• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.10
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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 $1100^{\circ}C$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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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.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.70-71
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• 2019

Interest in indoor air quality is increasing day by day due to various reasons such as industrial development. Because redmud, an industrial subsidiary, contains titanium dioxide, this study evaluated self-consolidation performance with Slump Flow Test, J-Ring Test, and L-Box Test by mixing redmud in a mixture of ultra-high performance concrete, and sought the optimal combination with high flowability. In addition, the UHPC mixing experiment with photocatalyst was conducted, and the photocatalyst was replaced by the weight ratio of cement and the redmud by the weight ratio of fine aggregate and mixed with the concrete mixture.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.585-588
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• 2008

This study investigated fundamental properties of the colored concrete Corresponding to the various temperatures for plasticity and additive volume of the redmud. the results were summarized as following. There was no difference on the air contents and slumpflow at each temperatures for plasticity. The color tone was high in accordance with increase of temperatures for plasticity, but the drying shrinkage length change was shown in the opposite tendency. The slumpflow was gradually declined, but the air content, compressive strength, color ton and drying shrinkage length change were overall increased when the additive volume of the redmud was increased.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.787-791
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• 2012

Characteristics of particle separation in water using labscale acoustic standing wave were studied. Acoustic standing wave is similar to either sound wave or ultrasonic, which makes a constant wave while returning to the origin by reflector. During that time, particulates dispersed in water are collected on the node of wave, where a sound pressure is zero. Acoustic standing wave transducer as of 28.0 kHz and 1.0 MHz were utilized and $6.8{\mu}m$ kaolin and $100.5{\mu}m$ redmud in average diameter were used as experimental materials in water. Once acoustic standing wave are generated in water, water temperature rises by $0.15{\sim}0.20^{\circ}C/min$ due to a sound pressure. Initial concentration of kaolin and redmud were controlled to have same as of 0.1, 0.2, 0.3, 0.4, 0.5 g/L, respectively. Removal efficiency of the turbidity in a reacting chamber after 5 minutes, when acoustic sound wave was formed in most distinct, was measured to have 18.2~56.2% for kaolin and 23.0~53.6% for redmud at 1.0 MHz. Particle separation was not observed at 28.0 kHz.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.05a
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• pp.96-97
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• 2015

In this search, by evaluating the field applicability of soil mixed pavement of Red mud is mixed into the soil mixed pavement field applicability, and tries to present the basic data about the site application of recycling of red mud and low carbon construction material to. As a result, the conventional soil concrete organization standards (SPS-KSCICO-001: 2003) meets the criteria for a bicycle road, making use of red mud, natural color as well as the natural loess is expressed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.104-105
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• 2020

Red mud is a highly alkaline waste by-product of the aluminum industry. Although recycling of red mud is being actively researched, a feasible technological solution has not been found yet. In this study, we propose that neutralization of red mud alkalinity could assist in its use as a construction material. Neutralized red mud ( pH 6-8) was prepared by adding sulfuric acid to liquefied red mud (pH 10-12). After adding liquid and neutralized red mud to the cement paste, the heat of hydration was measured. As a result of the experiment, the calorific value of the cement paste with liquid red mud was lowered and delayed compared to the cement paste with neutralized red mud.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.70-71
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• 2021

An increasing amount of red mud (RM) is being generated globally with the growth in alumi-num production. To avoid the RM becoming a pollutant, methods for effectively recycling RM at a low cost are being investigated. This study proposes a method for recycling RM as a construc-tion material. The cement paste with neutralized liquefied red mud had higher compressive strength than that of plain cement paste and cement paste with liquefied red mud without neutralization at 1 d of aging; this indicates that nitric acid neu-tralization increases the early-age strength.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.139-140
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• 2023

In this study, red mud with low recyclability was manufactured as liquid red mud, neutralized with sulfuric acid and nitric acid, and then added to cement paste to conduct research on physical and chemical properties. As a result, liquid red mud-added cement paste neutralized with sulfuric acid and nitric acid showed higher compressive strength after one day than cement paste with plain and non-neutralized liquid red mud. This indicates that nitric acid and sulfuric acid neutralization can increase initial strength.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.1
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• pp.37-44
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• 2017

Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. The development of alkali-activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. This study is to investigate the optimum water content, compressive strength, water absorption and efflorescence of alkali-activated slag-red mud soil pavement according to binder type. The results showed that the optimum water content, moisture absorption coefficient and efflorescence area of alkali-activated slag-red mud soil pavement increased but the compressive strength of that decreased as the redmud content increased.