Effect of Tailings Fine Content on the Properties of Cemented Paste Backfill from the Perspective Packing Density

In order to quantitatively study the influence of tailings fine content on the properties of cemented paste backfill (CPB) and further understand the mechanism of tailings fine content acting, the concept of packing density was introduced in this study. The packing density of each tailings sample was measured by the wet packing method after the samples with various fine contents were prepared. Moreover, CPBs with different tailings fine contents were tested by the mini slump test, rheological test, uniaxial compressive strength (UCS) test, and mercury intrusion porosimetry test. The results demonstrated that the flow spread and UCS both increase first and then decrease with the increase of tailings fine content, while the yield stress shows an opposite trend. The fine content of tailings affects the flowability of fresh CPB mainly through the packing density. When the fine content is high, the influence of the specific surface area of tailings cannot be ignored. The packing density is an important factor affecting the strength of CPB, and there is an obvious linear relationship between the packing density and UCS. The pore structure of CPB samples with different tailing fine contents is significantly different, and the macroscopic packing density changes the strength of CPB by affecting the microscopic pores.

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Microstructural evolution of cemented paste backfill: Mercury intrusion porosimetry test results

Cement and Concrete Research ◽

10.1016/j.cemconres.2007.08.016 ◽

2007 ◽

Vol 37 (12) ◽

pp. 1654-1665 ◽

Cited By ~ 90

Author(s):

Serge Ouellet ◽

Bruno Bussière ◽

Michel Aubertin ◽

Mostafa Benzaazoua

Keyword(s):

Microstructural Evolution ◽

Mercury Intrusion Porosimetry ◽

Cemented Paste Backfill ◽

Test Results ◽

Mercury Intrusion ◽

Paste Backfill

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Carbide slag–activated ground granulated blastfurnace slag for soft clay stabilization

Canadian Geotechnical Journal ◽

10.1139/cgj-2014-0007 ◽

2015 ◽

Vol 52 (5) ◽

pp. 656-663 ◽

Cited By ~ 20

Author(s):

Yaolin Yi ◽

Liyang Gu ◽

Songyu Liu ◽

Anand J. Puppala

Keyword(s):

Mercury Intrusion Porosimetry ◽

Soft Clay ◽

X Ray Diffraction ◽

X Ray ◽

Mercury Intrusion ◽

Carbide Slag ◽

Calcium Silicate Hydrates ◽

Blastfurnace Slag ◽

Ucs Test ◽

Curing Age

This study addresses the use of an industry by-product, carbide slag (CS), to activate another industry by-product, ground granulated blastfurnace slag (GGBS), for soft clay stabilization in comparison to Portland cement (PC). The properties of CS–GGBS stabilized clays were investigated through unconfined compressive strength (UCS) test, mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The results indicated that the optimum CS content for the CS–GGBS stabilized clay to yield the highest UCS was 4%–6%, varying slightly with curing age and GGBS content. The UCS of the optimum CS-GGBS stabilized clays was more than twice that of the corresponding PC stabilized clays. The main hydration products detected for the CS–GGBS stabilized clays included calcium silicate hydrates (CSH), calcium aluminate hydrates (CAH), and alumino-ferrite monosulfate (AFm).

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Effects of packing density and water film thickness on the fluidity behaviour of cemented paste backfill

Powder Technology ◽

10.1016/j.powtec.2019.10.046 ◽

2020 ◽

Vol 359 ◽

pp. 27-35 ◽

Cited By ~ 14

Author(s):

Jingping Qiu ◽

Zhenbang Guo ◽

Lei Yang ◽

Haiqiang Jiang ◽

Yingliang Zhao

Keyword(s):

Film Thickness ◽

Packing Density ◽

Water Film ◽

Cemented Paste Backfill ◽

Water Film Thickness ◽

Paste Backfill

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Damage Strengthening Constitutive Model of Cemented Paste Backfill

Advances in Civil Engineering ◽

10.1155/2021/5593983 ◽

2021 ◽

Vol 2021 ◽

pp. 1-10

Author(s):

Kangli Cheng ◽

Bingbing Tu ◽

Lang Liu ◽

Bo Zhang ◽

Huafu Qiu

Keyword(s):

Constitutive Model ◽

Uniaxial Compression ◽

Strain Curve ◽

Cemented Paste Backfill ◽

Test Results ◽

Stress Strain ◽

Filling Materials ◽

Paste Backfill ◽

Damage Constitutive Model ◽

Ucs Test

In order to consider the influence of mesoscopic characteristics of materials on the constitutive model of cemented paste backfill (CPB), the uniaxial compression variables and the damage constitutive model, considering the influence of porosity and pore size of filling materials, were derived based on the strain equivalence principle and Weibull probability distribution function. The nuclear magnetic resonance (NMR) tests and unconfined compression strength (UCS) tests were carried out on 8 groups of CPB specimens with different slurry concentrations and cement-tailings ratios. Then, the expression of damage strengthening coefficient is determined, and the stress-strain curves measured by the theoretical model were compared with the experimental ones. The results show that the uniaxial compression constitutive model proposed is in good agreement with UCS test results and can effectively describe the damage evolution law and the development process of stress-strain curve of CPB under uniaxial compression. The 28-day compressive strength of CPB can reach 8 MPa, the residual strength is about 1∼2 MPa, the elastic modulus is about 200∼2000 MPa, and the porosity is about 3∼5%. The CPB with slurry concentration of 74% and 76% and cement-tailings ratio of 1 : 4 and 1 : 6 is more reasonable, and the relevant mechanical parameters are more stable.

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Effects of curing methods on UCS test specimens and variability of mechanical properties of cemented paste backfill

International Journal of Geotechnical Engineering ◽

10.1080/19386362.2019.1666558 ◽

2019 ◽

pp. 1-10

Author(s):

Naguleswaran Niroshan ◽

Nagaratnam Sivakugan ◽

Ryan Llewellyn Veenstra

Keyword(s):

Mechanical Properties ◽

Cemented Paste Backfill ◽

Curing Methods ◽

Paste Backfill ◽

Ucs Test

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Investigation on Mechanical Characteristics and Microstructure of Cemented Whole Tailings Backfill

Minerals ◽

10.3390/min11060592 ◽

2021 ◽

Vol 11 (6) ◽

pp. 592

Author(s):

Armelle Estelle Belibi Tana ◽

Shenghua Yin ◽

Leiming Wang

Keyword(s):

Yield Stress ◽

Mechanical Characteristics ◽

Xrd Analysis ◽

Solid Content ◽

Chemical Components ◽

Cemented Paste Backfill ◽

Before And After ◽

Paste Backfill ◽

Solids Content ◽

Rheological Test

A paste backfill performance can be primarily evaluated through the mechanical and physical characteristics of the components involved. In this study, the effects of solid components’ tailings, binders and waters contents on microstructural evolution and mechanical properties of uncemented whole tailings backfill (CWTB) mixtures were investigated. Different mixtures of ordinary Portland cement of 1, 3 and 5 wt. % and solid concentrations at 72 wt. %, 74 wt. % and 75 wt. % were selected and rheological test was conducted to define the slump fluidity and yield stress. The microstructure of the solid component before and after the preparation and chemical composition were analyzed by the Scanning electron microscope and XRD analysis, respectively. The results show that a positive correlation between yield stress and slump values of CWTB paste slurries, the decrease of flow consistence leads to the reduction of the water content on the CWTB mixtures and the flow resistance of the paste. With the highest solids content, unconfined compressive strength (UCS) of CWTB varies between 0.1–0.9 MPa. Increasing the solid content affects the porosity and improves the strength resistance of CWTB mixtures. The findings in this study can therefore lead us to a statement that CWTB chemical components seem to be an important factor in cemented paste backfill (CPB) design and mine operations.

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Rheological Properties of Ultra-Fine Tailings Cemented Paste Backfill under Ultrasonic Wave Action

Minerals ◽

10.3390/min11070718 ◽

2021 ◽

Vol 11 (7) ◽

pp. 718

Author(s):

Weicheng Ren ◽

Rugao Gao ◽

Youzhi Zhang ◽

Maoxin Hou

Keyword(s):

Rheological Properties ◽

Yield Stress ◽

Ultrasonic Wave ◽

Mass Concentration ◽

Wave Action ◽

Cemented Paste Backfill ◽

Fine Tailings ◽

Paste Backfill ◽

Rheological Test ◽

Positive Effect

Ultra-fine tailings cemented paste backfill (UCPB) exhibits special rheological characteristics with the effect of an ultrasonic sound field. In this study, in order to explore the thickening effect of slurry under ultrasonic wave action, we examined the rheological properties with ultrasonic wave tests of UCPB and the rheological properties after ultrasonic wave tests of UCPB. We found that the rheological curve of the slurry changed; the Herschel–Bulkley (HB) model in the initial state transformed into the Bingham model under the action of ultrasound. Ultrasonic waves have a positive effect on reducing slurry viscosity and yield stress. The rheological test of the slurry with ultrasonic wave action had a positive effect on significantly reducing the apparent viscosity and initial yield stress of slurry with a 62% mass concentration. The rheological test of slurry with ultrasonic wave action and the rheological test after ultrasonic wave action both have positive effects on reducing the viscosity and yield stress of the slurry with a 64% to 68% mass concentration; the overall effect of reducing the viscosity and yield stress of UCPB is greater after ultrasonic wave action of UCPB.

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