• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.259-272
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• 2002

This study was tried to interpret the important major factors controlling some physicochemical properties by comparing mineralogical and physicochemical characteristics such as pH, cation exchange capacity, Methylene Blue adsorption amount, swelling, viscosity, strength (compressional and tensile), and surface area etc. Investigated bentonite samples are five Korean samples from Dusan, Naa, Oksan, Dongyang, and Yeonil deposits and two Japanese bentonites from Tsukinuno and Tomioka deposits which were formed under a similar geological environment of the Tertiary basin. Tsukinuno bentonite is only natural Na-type bentonite and the others are all Ca-type bentonites. Most of the properties are not explained by the montmorillonite content only though the most important factor controlling the physicochemical properties is the montmorillonite content. The layer charge of montmorillonite will strongly control cation exchange capacity and Methylene Blue adsorption. Zeolite bearing bentonites show the strong alkaline character and causes the increase of cation exchange capacity, however decrease swelling, viscosity and strengths. Pyrite bearing bentonites decrease green compressional strength and wet tensile strength. The exchangeable interlayer cations control some physicochemical properties. Na-type bentonite than Ca-type shows more strong alkaline character and much more advanced swelling and viscosity. Also the size and thickness of montmorillonite flakes seem to control some physicochemical properties. Bentonite mainly composed of montmorillonite of very thin and large flakes is characterized by the very high surface area, cation exchange capacity, viscosity, swelling, Methylene Blue adsorption, green compressional strength and wet tensile strength. Domestic Dusan bentonite shows the most excellent physicochemical properties, which is due to the high content(84%) and very well crystallinity of montmorillonite.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.1
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• pp.3-15
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• 1997

Iron oxide compounds in 8 selected Cheju Island soil samples have been analized by X-ray fluorescence spectrometer(XRF), X-ray diffractometry(XRD), selected chemical techniques, and $M{\ddot{o}}ssbauer$ spectroscopy. The result of this analysis by XRF shows that the rate of quantity of $Fe_2O_3$ in 8 soil samples was from 8.03wt.%(Daejeong paddy soil) to 18.21wt.%(Songag soils). Songag, Heugag and Gueom soils were detected to have lower peaks of intensity of hematite by XRD. In addition, these soils were not detected to have hematite and goethite peaks. Ferrihydrite, which is a short-range-order mineral commonly present in volcanic ash soil, was not detected by XRD due to low concentration and/or poor cristallinity. Ferrihydrite contents estimated from Feo values were 8.8~35.2g/kg for volcanic ash soils and 0.85g/kg for the Daejeong soil. Most of the soil samples represented by the paramagnetic $Fe^{3+}$ doublet obtained from $M{\ddot{o}}ssbauer$ spectra at room temperature and 18K were considered to arise from the presence of ferrihydrite, superparamagnetic goethite, and silicate minerals. Also the paramagnetic $Fe^{2+}$ doublets are attributable to primary minerals such as olivine, illite, chlorite, augite, biotite, and hornblende. Goethite and hematite were identified as the dominant crystalline iron oxides in these soils from $M{\ddot{o}}ssbauer$ spectra obtained at room temperature and 18K. All the soil samples exhibited strong superparamagnetic relaxation. Collapse of the $M{\ddot{o}}ssbauer$ magnetic hyperfine splitting at room temperature was due to the small size(${\sim}180{\AA}$) of the oxide particles and/or Al-subsituted goethite.

• Journal of the Korean Society of Groundwater Environment
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• v.5 no.1
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• pp.10-20
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• 1998

Heavy metal contamination in subsurface soils and stream sediments at the Suggok mine area were investigated on the basis of major, trace and rare earth elements geochemistry and mineralogy. The Sanggok mine area is mainly composed of Cambro-Ordovician carbonate rocks. The mine had been mined for Pb-Zn-Fe and Au- Ag, but already closed in past. For major elements, especially Fe (mean value=18.58 wt.%) and Mn (mean value=4. 18 wt.%) are enriched in soils, and the average enrichment indices of soils and sediments are 6.84 and 1.54, respectively. The average enrichment index of rare earth elements are 0.92 of mining drainage sediments and 0.52 of subsurface soils on the tailing dam. Concentrations of minor and/or environmental toxic elements in those samples range from 29 to 3400 for As,1 to 11 for Cd, 35 to 292 for Cu, 50 to 1827 for Pb, 1 to 22 for Sb and 112 to 2644 for Zn. Extremely high concentrations (mean values) are found in subsurface soils on the tailing dam (As=2278, Cd=7, Cu=206, Pb=1372, Sb=14 and Zn=2231 ppm, respectively). Average enrichment index normalized by composition of non-mining drainage sediments is 2.42 in mining drainage sediments and 25.47 in subsurface soils on the tailing dam. Based on EPA value, enrichment index of toxic elements is 0.53 in non-mining drainage sediments, 1.84 in mining drainage sediments and 23.71 in subsurface soils on the tailing dam. As a results from X-ray powder diffraction method, mineral composition of soils and sediments near the mine area varied in part, and are calcite, dolomite, magnesite, quartz, mica, chlorite and clay minerals. With the separation of heavy minerals, soils and sediments of highly concentrated toxic elements included some pyrite, arsenopyrite, sphalerite, galena, goethite and hydroxide minerals on the polished sections.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.7
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• pp.469-475
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• 2014

The study investigated the physicochemical characteristics and the ecological risk of the Northport sediment in B city and the releasing properties of heavy metals into seawater during the resuspension also studied. The major components of the sediment are fine silt and clay which contains high organic matter and AVS (Acid volatile sulfide) and the ecological risk of the heavy metals in sediment also very high. The release rate of heavy metals into seawater was in order of Pb>>Cu>Cr>>Zn>Cd during the resuspension in a batch experiment, and the heavy metal release mainly attributed to the oxidation of metal sulfides. Heavy metals which came from easily oxidisable metal sulfides rapidly contaminated seawater within about 1.0 h of the sediment resuspension. The sulfide oxidation during the resuspension increased the residual fraction of heavy metals in the sediment, decreased the organic bound fraction, and changed the other fractions of heavy metals in the sediment. The release of heavy metals from the sediment during resuspension was affected by the resuspension time, the oxidation rate of metal sulfides and resuspended concentration of the sediment particle.

• Resources Recycling
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• v.5 no.4
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• pp.25-31
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• 1996

The wastes ot l~mestone mines have been cause the extrar.ngance of the valuablz m e r a l s and destruction of the environment. Therefore, \\-c tied ta separation of calcite illid clay from the limestone mine wastes by rotntmg screen type separator made by ourselves in order to recyding such us a raw matcriala for cement maimfacture. CaO amtents in the separated coarse products increased from 37.36 wt% to 42+2 wt% at the condition ihat water content in wastes was lzss than 6wt%, the passing time of specimen in &amber was 15 semnds and the rotation speed was 6OLl qm. A process in order lo separate wastes effectively to having wide range aI part~dcs ize was cstablishcd and CaO contents of coarsc products through this process increased to 46.85 wt%. Tbis rcsult is insuEiicient to directly rcusing as a raw malerials for cement. However, it is supposed that coarse products would be able to be reuscd as a raw materials uf cement, if only it rs sclected dolomite in wastes, and really it may be possible in fields Othenvise, undcrsize products(less than 20 mm) would be able to recycling as a raw of cement bccause chcmicrl campasitions of thosc is kept almost constant v&cs on the overall process.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.29-37
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• 1977

The mineralization of soil nitrogen, amino acid composition of acid hydrolizable organic nitrogen of four Korean soils were investigated in comparison with four Japanese (Hokuriku district) soils which is similar in nitrogen content but different in characteristics of clay minerals. The mineralization rate and pattern were quite different between Korean and Japanese soils; Korean soils were low in amount of mineralized nitrogen but porduced much ammonium nitrogen during the later stage of incubation. In Korean soils the ratio of acid hydrolizable nitrogen to total; especially ${\alpha}$-amino nitrogen and hydrolizable ammonium nitrogen were low while hexosamine content was considerablly high (greater than 10%) In all soils the amount of mineralized nitrogen showed significant positive correlation with ammonium nitrogen and ${\alpha}$-amino nitrogen in acid hydrolizate. The amino acid composition of acid hydrolizate of paddy soils showed higher in basic amino acids and lower in acidic amino acids than those of up land soils (humic volcanic ash soil) from both countries. Alanine content was low in Korean soils. Proline showed increasing trend with nitrogen content but aspartic acid decreasing.