fp GIAI PHAP 8t CONG NGHE XANH
De xuat giai phap nham giam phat thai khi nha kmh trong qua trinh san xuat gang thep d Viet Nam
TS. NGHIEM GIA; KS. VU TRl/CfNG X U A N long Cong ty thep Viet Nam
KHAI QUAT VE PHAT THAI KHi N H A KINH TRONG S A N XUAT GANG THfiP
Cie nghien cflu ve khoa hpc khi hau vi he thong quan trie khi hau toan eau (GCOS) da chi ra ring, boat ddng eua eac nganh cdng nghiep va hoat ddng cua con ngUdi da phit thii ra nhilu loai khi thii nhi kinh (CO^, CH^, N,0, PFCs, SF ). Trong do, san xuat gang thep da sfl dung ngudn tai nguyen thien nhien (quing sit, than, da vdi, khi thien nhien...) vi sfl dung nhilt nang, diln nang tfl vice ddt chay nhien lieu hoi thach (than, dau, khi thien nhien) da tao nen ngudn phit thai khi nha kinh (KNK) kha ldn.
Nhflng nam gan diy, nginh thep Viet Nam va eic nganh edng nghiep da thflc hiln thi diem eac
"ChflOng trinh kiem toin nang Iflpng va sfl dung nang Ifldng hieu qua" d mdt sd cd sd sin xuat gang thep (Cdng ty CP gang thep Thii Nguyln (TISCO), thep Da Nang...).
Muc tilu chung li "sin xuat bin vflng, glim thilu phat thai KNK ddi mdi thilt bi cong nghi, cai thien sin xuat de nang cao hieu qua eua tflng nha may san xuat tht-p d Vict Nam".
SV P H A T THAI KHi T A C N H A N G A Y O NHIEM TRONG SAN XUAT GANG THEP
San xuat gang thep qua cac cdng doan nung say, thieu kit, nau chiy nguyln lieu dc tao ra gang, due phdi tfl gang vi can den tao ra 3 dang
chat thai (nUdc thai; khi vi bui thii;
chat thii rin) vdi mflc dd d nhiim khic nhau.
Cic qua trinh hda ly xiy ra trong Id luyen hit sfle da dang va phflc tap. Kit qua khdng ehi tao ra sin pham gang nhfl mong mudn ma edn phit ra khi thii, trong dd CO, li nhilu nhat. Qua trinh nau luyen da xuat hien chuyen ddi pha (ran -^
bien men -> chiy -> ddng die -> nung -^ gia cdng ip lUc -> lim ngudi ..) vi dflpc die trflng bing 4 qui trinh sau diy:
Ddt chay nhien lieu d l nung, nau chay nguyen lieu trong 16 gom:
Chiy cicbon (C); Chay dxit cicbon (CO); Chiy hydrd (H,); Chiy khi metan (CH^) vi cac caebua hydrd khac:
Hodn nguyen kim logi trong sdn xudt gang gom: hoan nguyen trfldc, hoan nguyen trflc tilp, hoan nguyln ndng chay tflng phan hoac toin phan quang sat.
Qud trinh dxy hoa trong luyen thep da hinh thdnh cdc pha khi, pha long gdm: dxy hda cae bon, dxy hda silic va dxy hda phdt pho. Qua trinh khfl tap chat (luu huynh, phdt pho).
Tat ei cic cdng doan eua sin xuat gang thep deu phit sinh ra Ifldng khi thii. Die bilt, edng nghe luyen gang truyen thong (gdm cie cdng doan: thilu ket, luyen cdc, luyen gang bang 16 cao) do tieu thu vi sfl dung mot Ifldng than kha ldn (than md iuycn cdc vi than antraxit phun thdi) lam nhiln lieu nin da phat ra Ifldng khi thai (CO,) ldn
nhat so vdi cic edng doan luyen thep v i can thep.
Cie nha miy luyen gang theo cdng nghe Id cao d Nhit Bin tieu hao than cdc la 382 kg/T HMT va than phun la 135 kg/T HMT (i Vilt Nam mflc tieu hao than coc 700^800 kg/T HMT va than phun;
90+100 kg/T HMT. Vi the, hien dang tim mpi biln phap de ha dan xudng mflc: 500 + 600 (kg cdc/T HMT).
Luyen thep bang Id diln ho quang cd sfl dung mot Ifldng nho than (de tao xi bpt, tang cicbon trong thep...). Qua trinh dot chiy, nung chiy nguyln vat lieu trong 16 EAF da phat khi thai (0,5+1 tan/T thep thd).
Luyen thep bang Id chuyen vdi nguyen lieu dau vao chu yeu la gang long (hot metal) vi phi thep (scrap). Qua trinh dxy hda cicbon trong gang Idng (3,5+4%) cd lflpng CO, phat thii ra ngoii. Theo nghien cflu va dinh gii cua OECD vi lEA Ifldng CO, phit thai la: 3,6 + 3,7 tan CO,/T thep thd.
Cac 16 nung trong edng nghe can ndng hiln nay phan ldn sfl dung 3 loai nhiln lilu; than, khi than, dan (FO/DO), khi thien nhien (NG) da phit thii KNK giy d nhiem moi trfldng. Cl Vict Nam phd bien diu^
nhien lieu trong eic Id nung phoili dau FO, DO vdi lUdng tieu hao dim FO ldn (tfl 25 ~- 36 lit/Tsp), d cac nflde phat trien ticu hao dau tror^
cin thep thap ( 1 5 - 2 1 lit/Tsp).
42lMdi trudng 567/201'^
GIAI PHAP & C O N G N G H E XANH
m
A Due mdu gang tgi Nhd mdy luyen gang Cong ty CP gang thep Thdi Nguyen (TISCO)
cAc GiAi PHAP GIAM K N K T R O N G S A N X U A T G A N G T H f i P 6 V I E T N A M
Gidm tieu hao nhiin lieu trong sdn sudt gang thep: Nhflng n a m qua vdi sfl hd t r d cua C h i n h p h u v i e i e td chflc q u o c t l n g i n h thep Viet Nam da cd n h i e u g i i i p h i p g i i m t i l u hao n h i l n lieu vdi m u e t i l u dat ra la;
Trong luyen gang g i i m t i l u hao than cdc tdi mflc 500 - 600 kg c d c / T H M T va t h a n p h u n tdi mflc 90+100 k g / T H M T ; C i n t h e p g i i m tieu hao d a u dfldi 20 lit/Tsp.
Doi tndt cong nghi vd thay doi nhien lieu de gidm phdt thdi khi CO,: Dau tfl chieu s i u doi m d i cdng n g h e (Ifla c h p n edng ngh? t i l u h a o it n h i l n heu, n a n g Iflpng, phat thai it, t h a n t h i l n vdi mdi trfldng, n a n g cao tuoi t h o t h i l t bj, rut ngan chu ky tao s i n p h a m , . . ) ;
Sfl d u n g n h i e n lieu sach va t i l t kipm n a n g Ifldng trong san xuat gang, phdi t h e p v i can t h e p d Vi?t N a m . Thay doi n h i e n lieu (tfl d u n g t h a n sang d u n g khi) va
tang eUdng sfl d u n g n a n g lflpng cd hieu qua (sfl d u n g nhiet dU, k h i dfl t i i tao n a n g Iflpng, bd tri h d p ly c i c thiet bi truyen d p n g . . . ) .
Xii ly vd ndng cao chdt lUdng nguyen heu ddu vdo: D o chat lupng k h o a n g s i n d c i e m o khai thac khac nhau va chfla nhieu tap chat ed hai cho cdng nghe luyen k i m n e n viec xfl ly nguyen, nhien Ulu d i u v i o cho tflng cdng doan san xuat luyen k i m la h i t sfle q u a n trpng, k h d n g nhflng t h u a n tien cho cdng n g h i m i cdn i n h hfldng trflc t i l p hoac g i i n t i l p den tieu hao n a n g Iflpng cho qua t r i n h edng nghe v i g i i m Iflpng phat t h i i KNK.
Xii' ly nguyin, nhien lieu cho qud trinh luyen gang: Nguyen, n h i l n lieu dau v i o eua edng nghe luyen gang chu y l u l i q u a n g sat, than m d luyen cde, than cam antraxit p h u n thoi v i o Id cao can p h i i dfldc xfl ly trfldc khi sfl d u n g .
T i n g c h i t lUdng q u a n g ( h i m l u p n g I-c) len 1% thi g i i m ty Ic than cdc d u d e 2% v i t i n g s i n
Ifldng gang Iln 3 % . Nhfl viy, v i l e giam ty 11 t h a n cdc d u n g cho luyen gang g i i n t i l p da l i m g i i m p h i t thai KNK C O , trong cong nghe luyen gang.
Xfl ly phdi t h e p v i xfl ly be m a t c u d n can n d n g (HRC) cho cong d o a n c i n nguoi can dflpc thUc h i l n va coi trong n h i m m u c dieh nang cao cdng suat n h i may, hieu s u i t sfl d u n g t h i l t bi, g i i m ticu hao nhien lieu va n a n g Iflpng cho s i n s u i t mpt d d n vi s i n p h a m , Dieu dd cd y nghia quan trpng trflc t i l p h o a c gian t i l p d i n vile g i i m thieu p h i t t h i i KNK v i BDKH.
Tiet kiem ndng litdng irong sdn xudt gang thep: T i l t k i i m nang Ifldng (TKNL) la m u e t i l u q u a n trong eua h i u h i t c i e linh vUc s i n xuat cdng nghiep, n d n g l i m n g h i i p v i dich vu kinh t c . . . cua mdi qudc gia, nd k h d n g nhflng m a n g y nghia kinh tc ma c6n y nghia BVMT va flng phd vdi nhflng thach lliflc vc BDKH toan eau. TKNL ty 1| t h u i n vOi v i | c g i i m phat thai KNK ( C O J Cae g i i i phap TKNL trong s i n
56 7/2014 Moi trddng 43
m
'^ GlAl PHAP & CONG NGHE XANH xuat gang thip di dfldc ip dung nhu sau:Ning cao hieu suat sfl dung nang Ifldng (nhilt nang, dien, khi...) giam thieu cie tdn that, lang phi ning lUdng trong tflng cdng doan sin xuat luyen kim.
Cai tien bo sung cic thiet bi phu trd, nguyln nhiln lieu phu trd nhim tang cfldng thuc day nhanh cie qui trinh hoi Iy luyen kim rut ngan thdi gian tao sin pham bing cich: Bd sung md dot cho 16 dien EAF; Sfl dung loai md dot tii sinh cho 16 nung phoi kit hpp vdi he thdng budng tich/hoin nhiet; Phun than antraxit bpt vio 16 cao, ket hdp vdi lim giau gid bing dxy dl giim tieu hao than coke...
Sii' dung khi thdi vd nhiet dU trong sdn xuat gang vd luyen coke cho sdn xudt phot thep: Trong khi thii 16 luyen coke, luyen gang, luyen thep 16 chuyen chfla Ifldng cic chit (nhfl:
CO, Hj, Cnllm ...) cd thi sfl dung lam nhiln lilu cho qua trinh nung, ddt, tii sinh ra nang Ifldng mdi bing eie giai phip sau:
Tan dung nhiet du eua khi thii vdi muc dich say nguyen vat lieu dl rut ngan cac qui trinh nang nhilt trong sin xuat luyen kim. Vile tan dung nhilt dfl tfl khi thii d Viet Nam da dfldc mdt sd nha may ip dung (tai 16 CONSTEEL cua Cdng ty thep Vilt, 16 DANARC PLUS tai Cdng ty thep Miln Nam);
Tai sfl dung khi thii trong qui trinh luyen kim lim nhiln lieu
(nung, dot) cho cac cdng doan ndi bp nha may hoic cap cho cae ho ngoii sfl dung.
Viee sfl dung cic loai khi thii thfldng dupe xem xet dinh gia thdng qua kiim toin nang lUdng de Ifla chpn phUdng in sfl dung phfl hop: say lieu, lim nhien lieu cho cac qui trinh san xuat luyen kim (dot Id nung, 16 hdi) hoic sin xuat diln bing turbin (TRT TG-BL...).
Ndng eao hieu qud ddu tU cdc dU dn trong ngdnh thep Viet Nam phii hdp vdi BDKH vd nUde bien ddng:
Ngoii nhflng tilu chi Ifla chon dau tfl cic dfl an trong nganh thip can phai tinh den nhflng thach thflc ve BDKH, BVMT va TKNL. Vi the can thflc hien dong bp va chu trong dau tu eac dfl in theo trinh tfl sau: Dau tfl cdng nghe trong khai thac vi che bien khoang sin tiln tien vi hien dai nham dat dfldc nang suat eao, hieu qua kinh t l ldn, an toin lao dpng va BVMT
Dau tu diy chuyen sin xuat cdc theo phuong phip dip coke khd thay cho dip coke fldt nham giam thieu 6 nhiim mdi trfldng tai cac nhi miy luyen coke.
Viee Tfla chpn dia diem vi kit cau nhi xUdng" cho cic dU an nha miy thep eua Viet Nam phu hpp vdi BDKH vi nflde bien dang.
Trong bdi canh phat triin san xuat ben vflng vi xu thi BDKH, vile Ifla chpn dia diem nhi miy sin xuat gang thep cin dfldc tinh din ci nhflng inh hfldng ve dieu kicn tU
nhiln va thach thflc do BDKH m nflde bien dang, bao, Itit...Ngoii vile Ifla chpn dja diem hdp ly, kien true nha xfldng phai dip flng eac yeu to inh hfldng cfla BDKH. Cong nghe phii dam bao phit triin ben vflng vi tilt kiem nang Iflpng. giim thieu Ifldng KNK phat thai tfl cac Id luyen kim, dam bao dieu kien t6t cho mdi trfldng lao ddng. Diln tich cic khu cdng nghiep luyen kim can bd tri khu trdng ciy xanh (tdi thieu bang 15% tong dien tieh) de tao moi trfldng xanh va hap thu mdt phan CO, tai khu vfle nhi miy.
KET LUAN
Tfl cac phan tich neu trln, nganh thep Viet Nam can tilp tuc hoan thien chiln Iflpc, chUPng trinh hanh dpng nham muc tilu phat trien nginh sin xuat gang thep vi BVMT ben vflng phfl hdp vdi eac kich bin BDKH va nflde bien dang.
Trfldc tien, phai chu trong den vi?c dao tao nguon nhan lUe, nang cao hieu biet, khdng chi trong linh vfle chuyen mdn, chuyen nginh mi cdn phii ket hpp vdi cic giii phap ky thuat thupc nginh khic cd lien quan nhfl: khoa hpc khi hiu, ning Iflpng, giad thdng, mdi trfldng...
Lfla chpn giai phip cdng nghe mdi phu hpp cho san xuit gang thep, sfl dung tilt kiem va hieu qui nang Ifldng, giai phip phat triin kinh te vdi BVMT nham giim Ifldng phat thai KNK, flng phd kip thdi vdi sii BDKH trong giai doan 2015-2015I
GEOCYCLE VIET NAM HOP T A C Xl/ LY CHAT THAI NHIEM PCB
/ " eocycic Vict Nam - Don vi -, •; kinh doanh trflc thupc Cdng ty TNHH Xl mang Holcim Viet Nam vi Cong ty Orion B.V (Hi Lan) vfla ky thda thuin hdp tic eung cap giii phap toan diln xfl ly chat thai nhilm PCB tai Vilt Nam,
Theo dd, Geocycle sc xfl ly phan dau thii nhiim PCB trong cie thilt
hi ngay tai Viet Nam. Phan thilt hi sau khi dfldc thid hit dau nhiim PCB, se dfldc Geocycle ddng gdi vi van chuyen sang Ha Lan cho Orion B.V. Hien tai, Geocycle li don vi dau tiln vi duy nhat dfldc cap phep xfl ly hda chat niy tai Viet Nam,
DUdc bilt, PCB li mdt nhdm cac hdp chat nhan tao dfldc sfl dung
rdng rai trong qua khfl, ehu ylu trong eac thilt hi diln nhflng da bj cam d nhieu nflde trong dd cd Vi$t Nam bdi nhflng nguy cd giy hai cho mdi trfldng vi sfle klide nhfl ung thu, ton thfldng gen, hi than kinh, he miln dieh, gay rdi loan sinh san...
PCB li nhflng hop chat rat ben vflng
vi khd xfl ly. N.H
44'Mdi trddng So 7/201'
