• 자원리싸이클링
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• 제23권3호
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• pp.30-36
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• 2014

동정광으로 동을 제련하는 동제련소에서는 대략 35-45%정도 철을 함유한 폐동슬래그가 다량 배출되어 대부분 폐기처분되고 있다. 따라서 폐동슬래그로부터 철을 회수하여 철을 자원화하는 것은 자원의 효율적인 활용측면과 환경문제를 감소하는 측면에서 관심이 크게 증대되고 있다. 본 연구에서는 동제련소에서 발생되는 다량의 철 성분이 포함된 폐동슬래그로부터 철의 품위향상을 위한 physico-chemical 분리 공정이 개발되었다. 개발된 공정은 먼저 폐동슬래그를 1 mm이하로 파쇄하는 공정(1차 파쇄공정)과, 이어서 $1225^{\circ}C$에서 90분 동안 탄소 환원하는 공정(탄소 환원공정), 그리고 환원된 슬래그로부터 $104{\mu}m$ 이하로 2차 파 분쇄하는 공정(2차 파쇄공정)과, 이어서 철 농축물을 분리 회수하는 습식자력선별 공정(습식 자력선별공정)으로 구성된다. 개발된 공정을 이용하여 환원된 폐동슬래그를 0.2 T의 자력세기에서 습식자력선별 함으로써 철 품위가 66 wt.%인 철 농축물을 얻었고, 같은 조건에서 철 회수율은 72%이었다. 따라서 분리 회수된 철 농축물은 철 원료로 사용될 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.280-286
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• 2014

Four thermophilic bacterial species, including the iron-reducing bacterium Geobacillus sp. G2 and the sulfate-reducing bacterium Desulfotomaculum sp. SRB-M, were employed to integrate a bacterial consortium. A second consortium was integrated with the same bacteria, except for Geobacillus sp. G2. Carbon steel coupons were subjected to batch cultures of both consortia. The corrosion induced by the complete consortium was 10 times higher than that induced by the second consortium, and the ferrous ion concentration was consistently higher in iron-reducing consortia. Scanning electronic microscopy analysis of the carbon steel surface showed mineral films colonized by bacteria. The complete consortium caused profuse fracturing of the mineral film, whereas the non-iron-reducing consortium did not generate fractures. These data show that the iron-reducing activity of Geobacillus sp. G2 promotes fracturing of mineral films, thereby increasing steel corrosion.

• 한국광물학회지
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• 제31권3호
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• pp.215-225
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• 2018

북한 무산 철광상과 중국 안산-번시 철광화대는 시생대 호상철광층으로 북중국 지괴의 동쪽 블록 중 용강 블록에 속한다. 무산 철 광상을 배태하는 변성퇴적암은 무산층군이고 안산-번시 철 광화대를 배태하는 변성퇴적암은 안산층군으로 이들은 주로 철질 규암, 각섬암, 편암, 혼성암으로 구성되어 있다는 공통점을 갖고 있다. 주 광종은 주로 철질 규암에 배태되어 있는 자철석이다. 광체의 모양은 무산 철 광상의 경우 습곡에 의해 말발굽 모양을 갖지만 안산-번시 철 광화대의 경우 대부분 층상의 모양을 갖는다. 호상철광층의 생성 연대는 무산 철 광상은 약 2.66-2.52 Ga이고, 안산-번시 철 광화대는 2.55-2.53 Ga로 보고되어 시기적으로 유사하며, 광상형은 모두 알고마 유형으로 알려져있다. 결론적으로 무산 철 광상과 안산-번시 철 광화대는 지질 및 형성 시기, 그리고 광상 특성이 매우 유사하다고 볼 수 있다.

• Korean Chemical Engineering Research
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• 제53권1호
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• pp.39-45
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• 2015

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity $Fe^{3+}$ solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of $Mg^{2+}$ and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-orewastewater treatments, as well as in the economic production of the nano-adsorbent.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제19권2호
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• pp.123-129
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• 2016

Purpose: This study was performed to evaluate the dietary nutrient intake status and hair mineral content of Korean young children. Methods: Fifty-five children who visited Seoul National University Bundang Hospital were divided into three groups by age: infants, toddlers, and preschoolers. The 24-hour recall method was used to collect the food intake data of the subjects. Hair mineral analysis was conducted using a Mass Spectrometer. Serum iron, ferritin, and calcium were also measured. Results: The mean energy intakes of the subjects were 730.3 kcal, 994.3 kcal, and 1,482.9 kcal for each age group. The mean percentage of energy intake compared to recommendation was 101.4% and was not different by age group. Toddlers of 37.8% and preschoolers of 54.5% consumed less than the Estimated Average Requirement (EAR) of calcium. Infants of 28.6%, toddlers of 10.8% and preschoolers of 9.1% consumed less than the EAR of iron. In the case of zinc, copper, and selenium, only 0% to 5% of toddlers and none of the preschoolers consumed less than the EAR of those minerals. The hair calcium, iron and copper concentrations were lower in toddlers and preschoolers than those in infants. Serum calcium levels of preschoolers were significantly lower than those of infants, whereas serum iron and ferritin levels were not. Conclusion: Hair calcium, iron, and copper concentrations were significantly lower in toddlers and preschoolers than in infants. Insufficient dietary intake of calcium and iron seems to be related with decreased hair mineral contents in young children.

• 한국재료학회지
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• 제16권8호
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• pp.497-502
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• 2006

Recently, many attention have been focused on illite as a material for the well-being industry. Illite contains various kinds of iron bearing materials and they restrict their usage. In this study, Fe impurities in the illite produced in Yeongdong-gun, Chungcheongbuk-do were characterized and their removal experiments were performed. According to the characterization of illite raw ore, it contained 1.54 wt.%$Fe_2O_3$ due to the existence of iron oxide($Fe_2O_3$) and pyrite($FeS_2$). The raw ore was crushed into 3 mm or less using cone crusher and then ground by rod mill for the liberation of impurity mineral. For the removal of iron bearing minerals, an acid treatment, a flotation, a magnetic separation, and a flotation combined with magnetic separator were performed respectively. When the illite raw ore was treated with magnetic separation and various kinds of acid, 1.54wt.%. $Fe_2O_3$ content was reduced to 0.78 and 1.0 wt.%, respectively. On the other hand $Fe_2O_3$ content was reduced to be 0.52 wt.% after flotation. These results indicate that iron bearing minerals cannot be reduced below 0.3wt.%$Fe_2O_3$. However, combination of magnetic separation and flotation enable us to get 0.24wt.% of illite concentrate. It is concluded that, for the refinement of illite from Yeongdong-gun, the flotation combined with magnetic separation is good for high purity illite.

• Journal of Magnetics
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• 제13권3호
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• pp.106-109
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• 2008

Almost monodisperse iron oxide nanoparticles with an average particle size ranging from 5 to 43 nm were fabricated using an environmentally friendly starting material, ferrous acetate. The smallest particles were formed in the presence of a reductant, 1,2-dodecanediol, while the particle size increased with increasing concentration of dispersing agents. The dispersants consisted of various combinations of oleic acid, oleylamine, trioctylphosphine, and polyvinylpyrrolidone. The threshold temperature to form crystalline particles was found to be $240^{\circ}C$. The 43 nm nanoparticles exhibited a room temperature saturation magnetization and coercivity of 57 emu/g and 47 Oe, respectively.

• Nutritional Sciences
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• 제8권1호
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• pp.71-76
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• 2005

The purpose of this study was to investigate the relationship between nutritional status of iron and bone minernl density in premenopausal women. In the study, we classified the subjects into osteopenia (-2.5-I, n=29) groups according to their lumbar spine bone mineral density. Anthropometric measurements, dietary intake analysis and blood biochemistry measurements were performed on the subjects. The average ages of those in the osteopenia and normal groups were 22.2 yrs and 23.0 yrs, respectively, with no significant difference. The average body mass index (p<0.05) of those in the osteopenia group (19.6) was significantly lower than that of the normal group (21.3). The mean protein intake of those in the osteopenia group was significantly lower than that (p<0.05) the subjects in the normal group. The osteopenia group consumed a significantly lower amount of iron (p<0.05) and non-heme iron (p<0.05) compared to the normal group. The intakes of total food, vegetables and milk of those in the osteopenia group were significantly lower than those of the subjects in the normal group. The serum ferritin (p<0.001) level of those in the osteopenia group was significantly lower than those of the subjects in the normal group. In conclusion, a balance of iron status may be helpful in the prevention of bone mass loss in premenopausal young women.

• 암석학회지
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• 제18권4호
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• pp.307-314
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• 2009

아르헨티나 북부 후후이주에 분포하는 자플라 함철광체는 고생대 실루리아기 해성층에 배태되는 철광석(ironstone)형 철광상이다. 자플라 함철광체는 적철석, 차모사이트, 능철석으로 구성되며 특징적으로 어란상 조직을 보인다. 주 함철광물인 적철석은 운모류의 벽개 및 외각부를 교대하며 산출되어 광체 형성시 화학적 작용에 의해 철광체가 형성되었다. 아르헨티나 북부에는 고생대 실루리아기 분지가 다수 분포하며 이들은 잠재적인 철광상으로 생각되며 이들의 경제성은 함철층의 연장성 및 품위, 개발 심도에 따라 좌우 될 것으로 생각된다.

• 한국식품영양학회지
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• 제8권3호
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• pp.230-238
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• 1995

Iron and zinc were bound by neutral detergent fiber (NDF) obtained from 15 kinds of vegetables being consumed commonly in Korea. Binding capacity of Fe and Zn of NDF ranged from 37.8% to 85.5% and from 81% to 25.5%, respectively showing higher binding capacity of Fe to NDF than of Zn. Both Fe and Zn binding capacity of NDF increased as pH increased and reached to a maximum at pH 7 In all vegetables. The amount of mineral (Fe and Zn) bound to NDF increased as mineral concentration Increased.