• Resources Recycling
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• v.13 no.2
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• pp.33-38
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• 2004

Concepts and experimental results for the unique utilization process which we could obtain the high purity calcium nitrate from blast furnace slag in the steel industry are described. Firstly we reacted the blast slag with nitric acid and separatively removed the insoluble silica by filtration. We adjust the pH of filtrate to 6∼8 with calcined lime, and then precipiated out the metal components like Fe, Al, Mg in the forms of hydroxides. Consequently concentration of the mother liquor and crystallization processes make us obtain the high purity (>98 wt%) calcium nitrate tetrahydrates, which is expected the valuable fertilizers.

• 한국연소학회:학술대회논문집
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• 2004.06a
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• pp.329-349
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• 2004

• 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 Korea Concrete Institute Conference
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• 2010.05a
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• pp.251-252
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• 2010

In this study, the basic properties of high performance concrete, to used oxidized electric-furnace-slag(EFS) aggregate, were examined. So we presented the possibility of using ㄸ EFS as concrete's aggregate.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.97-103
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• 2000

This study was performed to prove that vitrified slag can be utilized as sound absorbing materials by investigating on heavy metal elution and the properties of sound absorbing rate according to the thickness. The heavy metal elution experiment indicated that heavy metal was not eluted since it was fixed stable in the slag. Vitrified slag generally exhibited a maximum sound absorbing rate around at 600Hz-1kHz and 3kHz in the low and high frequency range, respectively. On the other hand, the absorbing rate increased beyond the range of 7kHz again. The sound absorbing rate varied a little according to the thickness of the material. However, Vitrified slag is likely to the effective as a sound absorbing wall material since it has a sound absorbing rate clover 80% in the low and high frequency region when used as a wall. The results obtained in this study showed that vitrified slag has the recyclable material properties and therefore, highly applicable to sound absorbing materials.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.471-478
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• 2012

The objective of the study is to find a way to utilize MSWI slag as filter material and to verify it. To do so, stability as filter material was tested, and used Ju-Munjin filter sand as control group to run actual filtering experiment to analyze filtering efficiency. According to result, MSWI slag is usable within designated waste acceptable standards. Also, it showed similar level of filtering capability to filter sand. Thus, MSWI slag could help to save and recycle resources if used as filtering material instead of filter sand As result of filtering test, SS and COD showed about same level of filtering capability similar to standard filter sand. MSWI slag has shown 26.96% higher with T-N, and 6.55% higher with T-P compared to standard filter sand. Also, remove efficiency comparison result with No. 40#(0.43mm) and mixed diameter showed equal or greater filtering capability.

• Ceramist
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• v.20 no.1
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• pp.103-118
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• 2017

1. 2014년도 우리나라 전체 폐기물 발생량은 146,607천 톤이며, 건설폐기물이 46.2%(67,644천 톤), 사업장 일반폐기물이 38.1%(55,914천 톤), 생활폐기물이 12.4%(18,219천 톤), 사업장 지정페기물이 3.3%(48,810천 톤)을 나타내고 있다. 2. 건설폐기물의 97.9%, 배출시설계 폐기물의 77.3%, 생활폐기물의 67.0%, 지정폐기물의 57.3%가 재활용되고 있다. 3. 2015년도 우리나라 시멘트산업에서 18,801천 톤의 순환자원을 재활용하였다. 폐기물이 6,136천 톤이고, 부산물이 12,665천 톤이다. 부산물은 11,000천톤이 제철슬래그이고, 1,600천 톤이 폐석고(탈황석고 중화석고)로 추정된다. 그리고 폐기물 6,136천 톤은 사업장 일반폐기물의 약 11.0%에 해당된다. 4. 시멘트 톤당 순환자원 사용량(재활용 원단위)은 일본이 400kg/톤 이상이고 우리나라는 300kg/톤 대를 나타내고 있다. 일본이 우리나라보다 재활용량/톤이 많은 이유를 다음에서 찾을 수 있다. (1) 고품위 석회석 원료 (2) 법 제도(지원금 포함) 5. 원료 대체율의 산출은 다음 두 산출방법으로 나타낼수 있다. (1) 이론적인 원료 상한 대체량에 대한 실제 원료 대체량 (2) 이론적인 원료 조합량에 대한 실제 원료 대체량 2015년도 우리날 전체 원료 대체량(17,770천 톤)은 (1)에 의한 대체율 : 71% (2)에 의한 대체율 : 27% 6. 자동차 슈레더 더스트(ASR)를 시멘트산업에서 자원화 하게끔 ASR처리의 보완 및 법적지원(지원금 포함)이 요망된다. 7. 부산물 및 폐기물의 자원화는 시멘트산업에서의 이용이 가장 우수한 장점을 갖추고 있다. 그러므로 시멘트산업에서 폐기물의 자원화를 적극 추진하게끔 제도의 보완 및 시설지원 등 정부의 대책수립이 간절하다.

• Resources Recycling
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• v.21 no.1
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• pp.30-40
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• 2012

Electric arc furnace slag is made in ironworks during steel refining, it is been increasing chemical and physical resistibility using ageing method of unstable state of melting steel slag for using concrete's fine aggregates. Which is been changing stable molecular structure of aggregates, it restrains moving of ion and molecule. In Korea, KS F 4571 has been prepared for using the electric arc furnace oxidizing slag to concrete aggregates(EFS). In this study, Electric arc furnace oxidizing slag is used in the PRCC(Polymer Rapid setting Cement Concrete) which is applied a bridge pavement of rehabilitation, largely. The results showed that the increment of compressive strength development by 10- 20%. The flexural strength of EFS-Con increased greatly as the electric arc furnace oxidizing slag changed. The compressive strength and flexural strength developed enough for opening the overlayed EFS-Con to the traffic after 4 hours of EFS-Con placement. The permeability of EFS-Con was evaluated as negligible due to its very low charge passed. Thus, EFS-Con could be used at repairing or overlaying the concrete at fast-track job sites.

• Resources Recycling
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• v.22 no.2
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• pp.62-70
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• 2013

Electric arc furnace slag is made in ironworks during steel refining, it is been increasing chemical and physical resistibility using ageing method of unstable state of melting steel slag for using concrete's fine aggregates. Which is been changing stable molecular structure of aggregates, it restrains moving of ion and molecule. In Korea, KS F 4571 has been prepared for using the electric arc furnace slag to concrete aggregates. In this study, Electric arc furnace slag is used in the PMC(Polymer Modified Concrete) which is applied a bridge pavement of rehabilitation, largely. In that case, this study evaluates the structural safety about increasing the specific weight. The 4-type bridges(RC slab bridge, RC rigid-frame bridge, PSC Beam bridge, Steel box girder bridge) pavement's increasing the total dead load is in 1 ~ 2%. Design moments in a load combination are increased less then 2%. safety factor is decreased less than 3%. Therefore, the structural safety has no problem for applying the electric arc furnace slag within PMC in bridge.

• Resources Recycling
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• v.23 no.3
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• pp.30-36
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• 2014

A large amount of waste copper slag containing about 35 ~ 45% iron has been generated and discarded every year from pyrometallurgical processes for producing copper from copper concentrate. Thus, recovery of iron from the waste copper slag is of great interest for comprehensive use of mineral resource and reduction of environment problems. In this study, a physico-chemical separation process for upgrading iron from the waste copper slag discharged as an industrial waste has been developed. The process first crushes the waste copper slag below 1 mm (first crushing step), followed by carbon reduction at $1225^{\circ}C$ for 90 min (carbon reduction step). And then, resulting material is again crushed to $-104{\mu}m$ (second crushing step), followed by wet magnetic separation (wet magnetic separation step). Using the developed process, a magnetic product containing more than 66 wt.% iron was obtained from the magnetic separation under a magnetic field strength of 0.2 T for the waste copper slag treated by the reduction reaction. At the same conditions, the percentage recovery of iron was over 72%. The iron rich magnetic product obtained should be used as a iron resource for making pig iron.