Effect of the Sodium Lignosulphonate from Different Material on Rheological Behavior of Coal Water Slurry

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1 21 3 No.3 Vol Journal of Chemical Engineering of Chinese Universities June (2007) ,2, 1,2, 1,2 (1., ; 2., ) Herschel-Bulkley TQ Q536.1 A Effect of the Sodium Lignosulphonate from Different Material on Rheological Behavior of Coal Water Slurry ZHOU Ming-song 1,2, YANG Dong-jie 1,2, QIU Xue-qing 1,2 (1.School of Chemical and Energy Engineering; 2.Guangdong Provincial Laboratory of Green Chemical Technology, South China University of Technology, Guangzhou , China) Abstract: The sodium lignosulphonate (SL) of the black liquor originated separately from wood, straw, bamboo and bagasse were used as dispersant for coal water slurry (CWS), and the influences of the complex molecular structure of SL on the viscosity-reducing ability, the rheological behavior and thixotropy of CWS were studied. The Haake rheometer was used to measure the rheological properties, and the rheological data the shear-stress/shear rate data of each CWS prepared with different SL were fitted by using the three-parameter Herschel-Bulkley model. Moreover, the thixotropy loop area was calculated to characterize the thixotropy of CWS. The results show that the CWS prepared with bamboo or bagasse SL exhibits evidently pseudoplastic characteristic, stronger thixotropy and better stability. However, the CWS prepared with wood or straw SL shows slightly dilatant characteristic, weaker thixotropy and worse stability. Furthermore, the difference of rheological properties of CWS is associated with the molecular weight and the functional groups content of the used SL. Key words: sodium lignosulphonate (SL); coal water slurry (CWS); rheological behavior; rheological model; thixotropy loop 1 (CWS) [1~3] ( ) ( )( D0161) (1980-) cexqqiu@scut.edu.cn 转载

2 ( 6-3 ) [4~6] h µm 30 µm 75.29% 30~75 µm 17.49% 75 µm 7.13% Table 1 1 Elemental and proximate analyses of coal sample M ad A ad V daf C ad H ad O ad N ad S ad Coal sample / % (wt) / % (wt) / % (wt) / % (wt) / % (wt) / % (wt) / % (wt) / % (wt) ST / HGI Yanzhou coal ~60 ( SL) ( ) ( ) ( ) ( ) (UV-1601PC ) (GPC) Waters 1515 Isocratic HPLP pump/waters 2487 Dual λ Absorbance Detector Ultrahydragel TM 120 Ultrahydragel TM 250 ph mol L 1 NaNO ml min :1 ( ) 1200 r min 1 10 min Haake RV- (Z41 ) 100 s 1 25 ( ) - HB43 (105 B 0.01 g) A( ) B( )

3 C( ) Haake RV- Z41 0 s 1 ~200 s s 1 ~0 s 1 3 min GPC 2 Sample Table 2 2 Lignin contents, sulfonic group contents and molecular weight of different SL Sulfonic group Carboxy content / content / mmol g 1 mmol g 1 Phenolic hydroxyl content / mmol g 1 Mass average molecular weight Lignin content / % (wt) Wood SL Straw SL Bamboo SL Bagasse SL Table 3 Effect of different SL on slurrying ability of CWS Dispersant Dosage Coal concentration Apparent viscosity Visual 7-day bleeding / % (wt) / % (wt) / mpa.s fluidity * ratio / % A Wood SL A A A 1.34 Bamboo A 3.19 SL A A Straw SL A A B 0.36 Bagasse B SL B 0.16 Note: A continuous flow; B interruptive flow; C no flow 3 1.0% 1.0% 0.6% 3 0.6% 1.0% [7,8] [9,10]

4 Herschel-Bulkley (τ = τ 0 +Kγ n ) [2,11,12] 3 τ 0 K n R Table 4 Rheological data for CWS with different SL Coal% = 65.50%, SL% = 1.0% Coal% = 64.00%, SL% = 1.0% Coal% = 64.00%, SL% = 0.6% Dispersant τ 0 / Pa K / Pa s n n R 2 K τ 0 / Pa / Pa s n n R 2 K τ 0 / Pa / Pa s n n R 2 Wood SL Bamboo SL Straw SL Bagasse SL Herschel-Bulkley 4 1.0% n Herschel-Bulkley n<1 n> % 1.0% 64.00% 0.6% 64.00% 1.0% 1.0% 0.6% n [14] 4 τ % 1.0% 0.6%

5 % K Haake [14~16] 4 (1.0% 0.6%) (64.00% 65.50%) ( ) 5 τ / Pa 200 wood SL bamboo SL 160 straw SL bagasse SL Fig γ / s 1 1 (Coal% = 65.50%, SL% = 1.0%) Thixotropic behavior of CWS with different SL (Coal% = 65.50%, SL% = 1.0%) 200 wood SL bamboo SL 160 straw SL bagasse SL wood SL bamboo SL straw SL bagasse SL τ / Pa 80 τ / Pa Fig γ / s 1 2 (Coal% = 64.00%, SL% = 1.0%) Thixotropic behavior of CWS with different SL (Coal% = 64.00%, SL% = 1.0%) 0 Fig γ / s 1 3 (Coal% = 64.00%, SL% = 0.6%) Thixotropic behavior of CWS with different SL (Coal% = 64.00%, SL% = 0.6%) 5 5 Table 5 Calculated area of the thixotropic loop of CWS with different SL Area of Coal% = 65.50% Coal% = 64.00% Coal% = 64.00% thixotropic loop SL% = 1.0% SL% = 1.0% SL% = 0.6% Wood SL Bamboo SL Straw SL Bagasse SL

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Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article was downloaded by: [Lanzhou Institute of Geology] On: 27 February 2013, At: 01:00 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered