Low-Carbon Binder for Cemented Paste Backfill: Flowability, Strength and Leaching Characteristics

Qiu, Jingping; Zhao, Yang; Long, Hui; Guo, Zhenbang; Jin, Xing; Sun, Xiaogang

doi:10.3390/min9110707

Cited by 22 publications

(3 citation statements)

References 64 publications

(65 reference statements)

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“…On the one hand, because of the increase in solid content, the distance between the aggregate particles of the CPB mixture is reduced. In the slump test, the sliding between aggregate particles is more likely to generate friction, and the fluidity deteriorates, thereby reducing the slump value [15,28]. On the other hand, an increase in solid content leads to an increase in the consistency of the CPB slurry, a decrease in fluidity, and a decrease in the slump value [29].…”

Section: Effect Of Response Surface Parameters On the Slump Of The Cpmentioning

confidence: 99%

Strengthening Behavior of Cemented Paste Backfill Using Alkali-Activated Slag Binders and Bottom Ash Based on the Response Surface Method

Sun

Wei

et al. 2020

Materials

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A new type of cemented paste backfill (CPB) was prepared by using the bottom ash (BA) from a thermal power plant as an aggregate, alkali-activated slag as a binder, and an air-entraining agent as an admixture. Based on the central composite design (CCD) response surface method, the mix ratio was optimized, and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) was performed on the optimal mix ratio. ImageJ software was utilized to determine the porosity of the experimental samples at various curing ages. The results indicate that the optimal mix ratio of the aggregate-binder ratio is 3.28, the alkali dosage is 3%, the solid content is 67.44%, and the air-entraining agent dosage is 0.1%. As the curing age increases, the porosity of CPB gradually decreases. A calcium aluminosilicate hydrate (C-A-S-H) gel is the main hydration product of alkali-activated slag. At the beginning of the hydration reaction, the slag gradually dissolves, and the C-A-S-H product binds the BA together. At 14 d, complete calcium hydroxide (CH) crystals appeared in the hydration product. Finally, the degree of C-A-S-H crystallization increased further to form a dense structure.

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Section: Effect Of Response Surface Parameters On the Slump Of The Cpmentioning

confidence: 99%

Strengthening Behavior of Cemented Paste Backfill Using Alkali-Activated Slag Binders and Bottom Ash Based on the Response Surface Method

Sun

Wei

et al. 2020

Materials

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“…Mining, as a traditional heavy industry, provides raw material support for national economic development [1,2], but also inevitably brings a negative impact on the environment [3][4][5]. In the 1980s, with the development of cemented paste backfill (CPB), tailings were used in large quantities for the preparation of high concentration backfill slurry and were recycled [6,7]. Meanwhile, CPB has gradually become a current research hotspot because of its excellent performance in controlling surface settlement, consuming mine solid waste, and backfill underground mining areas, which fits in with the theme of green development [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Resistance Loss and Erosive Wear during Pipe Transport of Paste Slurry

Qiu

Tian²,

Zhu³

et al. 2023

Sustainability

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Cemented paste backfill (CPB) as a solid waste treatment technology that prepares tailings as aggregate into a highly concentrated slurry to be transported to the underground mining area, is now widely used in mines. However, the pipeline resistance loss and erosion wear during CPB slurry transportation considering the coupling effect of inlet velocities, viscosities, and particle sizes have not yet been well evaluated and analyzed. Hence, the CFD-based three-dimensional network simulation of CPB slurry flow in an L-shaped pipe at different combinations of the three parameters was developed using COMSOL Multiphysics software. The results showed that the pipe resistance loss was most affected by the inlet velocity and viscosity, with the minimum pipe resistance loss occurring at an inlet velocity of 1.5 m/s, a viscosity of 2.0 Pa·s, and a particle size of 150 μm. In particular, pipe erosion wear was severest at the bend and was positively correlated with inlet velocity and particle size, and negatively correlated with slurry viscosity, with maximum pipe erosion wear occurring at an inlet velocity of 3.5 m/s, a viscosity of 3.0 Pa·s, and a particle size of 2000 μm. The findings would be important for the design of the CPB pipeline transportation, which will improve the safety and economic level of a mine.

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“…Alkali-activated binders could be designed to have superior properties compared to cement, namely the development of earlier and higher mechanical strengths [22], better resistance to acids and sulphates [23], and lower heat of cement hydration [24]. Numerous studies [17,18,[25][26][27] have been recently shown to better assess the mechanical, workability and microstructural properties of CPB materials by using alkali-activated slag (AAS) as a binder. These studies have shown that, compared to those made up of OPC, CPB samples containing AAS as binder were found to produce remarkably higher early-age strength and stability.…”

Section: Introductionmentioning

confidence: 99%

Rheological Properties of Cemented Paste Backfill with Alkali-Activated Slag

et al. 2020

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This study investigates the time-dependent rheological behavior of cemented paste backfill (CPB) that contains alkali-activated slag (AAS) as a binder. Rheological measurements with the controlled shear strain method have been conducted on various AAS-CPB samples with different binder contents, silicate modulus (Ms: SiO2/Na2O molar ratio), fineness of slag and curing temperatures. The Bingham model afforded a good fit to all of the CPB mixtures. The results show that AAS-CPB samples with high binder content demonstrate a more rapid rate of gain in yield stress and plastic viscosity. AAS-CPB also shows better rheological behavior than CPB samples made up of ordinary Portland cement (OPC) at identical binder contents. It is found that increasing Ms yields lower yield stress and plastic viscosity and the rate of gain in these parameters. Increases in the fineness of slag has an adverse effect on rheological behavior of AAS-CPB. The rheological behavior of both OPC- and AAS-CPB samples is also strongly enhanced at higher temperatures. AAS-CPB samples are found to be more sensitive to the variation in curing temperatures than OPC-CPB samples with respect to the rate of gain in yield stress and plastic viscosity. As a result, the findings of this study will contribute to well understand the flow and transport features of fresh CPB mixtures under various conditions and their changes with time.

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Low-Carbon Binder for Cemented Paste Backfill: Flowability, Strength and Leaching Characteristics

Cited by 22 publications

References 64 publications

Strengthening Behavior of Cemented Paste Backfill Using Alkali-Activated Slag Binders and Bottom Ash Based on the Response Surface Method

Strengthening Behavior of Cemented Paste Backfill Using Alkali-Activated Slag Binders and Bottom Ash Based on the Response Surface Method

Numerical Study of Resistance Loss and Erosive Wear during Pipe Transport of Paste Slurry

Rheological Properties of Cemented Paste Backfill with Alkali-Activated Slag

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