Coupled effects of cement type and water quality on the properties of cemented paste backfill

Wu, Aixiang; Wang, Yong; Wang, Hongjiang; Yin, Shenghua; Miao, Xiuxiu

doi:10.1016/j.minpro.2015.09.004

Cited by 128 publications

(34 citation statements)

References 22 publications

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“…e filling body is a product that is prepared artificially from different proportions of materials, and naturally the strength development is influenced not only by the preparation proportions but also by the intrinsic properties of the materials [35,36]. In other words, it reflects that there is some inevitable correlation between the strength development and the two factors mentioned above.…”

Section: Analysis Of the Present Prediction Modelmentioning

confidence: 99%

A Novel Prediction Model of Strength of Paste Backfill Prepared from Waste-Unclassified Tailings

Zhang

2019

Advances in Materials Science and Engineering

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Paste backfilling is an important support for the development of green mines and deep mining. It can effectively reduce a series of risks of underground goaf and surface tailings ponds. Reasonable strength of backfill is an effective guarantee for controlling ground stress and realizing safe mining function. Under the combination of complex materials and local conditions, ensuring the optimal design and effective proportion for paste backfill strength is the bottleneck problem that restricts the safety, economy, and efficiency of filling mining. The strength developing trend of paste backfilling prepared from waste rock and unclassified tailings has been studied. Different levels of cement contents, tailings-waste ratios, and slurry concentrations were investigated through orthogonal design to obtain the relationship between the UCS and the multi-influential factors. Combined with the experimental results and the previous strength prediction models, the waste rock-unclassified tailings paste strength prediction model was proposed. Introducing the water-cement ratio, the cement-tailings ratio, the amount of cement, and the packing density that characterizing the overall gradation of unclassified tailings and waste rock, as well as the curing time, a strength prediction model of multifactors was developed. Moreover, the microscopic structure of the paste prepared from waste-unclassified tailings was analyzed with an Environment Scanning Electron Microscope (ESEM), and the influence mechanism was ascertained. The weight coefficient of strength development is carded in this paper, and the strength model of unclassified tailings-waste paste considering five factors is obtained, which is of great significance to guide the mining engineering.

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Section: Analysis Of the Present Prediction Modelmentioning

confidence: 99%

A Novel Prediction Model of Strength of Paste Backfill Prepared from Waste-Unclassified Tailings

Zhang

2019

Advances in Materials Science and Engineering

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“…The mechanical stability of cemented waste rock under compression is usually of concern, as it is under pressure throughout the service period [14][15][16], mainly from four aspects: cementing materials, aggregate particles, additive materials, and environmental conditions. (1) In cementing materials (including its type, content, and even the mixed formulation of multiple cementing materials), it is believed that the mechanical parameters of cemented waste rock can be increased by improving its bonding performance [17][18][19][20]; (2) In aggregate particles, which include particle composition, content, and particle size distribution, it is considered that the internal structure of backfill can be strengthened by reducing the elements that can deteriorate the hydration product and optimize the spatial distribution of the particles [21][22][23][24][25][26][27][28][29][30][31][32][33]; (3) In additive materials, including nanomaterials, polymers, fibers, alkaline substances, and water-absorbing substances, it is believed that the hydration process can be improved, the formation of hydration products can be promoted, and even more reliable links can be generated at the cement-rock boundaries to optimize the loading structure of backfill [34][35][36][37][38][39][40][41][42]; (4) In environmental conditions, including temperature, corrosion, conservation, and stress field, it is considered that creating more favorable environmental conditions can improve the mechanical properties of cemented waste rock [43][44]…”

Section: Introductionmentioning

confidence: 99%

Particle Size Distribution of Cemented Rockfill Effects on Strata Stability in Filling Mining

et al. 2018

Minerals

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It is of great significance for engineering safety, economic benefits, environmental protection, and sustainable development to investigate the strata stability in filling mining with cemented rockfill. Consequently, this paper is based on a specific coal mine where we applied the fully-mechanized longwall mining and filling and designed a cemented rockfill material for which the particles satisfied the Talbot gradation. Uniaxial and triaxial compression experiments were carried out on the cemented rockfill specimen, which obtained the relations between the mechanical parameters (Poisson ratio, elastic modulus, compressive strength, cohesive force, internal friction angle, and tensile strength) and the particle size distribution of the aggregate. The excavation and filling processes in the coal seam were simulated based on the numerical software FLAC3D. The characteristics of the displacement and stress fields of the strata when the goaf was filled by cemented rockfill with different granule gradations were discussed. The influences of the particle size distribution and mining distance on the maximum subsidence displacement of the coal seam roof, internal stress of the backfill, and the stress of the rock mass in the coalface were analyzed. The feasibility and effectiveness of the filling mining with cemented rockfill to protect the integrity of the overlying strata were discussed. The results showed that optimizing the particle size distribution of the aggregate in cemented rockfill could increase the loading capacity of the backfill to improve the filling effect, effectively control the strata movement, and decrease the stress of rock mass in the coalface to reduce the potential danger.

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“…Slurry specimen S3 (whose mass fraction was 74%) had the largest initial yield stress at 115.25 Pa, while those of S1 and S2 were 76.55 Pa and 92.71 Pa, respectively. However, this value was lower than the boundary value for the initial yield stress of paste and paste-like backfilling slurries (160-220 Pa) [23,24]. The shear stress increased as the shear rate rose.…”

Section: Analysis Of Resultsmentioning

confidence: 71%

Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

2016

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Aeolian sand, tailings, and #32.5 Portland cement were used to produce backfilling aggregate, and physicochemical evaluations and proportioning tests were conducted. It is revealed that a mixture of aeolian sand and tailings can be used as a backfilling aggregate for the complementarities of their physicochemical properties; e.g., high Al 2 O 3 content in the aeolian sand and CaO content in the tailings, coarse particles of aeolian sand and fine particles of tailings, etc. In addition, the optimal backfilling aggregate was shown to have a mass fraction of 72%-74%, a cement-sand ratio of 1:8, and an aeolian sand proportion of 25%. Furthermore, viscometer tests were used to analyze the rheological characteristics, and the slurry in these optimized proportions exhibited shear thinning phenomena with an initial yield stress, which belongs to paste-like-a cemented backfilling slurry with a higher mass fraction than a two-phase flow and better flowability than a paste slurry. Finally, the application of this backfilling technology shows that it can not only realize safe mining, but also bring huge economic benefits, and has some constructive guidance for environmental protection.

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Coupled effects of cement type and water quality on the properties of cemented paste backfill

Cited by 128 publications

References 22 publications

A Novel Prediction Model of Strength of Paste Backfill Prepared from Waste-Unclassified Tailings

A Novel Prediction Model of Strength of Paste Backfill Prepared from Waste-Unclassified Tailings

Particle Size Distribution of Cemented Rockfill Effects on Strata Stability in Filling Mining

Cemented Backfilling Technology of Paste-Like Based on Aeolian Sand and Tailings

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