Mechanism of calcination modification of phosphogypsum and its effect on the hydration properties of phosphogypsum-based supersulfated cement

Liu, Shuhua; Ouyang, Jiayi; Ren, Jun

doi:10.1016/j.conbuildmat.2020.118226

Cited by 133 publications

(35 citation statements)

References 22 publications

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“…In the production of alkali-activated binders (geopolymers), gypsum-bearing wastes, in particular phosphogypsum, showed good results as a component of the mixture [53][54][55][56]. Hence, in [53] it was shown that the use of phosphogypsum helps to reduce the activation time of cinder-alkaline binder hardening at room temperature.…”

Section: Alkaline-activated Bindersmentioning

confidence: 99%

“…Two studies [55,56] also demonstrated the possibility of using phosphogypsum in the production of supersulfated cement (SSC) which included [56] up to 81% of crushed granulated blast furnace slag, 15% phosphogypsum, 3% Portland cement clinker, and 1% aluminate cement as a setting accelerator. In both studies, conventional phosphogypsum was used, as well as being modified in two ways: fired at a temperature of 500 °C and neutralized by adding 4% lime.…”

Section: Alkaline-activated Bindersmentioning

confidence: 99%

“…In [56], the influence of the temperature (150 °C, 350 °C, 600 °C, 800 °C) and the calcination time (0.5 h, 1 h, 1.5 h, 2 h) of phosphogypsum on the properties of SSC were investigated. The authors concluded that calcination, especially at high temperatures, significantly reduced the negative effect of impurities contained in phosphogypsum on the properties of SSC.…”

Section: Alkaline-activated Bindersmentioning

confidence: 99%

See 2 more Smart Citations

Utilization of Gypsum-Bearing Wastes in Materials of the Construction Industry and Other Areas

Alfimova

Pirieva

Titenko

2021

Construction Materials and Products

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rational environmental management is one of the priorities of the technological development of the Russian Federation and most countries of the world. Particularly important in this area is the work undertaken with previously generated and accumulated waste, a whole group of which is gypsum-bearing wastes (GBW), which includes by-products of various industries: phosphogypsum, borogypsum, chlorogypsum, ferrogypsum, citrogypsum, vitamin gypsum, etc. GBW features are similar compositions, prevalence, perennial volumes of stored reserves with stable dynamics of annual growth. This determines the relevance of research on the development of a unified methodology for converting GBW of various types into target products particularly for construction purposes, providing maximum energy efficiency and minimal generation of secondary waste. The starting point of the research is the monitoring of approaches developed by the scientific community which are presented in the article. It is shown that researchers are exploring several main areas of GBW conversion: components of Portland cement and clinker; single and multicomponent binders; direct raw materials for the production of building materials; and road construction. The latter two directions have the greatest potential capacity for the consumption of GBW. The general level of research on the issue is not exhaustive, but has the potential to improve on existing methods of processing and application and promote the search for new and more efficient methods

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Section: Alkaline-activated Bindersmentioning

confidence: 99%

Section: Alkaline-activated Bindersmentioning

confidence: 99%

Section: Alkaline-activated Bindersmentioning

confidence: 99%

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Utilization of Gypsum-Bearing Wastes in Materials of the Construction Industry and Other Areas

Alfimova

Pirieva

Titenko

2021

Construction Materials and Products

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“…Stockpiling and burying these phosphogypsum residues not only occupies a large amount of land, but also easily causes serious pollution to the atmosphere and groundwater. Environmental protection pressure caused by phosphogypsum discharge has become one of the important restrictive factors for the development of the phosphate fertilizer industry [ 7 , 8 , 9 ]. Phosphogypsum is not only an industrial waste, but also a valuable resource.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Optimization of Phosphogypsum Suspension Decomposition Conditions under Double Catalysis

Chen

2021

Materials

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Phosphogypsum (PG) is not only a solid waste discharged from the phosphate fertilizer industry, but also a valuable resource. After high-temperature heat treatment, it can be decomposed into SO2 and CaO; the former can be used to produce sulfuric acid, and the latter can be used as building materials. In this paper, the catalytic thermal decomposition conditions of phosphogypsum were optimized, and the effects of the reaction temperature, reaction atmosphere, reaction time and carbon powder content on the decomposition of phosphogypsum were studied. The research shows that the synergistic effect of carbon powder and CO reducing atmosphere can effectively reduce the decomposition temperature of phosphogypsum. According to the results of the orthogonal test under simulated suspended laboratory conditions, the factors affecting the decomposition rate of phosphogypsum are temperature, time, atmosphere and carbon powder content in turn, and the factors affecting the desulfurization rate are time, temperature, atmosphere and carbon powder content in turn. Under laboratory conditions, the highest decomposition rate and desulfurization rate of phosphogypsum are 97.73% and 97.2%, and the corresponding reaction conditions are as follows: calcination temperature is 1180 °C, calcination time is 15 min, carbon powder content is 4%, and CO concentration is 6%. The results of thermal analysis of phosphogypsum at different temperature rising rates show that the higher the temperature rising rate, the higher the initial temperature of decomposition reaction and the temperature of maximum thermal decomposition rate, but the increase in the temperature rising rate will not reduce the decomposition rate of phosphogypsum.

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“…In practice, the study of CaSO 4 ·2H 2 O gypsum—a typical natural crystalline hydrate, multipurpose raw material with a wide range of product varieties, primarily constructive—is of the greatest interest. [ 13–16 ] Gypsum physico‐chemical properties, especially thermal characteristics, have fundamental mineralogical significance for the description of the group of sulfate‐crystalline hydrates in particular, and crystalline hydrates in general. These data are also necessary for practical applications, in particular, to control the technological processes of firing gypsum raw materials.…”

Section: Introductionmentioning

confidence: 99%

Statistical approaches in the analysis of in situ thermo‐Raman spectroscopic data for gypsum as a basis for studying dehydration and phase transformations in crystalline hydrates

Pankrushina

Votyakov

Shchapova

2021

J Raman Spectroscopy

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The study of a gypsum single crystal was carried out using in situ thermo‐Raman spectroscopy in the temperature range of 80–870 K. The conventional peak fitting approach was used to qualitatively determine the temperature ranges of gypsum dehydration and phase transitions. The dependence of the intermediate products of gypsum dehydration on the measurement conditions and the state of sample was confirmed. A detailed analysis of the temperature behavior of ν1(SO4) in a single crystal indicated the coexistence of CaSO4·2H2O + γCaSO4 (380–440 K) and γ‐CaSO4 + β‐CaSO4 (680–740 K) phases, which was explained by the reaction front movement in a solid. For the first time, an approach based on statistical algorithms was applied for processing datasets of experimental temperature‐dependent spectra of crystalline hydrates, including the calculation of the Pearson's r coefficient, skewness, ∆corr parameter, based on the autocorrelation function. The use of statistical methods for individual spectral regions made it possible to reveal the temperature differences in the pretransition regions for individual modes or their groups. In particular, the region of ν2(SO4) symmetric bending vibrations of sulfate ions was found sensitive to dehydration and accompanying phase transition at 410 K, beginning at lower temperatures (380 K) as compared with other regions, which is associated with the lack of the hydrogen bond influence on sulfate ions after the loss of water. Thus, statistical approaches are a source of additional information to clarify the quantitative indicators of the observed effects. The use of statistics is promising in the study of multistage processes of dehydration and phase transformations in crystalline hydrates in cases where peak fitting is inconvenient.

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Mechanism of calcination modification of phosphogypsum and its effect on the hydration properties of phosphogypsum-based supersulfated cement

Cited by 133 publications

References 22 publications

Utilization of Gypsum-Bearing Wastes in Materials of the Construction Industry and Other Areas

Utilization of Gypsum-Bearing Wastes in Materials of the Construction Industry and Other Areas

Experimental Study on Optimization of Phosphogypsum Suspension Decomposition Conditions under Double Catalysis

Statistical approaches in the analysis of in situ thermo‐Raman spectroscopic data for gypsum as a basis for studying dehydration and phase transformations in crystalline hydrates

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