Experimental investigation of cement-based sealing materials for degasification using coal-bed methane drainage system

Hao, Min; Song, Xiaolin; Shi, Haitao; Zhou, Fang; Shi, Bobo

doi:10.1166/mex.2018.1424

Cited by 10 publications

(10 citation statements)

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“…Their combination extends the hydration process of the slurry. 41 , 42 As a result, the setting time of the sealing material is slightly shortened with the increase of the suspension agent content. Therefore, the ratio of the sealing material with effective setting time is A 5 B 2 C 1 D 5 E 4 F 3 ; that is, the water–cement ratio is 1.3, the accelerant content is 30%, the alkali activator content is 3%, the suspension agent content is 5%, the expansion agent content is 0.4%, and the reinforcing agent content is 3%.…”

Section: Orthogonal Test Results and Analysismentioning

confidence: 99%

“…Furthermore, the expansion agent (aluminum powder) reacts with H 2 O and Ca(OH) 2 to form H 2 (2Al + 2OH – + 2H 2 O → AlO 2– + H 2 ↑) and CaSO 4 , and the C 3 A minerals react to form ettringite crystals (C 3 A + 3(CaSO 4 ·2H 2 O) + 2Ca(OH) 2 + 24H 2 O → 3CaO·Al 2 O 3 ·3CaSO 4 ·32H 2 O). Their combination extends the hydration process of the slurry. , As a result, the setting time of the sealing material is slightly shortened with the increase of the suspension agent content. Therefore, the ratio of the sealing material with effective setting time is A 5 B 2 C 1 D 5 E 4 F 3 ; that is, the water–cement ratio is 1.3, the accelerant content is 30%, the alkali activator content is 3%, the suspension agent content is 5%, the expansion agent content is 0.4%, and the reinforcing agent content is 3%.…”

Section: Orthogonal Test Results and Analysismentioning

confidence: 99%

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Preparation and Performance Investigation of Optimized Cement-Based Sealing Materials Based on the Response Surface Methodology

Zhang

Wang

et al. 2022

ACS Omega

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A new cement-based sealing material, which used Portland cement (PC) as a raw material and supplemented several gel components, such as accelerant, alkali activator, suspension agent, expansion agent, reinforcing agent, was prepared in this work. The effects of these components on the fluidity, setting time, and expansion rate of these sealing materials were investigated by an orthogonal test. The results show that the water–cement ratio and the reinforcing agent content, the accelerant content and the water–cement ratio, and the expansion agent content and the accelerant content are the most important influencing factors on fluidity, setting time, and expansion rate, respectively. In addition, the regression models and response surfaces of the factors were established using a multiple linear regression method. By this means, the influences of the two main factors on each performance of this sealing material were accurately and intuitively reflected for obtaining the optimal value in the optimization area. The results indicate that the sealing materials possess the best performances when the water–cement ratio is 1.1, the accelerant content is 50%, the expansion agent content is 0.1%, and the reinforcing agent content is 3%, which is corresponding to a fluidity of 360–380 mm, an initial (final) setting time of 60 (80)–80 (100) min, and an expansion rate of 2–12%. Furthermore, the microstructures of the optimized sealing material also reveal that the main hydration products of PC are transformed from layered Ca(OH) 2 crystals into fine needle-like AFt crystals and C–S–H gels by the promotion effect of the optimizing ratio, thus leading to a more compact structure of optimized cement-based sealing materials.

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Section: Orthogonal Test Results and Analysismentioning

confidence: 99%

Section: Orthogonal Test Results and Analysismentioning

confidence: 99%

Preparation and Performance Investigation of Optimized Cement-Based Sealing Materials Based on the Response Surface Methodology

Zhang

Wang

et al. 2022

ACS Omega

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“…480 (III) material roadway of a fully mechanized excavation face located in the Zhangcun Coal Mine (Shanxi, China). e main materials used for the dust suppression testing were as follows [28]:…”

Section: Methodsmentioning

confidence: 99%

Experimental Investigations and Field Applications of Chemical Suppressants for Dust Control in Coal Mines

Liao

Feng

Fan

et al. 2018

Advances in Materials Science and Engineering

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It is known that high dust concentrations are severely hazardous to health of miners and the safe operations of coal mines. The results of the suppressions of coal dust via chemical dust suppressant methods have been of critical significance, and these methods have been widely applied in coal mines. In this research study, a type of complex dust suppressant composed of surfactants, synergists, and cellulose was prepared. The prepared suppressant was characterized by a high wetting ability and adhesive capacity. The results of the performance tests of this study’s proposed complex dust suppressant showed that its dust sedimentation time was only four seconds, which was observed to be much shorter than that of water alone. Also, the proposed suppressant displayed a viscosity which was 25 times that of water. In this study’s field tests, the proposed complex dust suppressant was used for dust control in a mining roadway of the Zhangcun Coal Mine. The field test results revealed that the average suppression efficiencies of the total dust and respirable dust had reached 89.2% and 87.7%, respectively. Furthermore, a 44.5% increase in the control of the total dust had been observed, and a 65.6% increase in the control of the respirable dust had been achieved with the proposed method, when compared with the results of the previously used water curtain technology.

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“…Another factor is that Ca(OH) 2 and Na 2 SO 4 enhance the reactivity of fly ash and expedite the hydration process, resulting in a significant formation of AFt. 44,45 According to the extreme difference analysis in Figure 7, it can be seen that the significance of the effect of each factor on compressive strength is in the following order: water−cement ratio (RA) > PVA fiber (RE) > FA (RB) > Na 2 SO 4 (RC) > Ca(OH) 2 (RD). The primary determinants were the ratio of water to cement and the presence of PVA fiber.…”

Section: Analysis Of Factors Affecting Compressive Strengthmentioning

confidence: 99%

Research on the Performance of Cement-Based Composite Borehole Sealing Material Based on Orthogonal Test

Xu,

Wei,

Xie

et al. 2024

ACS Omega

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In order to achieve better sealing of boreholes, the performance of sealing materials is modified to improve the efficiency of coalbed methane extraction. In this paper, a new type of cement-based hole sealing material was prepared by using silicate cement (PC) and cement sulfoaluminate (SAC) as raw materials, supplemented with various additives, such as fly ash, Na 2 SO 4 , Ca(OH) 2 , and poly(vinyl alcohol) (PVA) fiber. The effects of these additives on the fluidity, setting time, and compressive strength of the PC-SAC compounded cementitious pore sealing material were investigated by orthogonal tests, and the hydration process and hydration products were analyzed by X-ray diffraction (XRD), thermogravimetry-differential thermogravimetry (TG-DTG), and scanning electron microscopy (SEM). The results show that the water−cement ratio has the most significant influence on the various properties of the material; the two additives of Na 2 SO 4 and Ca(OH) 2 play a key role in the setting time of the material; the optimal group, i.e., water−cement ratio of 0.5, fly ash of 5%, Na 2 SO 4 of 1%, Ca(OH) 2 of 0.75%, and PVA fibers of 0.8%, is obtained by the orthogonal test method, which is the closest to the actual needs of the project. The hydration products of the optimized materials have obvious changes, and the needle-like AFt and C−S−H increase so that the performance of the materials has been significantly improved.

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Experimental investigation of cement-based sealing materials for degasification using coal-bed methane drainage system

Cited by 10 publications

References 0 publications

Preparation and Performance Investigation of Optimized Cement-Based Sealing Materials Based on the Response Surface Methodology

Preparation and Performance Investigation of Optimized Cement-Based Sealing Materials Based on the Response Surface Methodology

Experimental Investigations and Field Applications of Chemical Suppressants for Dust Control in Coal Mines

Research on the Performance of Cement-Based Composite Borehole Sealing Material Based on Orthogonal Test

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