• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.6
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• pp.299-304
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• 2012

Geopolymer was made using magnetic separation fly ash with NaOH(Sodium Hydroxide) and the water glass as alkali activators in this study. Compressive strength of geopolymers ceramics was measured and analyzed according to the type of materials. Under the conditions of fly ash without magnetic separation and 28 day curing after molding, the compressive strength of the geopolymer reached up to 28 MPa.

• Resources Recycling
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• v.11 no.3
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• pp.31-36
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• 2002

Magnetic separation was carried out in order to improve the magnetite grade of the spent iron oxide catalyst, that was composed with magnetite, ceria and soluble alkaline salt. The recovery of magnetite from the spent iron oxide catalyst was over 99%, and the magnetite contents was upgraded to about 80% from 70% via wet type magnetic separation at 500 Gauss. This improvement was due to the removal of alkaline salt by water instead of the magnetic separation.

• Resources Recycling
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• v.27 no.6
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• pp.11-22
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• 2018

Magnetic separators has been used in the mining and the recycling fields in general, and is still applied in wide variety of fields. It is classified into the equipments for separating coarse ferrous scrap from non-ferrous materials and the equipments for concentrating fine ferromagnetic particles below 3mm. Magnetic separation equipments for concentrating fine materials also falls into two categories of low intensity and high intensity magnetic separators. The former is used for ferromagnetic materials but also paramagnetic materials of high magnetic susceptibility, and the latter for paramagnetic materials of lower magnetic susceptibility. Both low and high intensity magnetic separators could be utilized either dry and wet. Recently, the High gradient magnetic separators(HGMS) used in the range of less than 0.7 tesla has been gradually replaced by the magnetic separator made of rare earth permanent magnets commercialized in the 1980s. In addition, the expansion of nanotechnology in terms of synthetic magnetic materials in the environmental and biological fields is expected to contribute positively to the development of magnetic separation technology.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.240-242
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• 2005

본 연구에서는 생활폐기물 소각장에서 발생하고 있는 바닥재를 이용하여 각 입도에 대해 자력의 세기에 따라 철/비철선별 하였다. 자력의 세기에 따른 분리량과 분리된 산물의 철함 유량을 조사함으로써 자력 및 비철 효율을 파악하고자 하였다. 또한, 비철 선별기를 사용하여 비철 선별 효율을 조사하였다. 자력선별결과, 자력의 세기가 증가할수록 자력선별에 의해 분리량이 증가하였으나, 분리된 산물의 철함유량은 감소하는 경향을 나타내었다. 이러한 결과는 자력세기의 증가가 철회수량의 증가보다는 불순물의 혼입량을 증가시키는 것으로 생각된다. 비철의 경우, 입자크기가 커짐에 따라 분리율이 높았으며, 4.75mm이상에서는 대부분의 비철이 회수되었다.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.217-227
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• 2009

Heavy minerals in the marine sand near Haeju bay, Hwanghae-do, North Korea were separated using the gravity and the magnetic separators. And their mineralogical study was carried out. Ilmenite, magnetite, hematite, zircon and monazite were observed as the valuable minerals, and quartz, orthoclase, muscovite, hornblende and garnet existed as gangue minerals. In the result of quantitative analysis with SIROQUANT program, the contents of the valuable minerals separated with the 2nd gravity separation (the shaking table separation), the 1st magnetic separation (rare earth magnetic separation) and the 2nd magnetic separation (the Eddy current magnetic separation) were increased into 4%, 10% and 76~89% (under the condition of 7000 G and 10000 G in magnetic strength), respectively. The contents of ilmenite, monazite and zircon recalculated from the chemical composition differed from the results of the quantitative analyses by SIROQUANT program, but the entire tendency bears some analogy with it. Under the conditions of 7000 G and 10000 G in 2nd magnetic separation the contents of ilmenites were concentrated with 53% and 66%, respectively. The content of monazite was 1.2% in the magnetic fractions of the 1st magnetic separation. The content of zircon was shown 1.4% under the condition of 10000 G in the 2nd magnetic separation, and was displayed 9% in +50 mesh of non-magnetic fraction of 1st magnetic separation, especially.

• Resources Recycling
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• v.16 no.6
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• pp.3-9
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• 2007

Although the ferrous material was separated by the magnetic separation before the incineration process, the municipal solid waste incineration bottom ash generated during incinerator in metropolitan area consists of many iron products which account for about $3{\sim}11%$ as well as ceramics and glasses. The formation of $NiFe_2O_4$ and $FeCr_2O_4$ with a $Fe_3O_4-Fe_2O_3$ (similar to pure Fe) on the surface of iron product was found during air-annealing in the incinerator at $1000^{\circ}C$, because Ni and Cr has a chemical attraction about iron is using to coat with Ni and Cr metals for poish or to prevent corrosion. Therefore, Fe-Ni Cr oxide can be formed on durface of the iron product and it can be separated from bottom ash through the magnetic separation. So, in this study, the separation ratio of heavy metals as magnetic separation and mineralogical formation of Fe-ion(heavy metal) in ferrous metals corroded were investigated. As the result, the separation ratio of Ni and Cr based on particle sizes accounted for about $45{\sim}50%$, and Cu and Pb accounted for below 20%. Also, the leaching concentration of Ni and Cr in bottom ash separated by magnetic separation was lower than that in fresh bottom ash.

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.297-302
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• 2001

• Proceedings of the KSEEG Conference
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• 2001.04a
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• pp.291-296
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• 2001

• Proceedings of the KSEEG Conference
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• 2002.04a
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• pp.217-220
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• 2002

• Journal of the Mineralogical Society of Korea
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• v.24 no.1
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• pp.1-17
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• 2011

Mineralogical study was carried out for heavy minerals in the sea sand near Ongjingun bay, Kyonggi-do separated using the gravity and magnetic separators. Ilmenite, zircon and minor monazite and garnet were valuable minerals with gangue minerals of quartz, K-feldspar, plagioclase, muscovite, hornblende, epidote and chlorite. Quantitative analysis with SIROQUANT program showed that the contents of ilmenite separated with the gravity separation (the shaking table separation), the 1st step magnetic separation (rare earth magnetic separation) and the 2nd step magnetic separation (the Eddy current magnetic separation) were increased into 0.8, 18.3, and 48.7%, respectively. The content of ilmenite, monazite and zircon were recalculated based on the chemical composition of the representative and heavy fraction products of raw sand, the 1 step and 2 step gravity separations, and the 1 step and 2 step magnetic separations. The content increased to 0.23, 0.55, 5.22, 16.17, and 44.99% in ilmenite, 0.11, 0.02, 0.16, 0.51, and 1.19% in monazite. Although the zircon content did not differ over the processes (0.13, 0.12, 0.11, 0.15, and 0.10%), the improved recovery of zircon is expected by applying sieving process because of its high content (27%) in the fine grain size fraction (< 140#) of the 2 step gravity separation.