc dua vdo su dyng 6k ddp ung nang suit nghiln yeu clu. Do so lugng mdy nghiln thanh khdng thay d l i ndn t i c dO quay eua mdy nghiln thanh dugc tdng Idn d l tdng ndng suit nghiln.
Kit qua dp dyng sdng cao tin trong sa d l nghiln tgi OJSC KMAruda, Lidn bang Nga, cung cho mdt s l kit qua kha quan [8]. 0 xudng nay sa d l nghiln 2 giai dogn gIm hai mdy nghiln bi lam vi0e song song trong sa d l v6ng kin vdi may phan d p ruOt xodn vd hai mdy nghiln bi giai dogn II lam vide trong vdng kin vdi xiclon dugc thilt k l tu dlu.
Sau dd hai sdng cao tan lo ludi 0,1mm dugc lip ddt d l thay t h i xicldn phdn d p trong day chuyin I cua xudng.
Tgi xudng tuyln eua Minera Cerro Lindo, Peru, tuyln qudng ding chi kem, theo thilt k l sa do nghiln gom mdy nghiln bi lam vi?c trong v6ng kin vdi xicldn dudng kinh 650 mm vd tai trpng tuln hodn 260 % dugc su dyng. Sau d6 4 sang chin dpng cao t i n l6 ludi 0,23 vd 0.18 mm lip dgt thay thi ede xicldn do vdy tai trpng tuln hoan giam xulng c6n 108 %, ndng suit tang 14 % va kich thudc danh djnh trong san phlm nghiln tang tu d80=141 pm len thdnh d80=160 pm.
5. K i t luan
• Nghiln Id qud trinh tieu thu dien nang Idn nhlt trong xudng tuyln nen Id chia kh6a 6k tuyln hieu qua. So d l nghiln vd thilt bj su dung cln dugc quan tdm nhilu ban.
• Quan niem truyin thing eua cae nhd san xult vd cdc nha thilt k l v l viec su dung thilt bj phdn d p ddc bidt Id xicldn trong sa d l nghiln vdng kin cln phai nhin nhan Igi.
• Nhugc dilm eg ban eua mdy phdn d p Id phdn d p ca theo ti trpng dan tdi hidn tugng qua nghiln, ddc bidt Id ede khoang vdt ndng. Tai trpng tuln hodn cao, 200-5-300 %, Idm tang dang k l t h i tich may nghiln, tang chi phi su dyng dien trong khdu nghiln.
• Thyc t l su dyng sdng chin dpng cao tin trong so do nghiln vdng kin cho thly e6 nhilu uu dilm nhu tdng higu suit phdn elp, giam qud nghiln, giam tai trpng tuln hodn, giam tieu thu dien, tdng nang suit khdu nghiln, tgo dilu kien thuan Igi cho cdc khdu sau vd hieu qua chung Id giam ehi phi san x u l t
• Dp mjn nghiln tdi uu cd t h i se thay dli nlu su dyng sdng thay t h i mdy phdn d p trong sa dd nghiln. Cd t h i giai phdng khodng vgt cd ich tdt ban trong khi khdng d n phai nghiln qud mjn hoac cd t h i nghien mjn ban md khdng sg tgo mun qud muc dan tdi thu hIi khodng vgt cd Ich cao hon.
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KHOA HOC VACONG NGHE MO•:• c l n dlu tu nghien cuu kha ndng thay thi may phan d p trong sa d l nghiln vdng kin bdng cac sang, dge bidt Id sdng chin ddng cao tin. cho cae dli tugng qudng chua cdc khodng vdt n$ng nhu qugng dong Sin QuyIn, qudng chi-kem Chg Diln, dli vdi qudng d l mun hda nhu qudng apatit Lao Cai....n
TAI LIEU THAM K H A O
1. Barkhuysen N. J. Implementing strategies to improve mill capacity and efficiency through classification by particle size only, with case studies. The South African Institute of Mining and Metallurgy Base Metals Conference 2009, plOI-114.
2. Benjamin H. Clark. The Derrick Stack Sizer™: Revolutionary Advancements in Wet Screening Technology, Proceedings of the 39th Annual Canadian Mineral Processors Conference 2007, p413-418.
3. E. Reed Albert. Characteristics of Screen- circuit Products, T.P.1820, Min.Tech., 5/1945.
4. Hukki, R. T & Allenius, H. A Quantitative Investigation of Closed Grinding Circuit, Society of Mining Engineers, AIME -Transactions Vol 241 12/1968.
5. Hukki, R. T & Eland H. The Relationship Between Sharpness of Classification and Circulating Load in Closed Grinding Circuits, Society of Mining Engineers, Transactions, 9/1965.
6. Hukki, R. T An Analysis of Mill and Classifier Performance in a Closed Grinding Circuit Society of Mining Engineers, Transactions 1967.
7 Valine S.B. and... Application of high frequency screens in closing grinding circuits.
Derrick Corporation. USA vd Goldex S A Peru, 2008.
8. Pelevin, A. E. and Lazebnaya M. V Application of Derrick Screens in Locked Grinding Circuit at the KMAruda Mining Complex Concentrating Plant, Mineral Processing Journal 2009.
9. Rogers R.S.C., K.A. Brame, An analysis of the high-frequency screening of fine slurries, Powder Technology, Volume 42, Issue 3, June 1985, Pages 297-304.
10. Wills B. Mineral Processing Technology Elsvier, 2003
11. Wills B. and Napier-Munn T. Mineral Processing Technology - An Introduction to the Practical Aspects of Ore Treatment and Mineral Recovery, Elsvier, 2006.
Bien tap: Tran Van Trach
SUMMARY Traditional approach cf inindral i
design is to incorporatB classifiers including classifiers and^or hydrocydones in grinding i Advantages of dassiliers are high capadly, lowq OQSIs and reiadvely sbudue simpfdiy. HcMever, majpr inherent disadvanlages include lowefiide dassificalion not only by SGOB but also by density and I result oveigrinding is an oulstandhg issue, r—
researches inb inoorporaticn of screens in £ circuits had shown oertain advantages of screens I conventional dsesiliers. This paper is to look at opi^ortunity of ifiing screens, of h ^ fiequen^ sr~
in particular, giindhg draiis instead of oonve dassHiers. Advantages of soeens over classifiers include high sofid oonlen of CNBTSBIB and mde.
products, norvoontamrated undersee products oversize pamoes. nossoe oenens or cos replaoement by high (iequency screens may n d . eojnomic gains at the oimnviulion stage. <' overgrindng and the ease of downstream
including fk^ation. devMatering and fibalion operations.
VAI NET VE THANH PHAN
(Tiep theo trang 43)
nghe gia cong chuan bi quang cang can phai da duac s6 luang quang, kich thuac hat quang toi m va can nghien cuu ty le phPi tron giua hai loa quang chua phong hoa, da phong hoa nham da dugc chit lugng hoa tach la cao nhlt.D
TAI LIEU THAM KHAO
1. Trin Nghi, Nguyen Quang Hung va nnk. Dacdilrr thach hoc-tudng da va thanh ph^n vat chit quang vijnc Tabhing-Pa Lu'a, tinh Quang Nam. Lien doan Oia ch^:
10. Cue Dia chat va Khoang san.
2. Than Van Lien va nnk. Nghien cuu lua chon giai phap cdng ngh? xu ly quang urani vung Thanh My. 0^
tai OT 04/09 NLNT. Bp Khoa hpc va Cong nghe.
Ngudi bien t$p: Tran Van Trach
SUMMARY
The paper introduces the grain component and the material component of two sort's weathered and non weathered Pa Lira uranium ore. Basing on this, the authors suggest the main directions for technology treating this ore.
C O N G N G H I | P M 6 S 0 2 - 2 0 1 2