[123doc.vn] - bat for the ceramic industrials

8/10/2019 [123doc.vn] - Bat for the Ceramic Industrials

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MC LC

CHNG I : TNG QUAN V NGNH CNG NGH SN XUT GM S ......................... 3

1.1 Lch s ngun gc ......................................................................................................................... 3

1.2 c im ca gm ....................................................................................................................... 4

1.3 Cc vn mi tr ng .................................................................................................................. 6

1.4 Quy trnh sn xut gm s............................................................................................................ 7

1.4.1. Nguyn li u ................................................................................................................. 7

1.4.2. Gia cng v chu n b ph i li u ..................................................................................... 8

1.4.3 T o hnh ..................................................................................................................... 13

1.4.4 S y ............................................................................................................................ 13

1.4.5 Nung .......................................................................................................................... 15

1.4.6 Trang tr s n ph m g m ............................................................................................. 18

CHNG II : K THUT SN C TT NHT (BAT) NG DNG TRONG NGNH GMS ......................................................................................................................................................... 20

2.1. Tng quan v BAT.............................................................................................................. 20

2.1.1. Khi ni m ............................................................................................................ 20

2.1.2. Th t bt u tin cc ni dung th c hi n trong BAT ............................................ 21

2.1.3. Quy trnh p d ng BAT ......................................................................................... 22

2.2. BAT trong ngn ng a nhim ngnh gm s ................................................................. 22

2.2.1. Cng tc qu n l BAT trong ngnh g m s ........................................................... 22

2.2.2. Cc bi n php gi m thi u tiu th nng l ng ..................................................... 24

2.2.3. BAT trong gi m pht th i kh th i ngnh g m s .................................................. 24

2.2.4. BAT trong gi m tiu th , ngn ng a, gi m pht th i v x l n c th i ngnh cngnghi p g m s .................................................................................................................... 34

2.2.5. BAT trong gi m tiu th , ngn ng a, gi m pht th i v x l ch t th i ngnh cngnghi p g m s .................................................................................................................... 37

2.3. Cc k thut m i ni bt nhm kim sot ngn ng a nhim trong ngnh gm s . .. 41

2.3.1. ng t b c x .................................................................................................... 41

2.3.2. Nung v s y vi sng ............................................................................................. 42

2.3.3. C i ti n xy l con thoi thay cho l r ng v l b u, s d ng nguyn li u gas v i nthay cho than v c i ............................................................................................................ 42


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2.3.4. T n thu nhi t t kh x l nung ti s d ng trong my s y ................................ 43

2.3.5. S d ng men khng ch v i bn s ch t l ng cao ............................................... 43

2.3.6. Ti t ki m nng l ng trong s n xu t .................................................................... 44

CHNG III : K T LUN V KIN NGH ................................................................................. 44

TI LIU THAM KHO.................................................................................................................. 45


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M U

CHNG I : TNG QUAN V NGNH CNG NGH SN XUT GM S

1.1 Lch s ngun gc Thut ng "gm s" c ngun gc t ting Hy Lp "Keramos 'c ngha l t

chy tri t v c s dng m t vt liu ca ngnh cng nghip gm. Nghin cu gn y cho thy r ng vic x l t stbt u vo khong 19.000 nmtrc Cng nguyn. gm lu i nht c tm thy min nam Nht Bnkhong gia 8000 -9.000 tr c Cng nguyn. Ngay t nm 4000 tr c Cng nguyngch nung c s dng xy dngngi n thp, cung in v v cc cng trnhkhc. Hn 2000 nm trc, ng i La M truyn k thut sn xut gch vo kh p ccn c chu u. Ti Ai C p, cc tm gm trng men c s dngnh bc t ngtrang tr cho cc kim t thp t 2600 nm tr c Cng nguyn v Trung Quc, ngh thut lm gm ca Trung Quc c bit n t 1000 nm tr c Cng nguyn.

Vit Nam, ng cha ta sn xut c gm t thi th ng c, cch y4500 nm. Vo thi u cc vua Hng chng ta c gm Phng Nguyn, g Mun(Vnh Ph) nung nhit 800 - 900

0C, xng gm bt u c tinh luyn.

T th k 11 chng ta sn xut c gm men i Vit ni ting v i cctrung tm H Bc, Thanh Ha, Thng Long, Nng. T th i Tr n c gm ThinTr ng (H Nam Ninh) v i sn phm bt a, bnh l ph men ngc, men nu. T cui i Tr n vo th k 14 bt u hnh thnh lng gm Bt Trng ni ting n ngynay.

Theo s liu thng k t Tng cc Hi Quan, nm 2011 c nc xut khu c 358,6 triu USD sn phm gm s, tng 13,15% so vi nm 2010. Thng k th tr ng xut khu sn phm gm s nm 2011 n v: USD

KNXK nm2011 KNXK Nm 2010 KNXK so nm 2010

Tr gi 358.625.582 316.933.450 13,15

Nht Bn 52.928.616 37.857.542 39,81

i Loan 40.216.835 32.908.220 22,21

Hoa K 36.279.219 33.035.918 9,82

Thi Lan 24.638.001 14.538.011 69,47


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c 24.494.204 28.004.490 -12,53

Campuchia 20.930.720 15.858.484 31,98

Php 19.089.427 17.703.291 7,83

Oxtrylia 17.765.757 14.446.436 22,98

Hn Quc 12.306.003 11.298.726 8,91

Malaixia 11.443.798 9.343.884 22,47

Anh 9.563.580 9.340.534 2,39

H Lan 5.356.151 6.822.069 -21,49

an Mch 4.696.103 3.894.019 20,60

Canada 3.727.315 3.621.967 2,91

Italia 3.175.658 2.923.093 8,64

Ty Ban Nha 2.979.201 3.671.258 -18,85

Thu S 2.953.406 3.373.830 -12,46

Nga 2.553.913 2.030.203 25,80

B 2.460.194 3.873.604 -36,49Thu in 1.879.613 2.037.690 -7,76

Trung Quc 1.322.112 1.850.612 -28,56

1.2 c im ca gm Thut ng "gm s" (sn phm gm s) c s dng cho cc vt liu v c

(c th mt s cht hu c), to thnh cc h p cht phi kim loi v lm t qu trnh

nung. Ngoi vt liu da trn t st, gm s ngy nay bao gm cc sn phm cmt phn nh t st hoc khng phi t st. Gm s c th bng thy tinh hoc khng bng thy tinh, khng trng men hoc trng men.

Qu trnh nung gm lm thay i nhit - th i gian ca cc thnh phnkhong cht,th ng to thnh mt hn h p vt liu m i. Tnh cht c trng ca sn phm gmbao gm bn cao, chu mi mn, tui th lu di, khng phn ng hahc v khng c hi, c kh nng chu nhit v la. Cc b c chnh trong vic snxut cc sn phm gm s ch yu l dng cc thnh phn nguyn liu to sn phmcui cng.


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Hnh di y l s c trng cho qu trnh sn xut gm s. Qu trnh ny c to thnh t cc b c sau:

To khun

Hnh 1: Cc giai on trong qu trnh sn xut gm s.

Khai thc nguyn liuv vn chuyn n nh

my gm s

in Cht ph tr

Nguynliu th

N c Cht h pth

Bo qun nguyn vt liutrong nh my gm s vvn chuyn ni b

Chun b nguyn vt liu

To hnh

Phi, sy kh

X l b mt

Nung

X l ti p theo

Sn phm

Kh gas lmsch

Ti ch

X l n c

Ti SDnguyn vtliu

Tingn

Kh thi

Rc thi

N c thi

To khun

Chun b trng men

Nhin liut

Philiu

Mu

Chtc s

Cht ph gia

Nhinliu


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1.3Cc vn mi trng Ty thuc vo quy trnh sn xut c th, cc nh my sn xut cc sn phm

gm pht thi vo khng kh, nc v t (cht thi). Ngoi ra, mi tr ng c th b nh h ng b i ting n v mi kh chu. Thnh phn v s l ng cc cht nhim

khng kh, cht thi v n c thi ph thuc vo cc thng s khc nhau. Cc thng s ny bao gm, v d cc nguyn vt liu c s dng, cc cht ph gia ph tr s dng, cc loi nhin liu s dng v cc phng thc sn xut:

Pht thi vo khng kh: cc ht vt cht / bi c th pht sinh t vic x l,ch bin nguyn liu th hoc hon thin sn phm v cng c bi nh c th phtsinh t vic t du nhin liu hoc nhin liu r n khc. L ng kh thi pht sinhtrong vic t hoc sy kh gm s v c bt ngun t cc nguyn liu th hoc t cc loi nhin liu s dng. Oxit cacbon, oxit nit, oxit lu hunh, flo v c v cch p cht clo, cng nh cc h p cht hu c c tm quan tr ng c bit trong pht thikh. Do vic s dng cc cht cho mc ch trang tr c cha kim loi nng, hoc dovic s dng cc cht nh nhin liu, kim loi nng cng c pht thi ra.

Pht thi n c: ch yu xy ra trong qu trnh sn xut sn phm gm s, c bit l trong sn xut gm s truyn thng, v qu trnh dn n c thi ch yu chacc thnh phn khong sn (ht vt cht khng ha tan).Ty thuc vo phng phpsn xut, n c thi c cha thm cc vt liu v c, s l ng nh ca r t nhiu vtliu hu c cng nh mt s kim loi nng. Ngoi n c thi sn xut thng c

lm sch v ti s dng trong mch tch hp; cng nh nc lm mt, nc ma vn c thi v sinh c th gp phn vo vic pht thi n c t nh my. Qu trnh tht thot/thi b: qu trnh tht thot xut pht t sn xut sn

phm gm s, ch yu bao gm cc cht sau y: o Cc loi bn khc nhau (bn thi t qu trnh x l n c thi, trng men, bn

thch cao, bn t qu trnh mi)o Thit b b hng t to hnh, sy kh, nung v vt liu chu nhit.o Bi thi t t kh sch v my kh bi.o S dng khun thch cao

o S dng cc tc nhn h p th ( vi dng ht, bi vi) o Cht thi bao b (nha, g, kim loi, giy, vv)o Ph liu r n, v d tro bi pht sinh t nung nhin liu r n.Cc phn ca quy trnh ly k tht thot nu trn, c th c ti ch v ti s

dng trong cc nhmy do c tnh sn phm hoc yu cu x l. Vt liu, m khngth c ti ch ni b, r i khi nh my nh cht thi v c cung cp ti ch bn ngoi hoc x l c s vt cht.

Tiu hao nng n ng/pht thi CO2: tt c cc lnh vc ca ngnh cngnghi p gm s l tn nhiu nng l ng, mt phn quan tr ng ca qu trnh ny l vicsy kh, tip theo l nung n nhit gia 800 v 2000 C. sn xut s, nng


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l ng chim t di 10 n 18% tng chi ph. sn xut gch, t tr ng ca chi phnng lng thay i t 17 n 25% v i mc ti a ln n 30%.

Bng di y cho thy s tiu th nng l ng c th trong ngnh cngghip gm s chu u

Loi n v 1980 1985 1990 1995 2000 2003 Ngi, tm l p GJ/t 2.65 2.45 2.19 2.06 2.38 2.31T ng v gchlt sn

GJ/t 11.78 9.16 6.76 5.45 5.74 5.6

Sn phm chunhit

GJ/t 4.88 4.96 6.51 4.91 5.41 5.57

Thit b v sinh

GJ/t 26.56 24.214 22.27 22.76 20.88 21.87

ng t st GJ/t 5.75 5.77 6.1 5.23Gm gia dng GJ/t 47.56 38.91 43.46 45.18Gm k thut GJ/t 34.72 50.39Bng 1.2: Tiu th nng l ng c th trong ngnh cng nghi p gm s chu u

Ngy nay kh thin nhin, kh ha lng (propane v butan) v du nhin liuEL c s dng ch yu t, trong khi du nhin liu nng, kh t ha lng(LNG), kh sinh hc /sinh khi, in v nhin liu r n (v d nh than , du m thancc) c th ng vai tr nh ngun nng lng cho l t. Vic s dng du nhinliu nng, than v du m than cc gi i hn ch s dng cho cc nh my gch.

1.4 Quy trnh sn xut gm s1.4.1. Nguyn li u

Theo truyn thng ng i ta chia nguyn liu sn xut gm s lm 3 loi chnh :Nguyn liu do: cc loi cao lanh v t st, chng to iu kin to hnh phi

liu do. Tnh do y l do cc khong st m ra.Nguyn liu khng do, loi c gi l nguyn liu y: lm gim s co ngt

khi sy v nung, to iu kin chng nt khi sy v nung, nhng ng thi cnglm gim kh nng to hnh. So v i nguyn liu do th nguyn liu y c cc ht th

hn, ht th ng khng xp, tng i n nh v khng bin tnh khi nung, khi nungkhng co ngt. Nguyn liu y in hnh nh thch anh, corundon, t st nung(samt) v.v...

Nguyn liu khng do, loi c gi l cht tr dung : theo quan im to hnhv sy th loi nguyn liu ny tng t nh loi 2, nhng chc nng chnh ca n lto pha lng khi nung. iu ny s to iu kin v thc y nhanh qu trnh k t khi.in hnh cho loi ny l trng thch alkali hay cc nguyn liu cha cc oxyt kimth chng hn.


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ng v mt bn cht to thnh vt liu gm th nhm 1 (nguyn liu do) l quantr ng nht v khong caolinit trong t st sau qu trnh nung hnh thnh pha tinh th mullit, l khong ng vai tr quyt nh hnh thnh nn nhng tnh cht ca gm.

Ngoi cc loi nguyn liu nutrn, trong cng nghi p sn xut gm k thut ng ita dng cc nguyn liu tng hp nh cc oxit TiO2, Al2O3, ThO2, BeO... v cc loinguyn liu khc

sn xut khun ng i ta dng thch cao, nha pxy.

sn xut bao nung v cc vt liu chu la h tr khi nung ng i ta dng samt,SiC, -Al2O3...

sn xut cht mu v men ngi ta dng cc oxit mang mu nh Cr 2O3, CoO,

CrO2, MnO2, hay cc oxit t him v mt s kim loi qu nh Au, Ag, Pt... 1.4.2. Gi a cng vchu n b ph i l i u

Gi vai tr r t quan tr ng v to iu kin ci thin nhiu tnh cht ca nguyn phi liu cng nh cht l ng ca sn phm nung.

Bao gm : -Lm giu v tuyn chn nguyn liu.Gia cng th v gia cng trung bnh cc loi nguyn liu.Gia cng tinh (nghin mn) nguyn phi liu.

Chun b phi liu theo yu cu tng loi sn phm ph h p vi cc phng php tohnh khc nhau

14.2.1. Nghin To mn cho nguyn phi liu, to iu kin cho phn ng nhit cao khi

nung v din tch ti p xc gia cc ht l n, mt khc qu trnh nghin mn to ra s khuyt tt trn b mt cc tinh th vt cht nhiu hn.Chia lm ba loi: nghin th, nghin trung bnh v nghin mn.Nghin th v nghin trung bnh

Nhm p v nghin nguyn liu dng cc ln n yu cu cho php n p vo mynghin mn.Thng dng my p ba, p hm, nghin bnh xe... cho thch anh, trng thch.Thng dng my thi t, my nghin tr c trn hay my nghin tr c loi c rng

cho cc nguyn liu mm hn nh phn, t st, cao lanh...Nghin mn

Yu cu nghin mn l kch th c ht vt liu sau khi nghin phi 63 m (tcqua ht sng 10000 l/cm

2) trong c ht t 1- 20 m phi chim a s.

Nguyn liu n p vo my nghin bi th ng yu cu 1 mm.


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1.4.2.2. Chun b phi liu: Yu cu c bn ca vic chun b phi liu l :- t c chnh xc cao nht v thnh phn ho v t l cc loi c ht, thnh

phn phi liu v cc tnh cht k thut ca n cc khu khc nhau trong dy chuyn

cng ngh m bo ng tnh cht cn mong mun ca cc loi sn phm sau khinung.

- t c ng nht cao v thnh phn ho, thnh phn ht, lng n c tohnh, cht in gii hay cc loi ph gia v.v... trong phi liu theo th i gian v v trkhc nhau.Kim tra nguyn liu v tnh bi phi liu

Ngi ta th ng tin hnh nghim ngt vic kim tra cht lng u vo ca tt c cc loi nguyn liu dng cho qu trnh sn xut, nht l i v i cc sn phm gm cyu cu cht lng cao (nh gm mn, gm k thut ...). Vic kim tra bao gm: phntch thnh phn ho, thnh phn khong, cc tnh cht cng ngh ca nguyn liu(chng hn nh do v lng n c to hnh thch h p ca t st, kh nng rt, mn, co khi sy v nung v.v...) t tnh ton bi phi liu sn xut xng(hay men) bao gm c p phi ca tng nguyn liu mt, c tnh theo % tr ng l nghay phn tr ng l ng. sch cng nh cht lng t yu cu ca nguyn liu, s phn tch chnh xc vtnh ton ng bi phi liu l nhng tin c bn cho sn phm cui cng t

cht l ng cao.Chun b phi liu:

Mc ch ca vic chun b phi liu l:- To ra phi liu ng theo bi c p phi.- Ti p tc nghin mn cc loi nguyn liu n c ht yu cu.- To c s ho tr n ng nht ca tt c cc loi nguyn liu trong phi liu, c

m ng nht, c nhng thng s cng ngh ti u ph h p vi cng on to hnhti p theo.

Phng php chun b phi liu truyn thng l nghin tr n chung cc loi nguynliu thnh huyn ph n c trong my nghin bi (phung ph p nghin bi t). Khi mynghin bi quay, s ch xt, va p ca bi n vo nhau v vo thn ca thng nghinlm cho liu c nghin mn v tr n u. Cho n nay y vn l phng php hiuqu nht do c nhng u imsau:

- Nc l mi tr ng tt giptng c ng qu trnh nghin v tr n u, phi liu s t ng nht cao.

- t st, cao lanh thng c m dao ng, ta ch cn cc nh chnh xc mca n tnh ng lng n c cho vo nghin (m khng cn sy kh nguyn liunu nh chn ph ng php nghin kh)


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- Tiu tn nng lng nghin b hn nhiu so v i nghin kh.- H sau nghin c th em dng ngay to hnh rt hay to hnh do sau khi quap lc khung bn.

Nhc iml lng hao mn bi n, lp lt th ng l n g p 5 ln so v i nghin

kh. Cho nn yu cu ca bi n v l p lt cn c tnh cht ging vt liu em nghin(coi l ng hao ht bi n, lp lt nh mt cu t ca phi liu) v sau mi ln nghincn b sung bi n. i v i snh mn v s vt liu lt nn dng hoa cng (granit)hay lm bng silex (mt dng thch anh v nh hnh), bi l cui (flint, l SiO2 vnh hnh) hay s cng (s crunn chng hn); i v i my nghin phi liu h titanat (TiO2, BaO v.v...) th vt liu lt v bi n l s rutin TiO2. L p lt c th lm bng cao su cng khng lm bn liu b i t p cht st t thn thng nghin.

T l n p liu thng nh sau: Liu nghin : bi n : nc = 1 : 1: 1 n 1 : 1: 0,5

tu theo yu cu m h ra, l ng v loi cht in gii cho vo. T l 1:1:0,5 dngcho h ra my sy phun trong sn xut tm p lt ceramic.Trnh t nghin nh sau:tr c ht ng i ta nghin nguyn liu gy v i khong

10% t st hay cao lanh lc ( iu chnh nh t ca huyn ph v ngn cn s lng). Lng t st v cao lanh lc cn li c khuy thnh huyn ph trong b khuy, sau qua kim tra thnh phn ht v c hai huyn ph s tr n chung v i nhautrong b khuy tr n. H ra phi c nh t biu kin thch h p (0,2-1 Pa.s) v tr ngl ng th tch l n.

Th i gian nghin ph thuc vo l n ca thng nghin v mn ca nguyn

liu v dao ng trong khong 10-60 h. Ng i ta theo trnh t nghin trn khi nguyn liu u vo t yu cu, ngha l tst, caolin lc tr ng thi ht mn t yu cu ( t st s l ng ht 2 m l nhn 50%). Ch cn thch anh v trng thch l cn phi nghin mn. Nu ta dng caolanh khng lc (c l ng ht th-ch yu l ct trong cao lanh-l n) th phi iu chnhqu trnh nghin nghin c cao lanh. Ngi ta cng c th nghin tr n tt c nguyn liu trong my nghin bi m khng cn dng my khuy tr n.Tnh phi liu :

Phi liu nhm gm xy dng :C s chn phi liu nh h ng ca nhm ny l thnh phn ho hc l thuyt

trn biu Apgutchinit v biu thnh phn t l cc c ht theo Winkler.

Phi liu snh vi :t st v cao lanh khong 62 %

Quc hay ct khong 26 %

vi hay phn khong 12 %


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Snh trng thch (hay snh cng) :t st tr ng n 40 %

Cao lanh n 20 %

Tr ng thch n 6 %

Phi liu ny nung nhit 13000C.

Phi liu cc loi sChun b v gia cng phi liu gm th :

Mt hng gm th ch yu l s dng trong lnh vc xy dng v dn dng baogm gch ngi,ng snh thot n c v dn n c, gch klinker, chum, vi, vt liuchu axit v cc loi vt liu xy dng dng dm, si nhn to nh keramzit, aglpritv.v...

Gia cng t nhin s b.

Khai thc nguyn liu dn thnh ng ti m hay kho. Nu nguyn liu c cngkh cao, dng cc (t i) th tin hnh ngm tm trong cc l ring c phun n ctha ng. Khu ny xc tin qu trnh hydrat ha, trng n th tch, k t qu lm cho cng gim, do tng.

Gia cng c kh

Ni chung gm th th ng gia cng v chun b theo cc phng php sau :

- Chun b phi liu bng phng php t.

- Chun b phi liu bng phng php kh.

- Chun b phi liu bng phng php bn kh hay na kh, na t.

- Chun b phi liu bng phng php nhit.Mi phng php u c u nhc im ring. Phng php kh thch h p vi t

st c cng cao, km do (phin thch st), t p cht nhiu.u dim l: d tr n u,iu chnh c c p phi ht theo c ht mong mun. Nhc im l: ch ph h p v i phng php to hnh bn kh.

Phng php t l phng php c in, r t ph bin trong cng nghi p gm s.u im: d nng cao cng mc, do phi liu, to hnh d dng, ph phm t,

cht l ng bn thnh phm v thnh phm cao.


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Chun b phi liu gm mn (gm tinh) :Yu cu chun b phi liu r t k cng k c khu tuyn chn nguyn liu ban u

nht l i v i mt hng s cao c p.

Nguyn liu ch yu sn xut gm mn l t st tr ng, cao lanh v trng thch.Cc loi nguyn liu ny phn ln c phn loi, tuyn chn, gia cng th, trung bnh ti m hoc cc c s gia cng ring, c tr g hp mn t yu cu 63m.

Thngth ng cc loi vt liu gy m i ch t mn trung bnh, tr ng h p ny phi chun b phi liu trong my nghin bi t gin on.

nng cao hiu qu nghin, th ng cc loi vt liu gy c cng cao cnp vo my tr c v i mt l ng bi kh l n (km theo mt lng t st hay cao lanhnht nh). Sau mt th i gian nghin kim tra mn nu gn t yu cu th cho ton b nguyn liu ( t mn) cn li v thm bi, n c theo t l nguyn liu/bi/n c= 1/1/1 r i ti p tc nghin thm 4 - 5 gi. Tr c khi tho h nht thit phi kim tra mn. H t tiu chun tho vo b khuy qua sng rung (4900 l/cm

2) v b phi

c khuy lin tc.t mc sau khi qua p lc khung bn c m 25 - 26%.t mc c trong kho v i th i gian t nht 7 ngy.Phi liu c em luyn trong my n p chn khng nhm tng do,

gim lng khng kh c trong t mc ( gim p 750 760 mmHg).Chiu dy mng t i vo bung chn khng cng mng cng tt. Chng ta c th tnh ton c n v thay i chiu dy mng t theo mun bng cch thay ikch th c mt l i phn phi di t u vo bung chn khng.

Phng php to hnh m thch h pH rt 28 - 40 %To hnh do 22 - 25 %Tin do 18 %Ep do 12 - 15 %Ep bn kh v kh 3 - 9 %

h rt c m thch h p, cng b cng tt cn phi pha long h bng chtin gii vi hm l ng v cht in gii thch h p.

1.4.2.3. Kim tra k thut phi liu Ni dung kim tra bao gm :- Kim tra chnh xc v ng nht v thnh phn ha, thnh phn ht v m.- Kim tra mu sc ca t mc sau khi nung.- Kim tra mt s tnh cht k thut ca phi liu nhit thng: do, c ng

mc, co sy v.v...- Kim tra cc tnh cht ca phi liu nhit cao (ch yu l nhit nung).


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1.4.3 T o hnhMc ch ca khu to hnh cng nh yu cu c bn ca n l tho mn cc ch

tiu v kch th c, hnh dng hnh hc, ng nht ca bn thnh phm v ca sn phm.

Theo mc ng nht (thnh phn, m, mt v cu trc) do cc phng php to hnh t c th tng qut c th s p x p theo th t sau:- rt sn phm r ng (h tha)- rt sn phm c (rt h y)- Xy trn my (loi u nn)- Xy trn my (loi dao bn) v k c vut, gn rp bng tay- p bn kh- p do- Nn p th cngC s la chn phng php to hnh bao gm nhiu yu t song tng qut l

cc iu ch yu sau:- Hnh dng v cc tnh cht c trng ca cc loi sn phm.- Tnh cht k thut ca phi liu.- Nng sut v gi thnh (ph).Cn c vo hnh dng sn phm chn phng php to hnh l cha , m iu

quan tr ng l phi cn c c vo c tnh k thut ca phi liu m i chn ng phng php ti u. *Cc phng php ti hnh - To hnh do : Phng php to hnh do bao gm vut trn b quay, gn rp trongkhun thch cao (chum, vi), xy trn my bn tua dao bn hay u nn, p do bngcc loi my (p ngi v gch bng my p ngi hay my n p chn khng).- To hnh bng phng php rt: Khi rt h vo khun thch cao, do thchcao c kh nng ht n c nn h chuyn ng theo h ng thnh khun bm voYu cu c bn ca h rt

- Lng n c t nht gim thi gian rt v th i gian sy.

- linh ng ca h tt c ngha l nht b m bo vn chuyn trong ngng v rt d.- H phi bn: khng c hin t ng lng, khng keo t, khng ng snh, nh t

h n nh.- Tc bm khun l n.- L ng cht in gii b nht (chn ng cht in gii ti u, hm l ng h p l)- Kh nng thot khun d, t khuyt tt nh r mt v.v...

1.4.4 S y


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Sn phm gm s sau khi to hnh lng n c c th t i 25%. Tc trong 1 kg philiu (hay sn phm mc) c 0.25 kg nc. vic sa mc, vn chuyn, trng men vnung d dng bt buc phi sy sn phm. Nhit ho hi ca 1 kg n c l 585 kcal,vy l ng nhit cn thit sy 1kg phi liu c th n 146 kcal.

Khi sy hi m s thot ra, nu chng thot ra t ngt, phn n c trn b mthay st b mt thot ra d dng nhng hi m bn trong lng sn phm thot ra r t khkhn do p sut ring phn ca n nhng v tr n c t p trung s tng t ngt,nu p sut y v t qu lc lin k t ca cc ht st (tc cng ph v ca mc) s gy nn hin t ng n sn phm ngay lc sy (hay lc nung).

Nh vy vn ch yu ca k thut sy l sy ng u bn thnh phmkhng b nt, sau l tm cc bin php k thut rt ngn th i gian sy, gim vnu t thit b, gim din tch sy v tng nng sut.

1.4.4.1. Qu trnh sy Mc ch ca qu trnh sy l loi b n c lin k t l hc (cn gi l n c t do,

nm cc l tr ng gia cc ht vt liu) hay n c lin k t ho l (bao gm n c h p ph, n c hydrat ho v cc loi khong st ba lp silicat l nc trng n ).Sn phm gm s ni chung l kh dy, lc sy n c b mt d bc hi gy nn chnh lch hmm trn b mt v trong lng sn phm, do n c trong lng s khuych tn ra ngoi b mt v ti p tc bc hi. Nh vy tc sy chng nhng ph thuc vo kh nng bc hi trn mt sn phm m cn ph thuc vo tc khuych

tn n c t bn trong ra bn ngoi.Qu trnh sy c c trng bng 3 giai on: giai on t nng, giai on hng

tc sy v giai on gim tc sy nh cho trong hnh 18.Giai on u ca qu trnh sy c c trng bng s t nng nhanh bn thnh

phm t nhit ban u n nhit ca cht ti nhit bo ho ( mt hmmcho tr c ca cht ti nhit). Nhit ca n tng ng v i cc ch s trn nhit k t, cn nhit mi trng , tng ng cc ch s trn nhit k kh.

Giai on th hai ca qu trnh sy c c trng bng on nm ngang trn

ng cong tc sy, iu ch ra r ng tc sy v tr s bng tc bc hi mtrn b mt ca bn thnh phm. Hmm ca bn thnh phm thay i hu nh theo ng thng.Giai on ba ca qu trnh sy c c trng b i s gim tc sy v s tng nhit ca bn thnh phm. Cng tchm ca giai on ny t l vi m trung bnh ca vt liu trong khong t m t i hn n m cui cng.1.4.4.2 K thu t s y:

Yu cu chung i v i thit b sy l- Tc sy l n nht cho php song vn m bo c cht l ng sn phm.

- Tiu tn nhit nng ring t.- Sy m bo ng u.


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- Cung bc hi m trn mt n v (m3) thit b l n

- D iu chnh cc thng s ca ng lc sy- C gi i ho vic bc d , vn chuyn sn phm v t iu kin v sinh.Trong cc yu cu trn, yu cu v t ng u l quan tr ng hn c.

Phi liu cha vt cht st v cao lanh ni chung l kh sy. t c mc ch sy nhanh, an ton, r , mi loi sn phm vi cc c tnh

k thut ca phi liu ring cn nghin cu k xy dng cho chng ch sy tiu.Vic la chn ng lc sy h p l s gp phn h gi thnh. Vic ny cn da votiu chun v cht l ng ca cc loi sn phm chn cho ng.

Sy sn phm gm xy dng do i hi v cht l ng sn phm v mt mu sckhng nghim ngt, cho php chn l sy tunel, ng lc sy l khi l hay khng khnng c gia nhit bng khi l.

Sn phm gm tinh vi nh s dn dng (bt, a, m chn), s v sinh, s cchin v.v... i hi mu sc tr ng, trong, sch, cn chn ng lc sy l khng kh nng c gia nhit bng hi n c qu nhit. Sy cc loi sn phm ny khi chn thit b sy phi cn c vo hnh dng, kch th c v khi l ng tng loi sn phm. Gmtinh vi thit b sy thch h p l l sy xch chuyn, sn phm s v sinh hay s inthch h p l l sy phng loi hin i, sn phm to hnh bng rt nu l gm tinhvi th thit b sy h p l li l bng sy hay a quay.V i s cch in cao th, phng thc sy nhanh, an ton, hin i nht l sy caotn.1.4.5 Nung

Nung l khu quan tr ng nht trong k thut sn xut gm s. Nnh h ng quytnh n cht l ng v gi thnh.

Khi nung, c th trong vt liu s xy ra phn ng nhit cao ca cc cu t trong nguyn liu, qu trnh k t khi, qu trnh xut hin pha lng, qu trnh ho tanv ti k t tinh cc tinh th. Tm li, ni tng qut khi nung xy ra ng th i cc qutrnh trao i nhit v trao i cht, cc qa trnh ny li do nhng bin i ho hc v bin i pha din ra r t phc t p.

Tuy nhin, iu quan tr ng nht l k t qu ca qu trnh nung: to ra vt liu m ic vi cu trc m i. Qu trinh nung khng nhng l iu kin hnh thnh nn vtliu m i, m ngay trong chnh bn thn qu trnh cng cha ng nguy c: c th lmcho sn phm b bin dng hay thm ch ph hoi s nguyn vn ca n, tc l lmcho sn phm c th b cong vnh hay thm ch nt, v . iu ny c bit d xy rakhi dng nhng nguyn liu t st r t nhy khi nung.

Sau giai on sy, nhin liu c a thm vo bung t v t trong khongth i gian t 4 5 gi . Th i gian bo n l 30 pht. Khi ngn la trong gm gi sngtr ng l lc than trong l chy u, lc dng t ci than t chy trong l.

Qu trnh ny ko di t 10 12 gi. Qu trnh nung t l than th cng cthc hin ch yu da vo kinh nghim nung t ca cc th l. Qu trnh chy trong


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l l mt qu trnh t nhin, nhit nung ph thuc vo cht l ng than cm, cch phi liu, u ch v s l ng than chng vo l.

Theo kinh nghim khi chng l th l ng than chng xung quanh t ng l vca l nhiu hn gia l. Than dng trong gm gi c u ch c t l than cao

hn d bn trong qu trnh nung (t l than 80%, cht n 20%).Qu trnh lm ngui l mt qu trnh t nhin, th i gian t khi chng l n khi ra

l phi mt t 4 5 ngy tu theo sn phm nung t l n hay nh. Trong qu trnh d l, v sn phm v nhin liu c x p chng xen k nn y cng l mt khu r tnng nhc, nh hng n sc kho ca ngi lao ng do bi than v hi nng. Nhng hn ch ca l th cng truyn thng t than:

Cng vic x p sn phm vo l v ra l r t nng nhc, tn nhiu lao ng,Sut tiu hao nhin liu cao,T l thu hi sn phm th p,Cht l ng sn phm

khng cao,Ch nung c trong mi trng oxy ho, khng nung c trong mitr ng kh (gm cht l ng cao cn nung trong mi tr ng kh),Khng iu chnh c nhit theo mun trong qu trnh nung,Hm l ng tro thi l n t 33 40%,Gy nhim mi tr ng do pht thi nhiu loi kh thi trong qu trnh nung nhkh: CO, CO2, SO2.1.4.6 Trng men1.4.6.1 Men s :

Men v bn cht l mt l p thu tinh mng (chiu dy 0.1-0.4 mm) ph ln b mtxng gm s. Nhit chy ca n c chn ph thuc vo nhit k t khi ca

xng gm s, thng thng dao ng trong khong 900-14000

C.Tuy nhin, so v i thu tinh thng thng th n cng c nhng tnh cht khc: nkhng ng nht, l p trn khi nung phn ng vi mi tr ng ca l nung, lp d i th phnng vi xng, trong l p men c nhng cht khng tan hay k t tinh.

Men c th c phn loi theo nhiu cch khc nhau.- Theo sn phm: men snh, men s.- Theo lng b mt: men lng, men sn.- Theo mi tr ng nung trong l:men xi ho hay men kh.

- Theo nhit nung: men d chy (nhit nung 710-1120

0

C), men chy trung bnh (nhit nung 1060-1200

0C), men kh chy (nhit nung 1200-1280

0C) v

men r t kh chy.(nhit nung trn 12800C, thng dng trng ln s).

- Theo thnh phn cht chy s dng: men ch, men alkali, men tr ng thch.Cch phn loi ny c lin quan cht ch n cch phn loi theo nhit nung.Chng hn men d chy c hai nhm chnh c nhit chy kh gn nhau l men ch(nhit nung 710-1120

0C) v men alkali (nhit nung (750-1060

0C)). Trong men

alkali thng dng thm bor (th ng dng Na2CO3, borax, clemanit). Men ch vmen alkali lm cho b mt men lng bng. Men chy trung bnh th ng dng cht


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chy l xit ch (d chy) v trng thch (kh chy). Men kh chy th ng dng trngthch v cc nguyn liu khc nh vi, ZnO, BaO... Men rt kh chy c ch tot quc, trng thch v cao lanh. Cht chy y l trng thch.

- Theo cch sn xut men c th chia ra thnh:

+ Men sng (hay l men nguyn liu)+ Men frit:+ Men mui:- Tu theo v ngoi ca men chng ta c th chia ra: men trong, men c, men

mu, men tinh th, men bng hay m (bn m )...1.4.6.2 Cc tnh ch t c a men

Tnh cht c vai tr to l n trong qu trnh thnh to cng nh s dng l s dn n nhit ca men. Cc tnh cht sau khi men hnh thnh nh cng, tnh cht in, bn ho hc.

Chiu dy l p men to thnh ph thuc vo x p ca xng gm, c bit khi l x p nh va (d = 50-2 nm) v vi xp (d < 2 nm) t hn s l ng l x p l n (d > 50nm), ph thuc vo th i gian nung men v tnh cht ca huyn ph, dy ca l pmen trng.

Khi nung trong men din ra cc qu trnh phn hu cc cht u, chng hn nhCaCO3 v cc phnng khc v chng nng chy.

trong thi gian nung th ng ny sinh gia men v xng mt lp trung gian c dy 10-50 m. L p trung gian ny c thnh phn ho, hm l ng v thnh phn pha

tinh th, pha kh v.v... khc vi xng v men. S xut hin l p trung gian ph thucvo thnh phn ho, thnh phn ht ca xng v men, vo th i gian v nhit nung, vo x p ca xng...

Trong cc nguyn liu hnh thnh l p trung gian th CaO l ph gia tt nht, ncng chng nt men tt. Do vy trong hu ht cc loi men u c CaCO3 a vo.Trong qu trnh nung CaO trong men tan ra th trong xng cng nh vy, ko theo s tan ca nhng phn t khc, qua lp trung gian c hnh thnh v pht trin t c hai pha. Ngoi CaCO3 ng i ta cn dng vlastnit (CaO.SiO2) v lmit (c tcdng km hai loi kia).

Ph gia CaCO3 cho vo menc tc dng chng nt men tt do:- Tng h s dn n cho xng.- Tng qu trnh to l p trung gian.- Cn tr s trng n ca xng. Men trong qu trnh s dng phi bn vi mi tr ng, chng hn n c, khng kh

(CO2), bn trong mi tr ng axit v kim long. y cn c vn men bn khigm c dng trong thc phm. Men s trn thc t khng thi ra cc cht c hi.Vn chnh l ch men nh la, r t khng bn v i cc cht axit t trong thc phm.


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Men s bn ho nu t kim. PbO v B2O3 cng lm gim bn ho. Cc xitnng cao bn ho: SiO2, Al2O3. Khi Al2O3 tng th bn ho tng nhng phi

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