The Enhancement on Rheology, Flowability, and Stability of Coal Water Slurry Prepared by Multipeak Gradation Technology

Abstract

Multipeaking gradation technology is an essential method for improving the slurry ability of coal particles. In this study, the coarse (150–300 μm), fine (54–74 μm), and micro (1–10 μm) coal particles with different ratios were applied to prepare coal water slurry (CWS). The ratio of coarse, fine, and micro particles in bimodal CWS, interval bimodal CWS, and triple-peak CWS was 60:40:0, 60:0:40, and 60:24:16, respectively. The effects of multipeaking technology on stability, flowability, and rheological behaviors of CWS were investigated systematically. The results indicated that the interval bimodal CWS had the best stability and flowability followed by the triple-peak CWS, and the bimodal CWS was the worst. It was demonstrated that the stability and flowability of CWS were enhanced with the increment of microparticles in slurry. Nevertheless, each slurry’s maximum solid content was 68% for bimodal CWS, 65% for interval bimodal CWS, and 70% for triple-peak CWS. It could be attributed to two effects of microparticles on the apparent viscosity of CWS, i.e., filling particle clearance and binding water. If the effect of filling particle clearance was dominant, then apparent viscosity was decreased, and it was beneficial to prepare CWS with high solid content like triple-peak CWS. However, when the effect of binding water was dominant, apparent viscosity was increased, and it was unfavorable for CWS preparation corresponding to interval bimodal CWS. It was worth noting that microparticles play a double side role in preparing highly concentrated CWS.

Improving the steric hindrance effect of linear sulfonated acetone–formaldehyde dispersant and its performance in coal–water slurry

“…This phenomenon may be caused by the stronger adsorption of PSAF-6 on the coal surface, which blocks the channel from interstitial water to adsorbed water. 54,55…”

“…This phenomenon may be caused by the stronger adsorption of PSAF-6 on the coal surface, which blocks the channel from interstitial water to adsorbed water. 54,55 Given the structural characteristics and the above experimental results for PSAF dispersants during CWS preparation, the possible interactions between coal particles, dispersants, and water can be inferred. Fig.…”

Tracing the technological trajectory of coal slurry pipeline transportation technology: An HMM-based topic modeling approach

“…This result responds to Das et al (2021) call for research on coal pulping technology. The development of pulping technology is the premise of increasing pipeline transport capacity and industrial applications (Hu et al, 2021). With the development of technology, technical research has gradually focused on the direction related to the "pumping".…”

Review and Perspectives of Anionic Dispersants for Coal–Water Slurry

“…The dispersion stability of coal particles in water is vitally significant for the transportation, atomization, combustion, and gasification of CWS. Normally, the stable dispersion of coal particles is related to the coal concentration of CWS, dispersant performance, and coal particle size distribution . As can be seen from eq for total interaction energy, to make coal particles stably dispersive, it is necessary to increase the repulsive interaction energy or decrease the attractive interaction energy between coal particles.…”

“…For coal particles in CWS, a certain size range is required to guarantee complete combustion and gasification, and a suitable size distribution is also required to attain high filling efficiency. With a reasonable granularity gradation of coal particles, a high-concentration CWS with good stability and fluidity and maximum packing efficiency would be acquired. ,− For instance, coal powders with bimodal particle size distribution obtained by the granularity gradation of fine particles and coarse particles are good for the preparation of CWS …”