• Title/Summary/Keyword: 유리고화체

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Supergene Alteration of Basaltic Ash in Udo Tuff Cone, Jeju Island (제주도 우도 현무암질 화산재의 표성 변질작용)

  • Jeong, Gi-Young
    • Journal of the Mineralogical Society of Korea
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    • v.23 no.2
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    • pp.141-150
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    • 2010

  • Basaltic ash of Udo tuff cone, Jeju Island, was almost fresh across strata, but significantly altered toward surface by supergene process. The supergene alteration of the Udo tuff was examined by using X-ray diffraction, scanning and transmission electron microscopy, and electron microprobe analysis for elucidating the alteration process of basaltic ash in terrestrial environments. Fresh ash particles were composed of glass matrix, plagioclase, olivine, and pyroxene. The glass matrix was selectively replaced inward by colloform alteration rinds of Fe-Ti-rich amorphous silicate nanogranules and smectite, often leaving glass core at the center of larger ash particles. Some of the dissolved species released from the altered ash particle precipitated as fine honycomb aggregates of smectite on the pore walls, contributing to the cementation and lithification of volcanic ash.

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Study on Pre-treatment Method for Vitrification of Concentrated Wastes (농축폐기물 유리화를 위한 전처리 방안 연구)

  • Cho, Hyun-Je;Kim, Deuk-Man;Park, Jong-Kil
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.8 no.3
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    • pp.221-227
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    • 2010

  • The solidification methods for powder wastes dried at CWDS(Concentrate Waste Drying System) in PWR have been studied in a variety of ways both at home and abroad. The solidification for these wastes has been performed using stabilization agents such as cement, paraffin and polymer. The applicability studies to maximize the reduction ratio of wastes and operational effectiveness for wastes treatment have been carried out, recently. It is necessary to pretreat the powder wastes before feeding wastes to vitrification facility because the fines flying brings about clogging of feeding pipes and off-gas treatment system or workers' exposure to radiation during maintenance. This paper describes an effective method for treatment of powder wastes to improve safety and stability of vitrification facilities.

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Dechlorination/Solidification of LiCl Waste by Using a Synthetic Inorganic Composite with Different Compositions (합성무기복합체 조성변화에 따른 모의 LiCl 염폐기물의 탈염소화/고형화)

  • Kim, Na-Young;Cho, In Hak;Park, Hwan-Seo;Ahn, Do-Hee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.14 no.3
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    • pp.211-221
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    • 2016

  • Waste salt generated from a pyro-processing for the recovery of uranium and transuranic elements has high volatility at vitrification temperature and low compatibility in conventional waste glasses. For this reason, KAERI (Korea Atomic Energy Research Institute) suggested a new method to de-chlorinate waste salt by using an inorganic composite named SAP ($SiO_2-Al_2O_3-P_2O_5$). In this study, the de-chlorination behavior of waste salt and the microstructure of consolidated form were examined by adding $B_2O_3$ and $Fe_2O_3$ to the original SAP composition. De-chlorination behavior of metal chloride waste was slightly changed with given compositions, compared with that of original SAP. In the consolidated forms, the phase separation between Si-rich phase and P-rich phase decreases with the amount of $Al_2O_3$ or $B_2O_3$ as a connecting agent between Si and P-rich phase. The results of PCT (Product Consistency Test) indicated that the leach-resistance of consolidated forms out of reference composition was lowered, even though the leach-resistance was higher than that of EA (Environmental Assessment) glass. From these results, it could be inferred that the change in the content of Al or B in U-SAP affected the microstructure and leach-resistance of consolidated form. Further studies related with correlation between composition and characteristics of wasteform are required for a better understanding.

  • https://doi.org/10.7733/jnfcwt.2016.14.3.211 인용 PDF KSCI