• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.1
• /
• pp.25-35
• /
• 2005

This study analyzed total concentrations and existing forms of heavy metals in soils of Ulsan using a sequential extraction method. Soil samples were collected from 6 categorized areas including green, residential, heavy traffic, petrochemical industrial complex(IC), mechanical and shipbuilding IC, and non-ferrous metal IC areas. which represent different emission characteristics. The highest total concentrations of heavy metals by a sequential extraction analysis were observed in the soils collected from the non-ferrous metal IC area, followed by the mechanical and shipbuilding IC and heavy traffic areas. Dominant(> 50%) existing forms of Cd, Cr and Ni were residual forms followed by Fe and Mn oxides in almost areas. Residual fractions in the non-ferrous metal IC areas were relatively lower than those in other areas. However, the fractions of organic and sulphides in the IC areas were higher. The dominant farms of Cu were much different with the investigated areas. In most areas, the dominant forms of Pb and Zn were Fe and Mn oxides, followed by residual fraction for Pb. The exchangeable and carbonate fractions represent mobility of metallic elements in soils. They are also significantly affected by the environmental renditions, such as pHs of soil and rainfall. In this study the exchangeable and carbonate fractions were lower than other fractions. Because the total concentrations of heavy metals in the soils of the non-ferrous metal IC area were extremely high, however, the mobile fractions of heavy metals in the IC area would be significant. Thus a large amount of heavy metals can be released into plants, water bodies, and soils. Therefore, urgent measures, such as source control for soil remediation of heavy metals, in the non-ferrous metal IC areas are essentially required. Analysis results obtained from the sequential extraction and the aqua regia extraction showed a high correlation, whose determination coefficients(R2) of heavy metals except Cd approximately ranged from 0.7 to 0.9.

• Journal of Korean Society for Atmospheric Environment
• /
• v.16 no.1
• /
• pp.23-35
• /
• 2000

PM10, which is below 10 ${\mu}{\textrm}{m}$ in a diameter, has a high deposition in the lung or the bronchus by breathing and is generally composed of a lot of organic matters, viruses, algae, mold, and metallic elements that are very toxic to people. This study identified the characteristics of concentration of PM10 and air-borne jmetallic elements produced in the industrial city, Ulsan, and analyzed the correlatuion between sources and generation patterns of PM10 and metallic elements. We classified the five areas(green, residential, heavy traffic, mechanic, and petrochemcal and non-ferrous metal) which might have different characteristics of sources of PM10 and metallic elements. The average concentrations of PM10 in the five areas were as follows(petrochemical and non-ferrous metal(99.9$\mu\textrm{g}$/㎥)>mechanic(77.5 $\mu\textrm{g}$/㎥)>heavy traffic(47.1 $\mu\textrm{g}$/㎥)>residential(39.3 $\mu\textrm{g}$/㎥)>green(32.8 $\mu\textrm{g}$/㎥)). Those of petrochemical and non-ferrous metal areas were higher than other areas. In this study, the average concentration trend of metallic elements contained in PM10 are shown as follows: Fe>Zn>Pb>Cu>Mn>Cr>As>Cd>Sn>Hg, respectively. The metallic elements identified in PM10 showed the highest concentration in the petrochemical and non-ferrous areas. Metal combinations showed that a high correlation among concentrations of heavy metals were as follows: As, Cd and Fe in the residential area; Zn, Mn, Cu and Pb in the mechanical area; and Zn, Cu, As, Pb in the petrochemical and non-ferrous industrial area.

• The Transactions of the Korean Institute of Electrical Engineers P
• /
• v.56 no.4
• /
• pp.157-160
• /
• 2007

The van der Pauw technique is one of the popular methods for determining the conductivity of flat metal samples. Traceability of the national standard for the conductivity has been achieved by direct current measurement techniques in national measurement institutes of many countries. But recently, alternative current measurement techniques for determining the conductivity of flat metal samples is also interested. In this study, we measured the conductivity of non-ferrous and ferrous flat metals at alternative current using van der Pauw technique. As measurement results, the conductivities of the samples were decreased according to increasing the test frequency even though the decreasing ratio was different.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2008.10a
• /
• pp.239-240
• /
• 2008

• Transactions of Materials Processing
• /
• v.24 no.4
• /
• pp.256-263
• /
• 2015

Electric resistance spot welding has been used to join overlapped steel sheets in automotive bodies. Recently to reduce weight in automotive vehicles, non-ferrous metals are being used or considered in car bodies for hoods, trunk lids, doors parts, etc. Various welding processes such as laser welding, self-piercing rivet, friction stir welding are being used. In the current study, a new electric resistance heated friction stir spot welding is suggested for the spot welding of non-ferrous metals. The welding method can be characterized by three uses of heat -- electric resistance heating, friction stir heating and conduction heating of steel electrodes -- for the fusion joining at the interfacial zone between the two sheets. The welding process has variables such as welding current, diameter of the steel electrodes, revolutions per minute (rpm) of the friction stir pin, and the insert depth of the stir pin. In order to obtain the optimal welding variables, which provide the best welding strength, many experiments were conducted. From the experiments, it was found that the welding strength could be reached to the required production value by using an electrode diameter of 10mm, a current of 7.6kA, a stirring speed of 400rpm, and an insert depth of 0.8mm for the electric resistance heated friction stir spot welding of 5052 aluminum 1.5mm sheets.

• Resources Recycling
• /
• v.20 no.4
• /
• pp.23-35
• /
• 2011

In order to review the recycling status of urban mine resources in Taiwan, background and history of recycling industries, system of the recovery fund management committee(RFMC), copper recycling with non-ferrous metals, recycling of ELV(end of life vehicles) and recycling of EAF dust were surveyed. Taiwan is a leading country of the world in the metal consumption per capita. Therefore, a lot of waste metals were generated. In other words, urban mine resources are abundant in Taiwan and have some advantages in recycling. There are more than thou-sand recycling plants in Taiwan. Half of them are non-ferrous metal recyclers.

• Economic and Environmental Geology
• /
• v.55 no.4
• /
• pp.339-352
• /
• 2022

As environmental criteria items are increased or strengthened, cases of heavy metal contamination by geogenic origin are increasing, and the need to distinguish between natural and anthropogenic origins in soil or groundwater exceeding the standard is increasing. In this study, geochemical occurrences of geogenic heavy metals were identified through statistical processing of the national geochemical map data and evaluation of geochemical characteristics of regions with high geoaccumulation indices. Cobalt, Cr, Cu, Ni, Pb, V, and Zn were targeted for which the national geochemical maps were prepared, and Co, Cr, Ni, and V derived from ultrabasic or ultramafic rocks were classified as factor 1. Copper, Pb and Zn of non-ferrous sulfide origin were classified as factor 2. In particular, enrichment of heavy metals by factor 1 occurs mainly in the serpentine distribution areas of the Chungcheong region, and there is a risk of contamination in neighboring areas. In the case of factor 2, geogenic occurrence is concerned not only in non-ferrous metal mineralization areas such as Taebacksan and Gyeongnam mineralization zones, but also in Au-Ag mineralization areas distributed nationwide.

• Proceedings of the Korean Institute of Resources Recycling Conference
• /
• 2005.05a
• /
• pp.228-230
• /
• 2005

본 연구에서는 생활 폐기물의 소각 바닥재를 사용하여 입도 분리한 후 각 입도별 철 비철 금속이 함유된 바닥재를 자력세기에 따라 분리하였다. 철의 분석결과 4mesh이상의 입자에서 대부분의 철이 회수되었고 4mesh이하에서는 철의 함유량이 적었지만 50mesh 이하의 입자에서는 자력에 의해 대부분 분리되었다. 또한 각 입도에 따른 자력세기별로 철의 회수율을 측정한 결과 $25{\sim}130gauss(30{\sim}150volt)$에서는 낮은 회수율을 보였고 380gauss(150volt이상)의 높은 자력에서만 분리가 일어남을 확인할 수 있었다. 비철은 대부분 4mesh에서 분포하였고 전체적으로 낮은 양이 존재하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.599-600
• /
• 2005

The measurement method of electrical conductivity of the metal use a generally DC technique. Traceability to national standards in many countries is achieved using DC measurement technique and recently it's interested in AC technique. As a results for AC technique, the properties of electrical conductivity of non-ferrous and ferrous metals is decreasing at low frequency level.

• Proceedings of the KSEEG Conference
• /
• 2003.04a
• /
• pp.32-36
• /
• 2003

The mining industry of Japan had rapidly grown after the World War II with the economic growth. There existed more than 350 mines all over Japan in the 1960’s. The mines however had been closed one after another under the influence of the world and domestic economic events such as the mining-related pollution in Japan after the middle of the 60’s, the Oil Crisises in 73 and 79 and the Strong Yen in 85 (Fig. 1). (omitted)