Comparative Studies of Alkali Activated South African Class F and Mongolian Class C Fly Ashes

Temuujin, Jadambaa; Mapiravana, Joseph; Bayarzul, U.; Zolzaya, Ts.; Darkhijav, B; Dlamini, Mandla N; Rüscher, Claus H.

doi:10.1007/s12649-017-9881-5

Cited by 7 publications

(2 citation statements)

References 11 publications

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“…Moreover, the use of fly ash for building materials and other advanced materials will allow for sustainable utilization of this resource. In previous work, Mongolian fly ash has been used in the preparation of geopolymers [8][9][10] zeolitic compounds [11][12] and rare earth oxide doped glass ceramics [13]. This short review will summarize the latest developments on the utilization of the coal combustion by-products.…”

Section: Introductionmentioning

confidence: 99%

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

Temuujin

Munkhtuvshin

Ruescher

2021

SSP

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With a geological reserve of over 170 billion tons, coal is the most abundant energy source in Mongolia with six operating thermal power stations. Moreover, in Ulaanbaatar city over 210000 families live in the Ger district and use over 800000 tons of coal as a fuel. The three thermal power plants in Ulaanbaatar burn about 5 million tons of coal, resulting in more than 500000 tons of coal combustion by-products per year. Globally, the ashes produced by thermal power plants, boilers, and single ovens pose serious environmental problems. The utilization of various types of waste is one of the factors determining the sustainability of cities. Therefore, the processing of wastes for re-use or disposal is a critical topic in waste management and materials research. According to research, the Mongolian capital city's air and soil quality has reached a disastrous level. The main reasons for air pollution in Ulaanbaatar are reported as being coal-fired stoves of the Ger residential district, thermal power stations, small and medium-sized low-pressure furnaces, and motor vehicles. Previously, coal ashes have been used to prepare advanced materials such as glass-ceramics with the hardness of 6.35 GPa, geopolymer concrete with compressive strength of over 30 MPa and zeolite A with a Cr (III) removal capacity of 35.8 mg/g. Here we discuss our latest results on the utilization of fly ash for preparation of a cement stabilized base layer for paved roads, mechanically activated fly ash for use in concrete production, and coal ash from the Ger district for preparation of an adsorbent. An addition of 20% fly ash to 5-8% cement made from a mixture of road base gave a compressive strength of ~ 4MPa, which exceeds the standard. Using coal ashes from Ger district prepared a new type of adsorbent material capable of removing various organic pollutants from tannery water was developed. This ash also showed weak leaching characteristics in water and acidic environment, which opens up an excellent opportunity to utilize.

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Section: Introductionmentioning

confidence: 99%

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

Temuujin

Munkhtuvshin

Ruescher

2021

SSP

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“…Mechanical activation is a process of mechanical breakdown (by grinding) of solids into smaller particles without changing their state of aggregation [11]. Mechanical activation was successfully applied to fly ash for geopolymer synthesis and has shown a significant increase in the final properties of result products [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Effect of Mechanical Activation of Fluidized Bed Fly Ash on Geopolymer Properties

Temuujin¹

2019

SSP

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This paper is focused on the elucidation of mechanical activation effect of circulating fluidized bed combustion fly ash (Amgalan Thermal Station, Mongolia) on mechanical properties of geopolymers. Fluidized bed fly ash was mechanically activated for 15-120 minutes with a vibratory mill. The effect of mechanical activation was quite visible on the particle size reduction and on the degree of amorphization.Geopolymer samples were prepared from the raw and milled fluidized bed fly ashes by alkaline activation. Chemical activation was performed with 10M sodium hydroxide solution, as well as solutions containing a mixture of sodium silicate and sodium hydroxide with a weight ratio of 2:1. The geopolymer cubic specimens were cured at 70°C for 24 hrs and their 7 days uniaxial compressive strength was measured. After curing and drying, the bulk density, water absorption and apparent porosity of geopolymer samples were evaluated.X-ray powder diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetry-differential thermal analysis (TGA-DTA) have been used for the structural characterization of the CFA and the resulting geopolymers. The highest compressive strength of 32.4 MPa was achieved for the fly ash milled for 30 minutes and activated with the solution containing the sodium silicate and 10M sodium hydroxide at a weight ratio of 2:1. Non-milled CFA based geopolymers showed the compressive strength of 16.2 MPa after activation with the same solution. Mechanical activation resulted in an increase in the reactivity of the fluidized bed fly ash and that enhances the geopolymerization reactions.

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On the properties of sustainable concrete containing mineral admixtures

Colangelo

Farina

Moccia

et al. 2022

Handbook of Sustainable Concrete and Industrial Waste Management

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Comparative Studies of Alkali Activated South African Class F and Mongolian Class C Fly Ashes

Cited by 7 publications

References 11 publications

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

The Latest Research in Mongolia on the Utilization of Coal Combustion By-Products

Effect of Mechanical Activation of Fluidized Bed Fly Ash on Geopolymer Properties

On the properties of sustainable concrete containing mineral admixtures

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