• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.21-22
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• 2019

This study is designed to apply natural clay replaceable redmud as ceramic material by mixing redmud with the materials used in existing brickmaking in laboratory environment. Therefore, through this study, the redmud is recycled as a raw material for clay bricks and presented as a basic material for the use of redmud in clay bricks.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1544-1551
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• 2024

A unique brick series based on Vietnamese clay was manufactured at 114.22 MPa pressure rate for γ-ray attenuation purposes, consisting of (x) metallic waste & (90%-x) red clay mineral & 10% (hardener mixed with epoxy resin), where (x) is equal to the values 0%, 20%, 40%, 50%, and 70%. The impacts of industrial metal waste ratio in the structure and radiation protective characteristics were evaluated experimentally. The increase in metallic waste doping concentrations from 0% to 70% was associated with an increase in the manufactured brick's density (ρ) from 2.103 to 2.256 g/cm³ while the fabricated samples' porosity (Φ) decreased from 11.7 to 1.0%, respectively. Together with a rise in fabricated brick's density and a decrease in their porosities, the manufactured bricks' γ-ray attenuation capacities improved. The measured linear attenuation coefficient (μ, cm^-1) was improved by 30.8%, 22.1%, 21.6%, and 19.7%, at E_γ equal to the values respectively 0.662, 1.173, 1.252, and 1.332 MeV, when the metallic waste concentration increased from 0% to 70%, respectively. The study demonstrates that manufactured bricks exhibit superior radiation shielding properties, with radiation protection efficiencies of 88.4%, 90.0%, 91.7%, 92.1%, and 92.4% for bricks with industrial metal waste contents of 0%, 20%, 40%, 50%, and 70%, respectively, at γ-ray energy (E_γ) of 1.332 MeV.

• 대한건축학회논문집:구조계
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• 제35권10호
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• pp.199-206
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• 2019

This study aims to recycle redmud which is a byproduct in the alumina industry. Redmud ceramics were prepared according to the type of raw materials by blending redmud with the raw materials used in the conventional clay bricks. In this paper, the compressive strength, water absorption ratio, and shrinkage of redmud ceramics prepared by mixing clay bricks were evaluated. Compressive strength and absorption ratio of redmud ceramics were compared with the clay brick criteria of KS L 4201. At the firing temperature of $1200^{\circ}C$, the specimens containing redmud only and the redmud with sandy loam and black clay were found to satisfy the 1st class of clay brick. The quality standard of compressive strength and absorption ratio was obtained by firing redmud with black clay and sandy loam at $1200^{\circ}C$. Also, when the redmud was mixed with black clay and feldspar, the 2nd class was satisfied when the sample was fired at $1100^{\circ}C$.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2489-2497
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• 2024

The current study aims to develop new clay bricks doped with metallic waste for radiation shielding applications. The aforementioned new bricks were fabricated with various metallic waste concentrations under a pressure rate reaching ≈114 MPa and firing temperature of 1100 ℃. The impacts of the metallic waste and the firing temperature on the developed brick samples' physical, radiation shielding, and structural properties were studied. In order to identify the fabricated bricks' mineral content, the X-ray diffraction pattern was used. Additionally, the fabricated bricks' porosity and density were experimentally determined, where the porosity was reduced by 28.03%, while their densities increased by ≈ 10.5% by raising the concentration of metallic waste. The linear attenuation coefficient (LAC) for the developed brick was investigated experimentally using a NaI (Tl) scintillation detector over the 0.033-1.408 MeV energy interval. The measured LAC values were enhanced by increasing the concentrations of metallic waste within the fabricated bricks over the examined energy interval. The fabricated brick's LAC enhancement improves the gamma-ray shielding characteristics. Therefore, the fabricated bricks are a cheap and suitable choice for radiation protection applications.

• 헤리티지:역사와 과학
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• 제46권2호
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• pp.206-219
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• 2013

발해의 고구려 계승을 보여주는 중요한 유적인 연해주 콕샤로프카-1 평지성에서 출토된 토벽체 4점을 과학적으로 분석하여 재료의 물리화학적 특성과 소성온도를 추정하고자 하였다. 분석 결과, 단면의 입자구성은 점토질과 석영, 장석 등이 혼재해 있으며, 일부 시편에서는 내부에 탄화된 유기물이 확인되었고, 이는 토벽의 강도를 높이기 위해 첨가된 것으로 판단된다. 결정구조 분석을 통해 주 구성광물을 동정한 결과, 석영(Quartz), 일라이트(Illite) 등이 확인되었으며, 일부 토벽의 표면 단장에 사용된 백색물질은 주 구성광물이 규선석(Silimanite)으로 밝혀졌다. 또한 대부분의 시편에서 적철석(Hematite)이 동정된 것과 다르게 뮬라이트(Mullite)가 존재하는 시편도 있는 것으로 보아 일부는 고온소성된 것으로 판단된다. 열분석에서는 $800{\sim}1,000^{\circ}C$ 사이에서 물라이트로 변화하는 발열피크가 존재하지 않고, $900^{\circ}C$ 이상에서 흡열피크가 존재하는 것으로 보아 $900^{\circ}C$ 이상에서 소성되었음을 추정할 수 있다.

• The Korean Journal of Ceramics
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• 제4권4호
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• pp.279-285
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• 1998

The $UO_2$ pellets are usually sintered under hydrogen gas atmosphere. Hydrogen gas may cause unexpected early failure of the refractory bricks in the sintering furnace. In this work, nitrogen was mixed with hydrogen to investigate the effect of nitrogen gas on a failure machanism of the refractory bricks and on the microstructure of the $UO_2$ pellet. The hydrogen-nitrogen mixed gas experiments show that the larger nitrogen the mixed gas contains, the less the refractory materials are reduced by hydrogen. The weight loss measurements at $1400^{\circ}C$ for fire clay and chamotte refractories containing high content of $SiO_2$ indicate that the weight loss rate for the mixed gas is about half of that for the hydrogen gas. Based on the thermochemical analyses, it is proposed that the weight loss is caused by hydrogen-induced reduction of free $SiO_2$ and/or $SiO_2$ bonded to $Al_2O_3$ in the fire clay and chamotte refractories. However, the retardation of the hydrogen-induced $SiO_2$ reduction rate under the mixed gas atmosphere may be due to the reduction of the surface reaction rate between hydrogen gas and refractory materials in proportion to volume fraction of nitrogen gas in the mixed gas. On the other hand, the mixed gas experiments show that the test data for $UO_2$ pellet still meet the related specification values, even if there exists a slight difference in the pellet microstructural parameters between the cases of the mixed gas and the hydrogen gas.

• 보존과학회지
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• 제32권4호
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• pp.511-520
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• 2016

본 연구는 고온 XRD 분석법을 적용하여 우즈베키스탄 카라테파 불교사원에서 수습한 점토 재질로 된 벽돌의 소성온도를 추정하는데 목적이 있다. 사원에서 수습한 점토벽돌의 구성광물은 석영, 사장석, 알칼리장석, 운모, 녹니석, 석회석, 각섬석 등이 동정되고, 일부 시료에서 석고가 확인되며, 석고는 벽돌의 점착력을 향상시킬 목적으로 사용된 것으로 판단된다. 소성온도 추정결과, 구운 벽돌인 UZ-1시료에서 석영, 사장석, 휘석계열의 광물이 동정되어 지질온도계를 이용한 소성온도는 $900{\sim}1200^{\circ}C$로 추정된다. 반면 점토벽돌인 UZ-5에 고온 XRD 분석법을 적용해 보면, $1000^{\circ}C$에서 석회석이 소멸하고, $1050^{\circ}C$에서 녹니석의 회절 피크가 약해지는 것으로 보아 소성온도는 $1000{\sim}1050^{\circ}C$인 것으로 추정된다. 또한 휘석계열의 광물은 재현실험에서 $1050^{\circ}C$에서 생성되는 것을 확인하였다. 결과적으로 고온 XRD 분석 결과에 의한 소성온도 추정은 일반적인 광물 동정법에 비해 보다 정확한 추정이 가능하며, 실험 하에서 광물의 소멸 및 생성 온도 영역을 살펴볼 수 있는 분석법임을 확인하였다.

• Advances in environmental research
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• 제1권1호
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• pp.83-96
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• 2012

The water sludge is generated from the treatment of water with alum. Disposing of sludge again to the streams raises the concentrations of aluminum oxides in water, which has been linked to Alzheimer's disease. The use of water treatment plant (WTP) sludge in manufacturing of constructional elements achieves both the economical and environmental benefits. Due to the similar mineralogical composition of clay and WTP sludge, this study investigated the complete substitution of brick clay by sludge incorporated with some of the agricultural and industrial wastes, such as rice husk ash (RHA) and silica fume (SF). Three different series of sludge to SF to RHA proportions by weight were tried, which were (25: 50: 25%), (50: 25: 25%), and (25: 25: 50%), respectively. Each brick series was fired at 900, 1000, 1100, and $1200^{\circ}C$. The physical and mechanical properties of the produced bricks were then determined and evaluated according to Egyptian Standard Specifications (E.S.S.) and compared to control clay-brick. From the obtained results, it was concluded that by operating at the temperature commonly practiced in the brick kiln, a mixture consists of 50% of sludge, 25% of SF, and 25% of RHA was the optimum materials proportions to produce brick from water sludge incorporated with SF and RHA. The produced bricks properties were obviously superior to the 100% clay control-brick and to those available in the Egyptian market.

• KIEAE Journal
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• 제2권2호
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• pp.45-50
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• 2002

In the last century, mainly our cultures destroyed a lot of ourselves as well as of our natural environment by deterioration, pollution and exploitation. Building activities are for a third responsible for these disasters and they are fully the reason for the growing Sick Building Syndrome. In result, Materials of the building should be derived as much as possible from nature, and walls should be made of yellow soil, or of bricks made from yellow soil The adobe can easily have larger or smaller dimensions, and different thickness as weil, according to the purpose for which they are meant, and the structural load-bearing function they have to fulfill. In spite of the importance of clay, research or experiment of clay has been quite weak. However, in stead of endowing the clay with the value as natural architectural material, we want to evaluate it as an important element of the environment.

• 보존과학회지
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• 제30권4호
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• pp.395-407
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• 2014

이 연구에서는 벽돌 재료인 토양이 온도별로 소성되면서 겪는 광물학적 변화와 이에 수반된 물리적 변화를 토대로 송산리 고분군 출토 벽돌의 소성온도를 해석하였다. 토양시료를 $500{\sim}1,200^{\circ}C$로 소성하였을 때, 구성광물의 상전이에 의해 광물조성과 미세조직이 변했고 이에 따라 색, 흡수율, 기공률 등의 물리적 특성도 달라졌다. 광물조성은 상안정범위에 따른 광물의 구조붕괴와 재결정으로 인해 온도별로 달라졌지만 색, 흡수율, 미세조직은 $1,000^{\circ}C$ 이하에서 변화 폭이 적었고 $1,000{\sim}1,200^{\circ}C$에서는 급격한 변화가 나타났다. 이를 토대로 송산리 고분군 벽돌시료의 소성온도를 해석한 결과, 송산리 고분군 벽돌은 $1,200^{\circ}C$ 이상의 과소성품, $1,100{\sim}1,200^{\circ}C$의 고온소성품, $900{\sim}1,000^{\circ}C$의 소성품과 소성되지 않은 것으로 판단되는 벽돌이 공존하는 것으로 확인되었다. 향후 이러한 광물학적 및 물리적 변화과정을 토대로 보다 정밀한 소성온도 해석이 가능할 것으로 사료된다.