• Title/Summary/Keyword: Slag recycling

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Studies of the Recovery of Iron Content from Iron and Steel-Making Slags by Magnetic Separation (자력 선별에 의한 철강 슬래그로부터의 철분 회수에 관한 연구)

  • Ban Bong-Chan;Yu Sung-Nam;Kim Dong-Su
    • Resources Recycling
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    • v.12 no.5
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    • pp.36-41
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    • 2003
  • Although slag has an enough potential as the secondary resources due to its high content of iron, quite a large amount of slags are simply landfilled when market prices of iron and steel are not so beneficial. The purpose of this study is to investigate the basic characteristics regarding the recovery of iron content from slag by magnetic separation method for the enhancement of its recycling rate. Three kinds of slags such as blast furnace slag, water-cooled converter slag, and air-cooled converter slag were tested taking the strength of magnetic field, revolving speed of drum, and feeding rate of slag as the influential factors on the magnetic separation. For blast furnace slag, the recovery of iron was observed to increase as drum speed and feeding rate were lowered. For water-cooled converter slag, iron recovery was raised as feeding rate was increased and drum speed was lowered. Also, finer slag particles were observed to be more favorable for the higher recovery of iron content. Regarding air-cooled converter slags, higher iron recovery was accomplished when both feeding rate and drum speed were increased or decreased. In addition, when the magnetic field strength was increased the iron recovery was raised, however, the iron grade of separated product was observed to diminish because of the co-separation of impurities.

The Phenomenon of the Slag Foaming and the Result of using Various Slag Deforming Agents in the Steelmaking Converter (제강(製鋼) 전로(轉爐) 정연시(精鍊時) 슬래그 폼(Slag Foam)발생(發生) 현상(現像) 및 진정제(鎭靜劑) 종류(種類)에 따른 사용효과(使用效果))

  • Chun, Sang-Ho;Song, Choong-Ok;Ban, Bong-Chan
    • Resources Recycling
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    • v.15 no.2 s.70
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    • pp.18-23
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    • 2006
  • Foaming of slag is a thermodynamically unstable phenomenon and has significant effects in iron and steelmaking processes. For better recycling method of pulp sludge, the application as an defoaming agent during steelmaking process was adopted and tested. The forming machine has been modified in order to produce the briquettes, which are made of pulp sludge and slag with different weight ratio. Influencing factors on the foaming phenomena have been studied and tested for better understanding of foaming phenomena. Experiments were carried out with $CaO-FeO-SiO_2$ based slags with Ar gas injection and addition of coke particles. The slag basicity and (%FeO) contents adapted as major factors to treasure foaming tendency of the slag system. It was found that foam index (${\Sigma}$) gradually decreased as both the basicity and the (FeO) content increase. Four kinds of antifoaming agent such as aluminium dross, cokes, rice bran and pulp sludge with steelmaking slag have been tested in actual process. Aluminium dross was the most effective, and pulp sludge with steelmaking slag also showed the desired results.

Properties of Alkali-activated Slag-Red Mud Soil Pavement Using Recycled Aggregate (순환골재를 사용한 알칼리활성화 슬래그-레드머드 흙포장재의 특성)

  • Kang, Suk-Pyo
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.4 no.3
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    • pp.276-283
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    • 2016
  • Red mud is an inorganic by-product produced from the mineral processing of alumina from Bauxite ores. the development of alkali-activated slag-red mud cement can be a representative study aimed at recycling the strong alkali of the red mud as a construction material. This study is to investigate the optimum water content, compressive strength, moisture absorption coefficient and efflorescence of alkali-activated slag-red mud soil pavement according to the recycling fine aggregate content. The results showed that the optimum water content, moisture absorption coefficient and efflorescence area of alkali-activated slag-red mud soil pavement increased but the compressive strength of that decreased as the recycled fine aggregate content increased.

Preparation of Glass-Ceramic by Recycling of Various Slags and Its Properties (다종슬래그를 재활용한 Glass-Ceramic의 제조 및 물성)

  • Lee, Duk-Hee;Shin, Dongyoon;Yoon, Mijung;Park, Hyun Seo;Yoon, Jin-Ho
    • Korean Journal of Materials Research
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    • v.26 no.5
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    • pp.266-270
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    • 2016
  • Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based high-strength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance cast-basalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker's hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.

Present State and Prospect on Reutilization of Metal - Bearing Solid Wastes in China

  • Chai, Liyuan;Chen, Weiliang;Min, Xiaobo;He, Dewen;Zhang, Chuanfu
    • Proceedings of the IEEK Conference
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    • 2001.10a
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    • pp.183-187
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    • 2001
  • Present states on reutilization of metal-bearing solid wastes in China including metal-containing gangue, red mud, nonferrous metallurgical slag or residue, arsenical slag, steel - iron slag, waste batteries, were described in detail. The wastes pile up at a large quantity, resulting in seriously potential harm to environment. Most of these wastes, however, contain valuable metals, which are regarded as important secondary resources for extracting metals. Waste slag and batteries with a high grade of metals are treated by a hydro-based and / or pyre-based method for extracting valuable metals. While gangue and waste slag with a low grade are as a raw material in architecture field. In the future, a novel technology, such as high-grads magnetization separation technique and biological technique, will be designed to treat these wastes for protecting environment and recycling valuable components. These wastes, furthermore, are synthetically reutilized to produce various architectural materials, including glass and ceramics.

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