Study on the effect of calcium and sulfur content on the properties of fly ash based geopolymer

2022 ◽  
Vol 314 ◽  
pp. 125650
Author(s):  
Xiao Chen ◽  
Jiachen Zhang ◽  
Mingyu Lu ◽  
Bowen Chen ◽  
Shuaiqi Gao ◽  
...  
Keyword(s):  
Fly Ash ◽  
2010 ◽  
Vol 148-149 ◽  
pp. 1511-1517
Author(s):  
Wei Gao ◽  
Qing Cai Liu ◽  
Cun Fang Lu ◽  
Jian Yang ◽  
Juan Wen ◽  
...  

Mercury is a toxic air pollution, and coal-fired utility plants are the largest anthropogenic emission source in China. Due to rapidly decreasing the cost and increasing the efficiency, it is becoming necessary to develop alternative technologies/materials for mercury removal. The adsorbents made from fly ash of coal-fired, and became spherical after sintering at temperature 500 . Finally, it has been treated by thermal precipitation sulfur, to remove mercury in fuel gas of coal-fired. High temperature deposition furnace was applied to increase sulfur content in fly ash based adsorbents produced in lab. SEM, BET, TGA and other measurement methods were used to characterize the surface morphology, sulfur distribution and specific surface. The experiments can increase its sulfur content of adsorbent, and the study found that sulfur attached to the surface, mesopore structure, microporous structure of fly ash-based adsorbents. So these treatments can increase their surface area and enhanced their adsorption capacity, while the sulfur was filled in interspace as small molecule S2 and S5. And the specific surface area increased by sulfur-loading and increasing temperature.


Author(s):  
L. L. Sutter ◽  
G. R. Dewey ◽  
J. F. Sandell

Municipal waste combustion typically involves both energy recovery as well as volume reduction of municipal solid waste prior to landfilling. However, due to environmental concerns, municipal waste combustion (MWC) has not been a widely accepted practice. A primary concern is the leaching behavior of MWC ash when it is stored in a landfill. The ash consists of a finely divided fly ash fraction (10% by volume) and a coarser bottom ash (90% by volume). Typically, MWC fly ash fails tests used to evaluate leaching behavior due to high amounts of soluble lead and cadmium species. The focus of this study was to identify specific lead bearing phases in MWC fly ash. Detailed information regarding lead speciation is necessary to completely understand the leaching behavior of MWC ash.


1997 ◽  
Vol 9 (6) ◽  
pp. 541-565 ◽  
Author(s):  
Cheryl R. Killingsworth ◽  
Francesca Alessandrini ◽  
G. G. Krishna Murthy ◽  
Paul J. Catalano ◽  
Joseph D. Paulauskis ◽  
...  

2021 ◽  
Vol 33 (3) ◽  
pp. 04021001
Author(s):  
Maheshbabu Jallu ◽  
Sireesh Saride ◽  
Arul Arulrajah ◽  
Subrahmanyam Challapalli ◽  
Robert Evans
Keyword(s):  
Fly Ash ◽  

Author(s):  
A. T. Kunakbaeva ◽  
A. M. Stolyarov ◽  
M. V. Potapova

Free-cutting steel gains specific working properties thanks to the high content of sulfur and phosphorus. These elements, especially sulfur, have a rather high tendency to segregation. Therefore, segregation defects in free-cutting steel continuously cast billets can be significantly developed. The aim of the work was to study the influence of the chemical composition of freecutting steel and casting technological parameters on the quality of the macrostructure of continuously cast billets. A metallographic assessment of the internal structure of cast metal made of free-cutting steel and data processing by application of correlation and regression analysis were the research methods. The array of production data of 43 heats of free-cutting steel of grade A12 was studied. Steel casting on a five-strand radial type continuous casting machine was carried out by various methods of metal pouring from tundish into the molds. Metal of 19 heats was poured with an open stream, and 24 heats – by a closed stream through submerged nozzles with a vertical hole. High-quality billets had a cross-sectional size of 150×150 mm. The macrostructure of high-quality square billets made of free-cutting steel of A12 grade is characterized by the presence of central porosity, axial segregation and peripheral point contamination, the degree of development of which was in the range from 1.5 to 2.0 points, segregation cracks and strips – about 1.0 points. In the course of casting with an open stream, almost all of these defects are more developed comparing with the casting by a closed stream. As a result of correlation and regression analysis, linear dependences of the development degree of segregation cracks and strips both axial and angular on the sulfur content in steel and on the ratio of manganese content to sulfur content were established. The degree of these defects development increases with growing of sulfur content in steel of A12 grade. These defects had especially strong development when sulfur content in steel was of more than 0.10%. To improve the quality of cast metal, it is necessary to have the ratio of the manganese content to the sulfur content in the metal more than eight.


Author(s):  
Shubham N. Dadgal ◽  
Shrikant Solanke

In modern days for structures in coastal areas it has been observed that the premature structural failures are occurs due to corrosion of the reinforcements of the designed structural member. The corrosion causes the structural damage which in turn leads to reduction in the bearing capacity of the concerned structural members. The aim of this study was to study the effect of partial replacement of fly ash to minimize the corrosion effect. Beams were designed and corroded by using artificial method known accelerated corrosion method. The beams were then tested for flexural and bond strength. Also the weight loss of the reinforced bars was been determined using electrical resistivity method. The fly ash will replace by 10% and 15%.The strength will calculate at varying percentage of corrosion at 10% and 15%. Beams will cast at M25 grade concrete. The flexural strength will test by using UTM and the bond strength will calculate using pullout test.


Author(s):  
Harshkumar Patel ◽  
Yogesh Patel

Now-a-days energy planners are aiming to increase the use of renewable energy sources and nuclear to meet the electricity generation. But till now coal-based power plants are the major source of electricity generation. Disadvantages of coal-based thermal power plants is disposal problem of fly ash and pond ash. It was earlier considered as a total waste and environmental hazard thus its use was limited, but now its useful properties have been known as raw material for various application in construction field. Fly ash from the thermal plants is available in large quantities in fine and coarse form. Fine fly ash is used in construction industry in some amount and coarse fly ash is subsequently disposed over land in slurry forms. In India around 180 MT fly is produced and only around 45% of that is being utilized in different sectors. Balance fly ash is being disposed over land. It needs one acre of land for ash disposal to produce 1MW electricity from coal. Fly ash and pond ash utilization helps to reduce the consumption of natural resources. The fly ash became available in coal based thermal power station in the year 1930 in USA. For its gainful utilization, scientist started research activities and in the year 1937, R.E. Davis and his associates at university of California published research details on use of fly ash in cement concrete. This research had laid foundation for its specification, testing & usages. This study reports the potential use of pond-ash and fly-ash as cement in concrete mixes. In this present study of concrete produced using fly ash, pond ash and OPC 53 grade will be carried. An attempt will be made to investigate characteristics of OPC concrete with combined fly ash and pond ash mixed concrete for Compressive Strength test, Split Tensile Strength test, Flexural Strength test and Durability tests. This paper deals with the review of literature for fly-ash and pond-ash as partial replacement of cement in concrete.


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