• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.134-135
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• 2018

In this paper, we investigate the characteristic of ASRC concrete with the addition of liquefaction red mud using red ud which can be used as an alkali activator of alkali-activated slag cement. as a result, the compressive strength and the efflorescence area increased, and as the amount of liquid red mud increased, the compressive strength decreased and the efflorescence area increased.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.3
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• pp.419-428
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• 2011

Recycling as a stabilizer of industrial by-product can be terms of the proper handling of industrial by-product and positive side in terms of recycling of waste. This study was performed to evaluate has the possibility as stabilizer by primary processing Pre-Red Mud and Bio-Solids which are generated as waste in soils contaminated with heavy metals and compared the efficiency with steel slug being applied in an existing site. In evaluation of the arsenic-fixing ability of stabilizer in batch test, Bio-Solids have the similar arsenic-fixing ability with Pre-Red Mud, which shows 17% h igher arsenic-fixing ability than PS Ball. Since the stabilization periods using Bio-Solids and Pre-Red Mud are faster than the PS Ball, they seems to be better stabilizer than PS Ball to decrease the leaching of arsenic in contaiminated soil.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.248-249
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• 2017

Red mud is an industrial by-product produced during the manufacturing aluminum hydroxide (Al(OH)₃) and aluminum oxide(Al₂O₃) from Bauxite ores. In Korea, approximately 2tons of red mud in a sludge form with 40~60% moisture content is produced when 1 ton of Al₂O₃ is produced through the Bayer process. An annual production of approximately 20tons are produced by company K, which is responsible for most of the domestic production. Therefore, in order to utilize Red Mud in the construction industry, this study evaluated the pore characteristics of ordinary portland cement mortar according to the red mud replacement ratio.

• 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.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.2
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• pp.26-33
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• 2016

The alkali-slag-red mud(ASRC) cement belongs to clinker free cementitious material, which is made from alkali activator, blast-furnace slag(BFS) and red mud in designed proportion. This study is to investigate strength and pore characteristics of alkali-activated slag cement(NC), clinker free cementitious material, and ordinary portland cement(C) mortars using polymer according to red mud content. The results showed that the hardened alkali-activated slag-red mud cement paste was mostly consisted of C-S-H gel, being very fine in size and extremely irregular in its shape. So the hardened ASRC cement paste has lower total porosity, less portion of larger pore and more portion of smaller pore, as compared with those of hardened portland cement paste, and has higher strength within containing 10 wt.(%) of alkali-activated slag cement(NC) substituted by red mud.

• Journal of the Korean GEO-environmental Society
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• v.23 no.4
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• pp.21-27
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• 2022

Recently, numerous studies are being performed to examine alkali-activated cement which uses industrial by-products, such as GGBS and fly ash, as well as alkali activators. Alkali-activated cement is a type of binder that exerts the same strength as cement without using cement by mixing industrial by-products with alkali activators. Alkali activators, which are used mainly for carbon-reducing technologies and alkali activation, are expensive and difficult to apply in the field due to risks related to strong alkalinity. Therefore, this study intends to explore methods to use red mud as a substitute for an alkali activator. To that end, this study has evaluated engineering properties, such as flow and strength, of CLSM that uses red mud and paper sludge ash as binders and its possibility to cause soil pollution. This study also aims to present the appropriate mixing ratios of red mud and paper sludge ash to produce CLSM.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.276-283
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• 2016

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, moisture absorption coefficient and efflorescence of alkali-activated slag-red mud soil pavement according to the recycling fine aggregate content. 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 recycled fine aggregate content increased.

• Environmental Engineering Research
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• v.7 no.1
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• pp.33-37
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• 2002

The two kinds of pellet-type red-mud adsorbents (bead-type, crushed-type) were from red mud, which is generated as a by-product during the production of aluminum hydroxide from bauxite ore. The adsorption experiments of Pb^{2+} ion in the aqueous solution by these red-mud adsorbents were studied with a continuous adsorption ccolumn. As a result, the crushed-type adsorbent shows better performance in adsorption of Pb^{2+} than the bead-type adsorbent between the two types of the pellet-type adsorbents. The continusous adsorption experiment shows that the pellet-type adsorbents made from red mud have good performance for removal of Pd^{2+}. The breakthrough curves of the red-mud adsorbents were compared with that of activated carbon.

• Journal of Environmental Science International
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• v.21 no.9
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• pp.1059-1068
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• 2012

The purpose of this study was to develope the environmentally favorable method of roller compacted soil concrete pavement using industrial waste red mud. Red mud was the major solid waste produced in the process of alumina extraction from bauxite(Bayer process). For recycling purpose, red mud was treated and applied to use as concrete admixtures. To this end, laboratory test such as compressive strength of soil concrete, and field test such as construction characteristics of soil concrete pavement, had been conducted. From the study results, the compressive strength of soil concrete was strongly related to its matrix proportion and compaction energy. The optimum mix proportion was comprised of cement 300 $kg/m^3$, water 110 $kg/m^3$, fine aggregate 600 $kg/m^3$, course aggregate 1400 $kg/m^3$, red mud admixture 50 $kg/m^3$ and compaction energy above 2.86 $cm-kgf/m^3$. The $7^{th}$-day and $28^{th}$-day mean compressive strength of soil concrete were 43.8 MPa and 53.3 MPa each under the optimum condition. Pavement application of soil concrete using red mud admixture indicated that the proposed method was simple in case of construction and showed a good surface texture.

• Journal of Soil and Groundwater Environment
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• v.27 no.1
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• pp.31-38
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• 2022

The common algae and industrial waste, chlorella and red mud, were co-pyrolyzed in carbon dioxide condition to fabricate iron-biochar composite. In order to investigate the direct effect of chlorella and red mud in the syngas generation and the property of biochar, experiments were performed using mixture samples of chlorella and red mud. The evolution of flammable gasses (H₂, CH₄, CO) was monitored during pyrolysis. The produced biochar composite was employed as a catalyst for persulfate activation for methylene blue removal. BET analysis indicated that the iron-biochar composite mainly possessed meso- and macropores. The XRD analysis revealed that hematite (Fe₂O₃) contained in red mud was transformed to Fe₃O₄ during co-pyrolysis. The composite effectively activated persulfate and removed methylene blue. Among the composite samples, the composite fabricated from the mixture composed of 1:2 chlorella:red mud showed the best performance in syngas generation and methylene blue removal.