Rheology of low-rank coal-water slurries at both high and low shear rates

Ahmed, Shehzad; Hasan, A.R.

doi:10.1016/0016-2361(93)90077-f

Cited by 13 publications

(7 citation statements)

References 2 publications

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“…Furthermore, a lot of investigator [17][18][19] found the CWS also follow the power-law model at high shear rates. In order to describe the viscosity of slurry at high shear rates, many authors [9,[19][20] introduced the effective viscosity l eff , which is given as:…”

Section: Rheological Propertiesmentioning

confidence: 99%

Resistance properties of coal–water slurry flowing through local piping fittings

Liu

Duan

2009

Experimental Thermal and Fluid Science

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Section: Rheological Propertiesmentioning

confidence: 99%

Resistance properties of coal–water slurry flowing through local piping fittings

Liu

Duan

2009

Experimental Thermal and Fluid Science

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“…Viscous forces at higher shear rates largely affect the slurry structure; the slurry structure turns into shear thinning behavior. 16 Shear thinning is a behavior that is suitable for the transportation of slurry. At high shear rate 1,000-100,000 also with fine particle size of slurry trend mostly toward pseudoplastic.…”

Section: Effect Of Coal Concentration Without Dispersant Additionmentioning

confidence: 99%

“…7 Today, in the world, one of the major scientific challenges is to well utilize a low-grade coal to produce power at the most economic level. [15][16][17] Coal slurry could be a combination of small-grained coal in the presence of water that might be utilized for direct combustion. [8][9][10][11][12][13][14] Coal that contained high moisture content has the benefit of high volatile matter, low cost of mining, lower sulfur contents, heavy metals, and nitrogen.…”

Section: Introductionmentioning

confidence: 99%

“…[8][9][10][11][12][13][14] Coal that contained high moisture content has the benefit of high volatile matter, low cost of mining, lower sulfur contents, heavy metals, and nitrogen. [15][16][17] Coal slurry could be a combination of small-grained coal in the presence of water that might be utilized for direct combustion. 18 Coal suspension behaves as a liquid fuel, which can be pipelined and can also be used for energy resources.…”

Section: Introductionmentioning

confidence: 99%

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Rheological improvement in performance of low‐rank coal–water slurries using novel cost‐effective additives

Amin

Tahir

Saleem

et al. 2020

Asia-Pacific J Chem Eng

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Coal-water slurry (CWS) has been targeted as a promising fuel and an alternative to fuel oil. CWS has numerous advantages of low and convenient transportation and high solid content. Pakistan is going through a severe energy crisis and among the top 10 countries facing energy crises reported by the United Nations. Besides, Pakistan has become the top seventh country in coal reserves (i.e., 185 billion tones) after the discovery of huge lignite coal reserves in Thar, Sind province. Previous studies investigated the use of additives to enhance CWS properties at a low shear rate and its utilization accordingly. Particularly, the present work studied the high range of shear rate to improve the properties of CWS for transportation and combustion purposes. This study on the improvement in performance of rheology properties of CWS is conducted to improve the properties by cost-effective additives. The coal concentration varies from 20% to 60%, whereas runs were carried out with and without the costeffective additives. The results demonstrated that the coal slurry showed shearthinning property when viscosity was increased at high concentrations in the absence of additives. The addition of additive changed the rheological behavior from pseudoplastic to dilatant region. The presence of a high fraction of coal increased the apparent viscosity of CWS. The static stability test of all coal samples was performed using rod drop method at concentrations of 40% to 60%. The study found that stability was achieved earlier with a lower concentration of 40% as compared with higher concentrations of 50-60%. It is expected that this research would be helpful for the country facing adverse energy crises that badly affect the economy and other social aspects of human life. K E Y W O R D Scoal, coal-water slurry, viscosity, rheology, calcium lignosulfonate

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“…It was found that CWS prepared from low-rank coals had excellent combustion characteristics in a gas turbine. [16] Das et al [13] modulated three varieties of noncoking coal (low-rank Indian coal) using three starch-based additives, and obtained a highly concentrated coal-water slurry with low viscosity. Tiwari et al [17] obtained a high concentration CWS, which was up to 69% of coal loading, from Indian coals using the newly developed naphthalenetoluene-based additive.…”

Section: Introductionmentioning

confidence: 99%

Study on Enhancing the Slurry Performance of Coal–Water Slurry Prepared with Low-Rank Coal

Yang

Qiu

et al. 2014

Journal of Dispersion Science and Technology

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Although coal-water slurry (CWS) with low-rank Shenhua coal has poor slurry performance, it is a good power coal with many advantages including low ash content and ease of incineration. This article establishes differences between the slurry performance of CWS prepared with low-rank Shenhua coal and medium-rank Shandong coal. Moreover, we examined the effects of coal powder gradation, water pre-adsorption, formulation of modified sodium lignosulfonate (SL-M) with other dispersants and stabilizer, and a combined preparation of coal samples on the apparent viscosity of CWS. Results showed that the existence of weak acid groups, strong water adsorption ability, and high-density mineral substances were the major factors that affected the slurry performance of low-rank Shenhua coal. Furthermore, when the average coal particle size was 26.19 lm, the apparent viscosity of CWS was lowest according to bimodal distribution. When low-rank coal was treated first with water pre-adsorption, the slurry performance of CWS was greatly improved and the apparent viscosity was only 1200 mPa Á s when the solid concentration was 63%, showing an increase of 3%. Finally, when low-rank Shenhua coal was combined with medium-rank Shandong coal, apparent viscosity was enhanced.

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Rheology of low-rank coal-water slurries at both high and low shear rates

Cited by 13 publications

References 2 publications

Resistance properties of coal–water slurry flowing through local piping fittings

Resistance properties of coal–water slurry flowing through local piping fittings

Rheological improvement in performance of low‐rank coal–water slurries using novel cost‐effective additives

Study on Enhancing the Slurry Performance of Coal–Water Slurry Prepared with Low-Rank Coal

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