Effect of the phosphogypsum calcination time on the compressive mechanical properties of phosphogypsum-based composite cementitious materials

Zheng, Tao; Lu, Yuexian; Luo, Shuang; Kong, Dewen; Fu, Rubin

doi:10.1088/2053-1591/ac5ef6

Cited by 11 publications

(4 citation statements)

References 32 publications

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“…Longer calcination times have been attributed to improving the material's densification by lowering porosity and boosting uniformity. A high purity end product can result from prolonged hightemperature calcination, which can help to remove volatile or impurity components [24].…”

Section: Crystalline Structure Analysis Of Powdersmentioning

confidence: 99%

Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method

Oad,

Pandya,

Rawat

et al. 2024

Phys. Scr.

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The powder material Gd3Ga3Al2O12:Ce (GGAG doped with Cerium) has garnered significant attention in radiation detection due to its high light yield and rapid decay time. Despite its potential, the synthesis of high-quality and reproducible GGAG:Ce scintillating powder remains a considerable challenge. In this study, we present a solvothermal approach with an annealing temperature of 1300 °C for producing cerium-doped GGAG powder with varying concentrations (4, 2, and 0.5 mol%). The structural and luminescent characteristics were meticulously examined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), photoluminescence (PL), radioluminescence (RL) spectroscopy, and X-ray photoelectron spectroscopy (XPS). XRD analysis confirmed the single-cubic phase garnet structure of the synthesized powder. By comparing the intermediate solvothermal products synthesized at different sintering temperatures (900 °C for 3 hours and 1300 °C for 1 and 3 hours), a direct correlation between solvothermal conditions and the structure/property relationships of the product was established. FESEM images revealed an ellipsoidal to irregular morphology of the as-synthesized GGAG:Ce microparticles, ranging from 0.1 to 0.3 µm, regardless of the Ce concentration. PL spectra demonstrated a strong emission peak at approximately 550 nm, characteristic of Ce3+ ions. RL data confirmed the peak luminescence at around 550 nm, with an almost twofold increase in intensity as the concentration of Ce3+ increased from 0.5 mol% to 4 mol%. XPS data disclosed the Ce3+/Ce4+ ratio in solvothermally synthesized GGAG:Ce, wherein Ce loading of 4 mol% demonstrated the increase in Ce3+ concentration to 95%, whereas the concentration of Ce4+ decreased to 5%. Notably, the highest luminescence efficiency was achieved with GGAG:Ce at a 4 mol% concentration. Thus, the solvothermal method employed in GGAG:Ce synthesis presents a straightforward approach, yielding rapid results with precise control over particle morphology and size.

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Section: Crystalline Structure Analysis Of Powdersmentioning

confidence: 99%

Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method

Oad,

Pandya,

Rawat

et al. 2024

Phys. Scr.

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“…The phosphogypsum used in the study is produced in Kaiyang, Guizhou province. Based on the existing research results of Zheng et al [35], the phosphogypsum directly obtained from the factory is roasted for two hours at 160 °C for further use. The cement used in this study is conch P.O.42.5 ordinary Portland cement, and its main performance indexes are shown in Table 1.…”

Section: Experimental Materialsmentioning

confidence: 99%

Evaluation of Thermal and Mechanical Properties of Foamed Phosphogypsum-Based Cementitious Materials for Well Cementing in Hydrate Reservoirs

Tang,

Zhao,

Cheng

et al. 2024

JMSE

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As detrimental byproduct waste generated during the production of fertilizers, phosphogypsum can be harmlessly treated by producing phosphogypsum-based cementitious materials (PGCs) for offshore well cementing in hydrate reservoirs. To be specific, the excellent mechanical properties of PGCs significantly promote wellbore stability. And the preeminent temperature control performance of PGCs helps to control undesirable gas channeling, increasing the formation stability of natural gas hydrate (NGH) reservoirs. Notably, to further enhance temperature control performance, foaming agents are added to PGCs to increase porosity, which however reduces the compressive strength and increases the risk of wellbore instability. Therefore, the synergetic effect between temperature control performance and mechanical properties should be quantitatively evaluated to enhance the overall performance of foamed PGCs for well cementing in NGH reservoirs. But so far, most existing studies of foamed PGCs are limited to experimental work and ignore the synergetic effect. Motivated by this, we combine experimental work with theoretical work to investigate the correlations between the porosity, temperature control performance, and mechanical properties of foamed PGCs. Specifically, the thermal conductivity and compressive strength of foamed PGCs are accurately determined through experimental measurements, then theoretical models are proposed to make up for the non-repeatability of experiments. The results show that, when the porosity increases from 6% to 70%, the 7 d and 28 d compressive strengths of foamed PGCs respectively decrease from 21.3 MPa to 0.9 MPa and from 23.5 MPa to 1.0 MPa, and the thermal conductivity decreases from 0.33 W·m−1·K−1 to 0.12 W·m−1·K−1. Additionally, an overall performance index evaluation system is established, advancing the application of foamed PGCs for well cementing in NGH reservoirs and promoting the recycling of phosphogypsum.

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“…It was reported that about 5 tons of phosphogypsum are produced for every ton of phosphoric acid produced. The global annual output of phosphogypsum is about 100–280 million tons, but the recycling rate is only 15% [ 3 ]. At present, the annual emission of phosphogypsum in China exceeds 75 million tons, and the cumulative stockpile has exceeded 500 million tons, but the comprehensive utilization rate is only about 40% [ 3 ].…”

Section: Introductionmentioning

confidence: 99%

“…The global annual output of phosphogypsum is about 100–280 million tons, but the recycling rate is only 15% [ 3 ]. At present, the annual emission of phosphogypsum in China exceeds 75 million tons, and the cumulative stockpile has exceeded 500 million tons, but the comprehensive utilization rate is only about 40% [ 3 ]. Red mud is a reddish brown alkaline industrial waste discharged during the process of refining alumina from bauxite [ 4 ]; its main components are Fe 2 O 3 , Al 2 O 3 , SiO 2 , NaO 2 , CaO, TiO 2 , etc., and the pH value is 10–13 [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Key Properties of Phosphogypsum-Red Mud-Slag Composite Cementitious Materials

Chen²,

Lin

et al. 2022

Materials

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Due to the low content of silicon and aluminum in red mud and the low reaction activity of red mud, when it was used to prepare composite cementitious materials, it was necessary to assist other aluminosilicates and improve their activity by certain methods. In this study, it was proposed to add slag to increase the percentage of silicon and aluminum in the system, and to improve the reactivity of the system through the activation effect of sulfate in phosphogypsum. The effects of slag and phosphogypsum contents on the mechanical properties and microstructures of composite cementitious materials were studied. X-ray diffraction analysis (XRD), thermogravimetric analysis (TG-DTG), and scanning electron microscopy (SEM) were used to analyze the effects of slag and phosphogypsum contents on the hydration products, microstructure, and strength formation mechanism of composite cementitious materials. The results show that with the increase of slag, the strength of the composite cementitious material increases gradually. When the slag content is 50%, the 28-day compressive strength reaches a maximum of about 14 MPa. Compared with the composite material without phosphogypsum, the composite cementitious material with 10–20% phosphogypsum showed higher strength properties, in which the 28-day compressive strength exceeds 24 MPa. The main reason for this is that the sulfate in phosphogypsum can cause the composite cementitious material to generate a large amount of ettringite and accelerate the dissolution of red mud and slag, increasing the release of aluminates, silicates, and Ca2+ to form more C-(A)-S-H and ettringite. In addition, a large amount of C-(A)-S-H makes ettringite and unreacted particles combine into a uniform and compact structure, thus improving the strength. When the content of phosphogypsum exceeds 40%, the 28-day compressive strength of the composite cementitious material drops below 12 MPa due to the presence of fewer hydration products and the expansion of ettringite.

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Effect of the phosphogypsum calcination time on the compressive mechanical properties of phosphogypsum-based composite cementitious materials

Cited by 11 publications

References 32 publications

Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method

Synthesis of cerium-doped gadolinium gallium aluminum garnet (GGAG:Ce) scintillating powder via solvothermal method

Evaluation of Thermal and Mechanical Properties of Foamed Phosphogypsum-Based Cementitious Materials for Well Cementing in Hydrate Reservoirs

Microstructure and Key Properties of Phosphogypsum-Red Mud-Slag Composite Cementitious Materials

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