Properties of MSW fly ash–calcium sulfoaluminate cement matrix and stabilization/solidification on heavy metals

2008 ◽  
Vol 152 (1) ◽  
pp. 196-203 ◽  
Author(s):  
G.R. Qian ◽  
J. Shi ◽  
Y.L. Cao ◽  
Y.F. Xu ◽  
P.C. Chui
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Cement Matrix ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate

Using of Different Type Cement in Solidification/Stabilization of MSWI Fly Ash

2011 ◽  
Vol 291-294 ◽  
pp. 1870-1874 ◽  
Author(s):  
Guo Xia Wei ◽  
Han Qiao Liu ◽  
Shu Guang Zhang
Keyword(s):  
Heavy Metals ◽  
Compressive Strength ◽  
Fly Ash ◽  
Setting Time ◽  
Solid Matrix ◽  
Cement Type ◽  
Calcium Sulfoaluminate Cement ◽  
Mswi Fly Ash ◽  
Calcium Sulfoaluminate ◽  
Aluminate Cement

Solidification tests of MSWI fly ash (FA) with three types of cement including ordinary Portland cements (OPC), calcium sulfoaluminate cement(CSA) and calcium aluminate cement (CAC) were carried out to discuss the effect of cement type on of the FA-cement solid matrix by means of setting time, compressive strength and heavy metals leachability. Results show that the setting time of the FA-cement mixtures using CSA and CAC is shorter than that of OPC. According to compressive strengths demand and the standard of landfill site of municipal solid waste, the dosage of OPC should be limited about 35% by weigh, the dosage of CAC should be limited about 25% by weigh, and the dosage of CSA should be limited more than 40% by weigh.

scholarly journals Quicklime and Calcium Sulfoaluminate Cement Used as Mineral Accelerators to Improve the Properties of Cemented Paste Backfill with a High Volume of Fly Ash

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4018
Author(s):  
Hangxing Ding ◽  
Shiyu Zhang
Keyword(s):  
Fly Ash ◽  
Co2 Emission ◽  
Mechanical Performance ◽  
High Volume ◽  
Hydration Heat ◽  
Cemented Paste Backfill ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Paste Backfill ◽  
Different Doses

In order to reduce the CO2 emission and cost of binders used in cemented paste backfill (CPB) technology, new blended binders with a large amount of fly ash (FA) were fabricated. Different doses of quicklime and calcium sulfoaluminate cement (CṠA) were used as mineral accelerators to improve the early workability of CPB. The effects of CṠA and quicklime on flowability, compressive strength, pore structure, hydration heat, and hydration evolution were investigated experimentally. The results showed that the addition of quicklime and CṠA reduced the spread diameter of the fresh backfill and improved the mechanical performance of the hardened CPB. With increasing quicklime and CṠA, the cumulative hydration heat of the blended binder distinctly increased in the first 6 h. CṠA improved the initial hydration by increasing the reactivity, and quicklime increased the hydration rate by activating FA. The blended binder (15% quicklime + 10% CṠA) with the lowest CO2 emission and cost had potential application in filling technology.

Influence of fly ash on the hydration of calcium sulfoaluminate cement

2017 ◽  
Vol 95 ◽  
pp. 152-163 ◽  
Author(s):  
Lukas H.J. Martin ◽  
Frank Winnefeld ◽  
Elsa Tschopp ◽  
Christian J. Müller ◽  
Barbara Lothenbach
Keyword(s):  
Fly Ash ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate

Study of Alite-Calcium Sulfoaluminate Cement Produced from a High-Alumina Fly Ash

2022 ◽  
Vol 119 (1) ◽  
Author(s):  
Tristana Y. Duvallet ◽  
Manuelle Paraschiv ◽  
Anne E. Oberlink ◽  
Robert B. Jewell ◽  
Thomas L. Robl
Keyword(s):  
Fly Ash ◽  
High Alumina ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate

scholarly journals Influence of Fly Ash on Mechanical Properties and Hydration of Calcium Sulfoaluminate-Activated Supersulfated Cement

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2514
Author(s):  
Zhengning Sun ◽  
Jian Zhou ◽  
Qiulin Qi ◽  
Hui Li ◽  
Na Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Flexural Strength ◽  
Heat Evolution ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Granulated Blast Furnace Slag ◽  
Compressive And Flexural Strengths

This paper aimed to report the effects of fly ash (FA) on the mechanical properties and hydration of calcium sulfoaluminate-activated supersulfated cement (CSA-SSC). The CSA-SSC comprises of 80% granulated blast furnace slag (GBFS), 15% anhydrite, and 5% high-belite calcium sulfoaluminate cement (HB-CSA) clinker. The hydration products of CSA-SSC with or without FA were investigated by X-ray diffraction and thermogravimetric analysis. The experimental results indicated that the addition of FA by 10% to 30% resulted in a decrease in the rate of heat evolution and total heat evolution of CSA-SSC. As the content of FA was increased in the CSA-SSC system, the compressive and flexural strengths of the CSA-SSC with FA after 1 day of hydration were decreased. After 7 days of hydration, the compressive and flexural strength of CSA-SSC mixed with 10 wt.% and 20 wt.% of FA rapidly increased and exceeded that of ordinary Portland cement (OPC), especially the flexural strength. Moreover, the compressive strength of CSA-SSC mixed with 30 wt.% of FA after 90 days of hydration was close to that of OPC, and flexural strength of CSA-SSC mixed with 30 wt.% of FA after 7 days of hydration was close to that of OPC. The hydration products of the CSA-SSC and CSA-SSC mixed with FA were mainly ettringite and calcium silicate hydrate (C-S-H).

Immobilization of heavy metals by calcium sulfoaluminate cement

2005 ◽  
Vol 35 (12) ◽  
pp. 2261-2270 ◽  
Author(s):  
S. Peysson ◽  
J. Péra ◽  
M. Chabannet
Keyword(s):  
Heavy Metals ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate

scholarly journals Performance and Durability of Rendering and Basecoat Mortars for ETICS with CSA and Portland Cement

2021 ◽  
Vol 6 (4) ◽  
pp. 60
Author(s):  
Tiago Trigo ◽  
Inês Flores-Colen ◽  
Luís Silva ◽  
Nuno Vieira ◽  
Ana Raimundo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Energy Consumption ◽  
Portland Cement ◽  
Bending Strength ◽  
Setting Time ◽  
Cement Matrix ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Composite Systems

The production of Portland cement (OP) is commonly associated to significant level of energy consumption and gas emissions. The use of calcium sulfoaluminate cement (CSA) can be a sustainable alternative binder, since its production releases about half of the CO2 emissions and its clinker requires 200 °C lower temperatures, when compared to OP. Furthermore, CSA has fast setting time and achieves higher strength in shorter periods, as well as reduced shrinkage. This paper discusses the incorporation of CSA in rendering mortars and basecoat mortars for ETICS (External Thermal Insulation Composite Systems). The physical-mechanical properties of mortars made with OP and CSA cements were experimental evaluated. The results showed that the introduction of CSA generally improves shrinkage, compressive strength, water absorption at low pressure, enhances the tensile bending strength and decreases the setting time. The amount of CSA introduced into the mixture significantly affected the properties of the cement matrix.

Conditioning of oily sludges with municipal solid wastes incinerator fly ash

1997 ◽  
Vol 35 (8) ◽  
pp. 231-238 ◽  
Author(s):  
Tay Joo Hwa ◽  
S. Jeyaseelan
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Specific Resistance ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Solid Wastes ◽  
Municipal Solid Wastes ◽  
Capillary Suction ◽  
Optimum Dosage

Conditioning of sludges improves dewatering characteristics and reduces the quantity of sludge to be handled. Anaerobic digested sludge collected from a sewage treatment plant contained 1.8% to 8% oil. The increase of specific resistance and capillary suction time (CST) with increasing oil content observed in these samples indicates the interference of oil in dewatering. It has been found that addition of municipal solid wastes incinerator fly ash decreases the specific resistances and capillary suction times of oily sludges rapidly up to 3% dosage. Beyond 3% fly ash, the decrease is less significant and the solids content in the sludge cake increases. This optimum dosage remains the same for sludges with varying oil contents from 1.8% to 12%. The total suspended solids of filtrate decreases with fly ash dosage but the toxic concentrations of heavy metals increases considerably. However at the optimum dosage of 3%, concentrations of heavy metals are within the limits for discharging into the sewers. The correlations of CST with the dewatering characteristics such as specific resistance, filter yield and corrected filter yield are established. These correlations can be used to obtain a quick prediction on dewaterability.

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