• Clean Technology
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• v.12 no.3
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• pp.175-181
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• 2006

The feasibility of the use of porous fossil diatoms for indoor air pollution control was investigated via the characterization of physical and chemical properties. The fossil diatoms were observed by SEM(Scanning Electron Microscope). Diatomite had well-distributed pores below 5 nm and relatively large surface area compare to sericite. However, no porosity in sericite was found. Results showed that diatomite had better performance than sericite in respect to porosity and large surface area. But diatomite which is thermally treated at $950^{\circ}C$ has no porosity and low surface area because of combustion of fossil diatoms or calcination of inorganic oxide at high temperature, and has poor adsorption capability of ammonia gas. In conclusion, porous diatomite has relatively high performance to adsorb noxious chemical compounds, such as ammonia gas and VOCs.

• Applied Chemistry for Engineering
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• v.31 no.3
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• pp.338-340
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• 2020

Sericite is used as a raw material for ceramics and paints, and recently it is widely used as adsorbents to remove heavy metals in wastewater. A new air filter containing sericite was developed using the principle of which components contained in the sericite react with moisture in the air to release oxygen. We tested whether the newly developed air filter actually improves fuel efficiency when mounted on a diesel vehicle. When the diesel vehicle used in the test was warmed up, the fuel efficiency increased by 10~17% compared to when an existing air filter was installed. However, the effect of the developed air filter on the amount of emissions (HC, CO, NOx) has not been investigated, and further research is required for the diesel vehicle emissions.

• Journal of Preventive Medicine and Public Health
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• v.21 no.2 s.24
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• pp.271-283
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• 1988

A Fourier transform infrared spectrophotometric method was described for the determination of quartz, mica(sericite) and feldspar(potassium feldspar) in respirable dust in Taebaek area. The results were as follows; 1) The concentration of minerals were determined from the intensity of absorption peak of quartz at $799cm^{-1}$, sericite at $539cm^{-1}$, and potassium feldspar at $648cm^{-1}$ respectively. 2) The precision(C. V. %) for the quartz determination was $7.70{\pm}2.68%$ from 10 to $200{\mu}g$ of quartz. 3) The precision for the sericite determination was $16.34{\pm}6.82%$ from 30 to $500{\mu}g$ of serictite. 4) The precision for the potassium feldspar determination was $5.28{\pm}1.74%$ from 30 to $500{\mu}g$ of potassium feldspar. 5) The concentration of respirable dust in Taebaek area was $4.90{\pm}3.29mg/m^3$ (0.4-93.7%), percent quartz was $1.80{\pm}4.14%$ (0.01-20.56%), percent sericite was $11.37{\pm}6.43%$ (0.00-29.69%), percent potassium feldspar was 8.15% (n=7, 3.41-19.70%). 6) The difference of respirable coal dust, quartz, and sericite concentrations in drilling, coal cutting, hauling and seperating was significant respectively (p<0.05).

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.35-44
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• 1976

The effect of quartz which exists in clays, especially in kaolin used for the production of chamotte sagger, on the strength of refractory was examined. In this study, a mixture of chamotte 50%, kaolin 25%, plastic clay 25% in ternary component system was selected as a batch composition. To this mixture 1%, 3% and 5% of feldspar and sericite were added respectively. The plastic clay used here was separated under 170 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. Feldspar and sericite were separated under 325 mesh by dry process. In order to change the particle size and the content of quartz, the kaolin was separated under 60, 115, 170 and 325 mesh by wet process, substituted quartz for coarse parts of it. Chamotte was classified into three grades, coarse (5-10mesh): medium (10-20mesh): fine(20-115mesh) and the ratio was 1:1:1. Samples were formed in 0.8xIx10cm size with 12.5% water at 160kg/$\textrm{cm}^2$ pressure, and fired at 130$0^{\circ}C$ for 1 hr. The fired samples were ivnestigated by means of x-ray diffraction analysis and microscopic observation, and the physical properties of them were also examined, such as firing shrinkage, apparent specific gravity and bulk specific gravity, apparent porosity, water absorption and modulus of rupture. The obtained results are as follows: 1. When screened kaolin with low content of quartz was added to fixed chamotte-plastic clay system, the sample lowered modulus of rupture and increased apparent porosity as the size of kaolin became finer. 2. When kaolin under 325 mesh with 7.2-15.81% quartz between 60-325 mesh was added to fixed chamotte-plastic clay system, the sample had higher apparent porosity and lower modulus of ruputure as the size and the amount of quartz became larger. 3. The addition of feldspar and sericite to chamotte-plastic clay system improved apparent porosity and modulus of rupture. The effect of feldspar was better when quartz content was low, although that of sericite was better than quartz content was high.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.471-481
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• 1996

Clay mineral geothermometry using sericites and chlorites in Bobae sericite mine reveals that these clay minerals formed at relatively high temperature. It appears that sericites formed at around $200{\sim}350^{\circ}C$ and chlorites formed at around $250^{\circ}C$. X-ray diffraction study of these minerals reveals that sericite $2M_1$ type and chlorite IIb type are dominant phases. Both polytypes indicate that the precipitation temperatures of these minerals shows fairly good agreement with the estimated temperature by clay mineral geothermometry. The Bobae sericite mine was formed at relatively higher temperature than several non-metal ore deposits occurred in the southern part of Korea.

• Economic and Environmental Geology
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• v.29 no.4
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• pp.447-454
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• 1996

Clay mineral geothermometry using sericites and chlorites in Bobae sericite mine reveals that these clay minerals formed at relatively high temperature. It appears that sericites formed at around $200{\sim}350^{\circ}C$ and chlorites formed at around $250^{\circ}C$. X-ray diffraction study of these minerals reveals that sericite 2M, type and chlorite lib type are dominant phases. Both polytypes indicate that the precipitation temperatures of these minerals shows fairly good agreement with the estimated temperature by clay mineral geothermometry. The Bobae sericite mine was formed at relatively higher temperature than several non-metal ore deposits occurred in the southern part of Korea.

• Journal of the Korean earth science society
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• v.26 no.7
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• pp.674-682
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• 2005

The Samsung mine is located in Jeongsan-myeon, Cheongyang-gun, Chungcheongnam-do, and is produces sericite ores. The purpose of this study is to investigate the geology and mineralogy of sericite one and its host-rock together with the alteration processes and age of sericitization. Geological survey, polarizing microscopy, X-ray powder diffraction, electron microprobe analysis, X-ray fluorescent analysis, differential thermal analysis, and K/Ar isotope study have been employed for this study. The mine area is composed of Precambrian granite-gneiss and mica schist, and also Jurassic biotite granite. Serictization has occured within the granite-gneiss, and is interpreted to be formed by hydrothermal alteration. The sericite was formed by the breakdown of orthoclase, plagioclase, and biotite, respectively. With sericitization intensity increase, $SiO_2\;and\;Na_2O$ contents are decreased, while $Al_2O_3\;and\;K_2O$ increased. The formation age of sericite has been determined to be Jurassic, which corresponds well to the intrusion age of the biotite granite nearby.

• Economic and Environmental Geology
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• v.26 no.1
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• pp.11-20
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• 1993

In the present study, three representative hydrothermal clay deposits, named the Seongsan, Ogmaesan and Haenam deposits, were selected for oxygen and hydrogen isotope studies. Oxygen and hydrogen isotopic compositions of quartz, sericite, alunite and kaolin minerals from Seongsan, Ogmaesan, Haenam deposits and surrounded rocks of clay deposits have been measured. The ${\delta}^{18}O$ values of quartz, kaolin, sericite and alunite in the Seongsan mine are +8.4 to +11.1‰, +3.6 to 5.4‰, +4.8 to +5.8‰ and + 3.0 to +6.6‰, respectively. In the Ogmaesan mine, the ${\delta}^{18}O$ values of quartz, kaolin, sericite and alunite are +8.0 to +13.6‰, +2.8 to +6.7‰, +4.8 to +8.4‰ and +0.9 to +2.4‰, respectively. The ${\delta}^{18}O$ values of the Haenam mine range from +7.9 to +10.1‰ for quartz and from +4.5 to +6.5‰ for sericite. The ${\delta}^{18}O$ values of the whole-rocks range from + 3.0 to + 7.8‰ for the granitic rocks. The ${\delta}^{18}O$ values of the whole-rocks range from + 3.2 to + 10.7‰ for the volcanic rocks. The 8D values of kaolin, sericite and alunite in the Seongsan mine are -78 to -86‰, -71 to -90‰ and -43 to -77‰, respectively. In the Ogmaesan mine, the ${\delta}D$ values of kaolin, sericite and alunite are -73 to -80‰, -74 to -88‰ and -57 to -98‰, respectively. The ${\delta}D$ values of the Haenam mine range from -76 to -85‰ for sericite. The ${\delta}D$ values of the whole-rocks range from -77 to -105‰ for the granitic rocks. The ${\delta}D$ values of the wholerocks range from -76 to -100‰ for the volcanic rocks. The main result obtained oxygen and hydrogen isotope data can lead to the following interpretations on the origin of hydrothermal fluids in the clay deposits: Through the oxygen isotopic study, the formation temperature of the clay deposits was estimated from the coexisting minerals such as quartz-kaolin minerals and -sericite. Formation temperature of the acidic alteration zone is 165 to $280^{\circ}C$ in the Seongsan deposits, 175 to $250^{\circ}C$ in the Ogmaesan deposits and 250 to $350^{\circ}C$ in the Haenam deposits. Three clay deposits has been formed by magmatic water mixed with meteoric water. Furthermore, from this isotopic data, it is clarified that kaolin minerals and alunite are hypogene in origin, and has been formed by oxidation of hydrogen sulfide in the steam-heated environment, and that alunite has been produced in the spectacular solfataric alteration observed at the surface of some present-day hydrothermal systems. Oxidation of the $H_2S$ is thought to be generated when the vapor phase generated by boiling of the deep-seated water under the water table.

• Economic and Environmental Geology
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• v.25 no.4
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• pp.397-416
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• 1992

In the present study, three clay deposits, named the Seongsan, Ogmaesan and Haenam deposits, were investigated. The altered zones are recognized in the hydrothermally altered rocks of the clay deposits from the center of the alteration to the margin: Kaolin, Kaolin-Quartz, Quartz, Sericite and Chlorite zones in the Seongsan deposits; Quartz zone, Alunite zone, Kaolin zone, Sericite zone and Chlorite zone in the Ogmaesan deposits; Quartz zone, Pyrophyllite zone, Sericite zone and Chlorite zone in the Haenam deposits. These zones can be grouped into two types of alteration: Acidic alteration such as Pyrophyllite zone, Alunite zone, Quartz zone, Kaolin zone, Kaolin-Quartz zone and a part of Sericite zone; Propylitic alteration such as Chlorite zone and a part of Sericite zone. All clay deposits belong to high-sulfidation (acid-sulfate) system. The rocks of the acidic alterations are composed of pyrophyllite, alunite, kaolin minerals, sericite, quartz and pyrite. On the basis of bulk chemical compositions, it was found that some components such as $SiO_2$, $TiO_2$, $Fe_2O_3$, FeO, MgO, CaO, $K_2O$ and $Na_2O$ were mobilized considerably from the original rocks. The mobility of these major elements is related to, and controls, mineral assemblages in each altered zone. Polytypes of sericite are determined as $2M_1$ and 1M by X-ray diffraction method. The amount of $2M_1$ is nearly equal to that of 1M in the Seongsan deposits whereas $2M_1$ is less and higher than that of 1M in the Ogmaesan and the Haenam deposits. These facts indicate that formation temperature of sericite is relatively high in the Haenam deposits, moderate in the Seongsan deposits, and low in the Ogmaesan deposits. The ratios of Na/(K+Na) for alunite in the Ogmaesan deposits determined by electron microprobe analyzer (EPMA) are higher than those in the Seongsan deposits. Thus, the alunite of the Ogmaesan deposits must have been formed from the solutions with relatively high aqueous Na/(K+Na) ratios and low pH at a high temperature rather than that of the Seongsan deposits. From all data, it is clarified that alunite is hypogene in origin, and has been formed by oxidation of hydrogen sulfide in the steam-heated environment, and that alunite has been produced by the spectacular solfataric alteration observed at the surface of some present-day hydrothermal systems.

• Economic and Environmental Geology
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• v.22 no.4
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• pp.341-354
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• 1989

Mineralogy and geochemistry of five pyrophyllite deposits in Yangsan-Milyang area such as Cheonbulsan, Dumyong, Dongrae, Youkwang, and Sungjin mines were investigated. Pyrophyllite ores consist mainly of pyrophyllite, sericite, and quartz with some amounts of kaolinite and pyrite. Polytype of pyrophyllite is 2M. Sericite has two polytypes of 1M and 2M1. The ${\delta}^{18}O$ values of pyrophyllite from the Cheonbulsan and the Dumyong mines were measured as 0.23-0.60‰ and 3.40‰, respectively, and those of montmorillonite and kaolinite from the Dumyong mine were in the range of 11.90-12.06‰. This low oxygen isotope composition provides conclusive evidence for hydrothermal activity in the studied area. Contents of major elements are more useful than those of trace elements to discriminate altered zones such as pyrophyllite, sericite, argillic, and andalusite zones from the surrounding rocks. Particularly, contents of $K_2O$, $Na_2O$ and CaO are helpful to identify alteration zones from the discriminant and the cluster analysis of multi-element data.