The structure formation mechanism in wet coal fines briquetting with an active binder

2020 ◽  
pp. 41-46
Author(s):  
Yu. A. Nifontov ◽  
Keyword(s):  
Structure Formation ◽  
Formation Mechanism ◽  
Coal Dust ◽  
Closed Surface ◽  
Layer By Layer ◽  
Near Surface ◽  
Theoretical Substantiation ◽  
Coal Particles ◽  
Coal Fines ◽  
Wet Coal

This paper presents the results of studies of the structure formation mechanism for briquettes made from coal fines (sludge, coal dust, and fines), with the use of powdered technical lignosulfonate (100 % Na base) as the binder. It has been established that, when briquetting fine coal fines with active finely-dispersed binders in an air-dry state, the structure formation mechanism of the briquette does not fully align with any of the existing hypotheses. As a result of the research, a theoretical substantiation is proposed for the hypothesis of wet coal sludge briquetting with the use of active finelydispersed binders in an air-dry state. It has been shown that the walls of capillaries and pores in the central part of the briquette experience precipitation from the fluid systems, dissolved by internal moisture, and of coarse particles and a certain amount of the binder entrained in the fluid. Further, a lean fluid advances to the surface of the briquette, consisting mainly of moisture and an excess amount of the active binder, dissolved in it. In the near-surface compacted area of the briquette, the binder is adsorbed on coal particles and the moisture released in the process of thermal destruction and adsorption evaporates. The practical use of the concepts obtained allows controlling the structure formation processes to improve strength without increasing the binder content through layer-by-layer reinforcement of the briquette mass with a closed surface, which significantly improves the process results.

Measuring the temperature response of large wet coal particles during heating

Fuel ◽  
1999 ◽  
Vol 78 (8) ◽  
pp. 991-994 ◽  
Author(s):  
C.A. Heidenreich ◽  
D.K. Zhang
Keyword(s):  
Temperature Response ◽  
Coal Particles ◽  
Wet Coal

scholarly journals Development of Environmental Friendly Dust Suppressant Based on the Modification of Soybean Protein Isolate

Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 165 ◽  
Author(s):  
Hu Jin ◽  
Wen Nie ◽  
Yansong Zhang ◽  
Hongkun Wang ◽  
Haihan Zhang ◽  
...  
Keyword(s):  
Water Retention ◽  
Soybean Protein ◽  
Coal Dust ◽  
Sodium Dodecyl ◽  
Environmentally Friendly ◽  
Protein Isolate ◽  
Dust Particles ◽  
Dust Suppression ◽  
Soybean Protein Isolate ◽  
Coal Particles

Aiming to further improve the dust suppression performance of the dust suppressant, the present study independently develops a new type of biodegradable environmentally-friendly dust suppressant. Specifically, the naturally occurring biodegradable soybean protein isolate (SPI) is selected as the main material, which is subject to an anionic surfactant, i.e., sodium dodecyl sulfonate (SDS) for modification with the presence of additives including carboxymethylcellulose sodium and methanesiliconic acid sodium. As a result, the SDS-SPI cementing dust suppressant is produced. The present study experimentally tests solutions with eight different dust suppressant concentrations under the same experimental condition, so as to evaluate their dust suppression performances. Key metrics considered include water retention capability, cementing power and dust suppression efficiency. The optimal concentration of dust suppressant solution is determined by collectively comparing these metrics. The experiments indicate that the optimal dust suppressant concentration is 3%, at which level the newly developed environmentally-friendly dust suppressant solution exhibits a decent dust suppression characteristic, with the water retention power reaching its peak level, and the corresponding viscosity being 12.96 mPa·s. This performance can generally meet the requirements imposed by coal mines. The peak efficiency of dust suppression can reach 92.13%. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to analyze the dust suppression mechanism of the developed dust suppressant. It was observed that a dense hardened shell formed on the surface of the pulverized coal particles sprayed with the dust suppressant. There is strong cementation between coal dust particles, and the cementation effect is better. This can effectively inhibit the re-entrainment of coal dust and reduce environmental pollution.

Near-surface structure formation in chemically imidized polyimide films

2001 ◽  
Vol 39 (16) ◽  
pp. 1824-1838 ◽  
Author(s):  
Mahendra Dabral ◽  
Xinyun Xia ◽  
W. W. Gerberich ◽  
L. F. Francis ◽  
L. E. Scriven
Keyword(s):  
Surface Structure ◽  
Structure Formation ◽  
Polyimide Films ◽  
Near Surface

scholarly journals Phenomenological thermodynamics and the structure formation mechanism of the CuTi2S4 rhombohedral phase

2016 ◽  
Vol 18 (15) ◽  
pp. 10600-10606 ◽  
Author(s):  
Michail V. Talanov ◽  
Vladimir B. Shirokov ◽  
Valery M. Talanov
Keyword(s):  
Phase Transition ◽  
Structure Formation ◽  
Formation Mechanism ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Rhombohedral Phase

The theory of structural phase transition in CuTi2S4 is proposed.

Formation Mechanism and Recombination-Enhanced Dissociation of a Hydrogen-Carbon Complex in Silicon

1992 ◽  
Vol 262 ◽  
Author(s):  
Yoichi Kamiura ◽  
Fumio Hashimoto ◽  
Minoru Yoneta
Keyword(s):  
Formation Mechanism ◽  
Chemical Etching ◽  
Surface Region ◽  
Electronic Energy ◽  
Hydrogen Atoms ◽  
Electron Hole ◽  
Near Surface ◽  
Depth Profiles ◽  
Schottky Structure ◽  
Hole Recombination

ABSTRACTWc have found that chemical etching induced an electron trap E3 (0.15) into n-typc Si. We attribute this trap to a hydrogen-carbon complex on the basis of available experimental data. By measuring DLTS depth profiles of the E3 trap, we propose a model of the formation mechanism of the hydrogen-carbon complex as follows. Hydrogen atoms arc adsorbed on the Si surface to terminate Si dangling bonds during chemical etching, and after the etching some unstably adsorbed ones diffuse into the near-surface region of silicon and are trapped by carbon to form the complex. The E3 trap is stable up to 100δC in the dark but is annihilated by the illumination of band gap light around 250K only outside the depletion layer of the Schottky structure. This provides unambiguous experimental evidence for the recombination-enhanced dissociation, in which the electronic energy released by the electron-hole recombination at the E3 level is converted into local kinetic energy of hydrogen to be released from carbon.

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