• Title/Summary/Keyword: 산업원료광물

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The Properties of Synthetic Calcium Ferrite for Ironmaking and Steelmaking using Industrial By-products - (2) (산업부산물을 활용한 제철·제강용 합성 칼슘 페라이트 특성 - (2))

  • Park, Soo Hyun;Chu, Yong Sik;Seo, Sung Kwan;Park, Jae Wan
    • Resources Recycling
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    • v.23 no.5
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    • pp.12-20
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    • 2014
  • Calcium ferrite is a major bonding material self-fluxed sintered ore, and it is used as a flux in the steelmaking process. Calcium ferrite is more effective binder for making sintered ore and flux for steel making because of it's low melting temperature. In this Study, calcium ferrite was made by using variety industrial by-products from steel plant. The property of calcium ferrites was investigated on the basis of test method using in the cement manufacturing process. Crystal analysis, compression test as well as thermal analysis were carried out to evaluate physical properties of calcium ferrite.

A Study on the Method for Quantifying CO2 Contents in Decarbonated Slag Materials by Differential Thermal Gravimetric Analysis (DTG 분석법을 활용한 슬래그류 비탄산염 재료의 CO2 정량 측정방법 연구)

  • Jae-Won Choi;Byoung-Know You;Yong-Sik Chu;Min-Cheol Han
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.12 no.1
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    • pp.8-16
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    • 2024
  • Limestone (CaCO3, calcium carbonate), which is used as a raw material in the portland cement and steel industry, emits CO2 through decarbonation by high temperatures in the manufacturing process. To reduce CO2 emissions by the use of raw materials like limestone, it has been proposed to replace limestone with various industrial by-products that contain CaO but less or none of the carbonated minerals, that cause CO2 emissions. Loss of Ignition (LOI), Thermogravimetric analysis (TG), and Infrared Spectroscopy (IR) are used to quantitative the amount of CO2 emission by using these industrial by-products, but CO2 emissions can be either over or underestimated depending on the characteristics of by-product materials. In this study, we estimated CO2 contents by LOI, TG, IR and DTG(Differential Thermogravimetric analysis) of calcite(CaCO3) and samples that contain CO2 in the form of carbonate and whose weight increases by oxidation at high temperatures. The test results showed for CaCO3 samples, all test methods have a sufficient level of reliability. On the other hand, for the CO2 content of the sample whose weight increases at high temperature, LOI and TG did not properly estimate the CO2 content of the sample, and IR tended to overestimate compared to the predicted value, but the estimated result by DTG was close to the predicted valu e. From these resu lts, in the case of samples that contain less than a few percent of CO2 and whose weight increases during the temperature that carbonate minerals decompose, estimating the CO2 content using DTG is a more reasonable way than LOI, TG, and IR.

Litholohical and Mechanical Characteristics of Crushed Limestone Aggregates (쇄석 골재용 석회암의 암석학적 및 역학적 특성)

  • 진호일;민경원;백환조;연규석
    • Magazine of the Korea Concrete Institute
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    • v.9 no.3
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    • pp.119-126
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    • 1997
  • Recently, duc to highly increased consumption of' ngg~.egatc>s f o ~ . construction. studies have focused on the effective utilization of rock wastes abandoned so far. This study was designed, firstly, to determine t,hc petrological, g'ochemical and mechanical cha~,acte~istics of' crushed limestone aggregates in thc Samhwa district for suitable construction aggregates and, secondly, to offer basic data for cff'ective utilization of low grade limestones. Results of' the petrographic st,udy indicates that the crushed limestone aggregates in the Samhwa district can bo separate4 into two groups, namely f'inc-grained and cowlxcgrained limestones. Dominantly distributed fine-grained limestone containing some dolomite has higher Mgo and $SiO_2$ contents compared to the coarse-graincd limestonr. It, can be classified as medium strength rock by the physical and mcxhanical pi.opertics. I3ased on the size of' mineral grains and chemical compositions, it is suggested that the crushed limestone aggregates in t,his study area would bctkr be u s ~ i for asphalt concr.ctt., road pavement, or railroad ballast materials than for cement concrete.

The Statistical Hypothesis Verification to Influence of Addition of Metakaolin and Silica Fume on Compressive Strength and Chloride Ion Penetration of High Strength Concrete (메타카올린 및 실리카퓸의 혼입이 고강도 콘크리트의 압축강도와 염소이온 투과에 미치는 영향에 관한 통계적 가설검증)

  • Min, Jeong Wook
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.1
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    • pp.215-225
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    • 2011
  • Metakaolin is a dehydroxylated form of the clay mineral kaolinite. Rocks that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of porcelain. The particle size of metakaolin is smaller than cement particles, but not as fine as silica fume. This paper investigates the effect of the concrete containing metakaolin as a mineral admixture on the compressive strength and resistance properties to chloride ion penetration. In this study, the experiment was carried out to investigate and analyze the influence of replacement ratio of metakaolin and micro silica fume on the compressive strength and chlorine ion penetration resistance of concrete. All levels were water/binder ratio 30%, replacement ratio of metakaolin and silica fume were 0, 5, 10, 15, 20% respectively. The compressive strength of concrete using metakaolin tends to increase, as the replacement ratio increases but the chlorine ion penetration resistance was not so as lager as silica fume concrete. Therefore, the optimum mixing ratio of metakaoline to satisfy a properties of compressive strength and chlorine ion penetration resistance was was approximately10%.

Leaching of Ca, Fe and Si in Electric Arc Furnace Steel Slag by Aqueous Acetic acid Solution for Indirect Carbonation (간접탄산염화를 위한 전기로제강슬래그 중 Ca, Fe 및 Si 성분의 초산수용액 침출)

  • Youn, Ki-Byoung
    • Resources Recycling
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    • v.26 no.1
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    • pp.37-42
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    • 2017
  • It has been reported that aqueous indirect carbonation process of calcium silicate mineral could be one of the most promising methods for $CO_2$ sequestration. The process consists of two main steps, extraction of Ca from calcium silicate and carbonation of the extracted solution by $CO_2$. Many types of acids such as HCl and $HNO_3$ can be used in the extraction step of the process. In the case of using aqueous acetic acid solution as the extraction solvent, acetic acid can be reproduced at the carbonation step of the extracted solution by $CO_2$ and recycled to extraction step for reuse it. Industrial by-products such as iron and steel slags are potential raw materials of the indirect carbonation process due to their high contents of calcium silicate. In this study, in order to examine the extraction efficiency of domestic electric arc furnace steel slag by aqueous acetic acid solution, extraction experiments of the slag were performed by using the aqueous acetic acid solutions of varying extraction conditions ; acetic acid concentrations, extraction temperatures and times.

Study on Burnability and Reactivity of High Al2O3 Content OPC Clinker for the Use of Industrial Waste (산업부산물 활용을 위한 고Al2O3 함량 OPC 클링커의 소성성 및 반응성에 관한 연구)

  • Kang, Bong-Hee;Choi, Jaewon;Ki, Tae-Kyoung;Kwon, Sang-Jin;Kim, Gyu-Yong
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.8 no.3
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    • pp.294-301
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    • 2020
  • This study evaluated the burnability and hydration reaction of clinker burned with high Al2O3 content OPC to apply large amounts of industrial by-products in the cement manufacturing process. Specifically, after preparing a clinker with a high C3A content by burning the OPC raw material with a high content of Al2O3 in a laboratory electric furnace, the burnability of the clinker was evaluated through XRD Rietveld analysis and polarization microscopy, and clinker hydration reactivity was reviewed through the Isothermal conduction calorimetry analysis and the cement compressive strength. As a result, the kiln burning temperature for the production of high Al2O3 content clinker lower, and the compressive strength was equal to or higher than OPC. Therefore it was confirmed the possibility to manufacturing energy-saving high Al2O3 content clinker using a large amount of industrial by-products.

Current Status and Necessity of Separation Technology to Secure Vanadium Mineral Resources (바나듐 광물자원 확보를 위한 선별 기술 현황 및 필요성)

  • Jeon, Hoseok;Han, Yosep;Baek, Sangho;Davaadorj, Tsogchuluun;Go, Byunghun;Jeong, Dohyun;Chu, Yeoni;Kim, Seongmin
    • Resources Recycling
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    • v.31 no.2
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    • pp.3-11
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    • 2022
  • Owing to the global development of high-strength alloys and renewable energy industries, the demand for vanadium, a key raw material in these industries, is expected to increase. Until now, vanadium has been recovered as a by-product of the industry, but interest in its direct recovery from minerals has increasing with its significantly increasing demand. In particular, the recovery of vanadium from stone coal ore and vanadium titano-magnetite (VTM) containing vanadium has been actively researched in China, which has the largest reserves and production of vanadium in the world. In Korea, a large amount of VTM also occurs in the northern part of Gyeonggi-do, and fundamental research and technical development is being conducted to recover vanadium. It is necessary to understand the current status of the separation technology used worldwide to satisfy the demand for metals such as vanadium, which currently depends on imports.

A Study on Industries's Leading at the Stock Market in Korea - Gradual Diffusion of Information and Cross-Asset Return Predictability- (산업의 주식시장 선행성에 관한 실증분석 - 자산간 수익률 예측 가능성 -)

  • Kim Jong-Kwon
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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    • pp.355-380
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    • 2004
  • I test the hypothesis that the gradual diffusion of information across asset markets leads to cross-asset return predictability in Korea. Using thirty-six industry portfolios and the broad market index as our test assets, I establish several key results. First, a number of industries such as semiconductor, electronics, metal, and petroleum lead the stock market by up to one month. In contrast, the market, which is widely followed, only leads a few industries. Importantly, an industry's ability to lead the market is correlated with its propensity to forecast various indicators of economic activity such as industrial production growth. Consistent with our hypothesis, these findings indicate that the market reacts with a delay to information in industry returns about its fundamentals because information diffuses only gradually across asset markets. Traditional theories of asset pricing assume that investors have unlimited information-processing capacity. However, this assumption does not hold for many traders, even the most sophisticated ones. Many economists recognize that investors are better characterized as being only boundedly rational(see Shiller(2000), Sims(2201)). Even from casual observation, few traders can pay attention to all sources of information much less understand their impact on the prices of assets that they trade. Indeed, a large literature in psychology documents the extent to which even attention is a precious cognitive resource(see, eg., Kahneman(1973), Nisbett and Ross(1980), Fiske and Taylor(1991)). A number of papers have explored the implications of limited information- processing capacity for asset prices. I will review this literature in Section II. For instance, Merton(1987) develops a static model of multiple stocks in which investors only have information about a limited number of stocks and only trade those that they have information about. Related models of limited market participation include brennan(1975) and Allen and Gale(1994). As a result, stocks that are less recognized by investors have a smaller investor base(neglected stocks) and trade at a greater discount because of limited risk sharing. More recently, Hong and Stein(1999) develop a dynamic model of a single asset in which information gradually diffuses across the investment public and investors are unable to perform the rational expectations trick of extracting information from prices. Hong and Stein(1999). My hypothesis is that the gradual diffusion of information across asset markets leads to cross-asset return predictability. This hypothesis relies on two key assumptions. The first is that valuable information that originates in one asset reaches investors in other markets only with a lag, i.e. news travels slowly across markets. The second assumption is that because of limited information-processing capacity, many (though not necessarily all) investors may not pay attention or be able to extract the information from the asset prices of markets that they do not participate in. These two assumptions taken together leads to cross-asset return predictability. My hypothesis would appear to be a very plausible one for a few reasons. To begin with, as pointed out by Merton(1987) and the subsequent literature on segmented markets and limited market participation, few investors trade all assets. Put another way, limited participation is a pervasive feature of financial markets. Indeed, even among equity money managers, there is specialization along industries such as sector or market timing funds. Some reasons for this limited market participation include tax, regulatory or liquidity constraints. More plausibly, investors have to specialize because they have their hands full trying to understand the markets that they do participate in

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Revaluation of Ore Deposits within the Yeongam District, Cheollanamdo-Province: The Eunjeok and Sangeun Mines (전남 영암지역 광상 재평가: 은적.상은 광산를 중심으로)

  • Heo, Chul-Ho;Park, Sung-Won;Lee, Jae-Ho
    • Economic and Environmental Geology
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    • v.43 no.2
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    • pp.73-84
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    • 2010
  • Gold and silver deposits within the Eunjeok and Sangeun mines are located in Yeongam district, Cheollanamdo-province. They are composed of vein ore bodies infilling the fractures of Cretaceous rhyolitic tuff. The Eunjeok mine have three gold and silver bearing hydrothermal veins which is infilling the fracture of rhyolitic tuff. Major ore minerals within the Eunjeok and Sangeun mines are arsenopyrite, pyrite, chalcopyrite, sphalerite and galena and minor ores are electrum, native silver and argentite. Sericitization is dominant in alteration zone and chloritization and dickitization is minor. Quartz veins in the Eunjeok and Sangeun mine have the similar paragenesis and vein textures such like breccia, crustiform, comb and vuggy morphology indicating the formation of typical epithermal environment. In order to carry out the preliminary feasibility study of mine according to the commodity and elucidate the occurrence features of mineral resources from Eunjeok and Sangeun mine, common commodity (Pb, Zn, Cu, Fe, Mo, W, Au and U), and industrial commodity (In, Re, Ga, Ge, Se, Te, Y, Eu and Sm) for 17 ore specimen were analyzed. It is tentatively thought that there is no exploitable mine for iron, lead, zinc, copper, tungsten and uranium based on the preliminary result. If the reserves are secured through the detailed prospecting in case of molybdenum and silver, it is tentatively thought that there will be exploitable deposits depending on international metal price. If we assume the vein width from 0.25 m to 2 m including alteration zone with the gold grade of 80g/t, it is inferred that the resources amount of the Eunjeok-Sangeun mines range from 6.5 to 65ton. However, as the vein structure of the Eunjeok and Sangeun mines is developed together with alteration zone, it should be estimated to include potential alteration zone in order to yield the average grade. It is needed to carry out more exploration in the near future because the reserves can be flexibly estimated according to the change of average grade considering the alteration zone.

Characterization of the Oxidation Roasting of Low Grade Molybdenite Concentrate (저품위(底品位) 휘수연석(煇水鉛石) 정광(精鑛)의 산화배소(酸化焙燒) 특성(特性))

  • Kim, Byung-Su;Lee, Hoo-In;Choi, Young-Yoon;Kim, Sang-Bae
    • Resources Recycling
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    • v.18 no.5
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    • pp.19-25
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    • 2009
  • Molybdenite concentrate ($MoS_2$) is the major mineral for the molybdenum industry, of which the industrial processing is first converted to technical grade molybdenum trioxide ($MoO_3$) by its oxidative roasting and purification, used as a raw material for manufacturing several molybdenum compounds. In the present work, detailed experimental results for the oxidative roasting of low grade Mongolian molybdenite concentrate are presented. The experiments were carried out in the temperature range of 793 to 823 K under an oxygen partial pressure range of 0.08 atm to 0.21 atm by using a thermogravimetric analysis technique. The molybdenite concentrate was an average particle size of $67\;{\mu}m$. In the oxidative roasting of low grade Mongolian molybdenite concentrate, more than 95% of molybdenite was converted to molybdenum trioxide in 60 min. at 828 K. The lander equation was found to be useful in describing the rates of the oxidative roasting and the reaction order with respect to oxygen concentration in a gaseous mixture with nitrogen was 0.11 order.