Reactivity of cemented paste backfill containing polycarboxylate-based superplasticizer

Haruna, Sada; Fall, Mamadou

doi:10.1016/j.mineng.2022.107856

Cited by 19 publications

(4 citation statements)

References 54 publications

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“…The conductive group gradually changes from strong conductivity (OH − ) to weak conductivity (RCOO − ) under alkaline conditions over time, and the electrical conductivity of the system would gradually decrease. [ 27 ] The faster rate of reaction of saponification, the faster conductivity drops. In order to investigate the saponification rate of different types of slump‐retention PCEs under alkaline conditions, the change in electrical conductivity over time was measured.…”

Section: Resultsmentioning

confidence: 99%

Effect of chain transfer agents in polycarboxylate superplasticizer on slump‐retention of concrete

Pang

Guo

Li³

et al. 2023

Can J Chem Eng

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Two types of slump‐retention polycarboxylate superplasticizers (PC‐M and PC‐S) were synthesized by using 3‐mercaptopropionic acid or sodium hypophosphite as chain transfer agents, the effects of polycarboxylate superplasticizers on slump‐retention of cement and concrete were investigated, and the mechanism of action and the structure of polycarboxylate superplasticizers were investigated by using conductivity, complexing Ca2+ concentration, gel permeation chromatography (GPC), nuclear magnetic resonance hydrogen spectroscopy (1H‐NMR), and nuclear magnetic resonance phosphorus spectroscopy (31P‐NMR). The results indicated that the slump flow of cement paste mixed with PC‐M was increased quickly within 60 min and then lost gradually, while PC‐S increased slowly and evenly within 240 min. The slump flow of concrete mixed with PC‐S reached 405 mm after 150 min, but the concrete mixed with PC‐M was almost no fluidity after 150 min. The conductivity of the PC‐M aqueous solution decreased quickly within 45 min, then slowly decreased, while the conductivity of the PC‐S aqueous solution decreased slowly within 180 min. PC‐M had a much greater complexation ability of Ca2+ than PC‐S. The composition and structure of the two slump‐retention polycarboxylate superplasticizers were altered by different chain transfer agents, and the hydrolysis‐adsorption capacity of each component was different. The rate of hydrolyzation‐adsorption of each component was PC‐M3 ≈ PC‐S3>PC‐M1>PC‐M2 ≈ PC‐S1>PC‐S2. The faster the adsorption rate, the faster the slump flow loss of concrete.

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Section: Resultsmentioning

confidence: 99%

Effect of chain transfer agents in polycarboxylate superplasticizer on slump‐retention of concrete

Pang

Guo

Li³

et al. 2023

Can J Chem Eng

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“…The mass loss below 500 • C was mainly from the dissipation of crystal water, interlayer water, and hydroxy groups from the structure of the hydration product. Among these, the mass loss below 240 • C resulted from the evaporation of crystal water and interlayer water; the mass loss in the range from 240 • C to 500 • C was mainly due to the dissipation of hydroxyl groups in the structure [43][44][45]. The mass loss in the range from 500 • C to 800 • C was mainly due to the dissipation of CO 2 from the carbonate product.…”

Section: Tg-dtgmentioning

confidence: 99%

Strength Investigation and Prediction of Superfine Tailings Cemented Paste Backfill Based on Experiments and Intelligent Methods

Zhang

et al. 2023

Materials

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The utilization of solid waste for filling mining presents substantial economic and environmental advantages, making it the primary focus of current filling mining technology development. To enhance the mechanical properties of superfine tailings cemented paste backfill (SCPB), this study conducted response surface methodology experiments to investigate the impact of various factors on the strength of SCPB, including the composite cementitious material, consisting of cement and slag powder, and the tailings’ grain size. Additionally, various microanalysis techniques were used to investigate the microstructure of SCPB and the development mechanisms of its hydration products. Furthermore, machine learning was utilized to predict the strength of SCPB under multi-factor effects. The findings reveal that the combined effect of slag powder dosage and slurry mass fraction has the most significant influence on strength, while the coupling effect of slurry mass fraction and underflow productivity has the lowest impact on strength. Moreover, SCPB with 20% slag powder has the highest amount of hydration products and the most complete structure. When compared to other commonly used prediction models, the long-short term memory neural network (LSTM) constructed in this study had the highest prediction accuracy for SCPB strength under multi-factor conditions, with root mean square error (RMSE), correlation coefficient (R), and variance account for (VAF) reaching 0.1396, 0.9131, and 81.8747, respectively. By optimizing the LSTM using the sparrow search algorithm (SSA), the RMSE, R, and VAF improved by 88.6%, 9.4%, and 21.9%, respectively. The research results can provide guidance for the efficient filling of superfine tailings.

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“…In the process of filling various types of mine goaf, binding materials usually account for 50%-75% of the filling cost, and to reduce the filling cost, the current research topics on new binding materials instead of conventional binding materials have become exceptionally active and have played a role in reducing costs and increasing efficiency to some extent in practical applications (Zhang et al, 2023;Guo et al, 2022;Haruna et al, 2022;Zhao et al, 2022). In the study of cemented filling materials, researchers analyzed the process of microstructural transformation of composite binding materials to Al-O tetrahedra and observed that CaSO 4 was completely hydrated to generate Aft during the reaction phase, resulting in a binding material with high early strength (Wang et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Study on the setting characteristics of filling slurry with different aggregate combinations

Deng,

Wang,

Liang

et al. 2023

Front. Earth Sci.

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To grasp the phase change characteristics of the filling slurry from fluid to solid state in time, conducted a study on the setting characteristics of the filling slurry with different aggregate combinations, and analyzed the law of the initial and final setting time with the change of the amount of cementation powder, filling plant tailings, tailing pond tailings, and water. The results show that the initial and final setting time of the filling slurry prepared from the tailings of the filling plant is proportional to the concentration, and is positively correlated with the slope decline of the sand-cement ratio. The filling slurry prepared from the tailings of the tailing pond shows roughly the same change trend as the above slurry, but the change law is not obvious, which cannot be expressed by one kind of functional model, and the initial setting time and final setting time are less than the above slurry, which is because the tailings of the tailing pond contain more fine particles, which play a role in delaying setting in the slurry. For example, for five kinds of filling materials with different aggregates of 4:1, 6:1, 8:1, 12:1, and 20:1 sand-to-ash ratios and concentrations of 66%–72%, the initial setting times of filling slurry prepared from tailings of filling plant and tailings of tailing pond were 75.3 h–112.3 h, 77.6 h–122.2 h, and the final setting times were 82.8 h–123.4 h, 85.5 h–133.9 h. Therefore, it shows that the use of filling plant tailings containing fewer fine particles to prepare filling slurry can obtain a better treatment effect of the mining area, and the shortening of the solidification and hardening process of filling slurry can accelerate the mining cycle operation, and increase the amount of solid waste disposal per unit time, thus creating the necessary technical conditions for the enterprise to improve production efficiency and sustainable development.

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Reactivity of cemented paste backfill containing polycarboxylate-based superplasticizer

Cited by 19 publications

References 54 publications

Effect of chain transfer agents in polycarboxylate superplasticizer on slump‐retention of concrete

Effect of chain transfer agents in polycarboxylate superplasticizer on slump‐retention of concrete

Strength Investigation and Prediction of Superfine Tailings Cemented Paste Backfill Based on Experiments and Intelligent Methods

Study on the setting characteristics of filling slurry with different aggregate combinations

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