• Title/Summary/Keyword: Phase Diagram

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Comparison of Hydrochemical Characteristics of Groundwater in the Southern Area and the Northwestern Area, Pusan (부산 남부지역 지하수와 서북부지역 지하수의 수리화학적 특성 비교)

  • 함세영;조명희;성익환;이병대;조병욱;심형수
    • Journal of the Korean Society of Groundwater Environment
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    • v.6 no.3
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    • pp.140-151
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    • 1999
  • Groundwater samples from the southern area composed of andesitic rocks and the northwestern area composed of granite in Pusan city, have been collected and analyzed. According to the Piper diagram. groundwater in the southern area belongs to Ca$\^$2+/-HCO$_3$$\^$-/ and Ca$\^$2+/-(Cl$\^$-/+SO$_4$$\^$2-/) types, and that in the northwestern area mostly belongs to Ca$\^$2+/-HCO$_3$$\^$-/ type and partly Na$\^$+/-HCO$_3$$\^$-/ type. Two factors (factor 1 and factor 2) were obtained from the result of the factor analysis in the southern area. Factor 1, consisting of Mg$\^$2+/, Ca$\^$2+/, Cl$\^$-/, SO$_4$$\^$2-/, NH$_4$$\^$+/, EC and NO$_3$$\^$-/ is represented by the dissolution of Ca-plagioclase and calcite, and the influence of anthropogenic sources. Factor 2, consisting of K$\^$+/, Na$\^$+/. SiO$_2$, SO$_4$$\^$2-/, and HCO$_3$$\^$-/ is mainly represented by the dissolution of feldspar. Three factors were obtained from the result of the factor analysis in the northwestern area Factor 1, consisting of Na$\^$+/, K$\^$+/, NH$_4$$\^$+/, Cl$\^$-/, SO$_4$$\^$2-/ and NO$_3$$\^$-/ explains dissolution of plagioclase and mica, the influence of anthropogenic sources and salt water. Factor 2, consisting of Ca$\^$2+/ and HCO$_3$$\^$-/ explains the dissolution of Ca-plagioclase. Factor 3, consisting of Mg$\^$2+/ and SiO$_2$, explains the dissolution of silicate minces. and contaminants. Based on the phase stability diagrams, groundwater both in the southern and in the northwestern area is mostly in equilibrium with kaolinite. Cl$\^$-/ with respect to Na$\^$+/, Ca$\^$2+/, Mg$\^$2+/, K$\^$+/, SO$_4$$\^$2-/ and HCO$_3$$\^$-/ indicates that both the northwestern area and the southern area are influenced by the salt water.

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A Study on the Optimal Process Parameters for Recycling of Electric Arc Furnace Dust (EAFD) by Rotary Kiln (Rotary Kiln에 의한 전기로 제강분진(EAFD)의 재활용을 위한 최적의 공정변수에 관한 연구)

  • Jae-hong Yoon;Chi-hyun Yoon;Myoung-won Lee
    • Resources Recycling
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    • v.33 no.4
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    • pp.47-61
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    • 2024
  • As a recycling technology for recovering zinc contained in large amounts in electric arc furnace dust (EAFD), the most commercialized technology in the world is the Wealz Kiln Process. The Wealz Kiln Process is a process in which components such as Zn and Pb in EAFD are reduced/volatile (endothermic reaction) in high-temperature Kiln and then re-oxidized (exothermic reaction) in the gas phase and recovered in the form of Crude zinc oxide (60wt%Zn) in the Bag Filter installed at the rear end of Kiln. In this study, an experimental Wealz kiln was produced to investigate the optimal process variable value for practical application to the recycling process of large-scale kiln on a commercial scale. Additionally, Pellets containing EAFD, reducing agents, and limestone were continuously loaded into Kiln, and the amount of input, heating temperature, and residence time were examined to obtain the optimal crude zinc oxide recovery rate. In addition, the optimal manufacturing conditions of Pellets (drum tilt angle, moisture addition, mixing time, etc.) were also investigated. In addition, referring to the SiO2-CaO-FeO ternary system diagram, the formation behavior of a low melting point compound, a reaction product inside Kiln according to the change in the basicity of Pellet, and the reactivity (adhesion) with the castable constructed on the inner wall of Kiln were investigated. In addition, in order to quantitatively investigate the possibility of using anthracite as a substitute for Coke, a reducing agent, changes in the temperature distribution inside Kiln, where oxidation/reduction reactions occur due to an increase in the amount of anthracite, the quality of Crude zinc oxide, and the behavior of tar in anthracite were also investigated.