• Resources Recycling
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• v.28 no.3
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• pp.53-58
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• 2019

Pb dross has been generated from recycling processes of waste acid lead batteries, and proper treatment of Pb dross was required because it contains As component, which has been found to be toxic. This study is aimed at concentrating As component by magnetic separation of ground product obtained from ball and mixer milling of Pb dross. No arsenic component was detected in the non-magnetic product of 10000 G magnetic separation using ground product with $-150{\mu}m$ by ball milling, and As could be concentrated upto 18.87 % by further 2000 G magnetic separation. The ball mill ground product with over $300{\mu}m$ was ground again by mixer mill to less than $150{\mu}m$, and then magnetic-separated by 4000 G followed by 2000 G magnet. The As component was concentrated upto 21.021 % in the magnetic fraction of 2000 G. It was confirmed that As component exsit as $Fe_2As$ by XRD measrument. These results indicate that As component could be concentrated from 0.6 % in the Pb dross to 21.021 % in the magnetic fraction by milling followed by magnetic separation.

• Resources Recycling
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• v.10 no.3
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• pp.43-50
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• 2001

Characteristics of crushing and magnetic separation on the spent batteries, were investigated for reclaiming spent carbon-zinc and alkaline manganese dioxide batteries. Crushing of carbon zinc battery was easier than that of alkaline $MnO_2$battery using impact type crusher with rotary blades. Most of magnetic products were distributed in the range of 8 mesh size. With crushing 1 ton of spent carbon-zinc and alkaline $MnO_2$batteries respectively, magnetic separation of 8 mesh oversize particles, we can get 214 kg and 235 kg of magnetic products which is composed of 94% and 88% of Fe.

• Economic and Environmental Geology
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• v.52 no.1
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• pp.1-12
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• 2019

Batch experiments for the soil washing coupled with the magnetic separation process were performed to remediate the soil contaminated with metal and oil wastes. The soil was seriously contaminated by Zn and TPH (total petroleum hydrocarbon), of which concentrations were 1743.3 mg/kg and 3558.9 mg/kg, respectively, and initial concentrations of Zn, Pb, Cu, and TPH were higher than the 2nd SPWL (soil pollution warning limit: remediation goal). The soil washing with acidic solution was performed to remove heavy metals from the soil, but Pb and Zn concentration of the soil maintained higher than the 2nd SWPL even after the soil washing with acidic solution. The 2nd soil washing was repeated to increase the Pb and Zn removal efficiency and the Zn and Pb removal efficiencies additionally increased by only 8 % and 5 %, respectively, by the 2nd soil washing (> 2nd SPWL). The small particle separation from the soil was conducted to decrease the initial concentration of heavy metals and to increase the washing effectiveness before the soil washing and 4.1 % of the soil were separated as small particles (< 0.075 mm in diameter). The small particle separation lowered down Zn and Pb concentrations of soil to 1256.3 mg/kg (27.9 % decrease) and 325.8 mg/kg (56.3 % decrease). However, the Zn concentration of soil without small particles still was higher than the 2nd SPWL even after the soil washing, suggesting that the additional process is necessary to lower Zn concentration to below the 2nd SPWL after the treatment process. As an alternative process, the magnetic separation process was performed for the soil and 16.4 % of soil mass were removed, because the soil contamination was originated from unreasonable dumping of metal wastes. The Zn and Pb concentrations of soil were lowered down to 637.2 mg/kg (63.4 % decrease) and 139.6 mg/kg (81.5 % decrease) by the magnetic separation, which were much higher than the removal efficiency of the soil washing and the particle separation. The 1st soil washing after the magnetic separation lowered concentration of both TPH and heavy metals to below 2nd SPWL, suggesting that the soil washing conjugated with the magnetic separation can be applied for the heavy metal and TPH contaminated soil including high content of metal wastes.

• Journal of Energy Engineering
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• v.4 no.1
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• pp.5-12
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• 1995

본 연구에서는 자력 및 정전기 선별법에 의한 발전용 석탄의 연소전 탈황탈회 가능성 조사를 미국 PETC와 공동으로 수행하였다. 정전기 선별법에 의한 석탄의 탈황실험은 국내무연탄 및 미국 유연탄 시료를 대상으로 수행하였으며, 본 선별법은 석탄으로부터 유황을 함유하는 광물은 물론 회분을 제거하는데 매우 효율적임을 확인하였다. 또한 본 연구에서는 고강도 자력선별기를 이용하여 국내무연탄에 대한 건식자력선별 가능성을 검토하였다. 삼척 및 동원탄광 시료에 대한 입도별 2단계 선별실험을 수행하였으며, 본 실험 결과 동원탄광 시료가 삼척탄광 시료보다 회분제거가 용이하였으며 유황분의 경우는 두 시료 모두 40∼50% 제거가 가능하였다. 기초실험을 통하여 향후 발전용 석탄의 연소전 탈황탈회처리시스템 개발에 필요한 기초자료를 제시하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.181-187
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• 2016

Silica is an essential material in the electronics industries of LCDs and OLEDs, which particularly require high purity. This study attempted to find the optimal design of a magnetic separator for silica sand containing iron compounds using CFD simulation. Three designs of magnetic separation were prepared and their efficiency was examined. As a result of the evaluation, the sufficient contact of particulate silica with the surface of magnetic emitters improved the magnetic separation effects. In addition, the loss of $SiO_2$ and the removal rate of $Fe_2O_3$ depended strongly on the particle size, flow rate and magnetic flux density. In addition, magnetic separation is quite effective for a particle size of $10{\mu}m$ with a 0.2 m/s flow rate.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.5
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• pp.249-255
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• 2017

Using a magnetic separation process, pond ash generated in thermoelectric power plants was separated into magnetic materials and nonmagnetic materials in order to make it into a raw material of geopolymers and unburned carbon; screening characteristics according to the particle sizes and magnet strength levels of the pond ash were observed. Based on the results of magnetic separation into fine particle (0.15~0.84 mm) and rough particle (0.84~2.4 mm) pond ash using 3000 G magnets, the weight fraction and ignition loss of nonmagnetic materials were found to be higher than those of magnetic materials, regardless of the particle size. In the case of fine particle pond ash, when the magnet strength was increased from 3000 G to 10000 G, even those materials that were weakly magnetic were separated into magnetic materials, leading to drastic increases in the weight fraction of magnetic materials, such that the ignition loss accounted for 66.9 % (22.8 wt%) of the entire ignition loss of 32.6 wt%, despite of the low ignition loss. Based on the results of measurement of the compressive strength levels of geopolymers made of magnetic-separated rough particle pond ash, the compressive strength of geopolymers made of magnetic materials containing small amounts of unburned carbon was found to be 20 MPa.

• Resources Recycling
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• v.15 no.6 s.74
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• pp.48-55
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• 2006

This study was carried out for establishing the physical recycling technique for commercializing process on household batteries. The procedure involves shape separator, crushing, magnetic separation, classification and eddy current separation in sequence. The separation capacity was 400-600 unit cell/hr with shape separation system. The impurities such as manganese and zinc in the magnetic product were below 0.1% respectively, the concentration of iron was above 99% in spent carbon zinc battery. Also non-magnetic products are composed of 22-30% En, 16-22% Mn, 1-3% Fe in the case oi spent zinc carbon battery. The amounts of other components such as carbon rod, plastics and separator were about 37-50%. From the eddy current separation of nonferrous products, the plate-type zinc components were separated up to 96% with 2,250-2,750 meter/min of the conveyor speed.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.183-196
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• 2020

This study aimed to recover native gold from the concentrate using microwave-nitric acid leaching and magnetic/hydro separation experiments. The insoluble-residue was filtered from leaching solution through microwave-nitric acid leaching experiment. As a result of the atomic absorption spectrometer(AAS) analysis of the filtered leaching solution, it was discovered that Au content was not eluted at all and it was observed from the back scattered electron(BSE) image that native gold was liberated in the insoluble-residue. When magnetic/hydro separation experiments were applied for the insoluble-residue, magnetic and non magnetic minerals were separtated from insoluble-residue. Magnetite was recovered from the magnetic minerals and as a result of applying the hydro separation experiment again for the non-magnetic mineral, native gold was recovered. The native gold was identified through the X-ray diffraction(XRD) analysis and BSE image.

• Journal of the Mineralogical Society of Korea
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• v.19 no.1 s.47
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• pp.1-5
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• 2006

In this study, we have investigated the purification characteristics of quartz which size was 0.1mm to 0.3 mm by using physical separation techniques. The A and B samples which contained 95,864 mg/kg and 4,568 mg/kg of impurities were reduced upto 126 mg/kg and 174 mg/kg of impurities, respectively. So, removal ratios of the total impurities were about 97.85 wt.% and 96.19 wt.%, individually. At that time, the yields of the purified quartz (over 99.98 wt.% $SiO_2$) were 79.05 wt.% and 75.43 wt.% by using purification process including magnetic separation, gravity separation and scrubbing process. The most benefit in purification process of both different raw materials for iron element can be achieved by magnetic separation. Also, gravity separation is extremely successful for reducing aluminium element.

• Journal of the Mineralogical Society of Korea
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• v.30 no.3
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• pp.103-112
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• 2017

In order to transform arsenopyrite into pyrrhotite and to decrease As content by less than 2,000 mg/kg, pulp sample and non-magnetic pulp sample were heated in a microwave oven at different heating times and were separated through wet-magnetic separation. As the microwave heating time increased, the phase of pyrrhotite was extended to become arsenopyrite entirely. The melting pores and micro-cracks occurred on the pyrrhotite due to hot spot phenomenon with microwave heating. The heated raw pulp sample (As content : 19,970.13 mg/kg) and non-magnetic pulp sample (As content : 19,970.13 mg/kg) which were heated in a microwave oven for 10 minutes were separated through wet-magnetic separation and magnetic fraction containing less than 2,000 mg/kg of As content was recovered only from the heated sample of magnetic separation. It was discovered that for the sulfide complex ore with As penalty imposed on, if microwave heating and wet-magnetic separation are effectively utilized, magnetic fraction. We expect to be able to obtain ore minerals with an arsenic content below the penalty charge.