• Resources Recycling
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• v.24 no.1
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• pp.28-34
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• 2015

Generally, when using copper slag mixed into the concrete, due to higher weight of copper slag, a reduction in the compressive strength and durability of the hardened concrete to increased bleeding is caused. In this study, hence copper slag, a kind of by-product was used as an alternative to the fine aggregate, it was carried out in combination with the use of fly ash in eliminating disadvantage and recycling aspects. As a result of this study, the mixing of fly ash is decreased in the 50% of bleeding, 5% of drying shrinkage, 30% of carbonation test and improvement of 10% of compressive strength than that of copper slag only at most.

• Resources Recycling
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• v.11 no.3
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• pp.46-59
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• 2002

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.503-507
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• 2001

In this paper the forming and the unique properties of PZH blast furnace slag, bearing TiO$_2$ 22~25%, have been introduced. The utilization of this kind of blast furnace slag, especially about recycling resource of TiO$_2$included in it, has been reviewed and discussed. According to research work experiences and tendency of new materials developing some suggestions about future research on PZH blast furnace slag have been put forward.

• Resources Recycling
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• v.16 no.3 s.77
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• pp.27-33
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• 2007

It is very important in the view point of resource recycling to recover valuable metals such as copper and tin from waste electric and electronic scrap. The waste electric and electronic scrap contains significant amounts of copper, tin, and so on. In this study, a new process for extracting copper and tin contained in the waste electric and electronic scrap using waste copper slag which is generated from the melting furnace of copper smelter was presented. Advantage of the proposed process is to reuse waste copper slag instead of new fluxes as slag formatives. In each experiment, the waste electric and electronic scrap and waste copper slag were melted inputting suitable amount of CaO as an additional flux. Up to 95% of copper and 85% of tin in the raw material were extracted in a Cu-Fe-Sn alloy phase.

• Resources Recycling
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• v.11 no.6
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• pp.24-30
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• 2002

Reduced and modified converter slag was ball milled and sieved to -200/+325 mesh. CaO,$SiO_2$, $Fe_2$$O_3$ was added to slag powder and mixed to make it similar to the composition of normal portlant cement. The pellet made of this powder was heated from $1250^{\circ}C$ to $1450^{\circ}C$ for 15 min～45 min. Most feasible condition for making slag cement clinker is the heating more than 20 min at $1450^{\circ}C$. The compressive strength of the mortar made of this slag cement clinker was better than that of normal port-lant cement in long time curing.

• Resources Recycling
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• v.9 no.1
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• pp.52-62
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• 2000

In order to maximize the recycling of converter slag to the more valuable fields, such as high quality aggregates for construction, cement industry and flux for ion making. It will be very important to control the compositions and properties of converter slag to suit the purpose of utilizastion. In this study, converter slag (STELCO, CANADA) was mixed with 5%~30% $SiO_2$and 7% carbon, and then reduced at $1650^{\circ}C$. After the reduction was completed, the reformed slags were cooled to room temperature in the furnace. All of the slags were then characterized using SEM-EDX, XRD and chemical analysis. Also the compressive strengths and densities of the reformed slags were measured to compare with natural aggregates. XRD analysis shows that th phases of reformed slags are changed from bredigite+merwinite mixed phases of 10% $SiO_2$added reduction to akermanite phases of 20% and 30% $SiO_2$ added reduction. But the SEM-EDX analysis revealed that the phase distribution of the reformed slags was changed very sensitively and complicately depends on the change of slag compositions. And also the properties of reformed slags are changed very much depend on the phase distribution. About one third of Cadmium and on fifth of Vanadium are remained in reduction reformed converter slag. Another heavy metal elements such as cobalt, zinc, lead are removed up to more than 90-95% of original slag. The compressive strength and density of 25% $SiO_2$ added and reformed slag is very near to natural granite. This is superior more than 10% to Thyssen's $SiO_2$ added and oxidized converter slag aggregates.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2001.05a
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• pp.339-344
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• 2001

• Resources Recycling
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• v.6 no.4
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• pp.17-23
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• 1997

• Resources Recycling
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• v.16 no.4
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• pp.33-39
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• 2007

Titanium scrap was re-melted and refined by using a DC-ESR (Direct Current Electro Slag Remelting) apparatus. A graphite rod was used as an anode. The used slag was $CaF_2-TiO_2-CaO$ slag system. The effect of slag composition on the shape and oxygen content of re-melted ingot was studied. The titanium ingot was produced very well from the $CaF_2-TiO_2$ slag system, and the oxygen content of the ingot was less than that of titanium scrap. The addition of CaO into $CaF_2-TiO_2$ slag system made the bad shape of titanium ingot. The oxygen content of the ingot was also higher than that of titanium scrap.

• Journal of Environmental Impact Assessment
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• v.5 no.2
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• pp.21-31
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• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.