• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2008.04a
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• pp.277-280
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• 2008

• Journal of the Korean Ceramic Society
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• v.51 no.2
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• pp.107-114
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• 2014

In the present work, we report a novel microstructure of scalenohedral calcite synthesized without any additives by a simple and ecofriendly carbonation process carried out in a liquid-gas system as well as the effects of experimental conditions on the crystal growth of the scalenohedral calcite phase. Various process parameters, pH, temperature, $Ca(OH)_2$ concentration, $CO_2$ flow rates, and the total volume concentration, were investigated to enhance the sensitivity of the process. The highest average length of the scalenohedral calcite was obtained at pH 6.0, temperature of $45^{\circ}C$, $Ca(OH)_2$ concentration of 0.2M, $CO_2$ flow rate of 80mL/min, and total volume of 1L. The synthesized calcite was characterized by XRD, SEM, and FTIR to identify the phases and surface morphology.

• Resources Recycling
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• v.29 no.4
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• pp.58-66
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• 2020

Carbonation (step I) and cryo-crystallization (crystallization at low temperature) (step II) were performed to synthesize Na compounds from sodium concentrated solution. In the step 1, the solubility and pH of carbon dioxide (95 wt.%) affecting carbonation could be changed by the variation of reaction temperature. The step II was performed at 2 ℃ after carbonation. The injection of carbon dioxide was carried out twice for the stable production and the saturated solubility of carbonate ions in solution. Firstly, we tried to inject CO₂ for controlling the solubility of CO₂ by changing the reaction temperature from 35 ℃ to 10 ℃, and the second injection was aimed at 10 ℃ for inducing nucleation of Na compound through carbonation after NaCl solution addition. In the cryo-crystallization step, the crystal growth of Na compounds could be induced by slowing the carbonation rate through reaction temperature change from 10 ℃ to 2 ℃. In this study, the effect on NaOH concentration was examined and the purity of Na compound was increased when 2M NaOH was used. In addition, the synthesized Na compounds were mostly rod-shaped and consisted of sodium carbonate or sodium carbonate with monohydrate.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.1
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• pp.74-81
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• 2005

The heat treatment of serpentines for mineral carbonation was studied systematically. Crystallographic, spectroscopic and thermochemical properties were investigated for serpentines before and after heat treatment. Drastic weight loss due to the removal of hydroxy groupe(-OH) occupied in serpentine crystalline was revealed after heat treatment. In XPS results, MgO was founded at heat treated serpentine powders while Mg(OH) was observed at untreated serpentine powders. Metallic oxides originated from serpentine ingredients were regenerated by heat treatment.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.205-206
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• 2023

In this study, the characteristics of cement were analyzed using carbon dioxide microbubble water as a mixed water for mineral carbonation of cement materials. Carbon dioxide reacts with the calcium compound of cement to produce calcium carbonate and affects the initial strength improvement. Therefore, in this study, temperature, air content, thermal analysis, and compressive strength tests were conducted to confirm the reaction between cement materials and carbon dioxide. As a result of the measurement, the reaction between cement and carbon dioxide was confirmed in a specimen using carbon dioxide microbubble water as a mixed water, which affected the initial strength improvement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.13-14
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• 2017

In this paper, research for use possibility as silica source of waste concrete powder discharged from direct and indirect carbonation has progressed. For the research, properties on the extruding panel using waste concrete powder with high silica content is evaluated. As the results, compressive strength of specimen is increased 24% compared to control specimen when waste concrete powder replaced 50%, that is discharged from carbonation process, as silica source.

• Economic and Environmental Geology
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• v.50 no.1
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• pp.27-34
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• 2017

Mineral carbonation for the storage of carbon dioxide is a CCS option that provides an alternative for the more widely advocated method of geological storage in underground formation. Carbonation of magnesium- or calcium-based minerals, especially the carbonation of waste materials and industrial by-products is expanding, even though total amounts of the industrial waste are too small to substantially reduce the $CO_2$ emissions. The mineral carbonation was performed with steelmaking reduction slag as starting material. The steelmaking reduction slag dissolution experiments were conducted in the $H_2SO_4$ and $NH_4NO_3$ solution with concentration range of 0.3 to 1 M at $100^{\circ}C$ and $150^{\circ}C$. The hydrothermal treatment was performed to the starting material via a modified direct aqueous carbonation process at the same leaching temperature. The initial pH of the solution was adjusted to 12 and $CO_2$ partial pressure was 1MPa for the carbonation. The carbonation rate after extracting $Ca^^{2+}$ under $NH_4NO_3$ was higher than that under $H_2SO_4$ and the carbonation rates in 1M $NH_4NO_3$ solution at $150^{\circ}C$ was dramatically enhanced about 93%. In this condition well-faceted rhombohedral calcite, and rod or flower-shaped aragonite were appeared together in products. As the concentration of $H_2SO_4$ increased, the formation of gypsum was predominant and the carbonation rate decreased sharply. Therefore it is considered that the selection of the leaching solution which does not affect the starting material is important in the carbonation reaction.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.18-24
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• 2016

Mineral carbonation is a technology for permanently storing carbon dioxide by reacting with metal oxides containing calcium and magnesium. In this study, we used sea water and alkaline industrial by-product such as paper sludge ash (PSA) for the storage of carbon dioxide through direct carbonation. We found the optimum conditions of both sea water content (mixing ratio of sea water and PSA) and reaction time required in the direct carbonation through various experiments using sea water and PSA. In addition, we compared the amounts of carbon dioxide storage with the cases when sea water and ultra-pure water were separately used as solvents in the direct carbonation with PSA. The amount of carbon dioxide storage was calculated by using both solid weight increase through the carbonation reaction and the contents of carbonate salts from thermal gravimetric analysis. PSA particle used in this study contained 67.2% of calcium. The optimum sea water content and reaction time in the carbonation reaction using sea water and PSA were 5 mL/g and 2 hours, respectively, under the conditions of 0.05 L/min flow rate of carbon dioxide injected at $25^{\circ}C$ and 1 atm. The amounts of carbon dioxide stored when sea water and ultra-pure water were separately used as solvents in the direct carbonation with PSA were 113 and $101kg\;CO_2/(ton\;PSA)$, respectively. The solid obtained through the carbonation reaction using sea water and PSA was composed of mainly calcium carbonate in the form of calcite and a small amount of magnesium carbonate. The solid obtained by using ultra-pure water, also, was found to be carbonate salt in the form of calcite.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.137-150
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• 2011

$CO_{2}$ mineral carbonation technology, fixation technology of $CO_{2}$ as carbonates, is considered to be an alternative to the $CO_{2}$ geological storage technology, which can perform small- or medium-scale $CO_{2}$ storage. We provide the current R&D status of the mineral carbonation with special emphasis on the technical and economical feasibility of $CO_{2}$ mineral carbonation taken into consideration of the domestic geological and industrial environment. Given that the domestic industry produces relatively large amount of the industrial by-products, it is expected that the technology play a pivotal role on the $CO_{2}$ reduction countermeasure, reaching the potential storage capacity to 12Mt-$CO_{2}$/yr. The economics of the overall process should be improved via the development of advanced technologies on the pretreatment of raw materials, method/solvents for metal extraction, enhanced kinetics of carbonation reactions, heat integration, and the production of highly value-added carbonates.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.5
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• pp.447-454
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• 2009

Electrolyzed reduced water was known as an alkaline solvent than piped water, natural water and mineral water etc. By means of reduction property, electrolyzed reduced water could dissolve a solute than other kinds of water without chemicals. In this study, serpentine dissolution in electrolyzed reduced water was investigated as a novel pre-treatment of serpentine which was a minerals for carbon dioxide sequestration. The elements (Ca, Si, Mg etc.) of serpentine were dissolved rapidly at early in the dissolvation then after some minutes the solubilities of serpentine elements showed stable state without abrupt changes. In spite of serpentine elements dissolution, chemical bondings and crystallographic structure of serpentine were not changed. It was explained that the dissolution mechanism of serpentine occurred from surface in electrolyzed reduced water and bulk structure sustained without collapse.