• Economic and Environmental Geology
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• v.32 no.6
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• pp.599-609
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• 1999

Talc durg has been used at Oriental Medical Hospital of Kyung San University, and was analysed for mineralogical and geochemical studies. It consists mainly of talc with small amount of tremolite, dolomite and bursite, and its chemical compositions of MgO 31.65% and $SiO_2$ 61.0%, and cotain less inpurtities. Moreover, talc from the Dong Yang Talc mine is associated with calcite, gypsum and anhydrite, which belong to more soluble mineral drugs than talc, and contains Ca and Fe. These elements may give at least medical medical to talc durg as in the case of actinolite. Therfore, talc of high quality from the Dong Yang Tacl Mine may be used instead of imported expensive talc durg. Diagrams of log $a_{Mg^{2+}}$-pH and log $a_{Mg^{2+}}/a{\array{2\\H^+} $-log $a_{H_4SiO_4}$- may be used as basic data to predict and examine soluble contents of durg for medical experiments.

• Resources Recycling
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• v.3 no.3
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• pp.12-20
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• 1994

Difficulties lies on using the dust from iron making process as a raw material for sintering process mainly because of high amount of Zn or alkali content and its ultra fine characteristics. To eliminate these toxic influence, new fluxing materials were tested and could get a very successful results. This fluxing materials, Calcium-ferrite of magnesio-ferrite were made from various waste materials such as lime stone sludge, bag filter dust, waste EP dust and dolomite sludge by simple way of pre-sintering. Sintering behavior as a fluxing materials was revealed to be good in any aspects and new concept of total recycling system could be established.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.349-360
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• 2016

This study determined mineralogical characteristics and discussed the meaning of mineralogical changes of the lower Choseon Supergrouop in the Weondong area based on the field geological investigation and the drilling core description using X-ray diffraction (XRD) mineral quantification and Scanning Electron Microscopy (SEM) observation. 100 samples with depth were collected from the core (250 m long) at a site in the study area. Especially, to investigate the changes from the upper Daegi Formation to the lower Hwajeol Formation, the samples were collected closely with the interval of about 0.3 m at this section. All samples were made into power using mortar for XRD. Mineral quantitative analysis was executed using Relative Intensity Ratio (RIR) method with corundum as an internal standard phase. Calcite, $2M_1$ illite and quartz are main constituents in most of samples. Dolomite and siderite are significantly observed in the Sesong Formation. As the results of quantitative analysis for the major minerals, the upper Daegi Formation is dominated by calcite with over 80%. The Sesong Formation includes high percentage of dolomite and siderite with the intercalation of thin layers containing high calcite and $2M_1$ illite contents. Hwajeol Formation is characterized by the alternation between thin layers of $2M_1$ illite and quartz-dominated layer (IQDL) and calcite-dominated layer (CDL). IQDL is more frequent in the lower part, whereas CDL is more common in the upper part. The boundary between Daegi Formation and the Sesong Formation is distinct, whereas the boundary between the Sesong Formation and the Hwajeol Formation tends to be changed gradually in mineralogy. The result of SEM observation shows that quartz and $2M_1$ illite are detrital, and a significant amount of calcite also shows detrital form with some recrystallized one, indicating that the repeated influx of terrestrial materials had changed the mineralogy of the shallow sea depositional environment in the early Paleozoic era.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.30-39
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• 2020

A new silicate coating technology was developed which reduces the impact of dust and loosening during seeding compared to existing silicate-coatings (Seed/Si/Zeolite), and therefore can lower the production costs of rice cultivation. In this method, 100 g of rice seed is coated with 18 mL of liquid silicic acid and then dressed with a mixture containing 80 g of dolomite and 5 g of iron. To determine the most effective method of application and ensure that seedlings developed healthily, a series of experiments were carried out. Infected seeds scattered in seedling boxes and pots (soil and hydroponic) were coated dry, without disinfection. In comparison to the seed which were not treated with the silicate-coating, the new seed (A) were 1.84 times heavier in weight, and were also improved in terms of coating strength and coating color. Compared to the seedlings grown from the non-coated seed, those grown from the new silicate-coated seed were of significantly higher quality (weight/length) and had erect, dark greenish leaves, which are ideal plant characteristics. This was most likely due to increased silicate uptake. The symptoms of bakanae disease in the non-coated seed peaked after 38 days to 54.2%, whereas the control value was 68.8% in the new silicate-coated seed (A). In the infected seedlings grown from the new silicate-coated rice seed, subnormal macro-conidia, namely, a sickle shape spore without a septum; a straight oblong shape spore without a septum and with a thick cell wall; and inter-septal necrosis of a normal spore were detected. It is believed that the strong alkalinity of silicic acid have acted as unfavorable conditions for pathogenicity. In seedlings grown from the new silicate coated rice seed under hydroponic conditions without nutrients, normal root activity and growth was maintained without leaf senescence. Therefore, it was possible to reduce the rate of fertilization. In the future, a new silicate-coated rice seed was required for the study of minimal nutrition for anti-aging of seedlings.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.21 no.2
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• pp.70-74
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• 2011

[ $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ]ceramics was investigated for the application to SOFC ceramic supporter with high porosity and mechanical strength. $ZrO_2$ powder was prepared by combustion method with glycine using the solution of $ZrO(NO_3)_2{\cdot}2H_2O$ dissolved into deionized water and calcination at $800^{\circ}C$ Porous $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics was prepared by sintering the mixture of prepared $ZrO_2$ powder, dolomite and carbon black at $1200{\sim}1400^{\circ}C$ for 1 h. The open porosity ofthe $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics sintered at $1300^{\circ}C$ was over 30 % and increased linearly with the amount of carbon black. The crystal structure of $(Ca,Mg)_{0.15}Zr_{0.7}O_{1.7}$ ceramics consisted of single cubic phase. The open pore of this ceramics was connected continuously and distributed well on the whole. This ceramics sintered at $1300^{\circ}C$ showed the porosity from 32 to 55 % and mechanical strength from 90 MPa to 30 MPa with increasing the content of added carbon black.

• Journal of the Korea Concrete Institute
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• v.22 no.3
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• pp.287-295
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• 2010

In this study, ordinary Portland cement was used and the air void was minimized by using minute quartz as the filler. In addition, steel fibers were used to mitigate the brittle failure problem associated with high strength concrete. This study is in progress to make an Ultra-high strength powdered concrete (UHSPC) which has compressive strength over 300 MPa. To increase the strength of concrete, we have compared and analyzed the compressive strengths of the concretes with different mix proportions and curing conditions by selecting quartz sand, dolomite, bauxite, ferro silicon which have diameters less than 0.6 mm and can increase the bond strength of the transition zone. Ultra-high strength powdered concrete, which is different from conventional concrete, is highly influenced by the materials in the mix. In the study, the highest compressive strength of the powdered concrete was obtained when it is prepared with ferro silicon, followed in order by Bauxite, Dolomite, and Quartz sand. The amount of ferro silicon, when the highest strength was obtained, was 110%, of the weight of the cement. SEM analysis of the UHSPC showed that significant formation of C-S-H and Tobermorite due to high temperature and pressure curing. Production of Ultrahigh strength powdered concrete which has 28-day compressive strength upto 341MPa has been successfully achieved by the following factors; steel fiber reinforcement, fine particled aggregates, and the filling powder to minimize the void space, and the reactive materials.

• Journal of the Korean earth science society
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• v.23 no.7
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• pp.575-586
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• 2002

Authigenic minerals found in sandstones and mudrocks of the Lower Hayang Group (Cretaceous) in the central part of the Kyungsang Basin are carbonate minerals (calcite, dolomite), clay minerals (illite, chlorite, C/S, I/S and kaolinite), albite, quartz and hematite. Characteristic diagenetic mineral assemblages are as follows: albite-chlorite (including C/S)-hematite in the Chilgog Formation, albite-illite-calcite in the Silla Conglomerate, illite-chlorite-hematite in the Haman Formation and albite-chlorite-dolomite in the Panyawol Formation, respectively. Among clay minerals reflecting the physical and chemical change of the diagenetic process, illite, the dominant clay mineral, occurs in every formation in the study area. Chlorite occurs mainly in green or gray sandstones and mudrocks, or in sandstones and mudrocks of the Chilogok Formation which contains a high content of volcanic materials. Based on the mineral assemblage, diagenetic minerals are strongly related with source rocks. Judging from the illite crystallinity, diagenesis of sandstones and mudrocks in the study area reached the late diagenetic stage or low grade metamorphisim. The diagenetic process was much influenced by intrusion of the Bulguksa granite, content of organic materials, grain size, and depositional environment rather than burial depth.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.56-61
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• 2016

In this study, the effect of natural minerals on the reaction kinetics for lignite-$CO_2$ gasification was investigated. After physical mixing of lignite from Meng Tai area with 5 wt% of each natural mineral catalysts among Dolomite, Silica sand, Olivine and Kaolin, $CO_2$ gasification was performed using TGA at each 800, $850^{\circ}C$ and $900^{\circ}C$. The experimental data was analyzed with volumetric reaction model (VRM), shrinking core model (SCM) and modified volumetric reaction model (MVRM). MVRM was the most suitable among three models. As increasing the reaction temperature, the reaction rate constant became higher. With natural mineral catalysts, the reaction rate constant was higher and activation energy was lower than that of without catalysts. The lowest activation energy, 114.90 kJ/mol was obtained with silica sand. The highest reaction rate constant at $850^{\circ}C$ and $900^{\circ}C$ and lower reaction rate constant at $800^{\circ}C$ were obtained with Kaolin. Conclusively, the better catalytic performance could be observed with Kaolin than that of using other catalysts when the reaction temperature increased.

• Journal of the Mineralogical Society of Korea
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• v.28 no.2
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• pp.83-93
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• 2015

This study investigated genetic, mineralogical and spectral characteristics of oil shale and coal samples in Dundgobi area, Mongolia. Based the Rock/Eval and Total organic carbon (TOC) analysis, kerogen type, hydrogen quantity, thermal maturity and depositional environment were confirmed. Moreover, the mineral composition of oil shale and coal samples were analyzed by XRD and spectroscopy. The result of Rock Eval/TOC analysis revealed that the samples of Eedemt deposit are immature to mature source rocks with sufficient hydrocarbon potential, and the kerogen types were classified as Type I, Type II and Type III kerogen. On the other hand, the samples from Shine Us Khudag deposit were mature with good to very good hydrocarbon potential rocks where kengen types are defined as Type I, Type II/III and Type III kerogen. According to the carbon and sulfur contents, the depositional environment of the both sites were defined as a freshwater depositional environment. The XRD analysis revealed that the mineral composition of oil shale and coal samples were quartz, calcite, dolomite, illite, kaolinite, montmorillonite, anorthoclase, albite, microcline, orthoclase and analcime. The absorption features of oil shale samples were at 1412 nm and 1907 nm by clay minerals and water, 2206 nm by clay minerals of kaolinite and montmorillonite and 2306 nm by dolomite. It is considered that spectral characteristics on organic matter content test must be tested for oil shale exploration using remote sensing techniques.

• Journal of Aquaculture
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• v.13 no.3
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• pp.223-230
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• 2000

A rearing experiment of the olive flounder was performed in a set of water-reuse system to test the reusability of the water in culture system with (i) a foam fractionator to separate particles from water and (ii) a culture tank contain mineral particles to filter the metabolic wastes by adsorption and/or decomposition. Two kinds of commercially processed loess particles and a dolomite particle (all 50 ${\mu}$diameter) were tested. The mineral particles were suspended in the culture tank and the water was pumped into the foam fractionator, where the particles were separated and drained out with foam from the system. In a circular culture tank of 4.8 m in diameter with 10 d water, the juvenile olive flounders (23.1 g/fish, 5,555 fish, 128 kg total body weight) were stocked. 90 % of the rearing water was reused and turnover rate of the water in the tank was two times per hour. Water temperature was maintained 17${\pm}$1$^{\circ}C$. At the end of 75 day-experimental rearing, 5,532 flounders, weighing 468 kg, were harvested. An individual flounder grew to 84.6 g of body weight. The final stocking density was 26.0 kg/$m^2$. No diseases were observed during the experiment.