Thong tin khoa hpc c6ng nghp m o A l Q T SO NGHIEN CLL TR.AO DOI VE THAI V.A L i t GIU BL N DO TREN THE GIOI TS Biii Thanh Hoang, TS Ngu>tn Quoc Thinh (len Khoa hgc Cong ngh4 Md - \ Inacomin Bien lap: ThS Hodng Minh Hung Tom tit: Bdt bdo dd tong quan cdc phuang phdp thdi vd liru giir bitn tren thi gidi, nghien cuu cac bai thdi him dd cu thi nhu -iughinish {.-ii-xcr-len), Binh Qud (Trung Qudc) vd Tdn Rai (Viet Wim), tir dua mgt sc'f nhdn xet trao ddi lien quan den vdn ndy Md dau Bun dd Id chit thai phdt sinh tii cac nha mdy san xuat alumin, Hipn tpi, tren the gidi, ty le xi> ly tdi sir dyng doi vdi bun dd cdn thip khoang 5%, phan Idn luang bun dd thai da va dang dupc d l thai va luu gitr bing cac phuang phap khac Vi vay, phuang phdp thai, luu giu thi ndo d l dam bdo tinh an todn, mdi trudng vd kinh t l Id mpt v i n de Idn vd cd nhieu tdc dOng tdi hoat dpng sdn xuat ciia cdc nhd mdy cdng dong dan cu vd mdi trudng ty nhien xung quanh Nghien ciru, tim hilu ve cdc phuang phdp thdi vd luu giu bun dd tren t h i gidi qua dd due riit kinh nghipm khoa hpc vd thyc tien d l vpn dyng phii hap cho dieu kten cua ngdnh cdng nghipp nhdm cdn mdi me d Vipt Nam Id rit can thilt Cac phuang phap thai va luu giu biin dd tren the gidi Cdc phuang phap thai vd luu giir biin dd gim cdc dpng sau [5]: 2.1 D6 thii xuong biin (Seawater discharge) Ld phuang phdp thai tryc tilp bun xulng btin, thudng Id bun duac dan dudng Ing xa bd vd vao bun bien sau LTu dilm cua phuang phdp ndy Id giam duac dp lyc ve nhu cau su dyng dat, khdng cdn tien hanh cat tpo ddng cCra bai thai, giam cac tac dpng tdi mdi trudng so vdi thai tren d i t lien nhu nhiem byi d nhiem nudc mdt vd nudc ngam cdc kim loai dpc hpi thoat tir bai thai Tuy nhien phuang phdp ndy Ipi cd nhuac diem dd la lam vting bien bj bao phu bdi mau tang dd dye ciia nudc biln d i n tdi pha hoai he sinh thdi, tilm an phdt tan cdc kim lopi ddc hpi vdo m6i tn/dng biln, tac dOng Idu ddi tdi hp smh thdi n6i Chung va chudi thuc dn ndi neng, mit di mpt luong kiem vd alumin cd gid trj di theo bun vd e'o djch thai, gia tdng sire ep cpng ding va thyc tiln Id phuang phdp ndy tien tdi phai ngirng dp dyng 2.2 Do thai vio vung trung (Lagooing) Biin dd tir nhd mdy dup'c bam vao cdc viing trung cac viing trung cd the Id ty nhien ho^c cdc thung lung cd ddp chdn dam bdo vCrng chdc cho tuu giu biin thdi Viec dp dyng phuang phdp thudng tan dyng vung cd dja hinh ty nhien hodc cdc Idng moong khai thac md ho^c d i t tpo thdnh Khi l i l n hdnh phuang phdp nay, can Idp lot xung quanh vd ddy d l hpn c h l toi da vi0c thodt djch tir bat thdi vdo nudc ngam Ldp Idt dan gtan nhit la dung mpt Idp d i t set l i y tir d i t dd thai qud trinh khai thac mo hope khu vyc, nhien, vdi mdt Idp ndy thdng thudng khdng dam bao De ndng cao kha ndng chong tham cd the dung kit hap vdi cac lopi mang nhya ehlng tham, vdi dja ky thu$t Lfu dilm cua giai phdp ndy Id giam chi phi sir dyng d i t nlu tpn dyng duac dja hinh phu hap, khdng yeu cau phai co dac ho0c Ipc bim d6 trudc do, han c h l duac nhiem nhd cd Idp chong thim Tuy nhidn, phuang phdp ndy d n c6 dipn tich Idn de luu chira, can c6 k l hoach va von d l ddp irng yeu c l u dong cira phgc h i i bai thai, mat di mpt luang kiem vd alumin c6 gia trj di theo bim va djch thai Mat khdc, neu khdng duac trung hda, se tpo nen mpt dpng h i cd dp kiem cao ddi hdi cao v l ddp irng an toan m6i trudng doi vdi ngudi, ddng vdt hoang dd, dich kiem va chit dOc hpi cao thodt doi vdi m6i trudng nudc mdt vd nudc ngim, chi phi xdy dyng va tri cao khd khan cai tao ddng cua bdi thai 2.3 D6 thii khd trii nhiiu Idp (Dry stacking) Bun sau qud trinh rua duac c6 ddc thdnh dpng hon hop cd ham lupng chat rdn tCf 48-55"?' KHCNM SO I 2017 * \I(H | Ki (IN( MO Thong tin khoa hpc cong nghp mo mdi tien hanh d l thai Hon hap bun duac vpn chuyin tdi bai thai bdng dudng Ing va duoc trai Idp tren di^n tich cua bdi thai de khir nude bdng thdo khd va bay hai dudi dnh ning mpt trdi phuang phdp ndy lam eho biin dd khd, ham luong chit r i n dat tdi 62-65% Ngodi thilt k l tien tiln cdn bao gom viec thdo nudc dp h ia dudi ddy nhdm tang tinh on dinh cho bai thdi Ngudi ta dp dyng phuang phap thai khd nhieu Idp doi vdi nhung noi thilu dien tich dit, su dyng d i t han c h l va ddt; d i t phdng, d i t tham thiu nhieu; nai cd yeu c l u cao doi vdi bdo vp mdi trudng; dia diem bdi thai ndm canh nha mdy alumin Tinh uu viet cua phuang phdp thai kho nhieu Idp Id: An todn giam duoc nguy hpi cho ngudi vd dpng vat hoang da; thai khd nhieu Idp cho phep tang chilu cao ciia bai thai, dieu md bai thdi udt thdng thudng khdng thyc hipn duac xet v l gdc dp kmh t l , nhu t h i , sir dyng dipn tich bai thai cung it han Nhupe dilm ciia phuang phdp la cd the khd khan d nhung khu vyc vuc cd c6 luanq luang mua nhieu nhilu kha ndng boc t hoi kem; chi phi qud trinh thai ton kdm han vi bun trudc thdi phai duac c6 dpc d mirc d0 nhat djnh, qua trinh thai phai thyc hipn theo cac quy trinh nghiem ngdt va cd t h i phai tiln hdnh cd vipc dung may bira de dao ldp bim cho mau khd [3,5] 2.4 Phutyng phip thai khd (Dry disposal) Bim dd sau qua trinh rua dugc Ipe khd dpng bdnh (c6 hdm lugng chit rdn >65%) Bim dd khd dugc vpn chuyin d l bai thai bdng dtd hodc bdng bdng tai chuyen diing Phuong phdp ,•> u - i UA J .a' i- •' u * ^ \i thai khd cd uu diem la: giam thieu dugc dipn tich bai thdi, phii hap vdi mpi dia hinh, k g c i n dpp Idn vd chi yeu cdu bd bao nno, y cd nguy ca tham hpa cd dja cnan vi u bun dd dong nhit duac k/u ' ^ ' ° ' : ' " f ° "f/^T^ sue khang cao d l i vdi hda Idng tiepxuc vai nudc vd dung djch; nguy co rd n chdt o nniem tir bun dd thip; than thien vdi moi truong va cai tao bai thai nhanh, de dang Nhup-c diem cua phuang phdp Id dau tu thiet bi cao va chi phi vpn hanh t i n cho khau Ipe kho bun d6 trudc thai [3] 2.5 Uch sir phit triin cua cic phuang phip thai bun dd Thdng qua nghien ciru phuang phap thai tir 1965-2007 cua 17 nha may alumin (chilm 440/^, tren tong so 76 tripu tan san phim alumin to^p cau ndm 2007) cho thay ty Ip dp dgng cdc phu-ong phap thdi dugc the hi0n tren hinh ^5] j^^^ng qua hinh cho thay xu hudng phdt ^^.j^j.^ ^^ phuong phap thai bim dd xulng biln , •, ,; vao »,A„ vung wim/^ trung trnnn roi rAi tdi trs-i trdi trii khd khA nhieu nhieu Idp Idn tdi thdi Ndm 1965, cd nha mdy thdi bim dd xulng ,,.,.,.,•, ,.• £ hlinh Lich su phat tnen cua , > , , , cac phtrang phip thai bun Bing Dirli^u vi thgc hanh thii eua 17 nha may nghidn cOv giai dogn tir nim 1965-2007 1959 t963 1965 1967 1972 1972 1972 1973 1973 1960 1963 1963 1964 1964 1967 1995 2005 Kiitvi Quvonsland Ak«nhi» L m K G«Akjmha CVG BauxkMt Wontoy Ali«nr>a Wagarup Km NMso I 2llI7*MonRl