간행물

광물과 암석 KCI 등재 Korean Journal of Mineralogy and Petrology 韓國鑛物學會誌

권호리스트/논문검색
이 간행물 논문 검색

권호

제12권 제1호 (1999년 6월) 5

1.
1999.06 서비스 종료(열람 제한)
Thermal behavior of dickite was studied by thermal analysis, X-ray diffraction analysis, electron microprobe analysis, and scanning electron microscopy, Dickite has an endothermic peak at about 650℃ and an exothermic one at 960℃ in the differential thermal analysis. The endothermic reaction is assigned to the decomposition of dickite to meta-dickite. Hydroxyl radicals are removed from dickite structure by the reaction, resulting in the weight loss about 10.5~14.5% and appearance of a 14a phase different from other kaolin minerals. The reaction slowly proceed in the range of 200℃. As the completion of decomposition, aciclular mullite forms at the expense of meta-dickite plates with random crystallographic relationship. Mullites have diverse silica versus alumina ratio. The exothermic reaction without weight loss seems to be due to the formation of spinel and amorphous silica. The spinel phase shows cryptocrystalline globular morphology accompanying a little amount of silica. From spinel phase shows cryptocrystalling globular morphology accompanying a little amount of silica. From this work, it is suggested that mullite is formed from meta-dickite much lower temperature than the reported one in the previous works.
2.
1999.06 서비스 종료(열람 제한)
The dehydroxylation of kaolinite was investigated in detail by means of energy-filtering transmission electron microscope with both orientations parallel and perpendicular to c. The dehydroxylation could be characterized by the broad background including (0.211) band (20~24˚ 2θ) on X-ray diffraction and by the three halo rings (d-spacing : 3.28~4.40a (near (02,11) band), 2.41~245a (near (20,13) band), 1.16~1.23a (near (0.8,44) band)), and (02,11) and (20,13) spots on electron diffraction. These indicate existence of a short-range order along the a and b axes. Interplanar spacing of (001) is reduced to about 6.86a and the sharp additional intensity maximum of about 14.2a reveals that metakaolinite has a modulated structure along c axis. It is proposed that the modulated structure is attributed to the domains consisting of more than two-layers due to the changes of positions of the vacant octahedral sites in successive layers.
3.
1999.06 서비스 종료(열람 제한)
Microbial mats, the yellow and reddish brown deposits formed from the mine drainage, occur on the bottom of drain and mine tailing pond of the Ilkwang mine in Pusan, Korea. The constituents of microbial mats and their biomineralization were studied by using XRD, IR, and SEM-EDX. The upper part of the microbial mat is yellow-colored and composed of tube-shaped and small spheroid bacterial materials, which are mainly made up of amorphous and poor-crystalline iron-oxide minerals. The shape and composition of bacterial materials suggest that they are probably belong to iron-oxide mineral aggregates. The iron-oxide minerals of the yellow microbial mats are mainly goethite, but those of the reddish brown microbial mats contain abundant hematite along with goethite. This implies that with the evolution of biomats, goethite may be transformed to hematite.
4.
1999.06 서비스 종료(열람 제한)
The medical mineral menas a single mineral or a complex of minerals. It is natural material. using the medical action of he major or the minor elements, and traditional medicine stuff which has been used since long time ago. Jusa, cinnabar as the mineral name, is the product of the hydrothermal process. It is used to relax the body and cure high blood pressure, apoplexy and cardiopathy. Jusais the major component of "An shin hwan" and "Woo hwang chung shim hwan" nowadays because it has such an excellent calm effect. In addition, it is used to cure cancers such as esophageal cancer and gastric cancer. Jusa composed of mercuric sulfide causes mercury poisoning such as Minamata disease. It is dealt with mineralogical property and chemical composition medical stuff in Korea and China, as well asmercury poisoning and medical action of Jusa in this study. In order to predct accumulation of the interior of the body of the major and minor elements in Jusa, leaching experiment of Jusa by artificial gastric juice was done as well as thermodynamic reaction modelling to know concentration of each species of body fluid. The minor elements of 24 species such as As, Pb, Cd, a and Fe by leaching reaction of Jusa and artificial gastric juice were leached. We can know the fact that as is less than 1 ppm, Hg is less than 25 ppm and Cd and m are not detected. In addition, mercury exists as species of Hg2+, HgCl+, HgCl2, HgCl3-, HgCl42-, HgClOH, HgS(H2S)2, Hg(HS)3-, HgS22-, HgOH and Hg(OH)2 by reaction modelling between Jusa and artificial gastric juice. The concentration of sulfide complexes is 24.2 ppm and that of others is less than 10 ppm. According to increasing pH, the concentration of HgS(H2S)2, Hg(HS)3+, HgS22- and Hg(OH)2 increases, whereas the concentration of HgCl+, HgCl2, HgCl3- and HgCl42- decreases. Therefore, Jusa is very useful for the development of new medicine because it is possible to predict formation of the body species and species accumulation on mercury known as a toxic element and concentration changes of toxicity and efficiency.city and efficiency.