Nghiên cứu khả năng lắng bùn đỏ sau hòa tách bauxit gia nghĩa, tây nguyên

i MC LC MC LC i DANH MC CC Kí HIU V CH VIT TT iv DANH MC CC BNG v DANH MC CC HèNH NH V TH vii M U Chng TNG QUAN .3 1.1 S hỡnh thnh v nhng tớnh cht c trng ca bựn 1.2 S phõn tỏch cỏc pha rn, lng ca bựn 11 1.3 Tỡnh hỡnh nghiờn cu quỏ trỡnh lng bựn 11 1.3.1 Trờn th gii 11 1.3.2 Trong nc 23 1.4 nh hng nghiờn cu 25 Chng 26 C S Lí THUYT QU TRèNH LNG TCH BN 26 2.1 Quỏ trỡnh lng cỏc ht rn 26 2.2 Lng t 26 2.2.1 Ht hỡnh cu 26 2.2.2 Ht khụng phi hỡnh cu 27 2.3 Lng vng mc 29 2.4 Cỏc yu t nh hng n quỏ trỡnh lng bựn 32 2.4.1 Thnh phn vt cht ca bauxit 32 2.4.1.1 Hm lng silic hũa tan 32 2.4.1.2 Hm lng pht 32 2.4.1.3 Hm lng gtit 33 2.4.1.4 Hp cht hu c 33 2.4.2 Kớch thc ht bauxit 34 2.4.3 Cỏc thụng s cụng ngh hũa tỏch 34 2.4.3.1 Lng np bauxit 34 2.4.3.2 Nng dung dch hũa tỏch 34 2.4.4 Nhit lng 34 ii 2.5 S cn thit phi cng húa quỏ trỡnh lng bựn 34 2.6 Cng húa quỏ trỡnh lng bựn bng cỏc cht tr lng 38 2.6.1 Cht tr lng v quỏ trỡnh phỏt trin 38 2.6.1.1 Cht tr lng 38 2.6.1.2 Quỏ trỡnh phỏt trin cht tr lng 38 2.6.2 Cht tr lng hu c t nhiờn - Tinh bt 39 2.6.3 Cht tr lng hu c tng hp 40 2.6.4 Cht tr lng hu c tng hp bin tớnh 42 2.6.5 Cỏc phng phỏp to thnh hp ht quỏ trỡnh lng 43 2.6.5.1 Phng phỏp kt t 43 2.6.5.2 Phng phỏp kt bụng 44 2.7 C ch tng tỏc kt bụng gia cht tr lng v bựn 45 2.7.1 C ch bc cu 45 2.7.2 C ch hot húa b mt 46 2.7.3 C ch liờn kt tnh in 47 2.8 Quỏ trỡnh hp ph 47 Chng 49 CHUN B MU V CC PHNG PHP NGHIấN CU 49 3.1 Chun b bựn theo cụng ngh Bayer chõu M 49 3.1.1 Qung tinh bauxit Gia Ngha 49 3.1.2 Dung dch hũa tỏch 51 3.1.3 Tớnh toỏn lng np bauxit 51 3.1.4 Quy trỡnh chun b bựn 52 3.2 Cht tr lng 53 3.3 Thit b nghiờn cu 54 3.3.1 Thit b tin kh silic v ho tỏch bauxit 54 3.3.2 Thit b lng 54 3.3.3 Mỏy o nht 55 3.3.4 Mỏy o c 55 3.4 Cỏc phng phỏp nghiờn cu 55 3.4.1 Xỏc nh kớch thc ht, thnh phn vt cht ca qung tinh bauxit v bựn Gia Ngha 55 3.4.2 Xỏc nh cỏc thụng s lng c trng 56 3.4.2.1 S thay i chiu cao ct bựn 56 iii 3.4.2.2 Tc lng giai on u 56 3.4.2.3 nộn trung bỡnh ca bựn 56 3.4.3 Xỏc nh nht ca dung dch natri aluminat 57 3.4.4 Xỏc nh c ca dung dch natri aluminat 57 Chng 58 KT QU V THO LUN 58 4.1 Thnh phn hoỏ hc v khoỏng vt ca qung tinh bauxit Gia Ngha 58 4.1.1 Thnh phn húa hc 58 4.1.2 Thnh phn khoỏng vt 58 4.2 Kho sỏt cỏc yu t nh hng n quỏ trỡnh lng bựn 61 4.2.1 St dng gtit 62 4.2.2 Kớch thc ht qung tinh bauxit 67 4.2.3 Lng np bauxit 72 4.2.4 H s pha loóng huyn phự 75 4.2.5 Nhit lng 79 4.3 Cng húa quỏ trỡnh lng bựn 83 4.3.1 Lng t nhiờn bựn 83 4.3.2 Cht hu c t nhiờn 85 4.3.3 Cht hu c tng hp bin tớnh (HX) 90 4.3.4 Kh nng kt hp 96 4.4 xut phng ỏn s dng cht tr lng cho quỏ trỡnh lng bựn sau hũa tỏch bauxit Gia Ngha 102 KT LUN CHUNG 105 TI LIU THAM KHO 106 DANH MC CC CễNG TRèNH CễNG B CA LUN N 113 PH LC 114 iv DANH MC CC Kí HIU V CH VIT TT Gii thớch Ký hiu g/cm3 gram/centimet g/mol gram/mol kg/t kilogram/tn g gram (n v o lng, g = 10-3 kg) g/kg gram/kilogram mg/l miligram/lớt ml mililớt (n v o th tớch, ml = 10-3 lớt) mV milivụn (n v o in th, mV = 10-3 vụn) mm milimet cm centimet m (n v o chiu di) m3 km2 kilomet vuụng % phn trm C C MKN mt nung MSi mụun silic hiu sut phõn hy nhụm hydroxit lt hiu sut hũa tỏch lý thuyt tt hiu sut hũa tỏch thc t àm micromet h gi (n v o thi gian) c t s caustic Na2Oc kim caustic HX hydroxamated PAA Polyacrylate PAM Polyacrylamide GN Gia Ngha S c Song v DANH MC CC BNG Bng 1.1 Thnh phn húa hc v khoỏng vt c bn ca bauxit Bng 1.2 Thnh phn húa hc c bn ca bauxit mt s nc Bng 1.3 Thnh phn húa hc ca mt s loi bựn Bng 1.4 Thnh phn khoỏng vt ca cỏc loi bựn khỏc Bng 1.5 S chuyn bin t gtit thnh hematit hũa tỏch bauxit 17 Bng 1.6 Cỏc nc cú tim nng ln hng u v bauxit 23 Bng 2.1 Giỏ tr h s i vi cỏc ht cú hỡnh dng khỏc 28 Bng 2.2 Giỏ tr h s i vi cỏc ht cú hỡnh dng khỏc 29 Bng 2.3 S liờn h gia kớch thc ht v thi gian lng t nhiờn 35 Bng 2.4 S n nh ca h keo v giỏ tr 36 Bng 2.5 Mt s hp cht thng dựng lm cht tr lng 38 Bng 2.6 c im ca mt s h thng tinh bt 40 Bng 2.7 Mt s hp cht thng dựng lm cht kt t 44 Bng 4.1 Thnh phn húa hc chớnh ca qung tinh bauxit Gia Ngha 58 Bng 4.2 Thnh phn khoỏng vt ca qung tinh bauxit Gia Ngha 58 Bng 4.3 Khoỏng vt st v tng hm lng st ụxit bauxit 62 Bng 4.4 Khoỏng vt st v tng hm lng st ụxit bựn 62 Bng 4.5 Din bin lng bựn thụng qua chiu cao ct bựn theo thi gian 63 Bng 4.6 Tc lng ca bựn giai on u 64 Bng 4.7 nộn trung bỡnh ca lp bựn 65 Bng 4.8 c ca dung dch natri aluminat 66 Bng 4.9 Thnh phn cp ht cỏc mu nghiờn cu 67 Bng 4.10 Din bin lng ca bựn thụng qua chiu cao ct bựn theo thi gian 68 Bng 4.11 Tc lng ca bựn giai on u 69 Bng 4.12 c ca dung dch natri aluminat 69 Bng 4.13 nộn trung bỡnh ca lp bựn 70 Bng 4.14 Phõn b kớch thc ht bựn sau lng 71 Bng 4.15 Thnh phn húa hc ca bựn 71 Bng 4.16 Din bin lng bựn thụng qua chiu cao ct bựn theo thi gian 73 Bng 4.17 Tc lng ca bựn giai on u 74 Bng 4.18 nộn trung bỡnh ca lp bựn 74 vi Bng 4.19 c ca dung dch natri aluminat 74 Bng 4.20 Din bin lng bựn thụng qua chiu cao ct bựn theo thi gian 76 Bng 4.21 Tc lng ca bựn giai on u 77 Bng 4.22 nht ca dung dch natri aluminat vi h s pha loóng khỏc 77 Bng 4.23 nộn trung bỡnh ca lp bựn 78 Bng 4.24 c ca dung dch natri aluminat 78 Bng 4.25 Thnh phn dung dch natri aluminat sau lng 79 Bng 4.26 Din bin lng bựn thụng qua chiu cao ct bựn theo thi gian 80 Bng 4.27 Tc lng ca bựn giai on u 81 Bng 4.28 nht ca dung dch natri aluminat cỏc nhit khỏc 81 Bng 4.29 c ca dung dch natri aluminat 81 Bng 4.30 nộn trung bỡnh ca lp bựn 82 Bng 4.31 S thay i chiu cao ct bựn v c ca dung dch natri aluminat 84 Bng 4.32 S thay i chiu cao ct bựn s dng tinh bt m 86 Bng 4.33 S thay i chiu cao ct bựn s dng tinh bt DR 87 Bng 4.34 Tc lng ca bựn giai on u 88 Bng 4.35 nộn trung bỡnh ca lp bựn 88 Bng 4.36 c ca dung dch natri aluminat 89 Bng 4.37 Thnh phn ca tinh bt s dng 90 Bng 4.38 S thay i chiu cao ct bựn s dng HX400 92 Bng 4.39 S thay i chiu cao ct bựn s dng HX600 94 Bng 4.40 Tc lng ca bựn giai on u s dng HX400 94 Bng 4.41 Tc lng ca bựn giai on u s dng HX600 95 Bng 4.42 nộn trung bỡnh ca lp bựn 95 Bng 4.43 c ca dung dch natri aluminat 95 Bng 4.44 S thay i chiu cao ct bựn theo thi gian 98 Bng 4.45 Tc lng ca bựn giai on u 99 Bng 4.46 c ca dung dch natri aluminat 100 Bng 4.47 nộn trung bỡnh ca lp bựn 101 Bng 4.48 So sỏnh cỏc thụng s c trng lng ca tinh bt DR v HX400 102 Bng 4.49 Ch lng v kt qu 103 vii DANH MC CC HèNH NH V TH Hỡnh nh nh 4.1 Gibxit dng tm, gtit dng que (phúng i 75 ln, di nicon) 60 nh 4.2 Gibxit dng (phúng i 75 ln, di nicon) 60 nh 4.3 Kớch thc ht bựn 71 th Hỡnh 1.1 S cụng ngh sn xut alumin t bauxit bng phng phỏp Bayer tng quỏt v rỳt gn .5 Hỡnh 1.2 Phõn b kớch thc ht mn v ht thụ c trng ca bựn 10 Hỡnh 1.3 ng cong lng c trng ca cỏc loi bựn 12 Hỡnh 1.4 Phõn b bauxit Vit Nam theo vựng 24 Hỡnh 2.1 S ph thuc ca chun s Ly, Re vo chun s Ar i vi quỏ trỡnh lng t mụi trng tnh 28 Hỡnh 2.2 ng cong c trng biu din chiu cao ct bựn v thi gian 31 Hỡnh 2.3 Cu to ht keo 35 Hỡnh 2.4 Nng lng tng tỏc ca h keo 37 Hỡnh 2.5 Cu trỳc ca amiloza 39 Hỡnh 2.6 Cu trỳc ca amilopectin 39 Hỡnh 2.7 Cu trỳc ca polyacrylamide 40 Hỡnh 2.8 Cu trỳc ca polyacrylate .50 Hỡnh 2.9 Copolyme ca acrylamide v acrylate 41 Hỡnh 2.10 Cht tr lng hydroxamated polyacrylamide cha ba nhúm chớnh: amid, carboxyl v hydroxamate 42 Hỡnh 2.11 S quỏ trỡnh kt bụng v nh hng ca nú n tc lng 45 Hỡnh 2.12 Liờn kt hai ht theo c ch bc cu 46 Hỡnh 2.13 Hỡnh dng phõn t cht tr lng trờn b mt bựn 46 Hỡnh 2.14 Liờn kt hai ht theo c ch hot hoỏ b mt 47 Hỡnh 2.15 Liờn kt hai ht theo c ch tnh in 47 Hỡnh 3.1 Quy trỡnh chun b kớch thc ht bauxit 50 Hỡnh 3.2 Quy trỡnh chun b dung dch luõn lu 51 viii Hỡnh 3.3 Thit b ho tỏch 54 Hỡnh 3.4 Thit b lng bựn 54 Hỡnh 3.5 Mỏy o nht 55 Hỡnh 3.6 Mỏy o c 55 Hỡnh 4.1 Gin nhiu x tia X ca qung tinh bauxit Gia Ngha 59 Hỡnh 4.2 S thay i chiu cao ct bựn theo thi gian 64 Hỡnh 4.3 c ca dung dch natri aluminat 66 Hỡnh 4.4 S thay i chiu cao ct bựn theo thi gian 68 Hỡnh 4.5 Tc lng bựn giai on u vi kớch thc ht khỏc 69 Hỡnh 4.6 c ca dung dch natri aluminat 70 Hỡnh 4.7 S thay i chiu cao ct bựn theo thi gian 73 Hỡnh 4.8 c ca dung dch natri aluminat 75 Hỡnh 4.9 S thay i chiu cao ct bựn theo thi gian 76 Hỡnh 4.10 nht ca dung dch iu kin pha loóng huyn phự khỏc 77 Hỡnh 4.11 c ca dung dch natri aluminat 78 Hỡnh 4.12 S thay i chiu cao ct bựn theo thi gian 80 Hỡnh 4.13 nht ca dung dch natri aluminat 81 Hỡnh 4.14 c ca dung dch natri aluminat 82 Hỡnh 4.15 S thay i chiu cao ct bựn v c ca dung dch natri aluminat 84 Hỡnh 4.16 S thay i chiu cao ct bựn 85 Hỡnh 4.17 S thay i chiu cao ct bựn 88 Hỡnh 4.18 c ca dung dch natri aluminat 89 Hỡnh 4.19 S thay i chiu cao ct bựn s dng HX400 93 Hỡnh 4.20 S thay i chiu cao ct bựn s dng HX600 93 Hỡnh 4.21 c ca dung dch natri aluminat 96 Hỡnh 4.22 S thay i chiu cao ct bựn theo thi gian 99 Hỡnh 4.23 Tc lng bựn giai on u 100 Hỡnh 4.24 c ca dung dch natri aluminat theo thi gian 100 Hỡnh 4.25 nộn trung bỡnh ca bựn theo thi gian 101 M U Theo kt qu thm dũ a cht, nc ta c xp vo quc gia cú tr lng bauxit ln trờn th gii, ch yu trung ti Tõy Nguyờn õy l tin quan trng cho xõy dng nn cụng nghip alumin - nhụm Vit Nam tng lai c trng ni bt ca bauxit Tõy Nguyờn l nhụm oxit tn ti dng khoỏng vt gipxit, cũn st ch yu dng gtit Theo cỏc nh khoa hc v ngoi nc, bauxit vựng ny d hũa tỏch cho phộp ỏp dng cụng ngh Bayer chõu M sn xut alumin Tuy nhiờn, hn ch ln l bựn hỡnh thnh sau hũa tỏch bauxit ny rt khú lng õy l ỏnh giỏ ỏng quan tõm i vi nhng ngi lm cụng ngh sn xut alumin Lng bựn l cụng on quan trng sn xut alumin bng cụng ngh Bayer vi chc nng tỏch cn dung dch natri aluminat Cú nhiu yu t nh hng trc tip cng nh giỏn tip n quỏ trỡnh lng bựn , ú phi k n nh: thnh phn vt cht v kớch thc ht ca bauxit, ch cụng ngh hũa tỏch, ch lng bựn v c bit l cht tr lng s dng Vi tm quan trng, ý ngha khoa hc v thc tin ca quỏ trỡnh lng cụng ngh alumin, ti nghiờn cu ca lun ỏn c chn vi tờn gi Nghiờn cu kh nng lng bựn sau hũa tỏch bauxit Gia Ngha, Tõy Nguyờn Ni dung trng tõm ca ti l nghiờn cu cỏc yu t nh hng n quỏ trỡnh lng v kh nng cng húa quỏ trỡnh lng bựn bauxit Gia Ngha bng cỏc cht tr lng l cht hu c t nhiờn v cht hu c tng hp bin tớnh Mc tiờu ca lun ỏn: - Xỏc nh cỏc yu t c bn nh hng n kh nng lng bựn - Xỏc nh kh nng cng húa quỏ trỡnh lng bựn bng cỏc cht tr lng hu c t nhiờn, hu c tng hp bin tớnh dng c lp hoc kt hp, ng thi lm rừ c ch tng tỏc ca chỳng vi bựn - xut phng ỏn s dng cht tr lng vi hm lng la chn v ch tng ng i tng v phng phỏp nghiờn cu: - i tng nghiờn cu l bựn ca bauxit Gia Ngha mt nhng ngun qung cú tớnh i din v tr lng v thnh phn vt cht cho bauxit khu vc Tõy Nguyờn - ó s dng phng phỏp nghiờn cu sau õy thc hin ni dung ca lun ỏn: phng phỏp tng hp, phõn tớch ỏnh giỏ, phng phỏp thc nghim v cỏc phng phỏp x lý kt qu thc nghim í ngha khoa hc v thc tin ca lun ỏn: õy l cụng trỡnh nghiờn cu c bn, ton din u tiờn nc ta v lng bựn cụng ngh sn xut alumin bng phng phỏp Bayer chõu M t qung tinh bauxit Gia Ngha + Lm rừ cn c khoa hc ca mt s yu t nh hng ỏng k ti kh nng lng ca bựn : thnh phn vt cht (hm lng gtit), kớch thc ht v lng np bauxit cho hũa tỏch, h s pha loóng huyn phự, nhit lng + Kho sỏt kh nng tr lng bựn ca cỏc cht hu c t nhiờn (tinh bt m, tinh bt DR), hu c tng hp bin tớnh (HX400, HX600) v phng ỏn kt hp (tinh bt DR vi HX600) i vi cht tr lng hu c t nhiờn, ó phỏt hin tinh bt DR ngun nguyờn liu sn cú nc, cú kh nng tr lng cao hn tinh bt m - cht tr lng truyn thng õy l mt phỏt hin mi úng gúp ỏng k vo vic phỏt trin loi cht tr lng hu c t nhiờn Cũn vi hai cht tr lng hu c tng hp bin tớnh HX400 v HX600 thỡ HX600 cho kt qu lng cao hn Phng ỏn kt hp gia cht hu c tng hp bin tớnh (HX600) v hu c t nhiờn (tinh bt DR) vi hm lng c chn t hiu qu kinh t - k thut tt S kt hp ny cng l mt úng gúp mi vic a dng húa phng ỏn s dng cht tr lng hu c t nhiờn v tng hp bin tớnh Kt qu la chn phng ỏn s dng c lp cht tr lng hu c t nhiờn (tinh bt DR) hay hu c tng hp bin tớnh (HX600) hoc phng ỏn kt hp c hai loi trờn khụng ch cú ý ngha ln i vi thc tin lng cụng ngh sn xut alumin m cũn gim c mc gõy ụ nhim mụi trng Ni dung v b cc ca lun ỏn: Ngoi phn m u v phn kt lun chung, ni dung ca lun ỏn c trỡnh by chng Chng Tng quan v bựn v quỏ trỡnh lng bựn Chng C s lý thuyt quỏ trỡnh lng tỏch bựn Chng Chun b mu v cỏc phng phỏp nghiờn cu Chng Kt qu v tho lun 99 Chiu cao ct bựn [mm] 500 450 400 350 B1 300 B2 B3 250 B4 B5 200 B6 150 100 50 0 20 40 60 80 100 120 Thi gian [phỳt] Hỡnh 4.22 S thay i chiu cao ct bựn theo thi gian Bng 4.45 Tc lng ca bựn giai on u Tc lng trung bỡnh [mm/phỳt] Thi gian [phỳt] B1 B2 B3 B4 B5 B6 - - - - - - 19,8 30 21 36 26 32 100 40 36 35 32 30 Tc lng [mm/phỳt] 30 26 25 21 19,8 20 15 10 B1 B2 B3 B4 B5 B6 Mu Hỡnh 4.23 Tc lng bựn giai on u Bng 4.46 c ca dung dch natri aluminat c dung dch natri aluminat (mg/l) Thi gian (phỳt) B1 B2 B3 B4 B5 B6 61000 61000 61000 61000 61000 61000 30 500 170 340 200 475 380 60 200 120 180 100 190 190 90 190 100 110 100 130 130 100 190 100 110 100 130 130 600 500 c [mg/l] B1 400 B2 B3 300 B4 B5 200 B6 100 0 20 40 60 80 100 120 140 Thi gian [phỳt] Hỡnh 4.24 c ca dung dch natri aluminat theo thi gian 101 Bng 4.47 nộn trung bỡnh ca lp bựn Thi gian (phỳt) Nng bựn ban u Co(g/l) 30 60 61 90 100 nộn trung bỡnh (g/l) B1 B2 B3 B4 B5 B6 180 243 205 238 203 212 219 285 247 288 238 255 236 309 268 309 262 270 241 312 273 312 268 276 350 300 nộn [g/l] 250 B1 B2 200 B3 B4 150 B5 100 B6 50 20 30 40 50 60 70 80 90 100 110 Thi gian [phỳt] Hỡnh 4.25 nộn trung bỡnh ca bựn theo thi gian T cỏc bng v hỡnh trỡnh by trờn cho thy, cỏc thụng s c trng lng ca bựn ng vi tt c cỏc mu u rt kh quan sau 60 phỳt v khỏ tng ng Mu t kt qu tt nht l mu B4 vi t l tinh bt DR v HX600 ln lt l 5:5, tng ng vi lng l 2,5+0,125 g/kg bựn khụ Tuy nhiờn, mu B2 (vi t l tinh bt DR v HX600 ln lt l 7:3, tng ng vi lng l 3,5+0,075 g/kg bựn khụ) cng cú kt qu gn tng ng mu B4 Cỏc c trng lng t c ca mu B4 nh sau: chiu cao ct bựn sau 60 phỳt lng 91 mm, tc lng phỳt u tiờn t 36 mm/phỳt, c ca dung dch natri aluminat sau 60 phỳt cú giỏ tr 100 mg/l, nộn trung bỡnh ca bựn 288 g/l Cỏc c trng lng t c ca mu B2 nh sau: chiu cao ct bựn sau 60 phỳt lng 92 mm, tc lng phỳt u tiờn t 30 mm/phỳt, c ca dung dch natri aluminat sau 60 phỳt cú giỏ tr 120 mg/l, nộn trung bỡnh ca bựn 285 g/l 102 Xột v tớnh t ch ngun nguyờn liu sn cú nc, phng ỏn kt hp tinh bt DR vi HX600 c chn theo t l 7:3 4.4 xut phng ỏn s dng cht tr lng cho quỏ trỡnh lng bựn sau hũa tỏch bauxit Gia Ngha T cỏc kt qu thu c nh trỡnh by ti cỏc phn trờn, cho phộp xut phng ỏn s dng cht tr lng cho quỏ trỡnh lng bựn GN: a i vi nhúm cht tr lng hu c t nhiờn, cn c vo kh nng cng húa quỏ trỡnh lng v t ch ngun nguyờn liu sn cú nc, nờn chn tinh bt DR b i vi nhúm cht tr lng hu c tng hp bin tớnh, HX600 cú tỏc dng tr lng tt hn hn so vi HX400 So sỏnh vi HX400 (bng 4.48), mt kt qu rt khớch l cú tớnh phỏt hin l kh nng cng húa ca tinh bt DR tt hn hn so vi cht tr lng ny Bng 4.48 So sỏnh cỏc thụng s c trng lng ca tinh bt DR v HX400 Chiu cao Tc lng c dung nộn trung ct bựn ban u dch natri bỡnh ca bựn (mm) (mm/phỳt) aluminat (mg/l) (g/l) Tinh bt DR 127 40,2 95 207 HX400 137 30,8 450 191 Cht Tr lng Nh vy, i vi nhúm cht tr lng hu c tng hp bin tớnh, v phng din kh nng cng húa lng ch nờn chn HX600, cũn thay cho HX400 nờn dựng tinh bt DR c V phng ỏn kt hp, theo kt qu thc nghim trờn, vic ng thi s dng HX600 v tinh bt DR l rt hp lý Theo s kt hp ny, mu t kt qu tt nht l mu B4 vi t l tinh bt DR v HX600 ln lt l 5:5, nhiờn, nh ó trỡnh by, t ch ngun nguyờn liu sn cú, tinh bt DR v HX600 c kt hp theo t l 7:3, tng ng vi lng l 3,5+0,075 g/kg bựn khụ Vi cỏc phng ỏn s dng cht tr lng nờu trờn cựng vi hm lng ó xỏc nh v thi gian l 60 phỳt, quỏ trỡnh lng t c cỏc thụng s c trng nh bng 4.49 Di õy l tng hp ch to thnh bựn (tin kh silic, hũa tỏch, pha loóng huyn phự) t bauxit Gia Ngha cú c ht c chn < 0,315 mm 103 Kh silic - Nng dung dch: 160 g/l Na2Oc - T s costic: c ~ - Nhit : 95 oC - Nng cht rn: 500 g/l - Thi gian: 6h Hũa tỏch - Nng dung dch: 160 g/l Na2Oc - T s costic: c~3 - Nhit : 145 0C - Lng np bauxit: 210 g/l - Thi gian: 1h Pha loóng huyn phự Bựn c pha loóng 1,1 ln bng nc bựn Kt qu s dng cỏc cht tr lng hu c t nhiờn, tng hp bin tớnh v kt hp hai cht ny c trỡnh by Bng 4.49 Bng 4.49 Ch lng v kt qu Ch lng Cht tr lng Hm lng, g DR HX600 0,25 DR + HX600 3,5+0,075 Nhit , 0C 95 0C Cỏc thụng s lng c trng S thay i chiu cao ct bựn, mm Tc lng giai on nộn TB, u, g/l c, mg/l mm/phỳt 127 40,2 207 95 114 46,6 230 122 92 30 285 120 cựng ch lng (thi gian 60 phỳt, nhit 95 0C), tỏc dng tr lng ca HX600 tt hn tinh bt DR Phng ỏn kt hp HX600 v tinh bt DR t kt qu gn nh tng ng vi trng hp dựng HX600 (bng 4.49) Hiu qu ny l s tỏc dng tnh in ng thi ca nhúm hydroxyl OH tinh bt v cỏc nhúm chc nng HXPAMs vi cỏc ht bựn to thnh bụng ln d lng Ngoi hiu qu k thut ca phng ỏn kt hp (rỳt ngn thi gian lng, c ca dung dch natri aluminat hon ton t yờu cu cho lc kim tra), cũn cú ý ngha c bit v s ch ng ngun cht tr 104 lng s dng, c th: ch dựng 30% HX600 cũn li 70% l tinh bt DR sn cú nc Vic thay th HX600 bng phn ln tinh bt DR khụng ch tng kh nng ni a húa ngun nguyờn liu sn xut m cũn tit kim ngoi t Nh vy, phng ỏn kt hp khụng ch cú ý ngha v mt k thut m cũn cú ý ngha v mt kinh t í ngha ny khụng ch gii hn i vi quỏ trỡnh lng bựn t bauxit GN m cũn c vi cỏc loi bauxit khỏc khu vc Tõy Nguyờn 105 KT LUN CHUNG T kt qu Nghiờn cu kh nng lng bựn sau hũa tỏch bauxit Gia Ngha, Tõy Nguyờn, cho phộp rỳt mt s kt lun sau: Bauxit GN thuc loi giu st, ch yu dng gtit, nờn kh nng lng t nhiờn (khụng s dng cht tr lng) bựn to thnh sau quỏ trỡnh hũa tỏch bauxit khụng kh thi thc t sn xut v mt thi gian v c dung dch natri aluminat cn t cho cụng on lc kim tra tip theo C ht bauxit cú nh hng ln ti quỏ trỡnh hũa tỏch bauxit v quỏ trỡnh lng bựn Ht bauxit cng mn thỡ hiu sut hũa tỏch cng cao, nhng kh nng lng bựn cng thp Vi bauxit GN, c ht 0,315 mm cú th ỏp ng ng thi cỏc yờu cu v hiu sut hũa tỏch v tc lng ca bựn Lng np bauxit cho hũa tỏch cng ln, mt bựn to thnh cng cao, tr lc i vi s ri ca cỏc ht s ln, lm chm quỏ trỡnh lng bựn Lng np bauxit phự hp c chn l 210 g/l v h s pha loóng huyn phự sau hũa tỏch c chn l 1,1 ln trỏnh s phõn húa dung dch natrialuminat nhit nh hn 75 0C cng nh s thay i thnh phn ca dung dch ny nhit cao hn 95 0C, nhit lng c chn l 95 0C Vi cựng hm lng s dng g/kg bựn 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(1970) , , ctp.62 95 H euk (1975) Teopu upoemaypuecux poecco, Moca 96 E (1964) A , Moca 113 DANH MC CC CễNG TRèNH CễNG B CA LUN N Cỏc cụng trỡnh ng trờn cỏc khoa hc Hng Nga, Trng Ngc Thn, V Cht Phỏc (2012) nh hng ca c ht bauxit ti kh nng lng bựn , Tp Khoa hc Cụng ngh Kim loi, s 42, 6, tr 37-41 Do Hong Nga, Truong Ngoc Than, Vu Chat Phac (2013) Influence of iron on red mud settling, Journal of Science & Technology Technical Universities, A, No 93, pp 49-53 Trng Ngc Thn, V Cht Phỏc, Hng Nga, Dng Ngc Bỡnh (2013) Cng húa quỏ trỡnh lng bựn Gia Ngha bng cht hu c tng hp bin tớnh, Tp Khoa hc Cụng ngh Kim loi, s 50, 10, tr 38-41 Cỏc cụng trỡnh ng trờn k yu hi ngh khoa hc quc gia v quc t Do Hong Nga (2012) Material composition of bauxite concentrate from Gia Nghia mine and general review of effects on the red mud settling process, Advances in Mining and Tunneling, Proceedings of the 2nd international conference on advances in mining and tunneling, HaNoi, Viet Nam, pp 236-240 ... thúc đẩy khả lắng bauxit lắng làm giảm khả lắng bauxit lắng tốt [93] Khi tiến hành lắng bùn đỏ bauxit có khả lắng cho thêm 10% bùn đỏ hòa tách nhiệt độ cao Kết rằng, khả lắng nén chặt bùn đỏ tốt... trình hòa tách Nghiên cứu rằng, với bauxit chứa lớn 10% SiO2 hòa tan độ nén bùn đỏ Kompanhiet nghiên cứu hành vi SiO2 tồn dạng khoáng khác đến trình lắng bùn đỏ Cụ thể, nghiên cứu lắng bùn đỏ số... lắng bùn đỏ sau hòa tách bauxit Gia Nghĩa, Tây Nguyên Nội dung trọng tâm đề tài nghiên cứu yếu tố ảnh hưởng đến trình lắng khả cường hóa trình lắng bùn đỏ bauxit Gia Nghĩa chất trợ lắng chất hữu