99/03149 High strength artificial aggregate using coal-ash as raw material

1999 ◽  
Vol 40 (5) ◽  
pp. 331
Keyword(s):  
Coal Ash ◽  
2012 ◽  
Vol 204-208 ◽  
pp. 2897-2902
Author(s):  
Qing Shuang Zhao ◽  
Ming Xia Xu

The coal ash wall board filled with core powder is a new kind of light and hollow board that can be produced in factories. It uses cement with high strength, coal ash and auxiliary chemicals as its raw material, after pouring concrete and reinforcing bars into its cavity, it will get ability to bear loads. In this paper, aiming at the material characteristic of coal ash, according to the structure of wall filled with core powder, create a simplified calculation model. According to its deformation characteristics and the formula of the frame - shear wall, we can get the equivalent strength of the wall to simplify the calculation to apply to engineering project.


2020 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Suharto Suharto ◽  
Muhammad Amin ◽  
Muhammad Al Muttaqii ◽  
Syafriadi Syafriadi ◽  
Kiki Nurwanti

Experimental study on the use of basalt stone originated from Lampung has been conducted to evaluate its potential for a partial substitute of raw material in production of cement clinker. The basalt stone contains minerals of anorthite, augite, and albite phases that are required for clinker formation. In this study, the main raw materials were 80% limestone, 10% silica sand, 9% clay and 1% iron sand. The raw material in these experiments were mixtures 90% or 80% of the main raw material and 10% or 20% of basalt stone. The effect of adding coal to raw materials was also studied to see the possibility of an increase in clinkerization temperature inside the raw material mixture, and at the same time to see the effect of coal ash on clinker composition. Clinker obtained from heating of raw materials at a temperature of 1100oC had LSF of 94.1% and 95.1% (heating time of 1 and 3 hours). If heating is carried out at 1200oC, the clinker had LSF of 97.7% and 98.0% (heating time of 2 and 3 hours, respectively). Depending on the temperature and duration of heating, the clinker mostly had SM in the range of 2.18-2.40% , and AM in the range of 0,78-1.80%. Characterization using XRD showed that the clinker consisted of larnite and gehlenite phases, and dominated by CaO.Batu basalt Lampung telah diuji potensinya sebagai pengganti sebagian bahan baku utama pembuatan klinker semen. Batu basalt tersebut memiliki mineral-mineral dalam fase anorthite, augite, dan albite yang diperlukan pada pembentukan klinker. Pada penelitian ini, bahan baku utama adalah batu kapur 80%, pasir silika 10%, tanah liat 9% dan pasir besi 1%. Campuran bahan baku klinker adalah 90% atau 80% bahan baku utama dan 10% atau 20% batu basalt. Efek penambahan batubara ke dalam bahan baku klinker juga dipelajari untuk melihat kemungkinan kenaikan temperatur klinkerisasi di dalam campuran bahan baku, dan sekaligus untuk melihat efek abu batubara terhadap komposisi klinker. Klinker hasil pemanasan bahan baku pada temperatur 1100oC memiliki LSF 94,1% dan 95,1% (lama pemanasan 1 dan 3 jam). Jika pemanasan dilakukan pada 1200oC, klinker memilik LSF 97,7% dan 98,00% (lama pemanasan 2 dan 3 jam). Tergantung pada temperatur dan lama pemanasan, klinker hasil percobaan ini umumnya memiliki SM 2,18-2,40%, dan AM antara 0,78-1,80%. Karakterisasi dengan XRD menunjukkan bahwa klinker terdiri dari fase larnite dan gehlenite, dan didominasi CaO.


2013 ◽  
Vol 594-595 ◽  
pp. 527-531
Author(s):  
Mohamad Ezad Hafez Mohd Pahroraji ◽  
Hamidah Mohd Saman ◽  
Mohamad Nidzam Rahmat ◽  
Kartini Kamaruddin ◽  
Ahmad Faiz Abdul Rashid

Millions tons of coal ash which constitute of fly ash and bottom ash were produced annually throughout the world. They were significant to be developed as masonry brick to substitute the existing widely used traditional material such as clay and sand brick which were produced from depleting and dwindling natural resources. In the present study, the coal ash from coal-fired thermal power plant was used as the main raw material for the fabrication of cementless unfired lightweight brick. The binder comprising of Hydrated Lime (HL)-activated Ground Granulated Blastfurnace Slag (GGBS) system at binding ratio 30:70, 50:50 and 70:30 were used to stabilize the coal ash in the fabrication process of the brick. Foam was used to lightweight the brick. The compressive strength and ambient density were evaluated on the brick. The results indicated that the brick incorporating HL-GGBS system achieved higher strength of 20.84N/mm2 at 28 days compare to the HL system with strength of 13.98N/mm2 at 28 days. However, as the quantity of foam increase at 0%, 25%, 50%, 75% and 100%, the strength and density for the brick decreased.


2019 ◽  
Vol 51 (3) ◽  
pp. 285-294
Author(s):  
Dang Wei ◽  
H.-Y. He

High strength lightweight glass-ceramics were fabricated with coal gangue and clay as main raw materials. The utilization ratio of coal gangue, the ratio of the coal gangue with clay, mineralization agents, forming process and sintering process on the properties of the fabricated glass-ceramics were optimized. The utilization ratio of coal gangue reached 75, and the ratio of coal gangue to clay was 3/1, as an optimal property was observed. The optimal sintering temperature was found to be 1370?C. At this optimal temperature, the sintered glass-ceramics showed the main phase of mullite and spindle and so showed high strength, low density, and low water absorbance. The appropriate amounts of codoping of the TiO2, ZnO, and MnO2/dolomite as mineralization agents obviously enhanced the properties of the glass-ceramics. Process optimizations further determined reasonable and optimal process parameters. The high strength lightweight glass-ceramics fabricated in this work may be very suitable for various applications including building materials, cooking ceramics, and proppant materials, et al.


2008 ◽  
Vol 73 (631) ◽  
pp. 1425-1432 ◽  
Author(s):  
Hiroshi KASAI ◽  
Jinhwan JEON ◽  
Hiroki WAMI ◽  
Eiichi FUJIKI ◽  
Kiminori TANAKA ◽  
...  

2010 ◽  
Vol 105-106 ◽  
pp. 758-760 ◽  
Author(s):  
Yan Bing Zong ◽  
Yu Li ◽  
Da Qiang Cang

Composition of stainless steel slag was compared with that of ceramic paste first. DTA curves of ceramic samples were obtained to determine the firing temperature schedule. It is concluded that the stainless steel slag mixed with certain chemically pure materials can serve as raw material for the production of high added value ceramics. Pilot plant scale tests show that the principal crystal phase is diopside, contributing to the making of high strength and high density ceramics. Heating rate, cooling rate and holding time should be controlled appropriately during sintering process for the sake of forming and growth of crystals. The total performance detection of ceramic samples accords with national standards in China when stainless steel slag is used to sinter calcium-magnesium-silicon type ceramic in roller kiln. The proportion of stainless steel slag is 45% during pilot tracey. Dissolution rate of chromium during stainless steel slag used as mainly diopside type of building ceramic is only 25.17 mg/kg ceramic, which resolves the harmless of chromium. This work provides a feasible and effective way for resource of stainless steel slag.


Author(s):  
Zetan Liu ◽  
Shiqiang Zhao ◽  
Tian Yang ◽  
Ji Zhou

AbstractIt is possible to improve the machinability of aluminum nitride-hexagonal boron nitride (AlN-h-BN) ceramics while maintaining high strength and high thermal conductivity. The composite ceramics with 0–30 wt% BN as secondary phase were prepared by hot pressed sintering, using yttrium oxide (Y2O3) as sintering aid. The phase composition, density, microstructure, mechanical properties, thermal conductivity, and dielectric properties were investigated. The sintering additives were favorable to purify the grain boundaries and improve densification, reacting with oxide impurities on the surface of raw material powder particles. The optimum BN content improved the flexural strength and fracture toughness of composite ceramics with 475 MPa and 4.86 MPa·m1/2, respectively. With increasing the amount of BN, the thermal conductivity and hardness of composites gradually decreased, but the minimum value of thermal conductivity was still 85.6 W·m−1·K−1. The relative dielectric constant and dielectric loss tangent of the samples ranged from 6.8 to 8.3 and from 2.4 × 10−3 to 6.4 × 10−3, respectively, in 22–26 GHz.


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