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HIROMOTO USUI
Department of Chemical Science and Engineering, Kobe University
Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Energy Engineering Environmental Science Materials Science & Nanotechnology

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Journal : Indonesian Mining Journal

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EFFECT OF COAL UPGRADING ON RHEOLOGY OF COAL WATER MIXTURE DATIN F. UMAR; BUKIN DAULAY; HIROMOTO USUI; YOSHIYUKI KOMODA
Indonesian Mining Journal Vol 10 No 3 (2007): INDONESIAN MINING JOURNAL Vol. 10 No. 3 October 2007
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol10.No3.2007.609

Abstract

Coal water mixture (CWM) is coal-water slurry in which particles of coal with a certain particle size distribution are suspended in water. CWM is required to have the highest possible coal concentration and a moderate viscosity in order to make handling easy. The main purpose of this study is to obtain the effect of coal upgrading on the rheology of CWM in terms of finding the most suitable dispersing additive in producing CWM with highest coal concentration. Two kinds of coal, raw and upgraded coal, from three areas in Indonesia have been used. Three kinds dispersing additives, i.e. formalin conden- sation product of naphthalene sulfuric acid (NSF), polystyrene sulfonic acid (PSS) and poly (meth) acrylate (PMA) were tested to produce CWM with good flow characteristics. The rheology of CWM was prepared, measured by a stress control type rheometer (Rheometric Scientific Co. Ltd., SR-5) in steady shear mode at 25ºC. The apparent viscosity of upgraded coals showed a better slurry-ability of CWM as a function of coal concentration for every dispersing additive compared to the raw coal.
THE EFFECT OF DISPERSING AND STABILIZING ADDITIVE ON THE STABILITY OF UPGRADED COAL WATER MIXTURE DATIN F. UMAR; BUKIN DAULAY; HIROMOTO USUI; YOSHIYUKI KOMODA
Indonesian Mining Journal Vol 10 No 1 (2007): INDONESIAN MINING JOURNAL Vol. 10 No. 1 February 2007
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol10.No1.2007.629

Abstract

The upgraded brown coal water mixture (UBCWM) stability with several dispersing and stabilizing additives was studied based on coal sedimentation time history. UBCWM was filled up in a settling column; which has four holes in the upper, upper middle, bottom middle and middle side to take samples. Results indicate that the addition of Naphthalene sulfonate formaldehyde condensate (NSF) as dispersant together with S-194 some kinds of bio polysacharide with long branches produced by Dainippon Pharmaceutical Co. Ltd. as stabilizer, produces UBCWM with the best stability compare with that by using polystyrene sulfonate (PSS) and polymethacrylate (PMA) together with carboxyl methyl cellulose (CMC) and S-60 also some kinds of bio polysacharide, but without branches pro- duced by Dainippon Pharmaceutical Co. Ltd . Even the addition of S-194 results UBCWM with good stability, from the economical point of view, the addition of S-194 is a problem. The price of S-194 is expensive, whereas CMC is abundant and cheap. Therefore, the use of CMC as stabilizing additive was also effective in preparing stable UBCWM according to the stability of the UBCWM by using S- 194 and CMC is not significantly different.
CHEMICAL AND PHYSICAL PROPERTIES OF UPGRADED BROWN COAL DATIN F. UMAR; HIROMOTO USUI; BUKIN DAULAY; IWAN RIJWAN; IKIN SODIKIN
Indonesian Mining Journal Vol 9 No 3 (2006): INDONESIAN MINING JOURNAL Vol. 09 No. 3 October 2006
Publisher : Balai Besar Pengujian Mineral dan Batubara tekMIRA

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30556/imj.Vol9.No3.2006.636

Abstract

Results of proximate analyses indicate that inherent moisture of the upgraded coals decrease signifi- cantly compared to that of the raw coals. Hence, the calorific value of the upgraded coals increases. The ash content of the upgraded coals did not change obviously due to the UBC process which was conducted at low temperature. However, the volatile matter content increase slightly due to the residue plugs over coal pores to prevent re-absorb of moisture. From ultimate analyses, carbon content of the upgraded coals increases, whereas the hydrogen and oxygen contents decrease. The UBC process hardly effects to the sulfur and nitrogen contents. The equilibrium moisture of the upgraded coals was determined by using ASTM Standard method, most of them were less than 9%. The functional group of C-H and C=O of the upgraded coals were slightly less than that of the raw coals. The aromaticity of coal, all of the upgraded coals was increase. The petrography of both the raw and the upgraded coals indicates that the mean vitrinite reflectance was slightly higher in the upgraded coal compared to that of the raw coal. There was no significant quantity and textural differences of maceral in both coals. The specific surface area of the upgraded coals was lower than that of the raw coals due to the plugging of pore structure and shrinkage by residual oil addition. The briquettability of Upgraded coal briquette according to drop shatter test and compressive strength indicates good characteristics of briquette.
Co-Authors BUKIN DAULAY BUKIN DAULAY Bukin Daulay DATIN F. UMAR DATIN F. UMAR DATIN F. UMAR IKIN SODIKIN IWAN RIJWAN YOSHIYUKI KOMODA