Computational investigation on the flow of high concentration fly ash slurries through converging-diverging bends

Author(s):  
Anubhav Rawat ◽  
S.N. Singh ◽  
V. Seshadri
2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Fulin Wang ◽  
Faguang Yang ◽  
Zhengping Yuan ◽  
Shijiao Yang

Good fluidity is the precondition to ensure the pipeline transportation of the filling slurry. The admixture in the filling slurry will affect the rheological properties of the slurry. In this paper, yield stress (YS), viscosity coefficient (VC), and expansion (ED) of the filling slurry were measured by the MCR52 rheometer and expansion tester, respectively, and the influence regularities of the three kinds of admixtures including fly ash (FA), polycarboxylate superplasticizer (PS), and polyethylene oxide (PEO) on the rheological properties of the filling slurry were obtained. The results show that when other conditions are fixed, the fluidity of the slurry becomes worse with the increase of the amount of fly ash but improves with the increase of the amount of the polycarboxylate superplasticizer; polyethylene oxide is not suitable for the improvement of the fluidity of the high-concentration full-tailing filling slurry, and the fluidity of the slurry becomes worse rapidly with the increase of the amount of polyethylene oxide.


Author(s):  
Burcu Ertit Taştan

Abstract This study demonstrates the removal of fly ash with Penicillium chrysogenum, a newly isolated species of fungus, and acute toxicity assessment with Daphnia magna. In the study, two different removal mechanisms were compared, both bio-removal and bio-sorption. Six different ash and three different biomass concentrations were used simultaneously. Although other fungal species in the literature failed at such a high concentration of fly ash, P. chrysogenum was able to tolerate it even at 10% concentration. The highest bio-removal yield was recorded as 100% at 0.5% fly ash concentration. Maximum bio-sorption yield was 95.27% after 24th hour. The evaluation results of fly ash bio-toxicity by D. magna showed that the no observed effect level (NOEL) was 0.2 mg/L and the low observed effect level (LOEL) was 0.5 mg/L. The element analysis, determined by ED-XRF, clarified that Ca, Si, Fe and S were the common elements in this ash. This is the first study in the literature where fly ash removal was carried out using P. chrysogenum for both bio-removal and bio-sorption and needs to be developed in the future.


2010 ◽  
Vol 13 (1-2) ◽  
pp. 89 ◽  
Author(s):  
L.M. Manоcha ◽  
K.A. Ram ◽  
S.M. Manocha

Fly-ashes are non-combustible mineral residues which are produced from coal in thermal power plants. Four different types of fly ashes were collected from different power station in Gujarat. Characterization through SEM shows that fly ash contains cenosphere i.e. gas bubble containing ceramic particle independent of their bulk density. Floatation technique was used for the separation of cenosphere from fly ash. Two solvents with extremely different densities were used for the separation of cenospheres. All methods gave approximately yield of less than 1 % cenosphere in fly ash. Color of cenospheres varied from gray to almost white and the value of density range from 0.4 – 0.8 g/cc. Further, chemical composition analysis revealed that cenospheres do not contain any high concentration of hazardous elements.


Wear ◽  
2017 ◽  
Vol 378-379 ◽  
pp. 114-125 ◽  
Author(s):  
Anubhav Rawat ◽  
S.N. Singh ◽  
V. Seshadri

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