Innovative Synergistic Valorization of Lignite Fly Ash and Steel Industry Scrap-Soil as Secondary Resources for Compacted Ceramics

2015 ◽  
Vol 660 ◽  
pp. 268-272 ◽  
Author(s):  
V. Karayannis ◽  
G. Papapolymerou ◽  
S. Zaoutsos ◽  
S. Lamprakopoulos ◽  
K. Ntampegliotis ◽  
...  

In the present research, the combined utilization of fly ash (FA), derived from a lignite-fed power station, along with scrap-soil (SS), a steel industry by-product, is investigated, for the development of eco-friendly ceramics, thus enhancing innovation and sustainability. The valorization of these low price and largely available industrial secondary resources as 100% the raw materials mixture in ceramic industry arises interesting technological, environmental and economical benefits. FA and SS were mixed in various proportions (0-70%wt. in SS), cold compacted at 20 tn load using an automated hydraulic press to form a series of 5 cm diameter disc-shaped specimens, and finally sintered at three different peak temperatures (1000oC, 1100oC and 1140oC) for 3h. Then, the specimen microstructure and physico-mechanical properties were characterized. According to the experimental results, a sintering temperature increase from 1000°C up to 1140oC significantly improves specimen densification, thus sharply enhancing the diametral tensile strength (DTS), from 0.5 MPa up to 12.8 MPa respectively for a 50-50%wt. FA-SS mixture. Mechanical strength also varies with the SS percentage in the raw materials. Physico-mechanical properties seem to be constant for specimens containing SS up to 60% at 1140oC.

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Hongyan Yan ◽  
Chuang Wang ◽  
Hui Li ◽  
...  

An Fe/FeAl2O4 composite was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method. The mass ratio was 6:1:2, sintering pressure was 30 MPa, and holding time was 120 min. The raw materials for the powder particles were respectively 1 µm (Fe), 0.5 µm (Fe2O3), and 1 µm (Al2O3) in diameter. The effect of sintering temperature on the microstructure and mechanical properties of Fe/FeAl2O4 composite was studied. The results showed that Fe/FeAl2O4 composite was formed by in situ reaction at 1300 °C–1500 °C. With the increased sintering temperature, the microstructure and mechanical properties of the Fe/FeAl2O4 composite showed a change law that initially became better and then became worse. The best microstructure and optimal mechanical properties were obtained at 1400 °C. At this temperature, the grain size of Fe and FeAl2O4 phases in Fe/FeAl2O4 composite was uniform, the relative density was 96.7%, and the Vickers hardness and bending strength were 1.88 GPa and 280.0 MPa, respectively. The wettability between Fe and FeAl2O4 was enhanced with increased sintering temperature. And then the densification process was accelerated. Finally, the microstructure and mechanical properties of the Fe/FeAl2O4 composite were improved.


2016 ◽  
Vol 881 ◽  
pp. 383-386 ◽  
Author(s):  
Raimundo J.S. Paranhos ◽  
Wilson Acchar ◽  
Vamberto Monteiro Silva

This study evaluated the potential use of Sugarcane Bagasse Ashes (SBA) as a flux, replacing phyllite for the production of enamelled porcelain tile. The raw materials of the standard mass components and the SBA residue were characterized by testing by XRF, XRD, AG, DTA and TGA. Test samples were fabricated, assembled in lots of 3 units and sintered at temperatures of 1150 ° C to 1210 ° C. The results of the physical properties, mechanical properties and SEM of the sintered samples, showed that the formulation, G4 - in which applied 10% of SBA replacing phyllite, sintering temperature 1210 ° C showed better performance as the previously mentioned properties due to the formation of mullite crystals, meeting the prerequisites of standards for enamelled porcelain tile, while reducing the environmental impact and the cost of production.


Author(s):  
Md Mehtab Alam and B.S Motgi

The paper deals with detailed study on microstructure and mechanical properties of aluminum 7068 reinforced with fly ash and silicon carbide by powder metallurgy, aluminum 7068, silicon carbide and fly ash were taken in powder form of required size and mixed together in varying proportion according to specification and compacted with pressure of 400MPa using hydraulic press to make samples and then samples were sintered at 600°c for 2 hours, the samples were tested for density, compressive strength, hardness and microstructure was analyzed using scanning electron microscope, energy dispersive x-ray study was carried out in order to confirm presence of silicon carbide and fly ash in aluminum matrix.


2021 ◽  
Author(s):  
Siti Humairah Abd Rahman ◽  
Anatoly Medvedev ◽  
Andrey Yakovlev ◽  
Yon Azwa Sazali ◽  
Bipin Jain ◽  
...  

Abstract With the development of new oil formations and with the advent of new directions in the global energy sector, new requirements for materials for well construction appear. With the close attention to environmental footprint and unique properties, one of the promising materials for well cementing is geopolymers. Being a relatively new material, they are characterized by low carbon footprint, high acid resistance and attractive mechanical properties. This article is aimed at developing new geopolymer slurries for the oil industry, their characterization and field implementation analysis. With the ultimate goal of developing a methodology for the analysis of raw materials and designing the geopolymer slurries, studies were carried out on various raw materials, including different types of fly ash. Based on the data obtained and rapid screening methods, an approach was developed to formulate a geopolymer composition recipe. Since not all cement additives directly work in geopolymers, special attention was paid to control the thickening time and fluid loss. The methods of XRD, XRF, ICP-MS, density, particle size distribution measurements as well as API methods of cement testing were used to understand the composition and structure of the materials obtained, their properties and design limitations. A special approach was applied to study the acid resistance of the materials obtained and to compare with conventional cements and slags. Using one of the most common sources of aluminosilicate, fly ash, formulations with a density of 13.5 – 16.5 lbm/galUS were tested. A sensitivity analysis showed that the type of activator and its composition play a critical role both in the mechanical properties of the final product and in the solidification time and rheological properties of the product. The use of several samples of fly ash, significantly different in composition, made it possible to formulate the basic rules for the design of geopolymers for the oil industry. An analysis was also carried out on 10 different agents for filtration and 7 moderators to find a working formulation for the temperature range up to 100°C. The samples were systematically examined for changes in composition, strength, and acid resistance was previously measured. Despite the emergence of examples of the use of geopolymers in the construction industry and examples of laboratory testing of geopolymers for the oil industry, to the best of our knowledge, there has been no evidence of pumping geopolymers into a well. Our work is an attempt to develop an adaptation of the construction industry knowledge to the unique high pressure, high temperature conditions of the oil and gas industry. The ambitions of this work go far beyond the laboratory tests and involve yard test experiments.


2019 ◽  
Vol 798 ◽  
pp. 364-369 ◽  
Author(s):  
Khemmakorn Gomonsirisuk ◽  
Parjaree Thavorniti

The aim of this work is to study the feasibility of preparation of fly ash based geopolymer using sodium water glass from agricultural waste as alternative activators. Rice husk ash and bagasse ash were used as raw materials for producing sodium water glass solution. The sodium water glass were produced by mixing rice husk ash and bagasse ash with NaOH in ball mill and boiling. The prepared sodium water glass were analyzed and used in geopolymer preparation process. The geopolymer paste were prepared by adding the obtained water glass and NaOH with fly ash. After cured at ambient temperature for 7 days, mechanical properties were investigated. Bonding and phases of the geopolymer were also characterized. The geopolymer from rice husk ash presented highest compressive strength about 23 MPa while the greatest for bagasse ash was about 16 MPa.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Numan Salah ◽  
Abdulrahman Muhammad Alfawzan ◽  
Abdu Saeed ◽  
Ahmed Alshahrie ◽  
Waleed Allafi

AbstractCarbon nanotubes (CNTs) are widely investigated for preparing polymer nanocomposites, owing to their unique mechanical properties. However, dispersing CNTs uniformly in a polymer matrix and controlling their entanglement/agglomeration are still big technical challenges to be overcome. The costs of their raw materials and production are also still high. In this work, we propose the use of CNTs grown on oil fly ash to solve these issues. The CNTs of oil fly ash were evaluated as reinforcing materials for some common thermoplastics. High-density polyethylene (HDPE) was mainly reinforced with various weight fractions of CNTs. Xylene was used as a solvent to dissolve HDPE and to uniformly disperse the CNTs. Significantly enhanced mechanical properties of HDPE reinforced at a low weight fraction of these CNTs (1–2 wt.%), mainly the tensile strength, Young’s modulus, stiffness, and hardness, were observed. The tensile strength and Young’s modulus were enhanced by ~20 and 38%, respectively. Moreover, the nanoindentation results were found to be in support to these findings. Polycarbonate, polypropylene, and polystyrene were also preliminarily evaluated after reinforcement with 1 wt.% CNTs. The tensile strength and Young’s Modulus were increased after reinforcement with CNTs. These results demonstrate that the CNTs of the solid waste, oil fly ash, might serve as an appropriate reinforcing material for different thermoplastics polymers.


2019 ◽  
Vol 814 ◽  
pp. 413-418
Author(s):  
Fang Wang ◽  
Ming Han Xu ◽  
Rui Hua Wang ◽  
Chao Yang ◽  
Ai Xia Chen ◽  
...  

The construction industry continues to develop and the requirements for cement performance are getting higher and higher. At the same time, in the steel industry, the discharge of steel slag is also increasing. The effective reuse of steel slag has become a prominent problem in the steel industry. . Therefore, it is envisaged to use steel slag as a raw material for the cement production process to produce cement and to produce high-performance cement. The main raw materials of this experiment are steel slag, limestone, sandstone and shale. Through the cement preparation process, the cement is made, and then the cement is made into concrete to test its performance. This experiment mainly studies the sintering temperature and holding time variable. In the experimental test, the analysis and comparison were carried out in five aspects of the degree of macroscopic cracking, particle size, density, microstructure and composition. In the comparison experiment of sintering temperature, with the increase of temperature, the flexural and compressive properties of cement gradually increased. In this test, 1200 °C is the most suitable temperature for the performance of the cement. Through the experimental comparison of different holding time, it is known that with the prolonging of the holding time, the microstructure and actual performance of the cement are continuously enhanced. Comprehensive consideration: the ratio of steel slag in cement ratio is 10%, sintering temperature is 1200 °C, and heat preservation is 2h. The steel slag cement prepared under this condition has the strongest performance.


2015 ◽  
Vol 754-755 ◽  
pp. 290-295 ◽  
Author(s):  
Alida Abdullah ◽  
Ku Amirrul Rahman Ku Yin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Mien Van Tran

This study was conducted to compare the mechanical properties of fly ash artificial geopolymer aggregates with natural aggregate (rock) in term of its impact strength, specific gravity and water absorption.The raw materials used were fly ash, sodium hydroxide, sodium silicate and natural aggregate. After the artificial geopolymer aggregate has been produced, its water absorption, specific gravity and aggregate impact test has been done. All results obtained were compared to natural aggregate. The result shows that the fly ash geopolymer aggregate are lighter than natural aggregate in term of its specific gravity. The impact value for fly ash artificial geopolymer aggregate slightly high compared to natural aggregate while it has high water absorption value compared to natural aggregate. As conclusion, the fly ash artificial geopolymer aggregate can be used as one of the construction materials in concrete as an alternative for coarse aggregate besides natural aggregate with more lightweight properties.


2011 ◽  
Vol 295-297 ◽  
pp. 581-584
Author(s):  
Li Qiang Zhang ◽  
Ping Huo ◽  
Yong Huang ◽  
Peng Li ◽  
Rong Yang

In laboratory condition, industrial zirconia and alumina were used as raw materials, whose particle size was controlled by ultrafine treatment of mechanical milling. The effects of different firing temperatures and soaking times on mechanical properties of Al2O3-based composite ceramics liner were researched. And the microstructure of samples was studied by scanning electron microscopy (SEM). The results indicate that mechanical properties of samples kept 3 h at sintering temperature of 1600°C with adding 30 wt% zirconia are the best.


2015 ◽  
Vol 660 ◽  
pp. 9-16 ◽  
Author(s):  
Wan Mastura Wan Ibrahim ◽  
Kamarudin Hussin ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Aeslina Abdul Kadir ◽  
Mohammed Binhussain

Bricks are widely used as a construction and building material due to its properties. Recent years have seen a great development in new types of inorganic cementitious binders called ‘‘geopolymeric cement’’ around the world. This prompted its use in bricks, which improves the greenness of ordinary bricks. The development of fly ash-based geopolymer lightweight bricks is relatively new in the field of construction materials. This paper reviews the uses of fly ash as a raw materials and addition of foaming agent to the geopolymeric mixture to produce lightweight bricks. The effects on their physical and mechanical properties have been discussed. Most manufactured bricks with incorporation of foaming agent have shown positive effects by producing lightweight bricks, increased porosity and improved the thermal conductivities of fly ash-based geopolymer bricks. However, less of performances in number of cases in terms of mechanical properties were also demonstrated.


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