• Title/Summary/Keyword: 소듐 실리케이트

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Effect of Heat Treatment and Acid Leaching of Siliceous Mudstone on the Purity of Silica Precursors (실리카 전구물질 순도에 미치는 규질이암의 열처리 및 산 침출 조건의 영향)

  • Cho, Kuk;Chang, Han-Kwon;Kil, Dae-Sup;Suh, Yong-Jae;Park, Jin-Ho;Jang, Hee-Dong
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.4
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    • pp.247-253
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    • 2007
  • The effect of heat treatment and acid leaching of siliceous mudstone on the purity of silica precursors, such as sodium silicate and silicic acid, was studied. As well as the temperatures for the heat treatment of siliceous mudstone, the concentrations of hydrochloric acid and sulfuric acid were varied to achieve the highest content of silicon in the precursors while minimizing energy and chemical consumption. It was found that the optimum conditions were achieved at the heat treatment temperature of $600^{\circ}C$ and hydrochloric acid of 1.56 M. The relative concentrations of silicon in the synthesized sodium silicate and silicic acid were as high as 99.2 and 99.5%, respectively.

Evaluation of Service Life of Silicate Impregnated Concrete (실리케이트 함침제를 사용한 콘크리트의 내구수명 평가)

  • Kim, Hyeok-Jung;Jang, Seung-Yup;Yoon, Yong-Sik;Kwon, Seung-Jun
    • Journal of the Korea Institute of Building Construction
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    • v.18 no.6
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    • pp.533-541
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    • 2018
  • Chloride attack, one of the major deterioration phenomena in RC(Reinforced Concrete) structure, causes corrosion of reinforcement, and this leads degradation of serviceability and structural problems. The application of silicate based impregnant to concrete surface are known for excellent constructability and cost-benefit for the maintenance of RC structure. In the work, the compressive strength and resistance of chloride diffusion for concrete were evaluated after improving property of concrete surface through two types of silicate based impregnant. Furthermore, based on the previous research and the result from the work, service life analysis was performed. After impregnating of silicate, strength and resistance of chloride diffusion were remarkably improved, and the service life increase to 159% for silicate A impregnation and 304% for silicate B impregnation, respectively.

Recovery Process of Vanadium from the Leaching Solution of Salt-Roasted Vanadate Ore (바나듐광 염배소물 수침출 용액으로부터 바나듐 회수공정 고찰)

  • Yoon, Ho-Sung;Heo, Seo-Jin;Park, Yu-Jin;Kim, Chul-Joo;Chung, Kyeong Woo;Kim, Rina;Jeon, Ho-Seok
    • Resources Recycling
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    • v.31 no.2
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    • pp.40-48
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    • 2022
  • In this study, the effects of solution components were investigated in the recovery of vanadium as ammonium metavanadate from vanadium-ore-salt roasting-water leaching solution. The vanadium-containing solution is strongly alkaline (pH 13), so the pH must be lowered to 9 or less to increase the ammonium metavanadate precipitation efficiency. However, in the process of adjusting the solution pH using sulfuric acid, aluminum ions are co-precipitated, which must be removed first. In this study, aluminum was precipitated in the form of an aluminum-silicate compound using sodium silicate, and the conditions for minimizing vanadium loss in this process were investigated. After aluminum removal, the silicate was precipitated and removed by adjusting the solution pH to 9 or less using sulfuric acid. In this process, the concentration and addition rate of sulfuric acid have a significant influence on the loss of vanadium, and vanadium loss was minimized as much as possible by slowly adding dilute sulfuric acid. Ammonium metavanadate was precipitated using three equivalents of ammonium chloride at room temperature from the aluminum-free, aqueous solution of vanadium following the pH adjustment process. The recovery yield of vanadium in the form of ammonium metavanadate exceeded 81%. After washing the product, vanadium pentoxide with 98.6% purity was obtained following heat treatment at 550 ℃ for 2 hours.

A Study on Characteristics of Concrete Impregnated with the Inorganic Surface Penetration Agents (무기계 표면침투제 용액으로 함침한 콘크리트의 특성 연구)

  • Bae, Ju-Seong;Kim, Hyeok-Jung;Park, Gook-Jun;Han, Jong-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.1
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    • pp.71-77
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    • 2010
  • The concrete structure's durability and integrity is reduced owing to various deterioration phenomena. Therefore, it is important to prevent the deterioration phenomena. This study inquired into the various experimental results of specimens with different dilution concentration and impregnation time by the each solution to present the economic and efficient using method of the inorganic surface penetration agents. As a results, the reasonable dilution concentration and impregnation time of colloidal silica solutions are 15% and 5 minute and for the sodium alumina silicate solutions are 17% and 10 second.

Heat Risk Assessment of Wood Coated with Silicone Compounds (실리콘 화합물로 도포된 목재의 열위험성 평가)

  • Jin, Eui;Chung, Yeong-Jin
    • Fire Science and Engineering
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    • v.33 no.2
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    • pp.9-19
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    • 2019
  • Experiments on the combustion characteristics of untreated wood specimens and those treated with four types of silicone compounds were carried out using a cone calorimeter according to the ISO 5660-1 standard. 3-Aminopropyltrimethoxysilane (APTMS), 3-(2-aminoethylamino) propylmethyldimethoxysilane (AEAPMDMS), and 3-(2-aminoethylamino) propyltrimethoxysilane (AEAPTMS) were used as the silane compounds. The flame retardants were synthesized with sodium silicate and amino silane compounds. The measured time to ignition after combustion at an external heat flux of $50kW/m^2$ was 9 s to 11 s. Time to ignition was marked with a delayed value in the 3 s to 5 s range. The peak heat release rate ($HRR_{peak}$) was reduced by 5 to 20% compared with the uncoated specimen, and AEAPMDMS showed the highest initial fire risk. The total heat release (THR) was decreased by 1 to 22%. Compared to the untreated specimen, the fire performance index (FPI) of the specimens coated with silicone sol compounds increased by 1.5 to 2.2 fold. The fire growth index (FGI) of the AEAPMDMS specimen was increased by 30% and the others were decreased by 93 to 94%. Therefore, the fire risk of wood coated with silicone compounds was improved in terms of the heat risk properties.