1. Using the ReaxFF reactive force field for molecular dynamics simulations of the spontaneous combustion of lignite with the Hatcher lignite model
作者: Chen, Bo; Diao, Zhi-jun; Lu, Hai-yun
FUEL 卷: 116 页: 7-13 出版年: JAN 2014
摘要The aim of this work is the investigation of the detailed mechanisms for the initiation reaction leading to the spontaneous combustion of lignite. To carry this out we have used the ReaxFF reactive force field to perform a series of molecular dynamics (MD) simulations on a unimolecular model compound. The initiation reaction observed in the ReaxFF MD simulations involves hydrogen abstraction from phenolic hydroxyl groups by O-2 followed by the formation of HO2. The main products observed in our simulations include H2O2, H2O, CH2O, and CO2. In addition, hydrogen abstraction reactions are responsible for the formation of H2O2 and H2O. The reaction products and the mechanisms involved in the initial stage of spontaneous combustion are consistent with previous results. The agreement of these results with available experimental observations demonstrates that ReaxFF MD simulations can provide an atomistic description of the initiation mechanism for spontaneous combustion and provide useful insights into the complicated reaction processes involved. (C) 2013 Elsevier Ltd. All rights reserved.
被引频次: 2
2. Petrographic characterization of coals as a tool to detect spontaneous combustion potential
作者: Avila, Claudio; Wu, Tao; Lester, Edward
FUEL 卷: 125 页: 173-182 出版年: JUN 1 2014
摘要Textural features of 25 worldwide coals were studied after slow oxidation processing (0.5 degrees C min(-1) from 20 to 250 degrees C in air) using oil immersion microscopy and image analysis techniques. The characterization of samples, before and after oxidation, showed important changes in vitrinite reflectance with high reactive coals, which also related to their intrinsic self-oxidation potential. The morphology of the coal particles was also altered after the oxidation, to produce at least six different morphotypes. Particles with 'homogeneous change of reflectance' and particles with 'oxidation rims' were predominant in the samples studied, which related to boundary reactive conditions (kinetic and diffusion control of the reaction respectively). These textural characteristics indicate how particles interacted with oxygen at low temperatures, which could be used to predict the most probable pathway during the early stages of oxidation which could then lead to a spontaneous combustion event. The magnitude of the reflectance change and the morphological characteristics of samples studied were also related to the reactivity properties, providing an additional source of information to identify coals prone to spontaneous combustion. (C) 2014 Elsevier Ltd. All rights reserved.
被引频次: 1
3. A fully coupled hydro-thermo-mechanical model for the spontaneous combustion of underground coal seams
作者: Xia, Tongqiang; Zhou, Fubao; Liu, Jishan; 等.
FUEL 卷: 125 页: 106-115 出版年: JUN 1 2014
摘要The spontaneous combustion of underground coal seams involves complex interactions between geomechanical effects, oxygen transport and flow, and energy transport in the porous coal media. Prior studies normally ignore the thermo-mechanical effects such as gas and coal expansion due to the self-heating of coal, and have not implemented these complex interactions fully into their simulations. In this study, a fully coupled model of coal mechanical deformation, gas flow and transport, and heat transport is developed and their complex interactions are defined through a suite of coal property models and equation-of-states. These include (1) coal porosity model; (2) coal permeability model; (3) gas equation-of-state; and (4) self-heating model.
Applying the model to quantitatively predict the time and locations of spontaneous combustion of underground gob-side entry in the Dongtan coal mine, the results are in good agreement with the in situ measurements. Besides, a significant self-accelerating-heating effect induced by the gas thermal expansion and subsequent gas pressure gradient increase is found in the self-heating process of coal
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through the comparison results from our model with other models. Furthermore, the self-heating susceptibilities of gob-side entry associated with extrinsic and intrinsic factors, incorporating coal permeability, pressure difference, oxygen-consumption rate, and reaction heat of coal oxidation, are gained insight using the verified model, which suggests the self-heating rate and gas velocity are positively correlated with above factors showing "S-type" upward trends, whereas the oxygen concentration has an "S-type" downward trend. The simulated results can provide some suggestions as to how to control the variables or parameters to retard or suppress the spontaneous combustion of porous coal media. (C) 2014 Elsevier Ltd. All rights reserved.
被引频次: 1
4. CFD simulations of the effect of wind on the spontaneous heating of coal stockpiles
作者: Taraba, Boleslav; Michalec, Zdenek; Michalcova, Vladimira; 等.
FUEL 卷: 118 页: 107-112 出版年: FEB 2014
摘要A commercial CFD software program, fluent, was used to study the effect of wind on the spontaneous heating process of a coal stockpile. A two-domain model was developed to simultaneously solve the governing equations of an open porous medium (coal stockpile domain) situated in a homogeneous atmosphere (wind flow domain). Simulations with air blowing from a fixed direction as well as real fluctuations of the airflow both in velocity and direction were performed.
Numerical calculations confirmed the promoting role of wind on the dynamics of the development of spontaneous heating. Under the conditions of the simulations, three possible shifts of the hot spot in the stockpile were distinguished when coal undergoes the self-heating process:
(1) Shift of the hot spot to the pile surface when spontaneous heating of coal is in progress.
(2) Movement of the hot spot inwards the stockpile as the wind speed increases.
(3) Transfer of the hot spot from the upper part of the stockpile to the lower part when the self-heating process progresses. Such movement was found for wind speeds <= 3 m s(-1) and clearly is mainly connected with the effect of buoyancy. (C) 2013 Elsevier Ltd. All rights reserved.
被引频次: 1
5. Comparison of spontaneous combustion susceptibility of coal dried by different processes from low-rank coal
作者: Choi, Hokyung; Jo, Wantaek; Kim, Sangdo; 等.
KOREAN JOURNAL OF CHEMICAL ENGINEERING 卷: 31 期: 12 页: 2151-2156 出版年: DEC 2014
摘要We compared the susceptibility to spontaneous combustion of low-rank coals dried by four different processes: flash drying, fluidized bed drying, non-fried carbon briquetting, and coal-oil slurry dewatering. The coals were characterized by FT-IR and XPS analysis. A crossing-point temperature (CPT) was estimated as a comparison criterion of the susceptibility of the coals to spontaneous combustion. O-2, CO, and CO2 emissions during the CPT measurement were also compared. The FT-IR and XPS analysis revealed that some of the oxygen functional groups on the surface of the coal were removed when the coal underwent the drying process. This phenomenon was particularly noticeable in the coal dried by oil. Accordingly, the CPT of the coal that went through this drying process was high. Among the samples, the coals dried by oil showed the highest CPT
6. Molecular dynamic simulation of spontaneous combustion and pyrolysis of brown coal using ReaxFF
作者: Bhoi, Sanjukta; Banerjee, Tamal; Mohanty, Kaustubha
FUEL 卷: 136 页: 326-333 出版年: NOV 15 2014
摘要Brown coal is a soft sedimentary organic rock which is complex in nature and is the main source of energy production. In this work, we have studied the combustion and pyrolysis of brown coal using reactive molecular dynamic (MD) simulation. To make the large scale (above 1000 of atoms) reactive system practical, ReaxFF MD system was used which is 100 times faster than the methods of quantum mechanics (QM). To examine the pyrolysis/combustion process and initiation mechanism of brown coal, a fuel lean (phi = 2), fuel rich (phi = 0.5) and stoichiometric (phi = 1) conditions were used in this work. The temperature used was high as per experimental reported condition so as to enable chemical reaction within a computationally affordable time. It was observed that the combustion of brown coal was initialized by thermal degradation subsequently forming small fragments. As the brown coal molecule oxidizes or thermally decomposes, hydrogen is abstracted and reacts with oxygen to form large amount of H2O molecules. Furthermore, the combustion of coal was also studied in the same conditions namely fuel rich, fuel lean and stoichiometric. Potential energy gradually decreases at high temperature while it was the reverse in pyrolysis. It was found that the effects of densities are lesser as compared to temperature. Some important intermediate like formaldehyde (HCHO) generated during the simulation reaction agreed well with the experimental data reported in literature. (C) 2014 Elsevier Ltd. All rights reserved.
7. Fine coal covering for preventing spontaneous combustion of coal pile
作者: Yang, Yongliang; Li, Zenghua; Tang, Yibo; 等.
NATURAL HAZARDS 卷: 74 期: 2 页: 603-622 出版年: NOV 2014
摘要In order to investigate the effect of fine coal covering around the bottom of coal stockpile on spontaneous combustion prevention, a two-dimensional math model was established to numerically simulate the fine coal covering coal pile and a coal pile temperature-rising experimental system was setup to study the two-dimensional heat and mass transfer characteristics of air diffusion in the horizontal direction and air heat convection in the vertical direction inside coal stockpiles covered by different thicknesses of fine coal. The results showed that (1) the fine coal located at the bottom of the coal pile can effectively inhibit air convection and diffusion, cut off oxygen replenishment, and prevent the temperature rise inside coal pile, and (2) thicker fine coal has more obvious effect. Finally, the field experiments on the fine coal covering coal piles for preventing selfignition of coal pile were carried out successfully. The results showed that the uncovered or exposed coal piles self-ignited rapidly within a very short period (18 days), while the coal pile covered with 1 m fine coal lasted for 123 days with a maximum coal temperature of only 59.9 degrees C. The characteristics of temperature distribution and diffusion inside coal stockpile were studied, and the high-temperature region was found in the region 1.3 m high and 2-3 m deep in the coal pile. The effects of environment temperature and precipitation on self-ignition of coal pile were also analyzed in field experiment. The experimental results proved that the fine coal covering technology can effectively prevent the spontaneous combustion of coal stockpiles.
8. Self-heating: Estimation of the heat release coefficient QA for Ni- and Cu-concentrates and sulphide mixtures
作者: Ngabe, Barnabe; Finch, James A.
MINERALS ENGINEERING 卷: 64 页: 126-130 出版年: OCT 1 2014
摘要The self-heating heat release rate coefficient QA (J g(-1) min(-1)) for Ni- and Cu-concentrates and sulphide mixtures has been determined. The QA for the concentrates were higher than those of the sulphide mixtures. This difference in QA between the materials, for which the reaction causing self-heating is surmised to be the same, may be attributed to differences in specific heat capacity C-p, a steric effect, and in the case of the mixtures, a galvanic effect. The lack of clear relationship between QA and the energy of activation E-a suggests at least both be measured to characterize the self-heating of sulphide materials. (C) 2014 Elsevier Ltd. All rights reserved.
9. Aqueous three-phase foam supported by fly ash for coal spontaneous combustion prevention and control
作者: Qin, Botao; Lu, Yi; Li, Yong; 等.
ADVANCED POWDER TECHNOLOGY 卷: 25 期: 5 特刊: SI 页: 1527-1533 出版年: SEP 2014
摘要This work deals with the preparation and characterization of fly ash (FA) supported aqueous three-phase foams containing N-2 for coal spontaneous combustion prevention and control. Uniform and dense three-phase foams featuring FA contents between 20 wt.% and 33 wt.% are prepared in batch mode using a home-made foam generating column with an internal Venturi tube. The effect of FA on the foamability, static and dynamic stability of the three-phase foams is discussed. Compared with two phase foams, the FA supported three-phase foams manifest higher static and dynamic stability, which increases with the FA content. Base on the excellent static and dynamic stability, a structure model to attach FA particles at the N-2-water interfaces of the three-phase foams was proposed to elucidate the observed behaviors. The as prepared FA supported three-phase foams, exhibiting excellent coal fire extinguishing characteristic, can be used as a promising fire extinguishing material, especially for preventing the large coal area spontaneous combustion or extinguishing fire in high and unknown locations in goaf. (C) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
10. Thermal mapping of self-heating zones on coal waste dumps in Upper Silesia (Poland)-A case study
作者: Nadudvari, Adam
INTERNATIONAL JOURNAL OF COAL GEOLOGY 卷: 128 页: 47-54 出版年: AUG 1 2014
摘要The evolution of self-heating areas on five chosen coal-waste dumps in Upper Silesia (Poland) was quantitatively investigated with the aim of finding a cheap and fast method of detecting and localising coal-waste fires on the dumps. The results show that Landsat 4-5 TM and ETM+ images from snow-covered terrain enable the burning areas of the dumps to be seen and that, in addition, they can be used to observe the evolution of these thermal anomalies. Furthermore, the analysis showed that the external temperature had an impact on surfaces of self-heating areas; when the air-temperature was low, the surface temperatures of these hot areas were lowered. In the study, it managed to observe the evolution of self-heating areas, i.e., the appearance of hot spots, their migration and their disappearance were observed. The method used is relatively rapid, low-cost and field temperature measurements are not essential. (C) 2014 Elsevier B.V. All rights reserved.
11. An electro-chemical method for determining the susceptibility of Indian coals to spontaneous heating
作者: Ray, Santosh Kumar; Panigrahi, Durga Charan; Varma, Atul Kumar
INTERNATIONAL JOURNAL OF COAL GEOLOGY 卷: 128 页: 68-80 出版年: AUG 1 2014
摘要Spontaneous combustion is an inherent problem to the coal mining industry. The paper describes an electrochemical method called wet oxidation potential technique for determining the susceptibility of coal to spontaneous combustion. Altogether 78 coal samples collected from thirteen mining companies spreading over most of the Indian Coalfields have been used for this experimental investigation and 936 experiments have been carried out by varying different experimental conditions to standardize wet oxidation potential method for wider application. The results of wet oxidation potential (WOP) method have been correlated with the intrinsic properties of coal by carrying out proximate, ultimate and petrographic analyses of the coal samples. Experimental results are first analyzed with principal components analysis and then by multiple regression analysis. Results obtained from this method have been compared with one of the widely used method, i.e. crossing point temperature (CPT) in India. The experimental investigation clearly indicates that WOP method with 0.2 N KMnO4 in 1 N KOH solution at 45 degrees C (susceptibility index PD12) should be used for finding out the susceptibility of coal to spontaneous combustion. PD12 results are well corroborated with CPT results. (C) 2014 Elsevier B.V. All rights reserved.
12. Heating processes during storage of Miscanthus chip piles and numerical simulations to predict self-ignition
作者: Everard, Colm D.; Schmidt, Martin; McDonnell, Kevin P.; 等.
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES 卷: 30 页: 188-196 出版年: JUL 2014
摘要Miscanthus x Giganteus (Miscanthus) energy crop was examined at laboratory scale to assess its self-heating and self-ignition risks during storage. Chipped Miscanthus (18 mm) from February and March harvests, in 2012, were assessed as well as ground Miscanthus (3 mm) from the March harvest. February and March crops had moisture contents of 41.6 and 20.2%, respectively. Self-ignition temperatures were independent of moisture although moisture did affect the time from the beginning of storage until storage temperature was reached. Ground Miscanthus had lower self-ignition temperatures than chipped Miscanthus. Isothermal respirometric tests carried out showed increase risk of self-heating in the February crop compared to the March crop due to increased microbial activity. Numerical simulations were used to determine critical enhanced start temperatures, e.g. caused by microbial decomposition, of the stored Miscanthus. Safe storage conditions have been derived from the investigations. The numerical simulations demonstrated that self-ignition was possible in Miscanthus chip piles with a height greater than 6 m if there was significant heat release from microbiological activity. Reliable assessment of self-heating and self-ignition risks in large scale Miscanthus energy crop clamps or piles are required to prevent losses due to decomposition and fire damage. (C) 2014 Elsevier Ltd. All rights reserved.
13. Theoretical analysis of coal stockpile self-heating
作者: Hooman, K.; Maas, U.
FIRE SAFETY JOURNAL 卷: 67 页: 107-112 出版年: JUL 2014
摘要This paper theoretically analyses the problem of coal stockpile self-heating under free convection (no wind) conditions. Scale analysis has been used to drive expressions for the stockpile temperature and inflection point (when the stockpile is completely dry) as functions of the key parameters including the coal type, moisture content, and particle diameter as well as the ambient air temperature. Theoretical predictions are then successfully compared with experimental data and CFD simulations results available in the open literature. (C) 2014 Elsevier Ltd. All rights reserved.
14. Investigation of the spontaneous combustion susceptibility of coal using the pulse flow calorimetric method: 25 years of experience
作者: Taraba, Boleslav; Pavelek, Zdenek
FUEL 卷: 125 页: 101-105 出版年: JUN 1 2014
摘要The paper summarises 25 years of experience with pulse flow calorimetry (PFC) as a method to assess the potential of coals to spontaneously heat up using the values of oxidation heat q(30) (W kg(-1)). During the period, about 300 coals of various rank and with natural moisture content were investigated, the maximum propensity to oxidation being found in subbituminous coals with moisture content of about 20%. The highest value of oxidation heat q(30) was found to be 10.5 W kg(-1). Oxidatively altered bituminous coals are presented as coals of evidently increased ability to oxidize, and the reasons for the increased oxyreactivity are reported. Limiting values of q(30) heat are then given to rank the coals according to the categories of self-heating risk. Finally, a comparison between oxidation heat q(30) and the values of the initial rate of heating (IRH) of adiabatic oxidation tests is presented. (C) 2014 Elsevier Ltd. All rights reserved.
15. Safe storage of selected fuels with regard to their tendency to spontaneous combustion
作者: Veznikova, H.; Perdochova, M.; Bernatik, A.; 等.
JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES 卷: 29 页: 295-299 出版年: MAY 2014
摘要European standard EN 15188 is dedicated to the assessment of the tendency of solid flammable substances to spontaneous combustion. Fossil fuels and biofuels that substitute them are a frequent reason of fires caused by spontaneous combustion. Even though having different properties, both types of fuels can be assessed according to this standard by the method of the determination of the dependency of self-ignition temperature against the ratio of volume to surface area of geometrically exactly defined solid body, or based on the theory of thermal explosion according to Frank-Kamenetskii. The comparison of calculated values confirmed the agreement of both methods results, and the tendency of fuels to spontaneous combustion can be assessed by them. (C) 2014 Elsevier Ltd. All rights reserved.
16. On the understanding and control of the spontaneous heating of dried tannery wastewater sludge
作者: Biasin, A.; Della Zassa, M.; Zerlottin, M.; 等.
WASTE MANAGEMENT 卷: 34 期: 4 页: 817-824 出版年: APR 2014
摘要We studied the spontaneous heating of dried sludge produced by treating wastewater mainly originating from tanneries. Heating up to burning has been observed in the presence of air and moisture, starting at ambient temperature. To understand and prevent the process we combined chemical and morphological analyses (ESEM) with thermal activity monitoring in insulated vessels. Selective additions of chemicals, either to amplify or depress the reactivity, have been used to investigate and identify both the chemical mechanism causing the sludge self-heating, and a prevention or a mitigation strategy. FeS additions accelerate the onset of reactivity, while S sustains it over time. On the contrary, Ca(OH)(2), Na2CO3, NaHCO3, FeCl2, EDTA, NaClO can limit, up to completely preventing, the exothermic activity. All the experimental evidences show that the reactions supporting the dried sludge self-heating involve the Fe/S/O system. The total suppression of the reactivity requires amounts of additives that are industrially incompatible with waste reduction and economics. The best prevention requires reduction or removal of S and Fe from the dried solid matrix. (C) 2014 Elsevier Ltd. All rights reserved.
17. Effectiveness of catechin and poly(ethylene glycol) at inhibiting the spontaneous combustion of coal
作者: Dou, Guolan; Wang, Deming; Zhong, Xiaoxing; 等.
FUEL PROCESSING TECHNOLOGY 卷: 120 页: 123-127 出版年: APR 2014
摘要The effects of various combinations of catechin and poly(ethylene glycol) (PEG) concentrations on the inhibition of coal oxidation were studied. The oxidation behaviors of coal samples both with and without the additives were examined, based on measurements of cross point temperature, oxygen consumption during low temperature oxidation and carbon monoxide emission rates. The results demonstrate that an additive consisting of a combination of both catechin and PEG 200 is capable of inhibiting the oxidation process. In situ monitoring of the surfaces of coal samples during oxidation also indicated that these additives suppress coal oxidation by accelerating the formation of ether bonds. Accordingly, a suppression mechanism is proposed. (C) 2013 Elsevier B.V. All rights reserved.
18. Estimating the Spontaneous Combustion Potential of Coals Using Thermogravimetric Analysis
作者: Avila, Claudio; Wu, Tao; Lester, Edward
ENERGY & FUELS 卷: 28 期: 3 页: 1765-1773 出版年: MAR 2014
摘要In this paper, the reactive properties of coals associated with low-temperature oxidation were studied using thermogravimetric analysis (TGA). Coal samples were pulverized into a size fraction of <106 mu m and analyzed using two non-isothermal thermogravimetric methods. The "adsorption of oxygen" test consisted of exposing coal samples to slow heating rates in air while measuring the weight increase produced by the oxygen adsorption. Two heating ramps were used (3 and S C min(-1)), recording the net mass increases from 20 to 250 degrees C. Results range from 0.0 to 4.4% weight gain, with the lowest heating rate giving the highest levels of adsorption. A second thermogravimetric test for spontaneous ignition potential (TG(spi)) was developed, which focused on the linear segment of the weight derivative curve between 150 and 350 degrees C at different ramp rates in air (3, 5, 7, 10, and 20 degrees C min(-1)). From these results, a relationship between the mass loss rate and temperature was obtained (TG(spi) index), where high values were produced by highly reactive coals. The "oxygen adsorption" test related to the chemisorption step, which precedes "spontaneous combustion". The "TG(spi)" test was more related to the combustion process, post-ignition. These results also agreed with the known behavior for the samples studied, indicating that these tests could be useful tools to identify coals prone to self-oxidation.
19. The Effect of Pore Volume of Hard Coals on Their Susceptibility to Spontaneous Combustion
作者: Dudzinska, Agnieszka
JOURNAL OF CHEMISTRY 文献号: 393819 出版年: 2014
摘要In this paper the results of the experimental studies on a relationship between pore volume of hard coals and their tendency to spontaneous combustion are presented. Pore volumes were determined by the gas adsorption method and spontaneous combustion tendencies of coals were evaluated by determination of the spontaneous combustion indexes Sz(a) and Sz(a') on the basis of the current Polish standards. An increase in the spontaneous combustion susceptibility of coal occurs in the case of the rise both in micropore volumes and in macropore surfaces. Porosity of coal strongly affects the possibility of oxygen diffusion into the micropores of coal located inside its porous structure. The volume of coal micropores determined on the basis of the carbon dioxide adsorption isotherms can serve as an indicator of a susceptibility of coal to spontaneous combustion.
20. Analysis of Index Gases of Coal Spontaneous Combustion Using Fourier Transform Infrared Spectrometer
作者: Tang, Xiaojun; Liang, Yuntao; Dong, Haozhe; 等.
JOURNAL OF SPECTROSCOPY 文献号: 414391 出版年: 2014
摘要Analysis of the index gases of coal for the prevention of spontaneous combustion is of great importance for the enhancement of coal mine safety. In this work, Fourier Transform Infrared Spectrometer (FTIRS) is presented to be used to analyze the index gases of coal in real time to monitor spontaneous combustion conditions. Both the instrument parameters and the analysis method are introduced at first by combining characteristics of the absorption spectra of the target analyte with the analysis requirements. Next, more than ten sets of the gas mixture containing ten components (CH4, C2H6, C3H8, iso-C4H10, n-C4H10, C2H4, C3H6, C2H2, CO, and CO2) are included and analyzed with a Spectrum Two FTIRS made by Perkin Elmer. The testing results show that the detection limit of most analytes is less than 2 x 10(-6). All the detection limitsmeet the monitoring requirements of coal spontaneous combustion in China, which means that FTIRS may be an ideal instrument and the analysis method used in this paper is sufficient for spontaneous combustion gas monitoring on-line and even in situ, since FTIRS has many advantages such as fast analysis, being maintenance-free, and good safety.
21. An experimental approach to selecting chemical inhibitors to retard the spontaneous combustion of coal
作者: Wang, Deming; Dou, Guolan; Zhong, Xiaoxing; 等.
FUEL 卷: 117 页: 218-223 子辑: A 出版年: JAN 2014
摘要Because of the complex structure of coal, selecting an efficient chemical inhibitor to retard or prevent its spontaneous combustion remains a challenging task. In the present work, the distributions and concentrations of functional groups on coal surfaces were analyzed using in situ FTIR. The active functional groups and their oxidation processes were elucidated so as to develop an efficient approach to selecting effective chemical inhibitors. The validity of the experimental approach was demonstrated by measuring various performance metrics for samples with and without a chemical inhibitor, including crossing point temperature (CPT), oxygen consumption, carbon monoxide (CO) emission rates and changes in active functional groups. The results indicate that the chemical inhibitor chosen using the proposed approach effectively slows the oxidation of coal, thereby demonstrating the validity of the selection method. (C) 2013 Elsevier Ltd. All rights reserved.
22. Study on the Gelation of Foamed Gel for Preventing the Spontaneous Combustion of Coal
作者: Zhang, Leilin; Qin, Botao
JOURNAL OF SPECTROSCOPY 文献号: 163742 出版年: 2014
摘要According to the existing deficiencies in fire prevention technology, a new technique named foamed gel is developed to prevent coal mine fire efficiently. Foamed gel, formed by adding the type F3 foam agent, polymer H, and AL into water, introducing nitrogen and stirring physically and mechanically, is a complex multicomponent foam system. The effects of the mass fraction and mixed ratios of polymer H and polymer AL blends on gelation were comprehensively studied. The results show that the optimum performance can be got when the mass fraction of blends was 0.6% and the mixed ratio was 5 : 5. In addition, the interaction between molecules of these polymer blends was also investigated with the help of atomic force microscope. It can be found that the polymers Hand AL, through having crosslinking reaction with each other, formed three-dimensional network structures, which can not only increase the nodes of the foamed gel system but also enhance the structures.
