• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.61-65
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• 2003

Zinc occurs in the nature as sulfide, carbonate, silicate, and oxide. In natural water, zinc is generally in the form of the divalent cation $Zn^{2+}$ as well as in the form of fairly weakly bound complexes. Human activities introduce zinc ion to the hydrosphere in many ways. The zinc complexes in the aqueous environment are accumulated not only in aquatic organisms but also in human body ultimately through physico-chemical and/or biological processes. (omitted)

• Magazine of the Korea Concrete Institute
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• v.2 no.4
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• pp.61-68
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• 1990

This experimental study is aimed to investigate the coating method of scoria lightweight aggregate for reo duction of water absorption and the physical dynamic characteristics of coated-scoria jightweight aggregate con¬crete. The coating methods are as follows: I) Non-coating method. II) Coating method of only cement paste. rn) Coating mehtod of surface-coating agent after coating by cement paste. IV) Coating method of only surfaee-coating agent. V) Coating method of cement pasted after coating by surface-coating agent. The summerized conclusion are as fallows ; 1) Specific gravity and the rate of water absorption were lowest when aggregate was covered by only surface-coating agent, especially, rate of absorption was about 10% of non-coating aggregate. 2) Coated-aggregate were about 0.87~0.97t/m3 and lightweight concrete made of coated-aggre¬gates were 1.80~ 1.94 t/m3 in unit weight. 3) Compressive strength of the lightweight concrete made of cement pasted-coating aggregate was about 200~215kg/crrl. 4) The higher the rate of water absorption of coarse aggregate, the higher the rate of deterioration of compressive strength.

• Journal of Environmental Science International
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• v.20 no.10
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• pp.1337-1345
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• 2011

The removal performances of divalent heavy metal ions ($Pb^{2+}$, $Cu^{2+}$, $Cd^{2+}$, $Sr^{2+}$ and $Mn^{2+}$) were studied using the Na-P1 zeolite synthesized from Jeju scoria in the batch and continuous fixed column reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite decreased in the order of $Pb^{2+}$ > $Cu2^{2+}$ > $Cd^{2+}$ > $Sr^{2+}$ > $Mn^{2+}$ based on the selectivity of each ion to ionic exchange site of Na-P1 zeolite for single and mixed solutions in batch or continuous fixed column reactor. For mixed solution, each heavy metal ion uptake was lower than that in single solution, and especially the uptake for $Mn^{2+}$ decreased greatly. In batch reactor, the uptakes of heavy metal ions by synthetic Na-P1 zeolite were described by Freundlich or Langmuir equation, but they followed the former better than the latter. In continuous fixed column reactor, the maximum ion exchange capacity obtained for each of heavy metal ions, was about 90----- of that in batch reactor. The uptakes of heavy metal ions by synthetic Na-P1 zeolite increased with the increase of initial heavy metal concentration and solution pH, and the decrease of the amount and particle size of synthetic zeolite.

• Journal of the Korean Magnetics Society
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• v.18 no.5
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• pp.168-173
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• 2008

Fe compounds of scoria distributed in northern area of Jeju island are investigated using X-ray fluorescence spectroscopy, X-ray diffractometry, and $^{57}Fe$ Mossbauer spectroscopy. The samples were prepared from four parasite volcanos. These samples consist of the typical basalt comprised of $SiO_2,\;Al_2O_3$, Fe compounds, and silicate minerals. The $M{\ddot{o}}ssbauer$ spectra showed doublets for olivine, pyroxene, and ilmenite as well as sextets for hematite and magnetite. The valence state of Fe is chiefly a 3+ charge state with a little 2+ charge state. It is expected that this results will add to the body of information related to the information mechanism of Jeju island. The geochemistry for these samples is the same results to mid-mountain's samples in Jeju Island.

• Journal of Environmental Science International
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• v.29 no.7
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• pp.739-748
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• 2020

The characteristics of heavy metal ion (Ni²⁺, Zn²⁺, and Cr³⁺) adsorption by zeolite synthesized from Jeju scoria using the fusion and hydrothermal method, were studied. The synthetic zeolite was identified as a Na-A zeolite by X-ray diffraction analysis and scanning electron microscopy images. The equilibrium of heavy metal ion adsorption by synthetic zeolite was reached within 60 min for Ni²⁺ and Zn²⁺, and 90 min for Cr³⁺. The uptake of heavy metal ions increased with increasing pH in the range of pH 3-6 and the uptake decreased in the order of Cr³⁺ > Zn²⁺ > Ni²⁺. For initial heavy metal concentrations of 20-250 mg/L at nonadjusted pH, the adsoption of heavy metal ions was well described by the pseudo second-order kinetic model and was well fitted by the Langmuir isotherm model. The maximum uptake of heavy metal ions obtained from the Langmuir model, decreased in the order of Zn²⁺ > Ni²⁺ > Cr³⁺, differing from the effect of pH on the uptake, which was mainly based on the different pH of the solutions.

• The Korean Journal of Quaternary Research
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• v.15 no.1
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• pp.37-45
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• 2001

Morphometric parameters such as cone height, cone height/width ratio($H_{co}$/$W_{co}$), cone height/difference between cone width and crater width ratio($H_{co}$/$W_{co-cr}$) and slope angle are measured to investigate the rates of slope development of scoria cones in Cheju Island. The parameters systematically decrease with increasing age of scoria cones, suggesting that comparative morphology of scoria cones is a useful age indicator. Cone age is most highly correlated with $H_{co}$/($W_{co-cr}$ or average slope angle because summit craters are infilled and eventually removed by erosional processes. The average slope angle is estimated as $\theta_{ave}$= $tan^{-1}$/〔2.$H_{co}$/$W_{co-cr}$〕. Cheju Island was formed through four eruptive stages during Pleistocene. The youngest cones of stage 4(0.1~0.025Ma) have a mean average slope angle of 23.6$\pm$1.7$^{\circ}$, whereas stage 3(0.3~0.1Ma) and stage 2(0.6~0.3Ma) cones have mean values of 18.9$\pm$$1.7^{\circ}C$and 12.6$\pm$$1.9^{\circ}C$, respectively.

• Journal of the Korean Magnetics Society
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• v.26 no.6
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• pp.213-218
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• 2016

This study reviewed mineral composition on Scoria samples of this area, atomic value state of oxidized steel, and magnetic property in order to look into characteristics of scoria that was distributed in southern area of mountainous areas, Halla Mt. of Jeju Island. By XRD analysis, mineral composition was confirmed, and characteristics of iron compounds existed in samples were investigated through $M{\ddot{o}}ssbauer$ spectroscope. Composing minerals could be learnt as feldspar basalt from XRD analysis because composting minerals were composed of quartz and feldspar anorite mainly, and iron compounds were made up with olivine, pyroxene, ilmenite, hematite, and magnetite. By $M{\ddot{o}}ssbauer$ spectroscope analysis on these iron compounds. it consisted of hematite and magnetite which showed hyperfine magnetic field of sextet mostly, and also doublet by olivine, pyroxene, ilmenite could be seen as appearing together. As a result of comparing with samples of Jeju western area having been announced in previous research, I.S. and Q.S. values of olivine, $Fe^{2+}$, were 122 mm/s and 3.09~3.13 mm/s respectively, and a fact could be known that $Fe^{2+}$ olivine having similar structure each other was contained, and the ratio of $Fe^{3+}/Fe_{tot.}$. was 85.90~92.82 %. From these findings, it was able to be presumed that they belonged to samples having been formed on the land at the same period of time. As a result of investigating area ratio of tetrahedron (A site) and octahedron (B site) regarding magnetite in samples, it was turn out to be 0.22~0.55 less than 2.

• The Journal of the Petrological Society of Korea
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• v.18 no.3
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• pp.237-253
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• 2009

The lava flows forming the Manjanggul lava tube are commonly said to have a potential source from the Geomunoreum scoria cone. We inferred the source of lava flows with the Manjanggul lava tube, based on many studies about lava tubes within lava flows of active volcano in the world. We made a lava flow field map from lithofacies, features and latitude of lava surfaces in the northeastern part of Jeju Island, and then examined closely the distribution and mutual relation of lava tubes in each lava flow field. As result, the Geomunoreum lava tube system is divided into a series of master tubes(Utsanjeungul, Bukoreumgul, Daerimdonggul, Manjanggul, Gimnyeonggul, Yongcheondonggul and Dangcheomuldonggul lava tube), a complicated networks of small tubes(Bengdwigul lava tube), and a series of unitary tubes(Gimyeongbilemotgul~Gaeusaemgul lava tube) in Geomunoreum lava flows. Particularly a canyon, 2km in length to NNE direction from the Geomunoreum scoria cone, is interpreted to be collapse trench of lava tube roof that belongs to an upflow part of the master tube in the Geomunoreum lava tube system, according to the location and direction. Accordingly, the source of lava flows, forming the Manjanggul lava tube, is the Geomunoreum scoria cone.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.715-727
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• 2020

Volcanostratigraphy in Ulleung Island is divided into 4 stratigraphic groups: Dodong Basaltic Rocks, Ulleung Group, Seonginbong Group and NariGroup. The main pyroclastics in them includes lapilli tuff intercalated within the Dodong Basaltic Rocks, lapilli tuff at the top of Sadong Breccia, Sataegam Tuff, Gombawi Welded Tuff, Bongrae Scoria Deposits, Maljandeung Tuff, Nari Scoria Deposits and Jugam Scoria Deposits. Analysing eruption types, The lapilli tuff in the Dodong Basaltic Rocks is derived from Surtseyan eruption, and the Bongrae, Nari and Jugam Scoria Deposits are caused by Strombolian eruptions or/and sub-Plinion eruptions, but the Sataegam Tuff and Maljandeung Tuff are derived from Plinian and phreatoplinian eruptions. Among them the large-scaled eruptions. In particular, the eruptions of Maljandeung were large enough to result in caldera collapse, and had falled out tephras to the eastern Korean peninsula but even Japan Islands. The magma with high potential to be still alive is judged to be trachyandesitic and phonolitic in composition. If the trachyandesitic magma explodes, it will probably result in a strombolian eruption and have a fairly low explosivity, but if the phonolitic magma explodes, it will probably result in a plinian eruption and have a much higher explosivity. If the eruption had a high explosivity, there is a possibility that it could easily be converted into a phreatoplinian eruption due to the influx of groundwater by the easy generation of fractures. These large-scaled eruptions could fall out tephras to the eastern Korean peninsula but even Japan Islands.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.38-40
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• 2003

$TiO_2$로 코팅된 scoria를 이용하여 공존물질 존재시 humic acid의 광분해 연구 결과 광촉매량의 증가에 따라 제거효율이 증가하였고, 양이온을 첨가하였을 때 제거효율이 증가하였다. 탄산염이온을 첨가하였을때는 상당한 차이를 보였으며 180분 후에도 30%정도의 제거 효율을 나타냈다.