Computational Investigation of the Influence of Fly Ash Silica Content and Shape on the Erosion Behaviour of Indian Coal Fired Boiler Grade Steels

2016 ◽  
Vol 97 (3) ◽  
pp. 375-380 ◽  
Author(s):  
Amrita Kumari ◽  
Suchandan Kumar Das ◽  
Prem Kumar Srivastava
Keyword(s):  
Fly Ash ◽  
Silica Content ◽  
Computational Investigation ◽  
Indian Coal ◽  
Erosion Behaviour

scholarly journals Fly Ash, from Recycling to Potential Raw Material for Mesoporous Silica Synthesis

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 474 ◽  
Author(s):  
Marius Gheorghe Miricioiu ◽  
Violeta-Carolina Niculescu
Keyword(s):  
Fly Ash ◽  
Mesoporous Silica ◽  
Energy Demand ◽  
Power Plants ◽  
Circulating Fluidized Bed ◽  
Structural Characteristics ◽  
Silica Content ◽  
Raw Material ◽  
Hard Coal ◽  
High Level

In order to meet the increasing energy demand and to decrease the dependency on coal, environmentally friendly methods for fly ash utilization are required. In this respect, the priority is to identify the fly ash properties and to consider its potential as raw material in the obtaining of high-value materials. The physico-chemical and structural characteristics of the fly ash coming from various worldwide power plants are briefly presented. The fly ash was sampled from power plants where the combustion of lignite and hard coal in pulverized-fuel boilers (PC) and circulating fluidized bed (CFB) boilers was applied. The fly ash has high silica content. Due to this, the fly ash can be considered a potential raw material for the synthesis of nanoporous materials, such as zeolites or mesoporous silica. The samples with the highest content of SiO2 can be used to obtain mesoporous silica materials, such as MCM-41 or SBA-15. The resulting mesoporous silica can be used for removing/capture of CO2 from emissions or for wastewater treatment. The synthesis of various porous materials using wastes would allow a high level of recycling for a sustainable society with low environmental impact.

EFFECT OF MIXING PROPORTION ON COMPRESSIVE STRENGTH OF FLY-ASH BASED GEOPOLYMER PASTE AND MORTAR USING TAGUCHI’S METHOD

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Sajid Khan Afridi ◽  
Vanissorn Vimonsatit
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Elevated Temperatures ◽  
Three Dimensional ◽  
Silica Content ◽  
Polymeric Chain ◽  
Low Carbon ◽  
Solid Ratio ◽  
Mix Proportion ◽  
Alkali Activated

Alkali activated pozzolan are known low carbon cementitious binders which can be used to replace cement. The material is also known as geopolymer because of its three dimensional polymeric chain and ring like structure consisting silica and alumina. A common type of pozzolan used is fly ash because of its rich silica content; therefore the term alkali activated fly-ash based binders is adopted. Despite much research and development of this material, there is no specific standard for design mix proportion. This research used the Taguchi’s design of experiment method to determine the optimum mix proportion of alkali activated fly ash based cement paste and mortar. Four factors were considered in the tests, silica fume, sand to cementitious ratio, liquid to solid ratio, and percentage of superplasticiser. Tests were conducted on the 9 batches of alkali activated fly-ash based paste and mortar samples to determine the compressive strength under ambient condition. Tests were also conducted to determine the residual strength of the samples after exposed to elevated temperatures. ANOVA analysis of the test results revealed the main factors contribution on the tested properties and led to the determination of the optimum design proportion of the factors considered in these tests.

scholarly journals Comparison of strength and durability characteristics of a geopolymer produced from fly ash, ground glass fiber and glass powder

2017 ◽  
Vol 67 (328) ◽  
pp. 136 ◽  
Author(s):  
H. Rashidian-Dezfouli ◽  
P. R. Rangaraju
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Glass Fiber ◽  
Glass Powder ◽  
Silica Content ◽  
Ground Glass ◽  
Alkali Silica Reaction ◽  
Strength And Durability ◽  
Cement Mixtures

Strength and durability characteristics of geopolymers produced using three precursors, consisting of fly ash, Ground Glass Fiber (GGF), and glass-powder were studied. Combinations of sodium hydroxide and sodium silicate were used as the activator solutions, and the effect of different sodium and silica content of the activators on the workability and compressive strength of geopolymers was investigated. The parameters used in this study were the mass ratio of Na2O-to-binder (for sodium content), and SiO2-to-Na2O of the activator (for silica content). Geopolymer mixtures that achieved the highest compressive strength from each precursor were assessed for their resistance to alkali-silica reaction and compared against the performance of portland cement mixtures. Test results revealed that GGF and fly ash-based geopolymers performed better than glass-powder-based geopolymer mixtures. The resistance of GGF-based and fly ash-based geopolymers to alkali-silica reaction was superior to that of portland cement mixtures, while glass-powder-based geopolymer showed inferior performance.

scholarly journals Erosion Analysis on Copper Fly-Ash Composite

2019 ◽  
Vol 9 (2S2) ◽  
pp. 568-570
Keyword(s):  
Fly Ash ◽  
Powder Metallurgy ◽  
Solid Particle ◽  
Solid Particle Erosion ◽  
Particle Erosion ◽  
Erosion Behaviour ◽  
Input Parameters

In the present study, solid particle erosion behaviour on copper – fly ash composite is studied. Composite with addition of 2.5 (wt.%) fly ash as reinforcement is prepared through powder metallurgy(P/M) technique. Solid particle erosion studies were carried out by varying the input parameters such as erodent velocity and erosion time. The results revealed that addition of fly ash reduced the resistance to erosion.

scholarly journals Mechanical Properties of Geopolymer Concrete with Flyash and Metakaolin

2019 ◽  
Vol 9 (1) ◽  
pp. 3863-3868 ◽  
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Sodium Hydroxide ◽  
Silica Content ◽  
Geopolymer Concrete ◽  
Long Term Effects ◽  
Concrete Production ◽  
High Silica ◽  
By Products

Trials has been made to produce efficient GPC which gives maximum strength. By-Products from industries such as Fly-Ash, Metakaolin and GGBS can be used in concrete replacement which in-turn reduces carbon-di-oxide (CO2 ) emission affecting to green house. Using the above said products also leads to reduction of water demand in concrete and also shows comparatively no effects on long term effects in concrete, these by-products can effectively be used in concrete production. The high silica content in Fly-Ash and Metakaolin increases the bonding in concrete which in-turn increases the mechanical properties of concrete. Geopolymer concrete of M50 grade was proposed to be produced using fly-ash and Metakaolin instead of cement.Alklai solutions Sodium Hydroxide (NaOH), Sodium Silicate (Na2SiO3) were replaced with water for better bonding and mixing. Molarity of Sodium Hydroxide with 10M and 12M was considered for this study. Ratio of Alkaline solution were considered as 1:2,1:2.5&1:3 to determine the optimum ratio which gives effective strength. In this experimental study, tests were carried on concrete specimens with percentage replacement of Fly-Ash with Buff Metakaolin in variable percentages of 20,40,60,80&100. Mechanical properties of concrete specimens were studied and were compared with control mix results.

Selective Synthesis of Phillipsite from Fly Ash of Low Silica Content by Hydrothermal Treatment.

2003 ◽  
Vol 29 (2) ◽  
pp. 299-304 ◽  
Author(s):  
Kunihiro Fukui ◽  
Motoki Kinugawa ◽  
Takashi Nishimoto ◽  
Hideto Yoshida
Keyword(s):  
Fly Ash ◽  
Hydrothermal Treatment ◽  
Silica Content ◽  
Selective Synthesis

Hydration Reactions in Cement Pastes Incorporating Fly Ash and Other Pozzolanic Materials

1986 ◽  
Vol 86 ◽  
Author(s):  
F. P. Glasser ◽  
S. Diamond ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Physical Properties ◽  
Silica Content ◽  
Cement Pastes ◽  
Blended Cements ◽  
Natural Pozzolans ◽  
High Calcium ◽  
High Silica ◽  
Class F Fly Ash

ABSTRACTA model for reactions that occur in hydrating portland cement is now generally well developed. Incorporation of various by-products to form blended cements modifies both the hydration reactions and the physical properties of the resulting pastes. A review of recent progress in understanding the effects of blending agents on these reactions is presented. The blending agents considered are low-calcium (Class F) fly ash, high calcium (Class C) fly ash, blast furnace slag, silica fume, biosilica and natural pozzolans. Effects of the blending agents on physical properties such as rheology are also considered. Particular attention is given to the essential role of alkalies in pore solutions and the beneficial reactions that occur with high silica content blending agents.

Sign in / Sign up

Export Citation Format

Share Document