Qung nhm

Th T, 18/05/2011, 05:12 CH | Lt xem: 869 Nhm l kim loi nh quan trng nht trong cuc sng con ngi v l mt trong bn kim loi mu c bn. Ngy nay, nhm v cc hp cht ca nhm c s dng rng ri trong nhiu lnh vc sn xut v i sng nh ch to my bay, t, k thut in, xy dng, sn xut gch chu la, sn xut sn, phn, dng c gia nh, ... V khi lng s dng, nhm ch ng sau thp. Nhm cn c s dng nhiu trong cng nghip quc phng, nn c coi l mt trong nhng kim loi chin lc. Pht trin cng nghip nhm s gp phn cng nghip ha v hin i ha t nc, to iu kin pht trin cc ngnh cng nghip lin quan trung ng v a phng, pht trin kinh t x hi, nng cao dn tr cho ng bo vng min ni. Cng nghip nhm pht trin s gp phn tng kim ngch xut khu, cn i ngoi t, tng thu ngn sch, to cng n vic lm v ci thin i sng cho hng vn ngi lao ng. Nu ch tnh ring ngoi t nhp nhm kim loi, hng nm nc ta phi chi mt lng ngoi t ln nh sau: Nm 2000 : khong 160 triu USD Nm 2005 : khong 250 triu USD Nm 2010 : khong 390 triu USD Nm 2015 : khong 480 triu USD Trong thin nhin, do hot tnh cao nn nhm ch tn ti dng cc hp cht, ch yu trong cc loi khong l felspat (trng thch) v glimme cng nh sn phm phong ha ca chng l cc loi t st. Trong s cc felspat v glime gm c : kali felspat (KAlSi3O8, natri felspat (NaAlSi3O8), canxi felspat CaAl2Si2O8, muscovit KAl2(AlSi3O10) (OH,F)2, margarit CaAl2(Al2Si2O10)(OH)2, zyanit Al2O(SiO4),... Trong s cc loi t st cha nhm th quan trng nht l boxit vi thnh phn l hn hp cc khong nhm hydroxit khc nhau, tip theo l cao lanh c thnh phn ch yu l Al 4(OH)8Si4O10, kryolit vi thnh phn l Na3(AlF6), v mt s khong t st cha nhm vi hm lng canxi, manh hoc st oxit cao. I. QUNG BOXIT Boxit l nham thch c mu t trng n en, ch yu l hn hp cc hp cht v c v nhm hydoxit. Loi boxit thng gp c mu . Cc loi hnh qung boxit quan trng l bsmit, gipsit (hydragilit), diaspo, alumogel.

Boxit c thnh phn tng i phc tp, nhng ch yu l hn hp cc khong nhm hydroxit, thng b nhim bn bi st oxit (to ra mu cho qung) hoc silic oxit. Thnh phn ha hc ca boxit dao ng gia 50-63% Al2O3, 12-32 % H2O, 15-25 % Fe2O3, 2-10 % SiO2 v 2-5 % TiO2. Hm lng nhm oxit v silic oxit l nhng yu t quyt nh cht lng ca qung boxit. Nhm oxit trong qung boxit ch yu trong thnh phn ca hydroxit nh diaxpo, bmit, gipsit hoc bayerit. Ngoi ra, nhm oxit trong boxit cn c th dng corundum v trong thnh phn khong ca nhm caolinit. Silic oxit trong qung boxit nm trng thi t do, nhng cng c th trong thnh phn khong alumosilicat v aluomopherosilicat. Silic oxit c nh hng bt li cho qu trnh ha tan qung boxit, v n to thnh natri alumosilicat t tan, lm tng tiu hao kim v nhm, ng thi lm tc ng ng v thit b. St trong qung boxit c th thuc vo cc nhm sau: - Nhm oxit v hydroxit bao gm hematit (a -Fe2O3, g -Fe2O3), hydrohematit (Fe2O3 aq.), manhtit (Fe3O4), hetit (HFeO2), limonit (HFeO2 aq.). - Nhm cacbonat bao gm siderit FeCO3, ankerit Ca(MgFe(CO3)2 - Nhm silicat gm samozit vi thnh phn ch yu l FeO, Al2O3, SiO2. - Nhm sulfit v sunfat nh FeS2, FeSO4.7H2O, Fe(SO3)(OH).2H2O, KFe(SO2)(OH)3. Titan oxit trong qung boxit cng trng thi t do l rutin v anataz, hoc cc dng hp cht khc nhau nh sphen CaTiO2SiO2, perobskit CaTiO3, ilmenit FeTiO3. Cc hp cht titan c th nh hng bt li cho qu trnh ha tan nhm.. 1. Tim nng qung boxit ca Vit Nam: Kt qu thm d a cht pht hin trn lnh th nc ta c tr lng qung boxit phong ph c Min Bc v Min Nam Vit Nam. Tng tr lng qung boxit ca Vit Nam c tnh khong 8 t tn, trong c 7,6 t tn cc tnh Ty Nguyn. Vi tr lng nh vy, nc ta ng trong s cc nc c tr lng boxit ln trn th gii. Qung boxit l ngun ti nguyn ln ca nc ta, l c s hnh thnh ngnh cng nghip luyn nhm, l ngun lc quan trng trong qu trnh cng nghip ha, hin i ha t nc. Mc d nhm kim loi l sn phm quan trng cho ngnh kinh t quc dn v nc ta c sn ngun nguyn liu cng nh cc iu kin khc sn xut nhm kim loi (thu in, nhn lc...) nhng hin nay chng ta vn cha sn xut c nhm kim loi. V

vy, mt trong mc tiu m chnh ph ra l xy dng mi ngnh cng nghip nhm Vit Nam, p ng nhu cu nhm trong nc, tranh th xut khu mt phn sn phm sang cc nc xung quanh, to c s vt cht k thut ban u v i ng qun l, k thut, ng thi tch lu vn pht trin cng nghip nhm lu di vi quy m ln, nhm khai thc ngun boxit sn c xut khu cc sn phm alumin v nhm. Vit Nam c hai loi hnh qung boxit: 1/ Loi qung bsmit v diaspo, tp trung ch yu Min Bc Vit Nam, phn b cc tnh H Giang, Cao Bng, Lng Sn, Bc Giang). Tng tr lng d on khong trn 350 triu tn, hm lng nhm dao ng trong khong 39-65 %. Modul silic (Al2O3 /SiO2) bng 5-8. C th, qung boxit phn b nh sau: - nhm t khong H Giang: ti nguyn c on khong 60 triu tn. - nhm t khong Cao Bng: ti nguyn c on khong 240 triu tn. - nhm t khong Lng Sn: ti nguyn c thm d v c on khong 50 triu tn. - M L Sn (Hi Dng) c tr lng cp B l 97.000 tn, tr lng cp C 1 l 24.000 tn , vi hm lng nh sau: Al2O3 SiO2 Fe2O3 TiO2 CaO MgO Mt khi nung 52% 6,4% 26% 2% 0,53% 0,24% 12%

- Vng Qu Hp - Qu Chu c ti nguyn d tnh khong 1 triu tn vi hm lng nh sau: Al2O3 : SiO2 : Fe2O3 : 30 - 50% 2,12 - 36% 18 - 30%

2/ Loi qung gipsit, tp trung ch yu Ty Nguyn v Min Nam Vit Nam, vi tng tr lng c tnh khong 7,6 t tn.

Tr lng qung boxit c thm d v chng minh Ty Nguyn v Min Nam Vit Nam l khong 2772 triu tn. Trong c th cc khu vc nh sau: * Ti nguyn vng c Nng - Phc Long khong 1.570 triu tn * Ti nguyn boxit vng Lm ng tp trung hai t khong l Tn Rai v Bo Lc. - Tr lng vng khong Tn Rai khong 57 triu tn cp C1, 120 triu tn cp C2, hm lng nh sau: Al2O3 SiO2 Fe2O3 TiO2 Mt khi nung 44,69 % 2,61 % 23,35 % 3,52 % 24,3 %

- Tr lng vng t khong Bo Lc khong 378 triu tn. Ni chung, qung boxit nguyn khai Lm ng u c cht lng khng cao, hm lng Al2O3 ch khong 35 - 37%. Ngi ta phi tuyn ra qung nguyn khai thu c tinh qung giu nhm hn. Sau khi tuyn, tinh qung boxit cc t khong Lm ng cng ch t hm lng 45 - 49% Al2O3. Ngoi ra, qung boxit min Nam cn c cc vng Kon Plong, Ph Yn, Qung Ngi, vi tr lng khong 106 triu tn. Nhn chung, boxit Vit Nam hu ht cc vng u c th khai thc l thin. Tuy nhin, tr nhng khu m ln Lm ng, tr lng qung cn li c phn b dn tri, va qung khng dy v hu ht u nm trong cc vng canh tc nng, lm nghip, nn s c nhng kh khn nht nh trong qu trnh khai thc sn xut nhm quy m ln, do ng chm trc tip n vic s dng t canh tc, vn cn bng nc mt, vn qung thi, vn nc thi v ni chung l vn sinh thi. 2. ng dng ng dng ch yu ca boxit l lm nguyn liu cho cng nghip luyn nhm. Ngnh cng nghip sn xut nhm kim loi tiu th 85% qung boxit trn ton th gii. Phn boxit cn li c s dng trong hai lnh vc l sn xut alumin chuyn dng (10%), bao gm alumin nung v alumin hot ha, v sn xut vt liu chu la (5%), v d gch chu la, ximng chu la v cc vt liu mi. II. QUNG CAO LANH

Qung cao lanh l nham thch mn, t trng cao, ch yu gm khong caolinit c ln tp cht, c to thnh khi phong ha cc nham thch felspat macma khc nhau. Cao lanh nguyn cht mu trng tinh, nhng qung cao lanh thng c cc mu khc nhau do nhim cc tp cht st v mangan. Thnh phn ha hc ch yu l Al4(OH)8Si4O10, vi cc tp cht nh thch anh, muskovit, rutil, zircon, manhtit v felspat cha phong ha ht. Qung cao lanh hnh thnh do s phong ha cc silikat nhm, c bit l cc loi felspat. Phn ln qung cao lanh tn ti cc m nguyn sinh, i khi cc m th sinh, t khi dng t st. 1. Tim nng qung cao lanh ca Vit Nam: Qung cao lanh nc ta c phn b nhiu ni nh: Lo Cai, Yn Bi, Ph Th, Thi Nguyn, Tuyn Quang, Hi Dng, Qung Ninh, Lt, ng Nai, Sng B. Trong nhng m qung cao lanh c thm d, khai thc l: - M Thch Khan, Ph Th gm 4 vng vi tng tr lng xc nh khong 3,2 triu tn. Trong s , vng m cao lanh Hu Khnh l vng m c gi tr cng nghip vi hm lng qung nh sau: Al2O3 SiO2 Fe2O3 Mt khi nung 18 - 49% 47,5 - 76,1% 0,11 - 2,9% 9,81%

- M Tri Mt, Lm ng, vi tng tr lng thm d l 11 triu tn. M c 4 thn qung, dy trung bnh 20 m. Hm lng trung bnh nh sau: Al2O3 18 - 49% SiO2 22,8 - 65% Fe2O3 0,5 - 7,9% Mt khi nung 0,16 - 22,5%

Trong tng tr lng c thm d m Tri Mt, khong 3 triu tn l c kh nng khai thc tt.

- M Bo Lc hin t cng sut khai thc, tuyn ra l 35.000 tn/nm. Cht lng qung boxit tinh sau khi tuyn ra l:

Al2O3 SiO2 Fe2O3 TiO2 Hm m

49% 2-3% 18-22% 3-4% 10%

- Cc m cao lanh Tn Mi (Qung Ninh), Trc Thn (Hi Dng), Tuyn Quang c khai thc dng lm gch chu la cho cng ty gang thp Thi Nguyn. Cao lanh Tn Mi dng dickit v c thnh phn ha hc nh sau: Al2O3 SiO2 Fe2O3 TiO2 Na2O K2O P2O5 MgO CaO 37,43% 43,88% 0,18% 0,03% 0,03% 0,05% 0,09% 0,15% 0,21%

Ngoi ra, mt s m quy m nh cc a phng nh Yn Bi, Ph Th, Hi Dng, ng Nai, Sng B c s dng khai thc cao lanh lm nguyn liu sn xut gm s dn dng, gm s k thut, phn nhm,...

2. ng dng

T cao lanh th khai thc cc m, ngi ta p dng cc phng php nh ra bn, tuyn ni, thm thu in,... thu c cao lanh k thut. Do nhng tnh cht c bit ca n (do trng thi m, rt cng v bn sau khi nung) nn cao lanh thng c s dng sn xut cc sn phm gm s. Ngoi ra, cao lanh cng c s dng lm ph gia sn xut giy (to b mt nhn, ht mc), sn xut cc vt liu chng thm trong xy dng,... Cao lanh cn l nguyn liu quan trng sn xut cc hp cht nhm.

III. THC TRNG KHAI THC V SN XUT

Nhn chung, cc m qung boxit Vit Nam c nhng c im chnh nh sau: u im: M tng i ln, lp t ph mng, chiu dy lp cha qung thay i t 1 n 12m, hon ton c th khai thc bng phng php l thin, d dng hon th v trng li rng hoc cy cng nghip, qung c hm lng nhm oxit mc trung bnh, qung Min Nam thuc loi thun tu gipsit nn d x l nhit thp, u t khng ln, chi ph vn hnh thp. Tuy qung nguyn khai c cht lng khng cao nhng bng phng php tuyn ra n gin c th nhn c tinh qung c cht lng tt sn xut alumin theo phng php Bayer. Nhc im: Lp qung mng nn khai trng pht trin nhanh, hu nh ton b qung u cn phi c tuyn ra nn tiu hao nhiu nc. Hu nh cc m u nm xa cng bin, h tng c s cha pht trin. V nhng im nu trn nn theo kin nhiu chuyn gia trong v ngoi nc, qung boxit Vit Nam nu x l ti ch sn xut alumin v nhm th c li hn l xut khu qung. 1. Sn phm nhm kim loi Hin nay, do cha sn xut c nn chng ta phi nhp ton b nhm. Trong tng lai, cng vi s pht trin kinh t, nhu cu v nhm kim loi s ngy cng tng. Mt khc, th trng nhp khu nhm cc nc xung quanh cng rt ln. iu i hi chng ta phi nhanh chng pht trin cng nghip khai thc boxit v luyn nhm p ng nhu cu trong nc v hng ti xut khu nhm khi c iu kin. i vi qung boxit khu vc Lm ng, l ni c tr lng boxit ln nht, hin nay chng ta mi ch khai thc v s dng sn xut nhm oxit v phn nhm. Trong nhng nm qua, Tng cng ty khong sn Vit Nam v cng ty Pechiney (Php) lin doanh tin hnh kho st tin kh thi v thc hin d n T hp boxit nhm Lm ng. y l mt trong nhng d n trng im, c quy m ln. Cui nm 2002, UBND tnh Lm ng xc nh khu vc khai thc m, tuyn qung v v tr xy dng cc nh my alumin, in phn nhm trong t hp. T hp boxit-nhm Lm ng nm a bn huyn Bo Lm (khu khong sng Tn Rai), c tng vn u t hn 667 triu USD. D n boxit Lm ng bao gm hai giai on:

- Giai on u t 2003 n 2013, d kin t hp boxit - nhm s t cng sut hng nm l 72.300 tn nhm in phn, 300.000 tn alumin (trong 141 nghn tn in phn nhm, cn li s xut khu), khai thc m 1.980.000 tn qung nguyn khai. - Giai on hai (giai on m rng) t 2013 tr i, cng sut s c nng ln gp 2 ln, t 146.100 tn nhm in phn, 600.000 tn alumin (trong 284 nghn tn in phn nhm, cn li s xut khu) v khai thc m 3.960.000 tn qung nguyn khai. Trong vi nm qua, 5 thn qung s 46, 51, 52, 53, 54 ti khu vc pha ty m Tn Rai c la chn a vo khai thc phc v cho c d n, c din tch 40 km2, nm cch th x Bo Lc 15 km, cch thnh ph HCM khong 200 km, cch Lt 120 km. ng thi cng chun b mt bng xy dng nh my alumin v nh my in phn nhm thuc a phn th trn Lc Thng huyn Bo Lm, c din tch khong 118,5 ha. Khu vc khai thc m v tuyn qung c tng din tch 42 km 2, nm a bn th trn Lc Thng v hai x Lc Ph, Lc Ngi (Bo Lm). V cng ngh khai thc, trong qu trnh khai thc s tin hnh lin hon t bc t ph n khai thc qung, thc hin theo cng ngh s dng bi thi trong kt hp vi bi thi ngoi. Boxit c khai thc ch yu trn cc nh i nhm h cao v dc ca i, to iu kin cho vic ti to rng v cy trng cng nh pht trin kinh t nng lm nghip sau ny. Trong qu trnh khai thc v tuyn ra, lng bn thi s c lng ng trong ca h nhn to. Nc c thi i hoc hi lu sau khi lng trong. V cng ngh sn xut nhm, t hp boxit-nhm Lm ng p dng cng ngh in phn tin tin ca tp on nhm Pechiney theo phng thc chuyn giao cng ngh, s dng in cc thiu sn, np liu im t ng, dng in 185 kA, b in phn AP-18. y l phng php in phn nhm nng chy theo cng ngh Hall-Heroult, tc l in phn alumin ha tan trong dung dch mui nng chy criolit nhit 950-960oC. Phng php ny l cng ngh sn xut nhm cng nghip duy nht, tn ti hn 100 nm nay. Sn xut alumin c thc hin theo phng php ho tch 105oC v p sut kh quyn. V mt giao thng vn ti, trong giai on u qung boxit khai thc c vn chuyn bng ng b, ch yu theo tuyn ng 20. Sau ny, trong giai on m rng s xy dng tuyn ng st Bo Lc - Th Vi xut khu alumin v nhp khu nguyn vt liu thch hp cho t hp. Theo tnh ton, sau 30 nm hot ng, ch vi cng sut ban u d n s ng gp cho nh nc gn 328 triu USD gm thu thu nhp doanh nghip v thu ti nguyn. Ngoi ra cn c cc ngun li khc nh thu ngoi t t xut khu alumin v tit kim ngoi t do khng phi nhp khu nhm (4709 triu USD). D n cng s c nhng ng gp rt quan trng cho s pht trin kinh t x hi ca a phng. 2. Cc hp cht nhm

Hin nay trn 90% sn lng Al2O3 k thut trn th gii c dng luyn nhm, ch khong 10 % c s dng cho cc lnh vc phi luyn kim. V vy vai tr ca nguyn liu giu nhm tr nn rt quan trng i vi cc ngnh sn xut gm, thu tinh, xi mng alumin, phn nhm, bt mi, cao su,.., nht l khi Vit Nam cha c ngnh cng nghip ring sn xut nguyn liu ny. Nhm oxit Al2O3l nguyn liu c s dng nhiu sn xut gch chu la, cc sn phm thy tinh, gm s v mt s loi xi mng chu nhit. Hng nm nc ta phi nhp khong 10.000 tn nhm oxit. Ngun nguyn liu alumin ca nc ta, ngoi boxit Lm ng cn c cao lanh Tn MiQung Ninh, cao lanh Yn Bi, boxit Lng Sn v Qung Ninh,... C th ni tr lng nguyn liu cho cng nghip tinh ch nhm oxit ca Vit Nam kh ln nn ngnh cng nghip ny c tng lai pht trin tt. Ti nc ta, nm 2001 Cng ty ha cht c bn Min Nam u t dy chuyn sn xut nhm oxit c cng sut 400 tn / nm, p dng cng ngh l thoi gin on tng m. Cht lng sn phm nhm oxyt ca cng ty t hm lng Al2O3 99,1 %, hm lng st 0,1 %. Nhm oxit k thut thng c sn xut bng cch nung nhm hydroxyt nhng nhit khc nhau nh sau : - Sy nhit di 300oC : thu c Al2O3.3H2O dng hydragilit - Sy tip 300-400oC: thu c Al2O3.H2O dng bsmit - Nung trn 500 oC : thu c g - Al2O3 (thnh phn chnh ca nhm oxit k thut thng thng) - Nung trn 1000 oC : g - Al2O3 chuyn ha thnh a - Al2O3 (corun, nhm oxit k thut nung) Hm lng Al2O3 thu c c th t ti 99 - 99,5% tu theo phng php ra v tinh ch. c bit mn, hm lng pha tinh th a - Al2O3 (corun) v mc chuyn ha thnh a - Al2O3 ph thuc rt nhiu vo phng php nung v cch x l nhit. Nhm oxyt k thut sn xut theo phng php Bayer truyn thng ch yu cha khong g - Al2O3. y l sn phm trung gian sau khi nung nhm hydroxyt nhit trn 500 oC. Nhc im ca sn phm loi ny l hm lng tp cht kim Na2O cao v kh tch, gy bt li cho sn xut gm v vt liu chu la. Khi s dng loi nhm oxyt k thut ny trong cng nghip gm s, ngi ta phi x l gia cng rt phc tp v tn km: phi nung s b nhit cao (khong 1450 oC) ri nghin mn li trong my nghin bi thp hoc nghin rung, tip theo phi ra st bng axit ri ra li bng nc sch, ri mi a vo s dng trong phi liu gm s.

Vo thp nin 1970 - 1980, trn th gii c nhiu cng trnh nghin cu x l nhm oxyt k thut dng cho gm v vt liu chu la, nhng khi p dng thc t th chi ph sn xut qu ln, hiu qu khng cao, gi thnh sn phm cao nhng cht lng li hn ch. Sang thp nin 1990, bng nhng tin b k thut, nhiu cng ty ha cht trn th gii p dng phng php sol-gel, sa lng ha hc hoc plasma ha hc sn xut cc loi Al2O3 k thut nung vi tinh khit 99,7 %, hm lng tp kim < 0,05 %, v c bit l c c ht siu mn (5-10 mm) vi thnh phn pha 95 % dng a - Al2O3. Loi nguyn liu ny to ra bc t ph trong cng nghip gm k thut, m ra kh nng sn xut cc loi b tng gm t xi mng, siu t xi mng hoc khng dng xi mng thy lc (xi mng alumin), gm ct gt, gm bn nhit, bn c, gm cch in cao th, vt liu chu la cao, alumin cht lng cao,... C th ni, trong th k 21 ngnh sn xut nhm oxyt k thut nung hon ton t b cc cng ngh truyn thng ca thp nin 80. Vi cng ngh mi, gi thnh sn phm nhm oxyt nung siu sch, siu mn khng t hn nhiu so vi nhm oxyt k thut dng g - Al2O3truyn thng. V vy, ngy nay sn phm nhm oxyt kiu mi tr thnh nguyn liu ph bin cho ngnh cng ngh gm k thut v vt liu chu la, b tng gm. sn xut nhm oxit a - Al2O3(corun) dng cho sn xut cc mt hng gm k thut v vt liu chu la cao cp, cc c s trong nc ta cn nh hng theo cng ngh hin i ca cc nc lm, l nung kt ta t ch phm trung gian keo gel Al 2(OH)3 thu c cc dng nhm oxit k thut nung siu mn, siu sch, t chuyn ha thnh a Al2O3 (corun) trong sn phm nhm oxit trn 95% (tiu chun quc t v cht lng nhm oxit k thut nung). Nhm hydroxyt l sn phm trung gian sn xut nhm oxit v nhm sunfat. Nhm hydroxyt thng c sn xut t qung boxit theo cng ngh Bayer vi nhng bc c bn nh sau: - p vn, sy v nghin mn qung - phi trn vi dung dch NaOH c - ha tch trong ni hp nhit v p sut cao trong vi gi - ra tch bn (gm cc hp cht st, titan, silic,...) - lc dung dch aluminat, khuy trn dung dch ny vi ngy trong thit b phn gii, tch nhm hydroxyt kt ta. Sn phm nhm hydroxyt dng gel c th c x l nhit to ra cc sn phm Al2O3 k thut tu theo nhit x l. nc ta ch c duy nht nh my ha cht Tn Bnh ti thnh ph H Ch Minh c dy chuyn sn xut nhm hydroxyt, vi cng sut n nh hin nay l 11.000 tn/nm. Nh my s dng qung tinh t khu m Tri Mt, Bo Lc. Nguyn liu boxit ny c ngun

gc bsmit v hm lng Al2O3 kh cao (khong 47 %), tuy nhin hm lng Fe2O3 v SiO2 cng kh ln, c bit l Fe2O3. u im ca loi boxit ny l ngm nc nn mm, d gia cng. Cng ngh sn xut nhm hydroxyt c p dng ti nh my Tn Bnh l cng ngh Bayer. Sn phm nhm hydroxyt ca nh my ha cht Tn Bnh t cht lng nh sau: Al2O3 : min. 63% Na2O Hm m : max. 0,2% : max. 13%

Do nhng hn ch nh hm m, lng kim d cao, c ht th,... nn sn phm nhm hydroxyt ca nh my Tn Bnh khng th dng cho gm k thut v vt liu chu la. Cht lng nhm hydroxyt ca Tn Bnh cn thp hn so vi sn phm nhp t Trung Quc. Nhm sunfat Al2(SO4)3(phn nhm) c s dng ch yu x l nc ti cc nh my nc hoc cc h gia nh. Nhm sunfat thng c sn xut t nhm hydroxyt v axit sunfuric. Hin nay nh my ha cht Tn Bnh sn xut cc sn phm nhm sunfat cp 15% Al2O3 v 17% Al2O3, cng nh cc sn phm nhm kali sunfat v nhm amoni sunfat. Nhng nm trc y, nhiu c s sn xut phn pha Bc nh Ph Th, c Giang, Hi Dng dng cao lanh sn xut phn nhm (bng phn ng vi axit sunfuric) dng cho mc ch x l nc v phn tinh ch dng trong sn xut giy. Nhng cht lng sn phm phn nhm theo phng php sn xut ny rt thp v ln nhiu tp cht v d axit. n nay, do c ngun nhm hydroxyt ca nh my ha cht Tn Bnh nn phn ln cc c s trn dng nhm hydroxyt sn xut phn thay cho cao lanh, nh tng cht lng sn phm, gim tiu hao axit v gim lng b thi. IV. TNH HNH TH TRNG 1. Nhu cu th trng Nc ta nm trong khu vc c nhu cu nhp khu nhm vo loi ln nht trn th gii. Hng nm cc nc ASEAN, Nht Bn, Hn Quc, i Loan phi nhp trn 4 triu tn nhm, Trung Quc v Nga nhp 3-4 triu tn alumin in phn nhm. Vi v tr a l thun li v mi quan h kinh t truyn thng, y l th trng khu vc tim tng cho cc sn phm nhm ca nc ta. Nhu cu v sn phm nhm trong nc ta hin nay cng kh ln, mi nm nc ta nhp khong 70.000 tn nhm kim loi. D bo nhu cu nhm trong nhng nm ti s nh sau:

Chng loi 2005 Nhm thi 60.000 Nhm hnh 39.000 Nhm tm, l 29.500 Cc loi khc 10.050 Tng cng 138.550 D bo nhu cu nhm n 2015

2010 80.000 65.000 35.000 15.000 195.000

2015 100.000 80.000 40.000 20.000 240.000

V nhm oxyt, nhu cu nc ta hin nay nh sau: Lnh vc s dng Vt liu xy dng Vt liu chu la Thy tinh Gm s Tng cng Nhu cu hin nay (tn Al2O3/nm) 450 - 500 1900 - 2300 500 150 - 200 3000 - 3500 tn

D bo, sau nm 2005 ch ring nhu cu nhm oxyt k thut dng cho cng nghip silicat (bao gm cc ngnh thy tinh, gm s, gm k thut, vt liu chu la) s tng ln n 15.000 - 20.000 tn /nm. Nu tnh c ti nhu cu ca cc ngnh khc, nht l khi Vit Nam thc hin chin lc pht trin ngnh cng nghip luyn nhm, th trin vng th trng ca ngnh sn xut v cung cp nhm oxit k thut trong tng lai l rt ln. Nc ta cng c nhu cu ln v sn phm phn nhm, ngoi ra phn nhm cn c th c xut khu sang mt s nc trong khu vc. Nm 2001, Cng ty Ha cht c bn Min Nam xut c 1500 tn phn nhm. 2. Tnh hnh ngnh cng nghip nhm mt s nc Nhng nc v khu vc c nhiu qung boxit l cc nc a Trung Hi ca chu u nh Php, Italia, Nam T, Rumani, Hy Lp, v mt s nc chu u khc nh Hungari, Nga, Cadctan. Nhng m boxit ln nht th gii nm cc nc chu M nh Hoa K, Guyana, Haiti, Giamaica. Cc nc nh n , Trung Quc, Auxtralia, Gana, Camrun, Modmbich, Madagasca, Th Nh K, Innexia, ... cng c nhng m boxit ln. Hin nay, trn th gii c khong 20 nc khai thc boxit, 25 nc sn xut alumin v 40 nc sn xut nhm bng phng php in phn. Nm 2000, tng sn lng cc sn phm trn ton th gii nh sau:

- boxit - alumin - nhm

: : :

135 triu tn 52,8 triu tn 24,4 triu tn

Nhng nc sn xut boxit, alumin v nhm quy m ln trn th gii hin nay l (sn lng nm 2000, triu tn): Nc Australia M Trung Quc Braxin Jamaica Nga n Surinam Vnzula Ucraina Canada Cdcxtan Ty Ban Nha Italia c Boxit 52,34 0 8,00 13,84 11,30 4,0 6,67 3,80 4,70 0 0 3,73 0 0 0 Alumin 15,681 4,786 4,330 3,743 3,640 2,890 2,100 1,900 1,750 1,360 1,200 1,200 1,100 1,023 1,000 Nhm 1,769 3,668 2,820 1,271 0 3,274 0,665 0 0,571 0,104 2,373 0 0,366 0,189