Rheological properties of cemented coal gangue backfill based on response surface methodology

Zhu, Lingli; Jin, Zhenghao; Zhao, Yu; Duan, Yihang

doi:10.1016/j.conbuildmat.2021.124836

Cited by 32 publications

(7 citation statements)

References 27 publications

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“…When a message is more frequently appearing, it is more widely disseminated. In addition, IE can indicate the value of information from the perspective of information dissemination [40,41]. Therefore, IE value can be used as a measure of high or low information value.…”

Section: Information Entropymentioning

confidence: 99%

Fly Ash and Slag as Partial Replacement of Cement for the Synthesis of Low Carbon Cementitious Materials

Hu¹,

Li²,

Zheng³

et al. 2023

Journal of Renewable Materials

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Tailings known as solid waste are generated by the mining industry. The development of tailings as wet shotcrete aggregates has significant economic and environmental benefits. The fine particle size of the tailings results in a large consumption of traditional cement as a cementitious material and insignificant improvement in strength. Therefore, a composite cementitious system of cement and solid waste resources (fly ash and slag powder) is explored for this study. In this paper, the response surface methodology (RSM) is used to optimize the experimental design and a multivariate nonlinear response model with cement, fly ash and slag powder contents as variables are constructed, which can investigate the effect of the composite cementitious system on the strength of tailing wet shotcrete (TWSC). In addition, the information entropy (IE) is introduced and combined with the RSM to evaluate the composite cementitious system. Finally, the desirability function (DF) combined with RSM is used to optimize the composite cementitious system. The results show that the response model constructed in this paper has R 2 = 0.96 and P-value < 0.01 (the test result of the model is P-value < 0.01), which indicates that the model has high reliability. The higher the content of slag powder and cement in the composite cementitious system, the higher the strength and comprehensive score of the TWSC. There is a critical value of fly ash content, which makes the maximum cementation of the composite cementing system. The optimal mix proportion of the composite cementitious system is obtained based on RSM-DF, which leads to the strength of TWSC at different curing time to achieve the expected index.

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Section: Information Entropymentioning

confidence: 99%

Fly Ash and Slag as Partial Replacement of Cement for the Synthesis of Low Carbon Cementitious Materials

Hu¹,

Li²,

Zheng³

et al. 2023

Journal of Renewable Materials

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“…When shear stress forced on the filling slurry does not reach the yield stress (τ 0 ), it behaves like an elastic solid with no fluidity. Only after shear stress exceeds the yield stress does it take on the properties of a liquid (Liu et al, 2020;Zhu et al, 2021).…”

Section: Rheological Parameters Testmentioning

confidence: 99%

Remediation of grassland subsidence and reduction of land occupation with tailings backfill technology: a case study of lead-zinc mine in Inner Mongolia, China

Chen

Guo

Zhou³

et al. 2023

Front. Environ. Sci.

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The mining industry provides essential mineral resources for human society’s development. However, this industry generates a large quantity of waste material while rapidly extracting valuable elements from ore, such as processed tailings. The existence of mined voids will cause surface subsidence, and the surface stockpiling of tailings and waste rocks occupy a large amount of land and the risk of Tailings Storage Facility (TSF) failure. This paper proposes tailings backfill technology to mitigate surface subsidence and provides an alternative disposal method for tailings generated during ore extraction. Tailings backfill technology prepares the slurry by adding a certain amount of cementitious material into the tailings and transporting it to the underground goaf through a pipeline. The backfill slurry could then gradually build up its strength during the hydration of. Cementitious material. A case study of a lead-zinc mine in the Inner Mongolia Autonomous Region of China using tailings backfill technology was introduced in detail to solve the problems of grassland collapse caused by mine excavation and environmental damage due to tailings disposal. Spread test and rheological test were carried out to study the flow characteristics of filling slurry and the uniaxial compressive strength (UCS) of backfill was tested as well. The result illustrates that the spread of the filling slurry with a solid content between 72% and 76% and cement-tailings ratio between 1:4 and 1:8 is greater than 14 cm, and the UCS of backfill is above 1 MPa. The research shows that the tailings backfill technology recycles tailings waste while mitigating surface grassland subsidence and land occupation of waste disposal. Tailings backfill technology can significantly reduce tailings discharge or even achieve no discharge. A leaching test for heavy metal element classification of the backfill sample was carried out. The results show that the heavy metal detection indicators meet the environmental protection standard requirements and will not cause secondary environmental pollution. Therefore, tailings backfill technology can realize green and efficient management of mine waste and has great application and promotion prospects.

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“…Faced with the present situation of the severe global resources environment situation, the demand for low-carbon and sustainable development, and the current shortage in construction and building materials, researchers have made many explorations into the efficient utilization of coal gangue as a substitute for the construction materials, such as backfilling in mining areas [ 11 , 12 , 13 , 14 ], as roadbed materials and concrete aggregates [ 15 , 16 , 17 , 18 , 19 ], preparing unburned bricks, etc. [ 20 ].…”

Section: Introductionmentioning

confidence: 99%

Study on the Reactivity Activation of Coal Gangue for Efficient Utilization

Hu,

Han,

Sun

et al. 2023

Materials

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In this study, the research aim is to enhance the activity index of activated coal gangue and study its activation mechanism. The activation process of coal gangue was optimized through orthogonal tests, and the Back-Propagation (BP) neural network model was improved using a genetic algorithm. With the effects of grinding duration, calcination temperature, and calcination duration, the morphological changes and phase transformation processes of coal gangue were studied at the micro and meso levels to clarify the activation mechanism. The results indicated that the effect of calcination temperature on the strength activity index of coal gangue was most significant, followed by grinding duration and calcination duration. The potential activity of coal gangue can be effectively stimulated through mechanical and thermal activation, and the content of potential active minerals in coal gangue powders was also increased. The activation process of coal gangue for the optimal scheme was obtained as grinding at 76 min first and thermal treatment at 54 min at 749 °C. As the thermal activation under 950 °C, some unstable external hydroxyls, and internal hydroxyls in kaolinite from coal gangue were removed, the AlⅥ-O octahedron was destroyed, and kaolinite was transformed into spatially disordered metakaolinite with very high activity.

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Rheological properties of cemented coal gangue backfill based on response surface methodology

Cited by 32 publications

References 27 publications

Fly Ash and Slag as Partial Replacement of Cement for the Synthesis of Low Carbon Cementitious Materials

Fly Ash and Slag as Partial Replacement of Cement for the Synthesis of Low Carbon Cementitious Materials

Remediation of grassland subsidence and reduction of land occupation with tailings backfill technology: a case study of lead-zinc mine in Inner Mongolia, China

Study on the Reactivity Activation of Coal Gangue for Efficient Utilization

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