scholarly journals Effects of Fluorogypsum and Flue-Gas Desulfurization Gypsum on the Hydration and Hardened Properties of Alkali Slag Cement

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1475
Author(s):  
Cheng Wang ◽  
Hang He ◽  
Yuli Wang ◽  
Wenyue Xue
Keyword(s):  
Flue Gas ◽  
Setting Time ◽  
Control Sample ◽  
Heat Of Hydration ◽  
Flue Gas Desulfurization ◽  
Slag Cement ◽  
Fgd Gypsum ◽  
Gypsum Content ◽  
Waste Gypsum ◽  
The Difference

In order to explore the influence of the types of waste gypsum on the properties of alkali slag cement, fluorogypsum (FG) and flue-gas desulfurization (FGD) gypsum were comparatively investigated. Moreover, the action mechanisms of FG and FGD gypsum on the properties of alkali slag cement were analyzed. The results show that both the FG and FGD gypsum prolonged the setting time of the alkali slag cement paste. However, the prolongation effect of FG was more pronounced than the FGD gypsum. When the compressive strength was maximum, the contents of FG and FGD gypsum were 5 and 6 wt.%, respectively. At 3 and 28 days, compared to the control sample, the compressive strengths increased by 59.3% and 24.3%, and 66.9% and 33.9%, respectively. Furthermore, the XRD, TG-DTA and SEM-EDS results showed that, with the increase in the contents of FG and FGD gypsum, ettringite was more easily produced and the hydration products were more abundant in the system. The greater the gypsum content of the paste, the less accumulated was the heat of hydration. The change of micro-structure caused by the formation of ettringite was the main reason for the difference in the properties of cement.

On Experimental Study of Development Calcined Gypsum from Flue Gas Desulfurization by Microwave Technology

2013 ◽  
Vol 368-370 ◽  
pp. 780-784 ◽  
Author(s):  
Zhi Man Zhao ◽  
Chun Jie Wang ◽  
Can Qion Li ◽  
Xiao Mei Zhang
Keyword(s):  
Microwave Irradiation ◽  
Flue Gas ◽  
Calcium Sulfate ◽  
Setting Time ◽  
Flue Gas Desulfurization ◽  
Crystal Formation ◽  
Special Effect ◽  
Fgd Gypsum ◽  
Calcined Gypsum ◽  
Cylindrical Crystal

Flue gas desulfurization gypsum (FGD gypsum) was irradiated with microwave, it could be changed calcined gypsum from flue gas desulfurization (CGD). The microwave respectively irradiated five groups FGD gypsum at 100-110°C, 110-120°C, 120-130°C, 130-140°C and 140-150°C, then the fineness and setting time were respectively measured, and compressive/flexural strength were also determined after 2 hours. Experiments show that, CaSO4·0.5H2O crystal of CGD would be more quantity and bigger volume with irradiation temperature increasing. The reason was considered that there were special effect of microwave irradiation to calcium sulfate crystalsthat by scanning electron microscope, and found the Ca, S, O and other elements in cylindrical crystal by Edax. The formation mechanism of CaSO4·0.5H2O crystal by microwave irradiation is different from traditional CaSO4·0.5H2O crystal formation theories.

scholarly journals Effect of Flue Gas Desulfurization Gypsum on the Properties of Calcium Sulfoaluminate Cement Blended with Ground Granulated Blast Furnace Slag

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 382 ◽  
Author(s):  
Danying Gao ◽  
Zhenqing Zhang ◽  
Yang Meng ◽  
Jiyu Tang ◽  
Lin Yang
Keyword(s):  
Blast Furnace ◽  
Mechanical Strength ◽  
Flue Gas ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Flue Gas Desulfurization ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

This work aims to investigate the effect of additional flue gas desulfurization gypsum (FGDG) on the properties of calcium sulfoaluminate cement (CSAC) blended with ground granulated blast furnace slag (GGBFS). The hydration rate, setting time, mechanical strength, pore structure and hydration products of the CSAC-GGBFS mixture containing FGDG were investigated systematically. The results show that the addition of FGDG promotes the hydration of the CSAC-GGBFS mixture and improves its mechanical strength; however, the FGDG content should not exceed 6%.

scholarly journals THE INFLUENCE OF THE USE OF RECYCLED GYPSUM ON THE PROPERTIES OF GYPSUM PRODUCTS IN LABOR CONDITIONS

2020 ◽  
Vol 26 ◽  
pp. 81-85
Author(s):  
Hana Sekavová ◽  
Jakub Herrmann ◽  
Zdeněk Prošek ◽  
Miroslav Nyč ◽  
George Karra’a
Keyword(s):  
Flue Gas ◽  
Flue Gas Desulfurization ◽  
Volume Changes ◽  
Fgd Gypsum ◽  
Labor Conditions ◽  
Setting Times ◽  
Elasticity Module ◽  
First Results ◽  
Recycled Gypsum ◽  
Recycled Material

The article presents the first results from research, which is deal with recycling of plaster boards and use of the resulting material. The research is carried out within the project MPO Trio c. FV30359 “Recyklace sádrokartonových desek a nová materiálová využití s pridanou hodnotou – GIPSRec”. The plasterboards are produced of stucco, which is calcinated of Flue Gas Desulfurization Gypsum (FGD Gypsum). There is possibility to replace a part of this stucco with recycled material. There is opportunity for saving costs for production. The question how this utilization can change the properties of the products is very important and it is necessary to find the possible improvement or deterioration. This is the objective of this research. The effect on properties was monitored on the samples which was prepared of only pure stucco and of stucco with part of recycled material. There was observed water ratio (splash test), setting times, volume changes, flexural strength, compressive strength and elasticity module.

scholarly journals Enhanced Cd(II) Uptake by the Bassanite Phase Contained in Waste Calcite Produced via the Carbonation of Flue Gas Desulfurization (FGD) Gypsum

2011 ◽  
Vol 52 (6) ◽  
pp. 1303-1307
Author(s):  
Kyungsun Song ◽  
Young-Nam Jang ◽  
Jun-Hwan Bang ◽  
Soo-Chun Chae ◽  
Wonbaek Kim
Keyword(s):  
Flue Gas ◽  
Flue Gas Desulfurization ◽  
Fgd Gypsum

PHYSICAL PROPERTIES AND ENVIRONMENTAL PERFORMANCE OF STEAM-CURED CONCRETE CONTAINING FLUE-GAS DESULFURIZATION GYPSUM

2021 ◽  
Vol 16 (1) ◽  
pp. 3-15
Author(s):  
Hongseok Jang ◽  
Seungyoung So
Keyword(s):  
Physical Properties ◽  
Flue Gas ◽  
Environmental Performance ◽  
Cementitious Materials ◽  
Flue Gas Desulfurization ◽  
Test Results ◽  
Fgd Gypsum ◽  
Environmental Test ◽  
Environmentally Safe ◽  
Increased Strength

ABSTRACT Flue-gas desulfurization (FGD) gypsum has occasionally been used as an additive to cement. Consequently, appropriate facilities are required to ensure the environmentally safe processing of FGD gypsum and the resulting cement material properties. Such facilities are yet to be developed because the amount of FGD gypsum used is still small when compared with the vast amounts of FGD gypsum generated. In this study, we analyze the effect of FGD gypsum addition on the physical properties, stabilization, and radon count of steam-cured mortar and compare its performance with air-cured mortar. Our results show that the steam-cured pozzolanic hydration products of ettringite and C-S-H promote the densification of the mortar structure, thereby resulting in nanopore size reduction and increased strength of FGD gypsum mortar subsequent to the steam-cured hydration process. Further, our environmental test results indicate that steam-cured pozzolanic materials composed of FGD gypsum are environmentally safer than air-cured cementitious materials.

Study on CaSO3 and CaO as Additives of Slag Cement

2013 ◽  
Vol 634-638 ◽  
pp. 297-301
Author(s):  
Guo Zhuo Gong ◽  
Shu Feng Ye ◽  
Jin Hong Li ◽  
Wen Fen Yang ◽  
Qiang Xie
Keyword(s):  
Flue Gas ◽  
Blast Furnace Slag ◽  
Setting Time ◽  
Cement Clinker ◽  
Slag Cement ◽  
Retarding Effect ◽  
Desulfurization Process ◽  
Main Components ◽  
Furnace Slag

CaSO3and CaO are main components in solid waste from flue gas semi-dry desulfurization process. A series of slag cements were prepared from cement clinker and blast furnace slag, in the process of which CaSO3 and CaO were added. The composition and macrostructure of the derived cements were studied in detail with the aid of XRD and SEM. Furthermore, the influence of amount of CaSO3and CaO on the mechanical properties and setting time for slag cement were evaluated, the mechanisms of which were also discussed. The results show that due to the formation of AFt and AFm in the hydration process, the CaSO3has an obvious setting retarding effect on the slag cement, and quality slag cement can be obtained when the amount of slag and CaSO3are 20% and 2%, respectively, the compressive strengths of which at 3, 7, 28 d are 30.8, 39.1, 53.7 MPa, and bending strengths at 3, 7, 28 d are 9.6, 10, 11.9MPa, respectively. Besides, CaO added which can play a role of alkali-activator for slag cement can not cause the soundness problem of slag cement.

Remediating oxytetracycline-contaminated aquaculture water using nano calcium peroxide (nCaO2) produced from flue gas desulfurization (FGD) gypsum

2021 ◽  
pp. 101861
Author(s):  
Piyarat Vijuksungsith ◽  
Tunlawit Satapanajaru ◽  
Chanat Chokejaroenrat ◽  
Chalor Jarusutthirak ◽  
Chainarong Sakulthaew ◽  
...  
Keyword(s):  
Flue Gas ◽  
Flue Gas Desulfurization ◽  
Calcium Peroxide ◽  
Fgd Gypsum ◽  
Aquaculture Water

scholarly journals Fertilization efficiency of wood ash pellets amended by gypsum and superphosphate in the ryegrass growth    

2017 ◽  
Vol 63 (No. 2) ◽  
pp. 47-54 ◽  
Author(s):  
Ochecová Pavla ◽  
Mercl Filip ◽  
Košnář Zdeněk ◽  
Tlustoš Pavel
Keyword(s):  
Flue Gas ◽  
Plant Biomass ◽  
Wood Ash ◽  
Flue Gas Desulfurization ◽  
Biomass Ash ◽  
Single Superphosphate ◽  
Fgd Gypsum ◽  
Soil Enrichment ◽  
P Content ◽  
Uptake Of Nutrients

Application of biomass ash to soil can save mineral nutrients due to its relatively high contents of Ca, K, and P. The study assessed the effect of powdered ash and pellets made from wood fly ash (WFA), combined moreover with additives rich in S (flue gas desulfurization gypsum – FGDG) and P (single superphosphate – SP) on the yield and uptake of nutrients (Ca, K, P, and S) by ryegrass (Lolium perenne L.), the accumulation of nutrients in plant biomass at individual four cuttings, and the available nutrients amount in the acidic loamy soil after the last harvest. Plants grown in pots enriched by wood ash showed significantly higher yield and nutrient uptake than in the unamended treatments. The uptake of nutrients by plants, content of nutrients in plants and in soil was substantially positively influenced by both components added to the wood ash, especially by FGD gypsum. The combination of wood ash with additives proved to be effective. The soil enrichment by WFA + SP + FGDG increased the availability of SP-contained P and available P content in soil even after harvest.  

Study on Preparation of High Strength Gypsum by Flue Gas Desulfurization Gypsum

2013 ◽  
Vol 405-408 ◽  
pp. 2681-2685
Author(s):  
Ji Xiu Zhang ◽  
Peng Xuan Duan ◽  
Ye Zhang
Keyword(s):  
Thermal Expansion ◽  
Power Plant ◽  
Product Development ◽  
Flue Gas ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
High Strength ◽  
Flue Gas Desulfurization ◽  
Test Results ◽  
Fgd Gypsum

In this paper, the flue gas desulfurization gypsum (FGD) generated from thermal power plant is used to produce high strength gypsum. The basic properties of super high strength gypsum prepared by FGD gypsum are investigated based on the test results of strength, thermal expansion rate, crystal appearance and size. The results indicate that the properties of high strength gypsum prepared by FGD gypsum above α50 standard. This can be a reference for gypsum-based α super high-strength gypsum related product development.

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