scholarly journals Synthesis of a novel amphoteric copolymer and its application as a dispersant for coal water slurry preparation

2021 ◽  
Vol 8 (1) ◽  
pp. 201480
Author(s):  
Lun Du ◽  
Guanghua Zhang ◽  
Dongdong Yang ◽  
Jie Luo ◽  
Yewei Liu ◽  
...  
Keyword(s):  
Static Stability ◽  
Feed Ratio ◽  
Rheological Models ◽  
Water Slurry ◽  
Angle Measurements ◽  
Coal Particles ◽  
Contact Angle Measurements ◽  
Coal Water Slurry ◽  
Slurry Preparation ◽  
Excellent Stability

In this work, a novel amphoteric copolymer named Poly(sodium p-styrenesulfonate– co -acrylic acid- co -diallyldimethylammonium chloride) (P(SS- co -AA- co -DMDAAC)) was synthesized via free radical polymerization. Afterwards, P(SS- co -AA- co -DMDAAC) was explored for use as a dispersant in coal water slurry (CWS) preparation. The structure of P(SS- co -AA- co -DMDAAC) was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance. The synthetic conditions were optimized as the feed ratio of AA to SS was 1 : 1 (for Yulin coal) or 1.5 : 1 (for Yili coal), and DMDAAC dosage was 4.0 wt% (for Yulin coal) and 6.0 wt% (for Yili coal) toward total monomers. The performances of P(SS- co -AA- co -DMDAAC) as a dispersant for CWS were evaluated by various technologies, such as apparent viscosity, zeta potential, static stability and contact angle measurements. The results revealed that the optimized dosage of P(SS- co -AA- co -DMDAAC) in CWS preparation was 0.3 and 0.4 wt% for Yulin coal and Yili coal respectively. In this optimum condition, CWS prepared using P(SS- co -AA- co -DMDAAC) as dispersant showed a typical shear thinning behaviour and excellent stability, which are desired in industries. The rheological models also confirmed the pseudo-plastic characteristics of CWS. Finally, compared with the widely used anionic dispersant naphthalene sulphonate formaldehyde condensate (NSF) and poly(sodium p-styrenesulfonate) (PSS), P(SS- co -AA- co -DMDAAC) developed in this work exhibited better slurry making performance. The introduction of cationic functional groups promoted the adsorption of the dispersant, which further enhanced the electrostatic repulsion and steric hindrance among coal particles. Accordingly, the viscosity of CWS decreased and static stability enhanced.

scholarly journals Effect of Hydrodynamic Cavitation Assistance on Different Stages of Coal Flotation

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 221
Author(s):  
Hua Han ◽  
An Liu ◽  
Huaifa Wang
Keyword(s):  
Contact Angle ◽  
Hydrodynamic Cavitation ◽  
Screening Tests ◽  
Separation Stage ◽  
Coal Flotation ◽  
Angle Measurements ◽  
Coal Particles ◽  
Constant Rate ◽  
Contact Angle Measurements ◽  
Flotation Performance

In this study, the effect of hydrodynamic cavitation (HC) on the conditioning stage (HCCS), separation stage (HCSS), and whole stage (HCWS) of coal flotation was investigated by flotation tests, laser granulometry, and contact angle measurements. The flotation results indicate that compared to conventional flotation, all HC-assisted flotation methods can improve concentrate combustible recovery and flotation constant rate. HCCS and HCSS show similar levels of improvement, while HCWS has a better flotation efficiency. The screening tests demonstrate that HC has the advantage of being able to liberate coarse coal particles (+0.25 mm) prior to being combined with gangues. On one hand, HC promotes the dispersion of both particles and agents, while longer cavitation time in HCCS does not lead to better flotation performance. On the other hand, enhancement of the adsorption of the collector on the surface of coal particles in HCCS is confirmed by flotation concentrate contact angle tests. However, HCSS leads to a decrease in concentrate hydrophobicity, compared to conventional flotation. The micro-nanobubbles generated by HC play an important role in improving flotation performance. HCWS offers the advantages of both HCCS and HCSS, and the cooperated mechanism of different HC modes enhances the recovery of coal particles in flotation.

Combustion of Coal-Water Slurry in a Two-Cycle Diesel Engine: Effects of Fuel Amount and Timing

1990 ◽  
Vol 112 (3) ◽  
pp. 376-383 ◽  
Author(s):  
T. Uzkan ◽  
C. E. Horton
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Cylinder Pressure ◽  
Release Rates ◽  
Energy Of Combustion ◽  
Water Slurry ◽  
Coal Particles ◽  
Coal Water Slurry ◽  
Temperature Heat ◽  
Pilot Fuel

Coal-water slurry having micronized coal particles with approximately 50 percent coal loading is successfully ignited and combusted in one cylinder of a two-cylinder 645 EMD engine by using diesel fuel pilot ignition aid. The effects of three different parameters, namely, (a) pilot timing, (b) pilot amount, and (c) CWS fuel amount, are investigated in detail. The physical trends of combustion under single parametric variations are presented in terms of the cylinder pressure, temperature, heat release rates, and cumulative heat release curves. CWS combustion with less than 5 percent of the energy of combustion coming from pilot fuel is achieved.

Effect of Particle Size Distribution and Selective Alcohol Additives for Preparation of High Concentration Coal-Water Slurry

2020 ◽  
Vol 12 (2) ◽  
pp. 102-111 ◽  
Author(s):  
Debadutta Das ◽  
Anupama Routray ◽  
Swetashree Pattanaik ◽  
Pankaj K. Parhi ◽  
Bijnyan R. Das ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Static Stability ◽  
Industrial Applications ◽  
High Concentration ◽  
Oh Groups ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Water Alcohol

Background: The alternative of oil is highly essential in the present context due to the acute shortage of oil as well as increasing demand for it from different public and private sectors. Since 1980, attention has been focused on coal-water slurry as an alternative fuel for the power generation industry and a suitable substitute for oil in several industrial applications. One of the exciting areas in Coal Water Slurry (CWS) is coal–water-alcohol slurry in which different alcohol compound can act as a dispersant for the stabilisation of coal–water slurry. Objective: The objective of this paper is to prepare a high concentration coal–water-alcohol slurry using glycerol, glycol and ethanol as an additive, and different particle size distribution of coal. This will increase the surface activity of the coal thereby, decreasing the viscosity of the slurry. Method: Two bimodal samples are prepared in which coarse particles are (212 μm - 300 μm), (150 μm – 212 μm) and fine particle below 75 μm. Three types of alcohol additive namely glycerol, glycol and ethanol are used as a dispersant. Malvern Particle size analyzer is used to measure the particle size distribution of the coal samples. Rheological study of CWAS was conducted using HAAKE RHEO STRESS 1. Result: From the experiment, it has been concluded that the optimum addition of glycerol in water is taken as 90:10 of water and glycerol ratio because after that, there is no further decrease in the value of viscosity. An optimum value of glycol and ethanol mixed in water was determined and found as in the ratio of 86:14 and 82:18, respectively. Conclusion: From different parameter studies like coal concentration, pH, temperature, apparent viscosity and stability, it has been concluded that coal-water-glycerol slurry is better than other coal water- alcohol slurry. This is because of the presence of more OH- groups in glycerol. The static stability of this coal-water-alcohol slurry exists for the maximum period of 31 days.

Adsorption of ammonia nitrogen on lignite and its influence on coal water slurry preparation

Fuel ◽  
2019 ◽  
Vol 238 ◽  
pp. 34-43 ◽  
Author(s):  
Yanan Tu ◽  
Ping Feng ◽  
Yangguang Ren ◽  
Zhihua Cao ◽  
Rui Wang ◽  
...  
Keyword(s):  
Ammonia Nitrogen ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Slurry Preparation

scholarly journals Energy-Saving Vibration Impulse Coal Degradation at Finely Dispersed Coal-Water Slurry Preparation

2015 ◽  
Vol 37 ◽  
pp. 01034
Author(s):  
V.A. Moiseev ◽  
V.G. Andrienko ◽  
V.G. Pileckij ◽  
L.P. Zarogatskij ◽  
Yu.S. Borovikov ◽  
...  
Keyword(s):  
Energy Saving ◽  
Water Slurry ◽  
Coal Water Slurry ◽  
Coal Degradation ◽  
Slurry Preparation

Methods for Improving Slurry Ability of Yangchangwan Bituminous Coal

2012 ◽  
Vol 560-561 ◽  
pp. 627-631
Author(s):  
Mei Li ◽  
Sheng Fu Bao ◽  
Li Feng Qiu
Keyword(s):  
Rheological Behavior ◽  
Bituminous Coal ◽  
Earth Metal ◽  
Static Stability ◽  
Optimal Dosage ◽  
Acid Salt ◽  
Water Slurry ◽  
Anthracite Coal ◽  
Coal Water Slurry ◽  
Methyl Naphthalene

Yangchangwan (YCW) bituminous of Ningxia is a weakly reductive coal, which was characterized with low ash content, low sulfur content, low H/C and ash fusion, but high moisture, oxygen, inertinite and alkaline earth metal contents, also difficult to make slurry. Influence of dispersant kind and dosage on YCW CWS rheological behavior was studied using 8 dispersants. Examination was conducted in the lab. The results show that the dispersant and its dosage not only influence the apparent viscosity but also the rheological behavior of CWS. Methyl naphthalene acid salt formaldehyde condensation(MF) is the best dispersant for YCW bituminous coal and the optimal dosage is 1%. CWS were also prepared using compounded dispersants of sodium lignosulphonate and Methyl naphthalene acid salt of formaldehyde condensation and in order to investigate the slurry ability of CWS with compounded dispersants. The results show that compounded dispersants have a greater impact on the liquidity and stability of CWS, the optimal ratio of two dispersant is 3:7. Slurry technologies of blended coals were also studied in this paper, YCW bituminous coal with lower slurry ability , lower static s stability and poor theological behavior and Dafeng(DF) anthracite coal with good properties of CWS and the better theological behavior. The effect of the ratios of two coals on the static stability and viscidity of CWS was studied. The results show that CWS is better static stability ability and viscidity when the chemical additive quantity is at 1 parts per hundred and the ratio of two coals is 3:7.The effects of coal blending on the features of coal-water slurry are nonadditivity. It can effectively improve the concentration of coal water slurry, for coal which has difficulty in preparing coal-water slurry.

scholarly journals Evaluation of the effects of coal grinding in terms of coal water slurry preparation

2016 ◽  
Vol 8 ◽  
pp. 01023 ◽  
Author(s):  
Jolanta Robak ◽  
Karina Ignasiak ◽  
Michał Rejdak
Keyword(s):  
Water Slurry ◽  
Coal Water Slurry ◽  
Slurry Preparation
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