scholarly journals Disposal of fly ash in the production of ash-concrete within the coal-watercoal cluster

2021 ◽  
Vol 263 ◽  
pp. 01007
Author(s):  
T.V. Zommer ◽  
E.V. Tkach ◽  
S.N. Chernyshev ◽  
V.L. Zommer

Technologies for the disposal of industrial waste in the production of building materials are becoming particularly relevant in connection with the global trend of systematic reduction of the negative anthropogenic impact on the environment. Therefore, one of the goals of the pilot project of the innovative coal-watercoal cluster of housing and communal services is the utilization of ash waste from the combustion of coal-water fuel suspension in the production of building materials. The methodology of ash waste disposal consists in the modification of Portland cement with fine fly ash additives in the production of heavy concrete. As a result of the experiments, the authors proposed a recipe for a concrete mixture with ash waste additives. Tests of control samples of concrete and proposed samples of ash concrete with the addition of ash from the combustion of coal-water slurry were carried out. The brand of the proposed ash concrete in terms of compressive strength, corresponding to the design brand, is determined. Thus, we save the consumption of Portland cement as a binder, which is the most expensive component of concrete. At the same time, we dispose of man-made waste as a safe additive in the production of concrete with specified performance characteristics. The result obtained with the utilization of ash waste as an effective and safe aggregate for heavy concrete can be used in the implementation of a pilot project of an innovative coal-watercoal cluster of housing and communal services. Ash concrete with the addition of ash from the combustion of coal-water slurry can be recommended for use in industrial and civil construction.

2014 ◽  
Vol 629-630 ◽  
pp. 306-313 ◽  
Author(s):  
Mao Chieh Chi ◽  
Ran Huang ◽  
Te Hsien Wu ◽  
Toun Chun Fou

Circulating fluidized bed combustion (CFBC) fly ash is a promising admixture for construction and building materials due to its pozzolanic activity and self-cementitious property. In this study, CFBC fly ash and coal-fired fly ash were used in Portland cement to investigate the pozzolanic and cementitious characteristics of CFBC fly ash and the properties of cement-based composites. Tests show that CFBC fly ash has the potential instead of cementing materials and as an alternative of pozzolan. In fresh specimens, the initial setting time of mortars increases with the increasing amount of cement replacement by CFBC fly ash and coal-fire fly ash. In harden specimens, adding CFBC fly ash to replace OPC reduces the compressive strength. Meanwhile, CFBC fly ash would results in a higher length change when adding over 30%. Based on the results, the amount of CFBC fly ash replacement cement was recommended to be limited below 20%.


2013 ◽  
Vol 726-731 ◽  
pp. 1972-1976 ◽  
Author(s):  
Li Jun Nie ◽  
Yang Liu ◽  
Mei Huang

The coal-water slurry produced with Datong coal was tested in a home boiler for heating. The experiment results of dust collection with the new tube type electrostatic precipitation of fly ash of coal water slurry combustion fit the emission standard of air pollutants for boilers (GB 13271-2001). The parameters for the electrostatic precipitation are as follows: the drift velocity of fly ash of coal water slurry combustion, 10.39 cm/s, the number of the tube, 64, the size of the tube, 25.6cm×25.6cm×20cm, the power, 0.24kW.


2019 ◽  
Vol 140 ◽  
pp. 05015
Author(s):  
Natalia Konovalova ◽  
Elena Rush ◽  
Dmitry Bespolitov ◽  
Pavel Pankov

The possibility of recycling large-tonnage waste of heat power engineer-ing and mining industry in road construction is shown. Compositions of road-building materials were researched, containing siftings of rock grinding, fly ash, Portland cement, modified with a stabilizing additive of polymeric nature. X-ray phase analysis showed availability of quartz in fly ash, calcite, feldspars, goethite and X-ray amorphous phase, what is consistent with the data of infrared spectroscopy. By atomic emission spectrometry with inductively coupled plasma it was revealed that fly ash is latent-active and can be disposed in compositions in the presence of a stabilizing additive. The X-ray phase analysis of grinding siftings showed that it contains quartz, feldspars, chlorite, calcite and dolomite. The specific activity of natural radionuclides (226Ra, 232Th, 40К) of fly ash and grinding siftings was 248 and 110 Bq/kg, which allows using such waste in construction without restrictions. It was revealed that the initial mineral raw materials belong to multiphase polymineral systems; therefore, when modifying them with stabilizing additives, binding of finely divided particles should be taken into account. It was revealed that the optimal content of Portland cement and fly ash in samples is 8 and 10 wt.%. It was found that an increase in the mass fraction of fly ash in the composition of soil-concrete up to 30 wt.% leads to softening of the samples and a decrease in their strength characteristics.


2019 ◽  
Vol 25 (3) ◽  
pp. 340-347
Author(s):  
Ting WANG ◽  
Xiaojian GAO ◽  
Jian WANG

As a byproduct of phosphoric acid industry, phosphogypsum has many environmental problems. In order to recycle phosphogypsum to manufacture lightweight building materials, cementitious additives including fly ash, ground granulate blast-furnace slag and Portland cement were added to improve strength and water-resistance and different volume of foam was added to reduce the bulk density. The results show that hydrated lime can improve mechanical strength and water resistance of PG paste and the optimal dosage of hydrated lime is 6 %. Higher addition of fly ash or ground granulated blast-furnace slag improves the fluidity and delays the setting time of PG paste. The addition of 10 ~ 20 % fly ash results in a little reducing influence and 10 % ground granulated blast-furnace slag leads to an increase of 20.7 % for 28 days compressive strength of hardened PG specimen. The higher addition of Portland cement results in the better mechanical strength and water resistance of PG specimens. The 28day compressive and flexural strength reaches 25.9 MPa and 8.9 MPa respectively for the 25 % Portland cement mixture. PG based lightweight building materials can prepared by the addition of 60 % volume of air foam, with compressive strength of 1.7 MPa, bulk density of 521.7 kg/m3 and thermal conductivity of 0.0724 W/(m·K). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19910


2015 ◽  
Vol 3 (1) ◽  
pp. 53-56
Author(s):  
Кирил Безгласный ◽  
Kiril Bezglasnyy ◽  
Роман Скориков ◽  
Roman Skorikov ◽  
Артем Шаля ◽  
...  

This article shows the obstacles of using thermal power plant’s ash waste on an industrial scale. The results of determining the activity of fly ash and hydroremoval ash in a mixture with Portland cement are given. Schemes of translation ash from the category of waste with heterogeneous characteristics in the raw material with stable properties are offered. The most rational ways of using ash from thermal power plants in building materials are presented


2013 ◽  
Vol 340 ◽  
pp. 382-387 ◽  
Author(s):  
Xiao Li Zhao ◽  
Wei Zhu

Sludge-coal water slurry (SCWS) can be produced by mixing coal water slurry (CWS) with sewage sludge according to differenct ratio. This paper focuses on the combustive feasibility of SCWS in a commercial circulating fluidized bed, and on the emission characteristics of polychlorinated biphenyls (PCBs) in flue gas fly ash and bottom ash during combustion of SCWS. The results indicated that incineration can do very well with the temperature 1000 degree, sludge coal water slurry (SCWS) can be effective in improving sludge incineration rate, if the proportion of sludge is 20%~30%,amounts of PCBs is relatively small in flue gas fly ash and bottom ash. So the best burning rate is 20%-30%. Although incineration flue gas fly ash and bottom ash emission standard don't have PCBs regulations, but since PCBs are toxic organic pollutants, it should be strictly regulated.


2006 ◽  
Vol 60 (9-10) ◽  
pp. 245-252 ◽  
Author(s):  
Zvezdana Bascarevic ◽  
Miroslav Komljenovic ◽  
Ljiljana Petrasinovic-Stojkanovic ◽  
Natasa Jovanovic ◽  
Aleksandra Rosic ◽  
...  

In this paper the results of the investigated properties of fly ash from four thermal power plants in Serbia are presented. The physical, chemical, mineralogical and thermal characterization of fly ash was carried out, in order to determine the possibility to utilize this material in the building materials industry, foremost in the cement industry. It was determined that, although there are differences concerning the physical, chemical, and mineralogical characteristics of the investigated samples, they are very similar concerning their thermal characteristics. It was concluded that using fly ash as one of the raw components in the mixture for Portland cement clinker synthesis, not only enables the substitution of natural resources, but it might have a positive effect on the lowering of the sintering temperature.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5798
Author(s):  
Peeter Paaver ◽  
Oliver Järvik ◽  
Kalle Kirsimäe

Growing concerns on global industrial greenhouse gas emissions have boosted research for developing alternative, less CO2 intensive binders for partial to complete replacement of ordinary Portland cement (OPC) clinker. Unlike slag and pozzolanic siliceous low-Ca class F fly ashes, the Ca- and S-rich class C ashes, particularly these formed in circulating fluidised bed combustion (CFBC) boilers, are typically not considered as viable cementitious materials for blending with or substituting the OPC. We studied the physical, chemical-mineralogical characteristics of the mechanically activated Ca-rich CFBC fly ash pastes and mortars with high volume OPC substitution rates to find potential alternatives for OPC in building materials and composites. Our findings indicate that compressive strength of pastes and mortars made with partial to complete replacement of the mechanically activated CFBC ash to OPC is comparable to OPC concrete, showing compared to OPC pastes reduction in compressive strength only by <10% at 50% and <20% at 75% replacement rates. Our results show that mechanically activated Ca-rich CFBC fly ash can be successfully used as an alternative CSA-cement type binder.


2016 ◽  
Vol 865 ◽  
pp. 249-254 ◽  
Author(s):  
Adam Hubáček ◽  
Martin Labaj ◽  
Martin Ťažký

The demand for concrete structures grows worldwide, which raises fears about sustainable development of Portland cement production. Its carbon footprint is relatively small compared to alternative building materials, but still it is not negligible. This argument together with lower cost and possibility of utilization of material, which would otherwise be disposed as waste, lead the research towards concrete with higher content of Portland cement replaced with fly ash. The experiment is divided into two parts: the first one determines influence of high volume fly ash replacement of Portland cement on behavior and properties of cement paste and mortar. The second part optimizes composition of concrete mix, in particular the granulometry of the cement-fly ash system in order to achieve maximal possible values of mechanical properties at high dosage of fly ash.


2014 ◽  
Vol 982 ◽  
pp. 114-118 ◽  
Author(s):  
Martin Keppert ◽  
Kirill Polozhiy

Fly ashes collected in Air Pollution Control lines of Municipal Solid Waste Incinerators (MSWI) differ highly from fly ashes generated during coal burning what complicates their utilization in building materials production. Nevertheless after a treatment such ashes can have properties relatively comparable with coal fly ashes and thus can be used as Supplementary Cementitious Material (SCM). The water extracted MSWI fly ash was used as partial Portland cement replacement in mortars. The mortars strength evolution in time was monitored; behavior typical for pozzolans – slower increase of strength – was observed. Influence of thermal load on strength of mortars was studied as well. It can be concluded that water extracted MSWI fly ash can be used as 10 % Portland cement substitute without loss of mechanical properties.


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