• Resources Recycling
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• v.28 no.6
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• pp.96-105
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• 2019

Automobile shredder residue (ASR) is the final waste produced when end-of-life vehicles (ELVs) are shredded. ASR can be separated using mineral-processing operations such as comminution, air classification, magnetic separation, and/or electrostatic separation. In this work, trajectory analyses of conductors (copper) and non-conductors (glass) in the ASR have been carried out using induction electrostatic separator for predicting or improving the ASR-separation efficiency. From results of trajectory analysis for conductors, the trajectories of copper wire by observation versus simulation for coarse particles of 0.5 and 0.25 mm showed consistent congruity. The observed 0.06 mm fine-particles trajectory was deflected toward the (-) attractive electrode owing to the charge-density effects due to the particle characteristics and relative humidity. In the case of non-conductors, the actual trajectory of dielectric glass deflected toward the (-) electrode, showing characteristics similar to those of conductive particles. The analyses of stereoscopic microscope and SEM & EDS found heterologous materials (fine ferrous particles and conductive organics) on the glass surface. This demonstrates the glass decreasing separation efficiency for non-ferrous metals during electrostatic separation for the recycling of ASR. Future work will require a pretreatment process for eliminating impurities from the glass and advanced trajectory-simulation processes.

• Journal of the Korea Society of Computer and Information
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• v.28 no.4
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• pp.105-112
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• 2023

In this paper, we propose a new method for displaying colored defects by measuring the relative density with the wide-area and local densities of X-ray. The relative density of one pixel represents a relative difference from the surrounding pixels, and we also suggest a colorization of X-ray images representing these pixels as normal and defective. The traditional method mainly inspects materials such as plastics and metals, which have large differences in transmittance to the object. Our proposed method can be used to detect defects such as sprouts or holes in images obtained by an inspection machine that detects X-rays. In the experiment, the products that could not be seen with the naked eye were colored with pests or sprouts in a specific color so that they could be used in the agricultural product selection system. Products that are uniformly filled with a single ingredient inside, such as potatoes, carrots, and apples, can be detected effectively. However, it does not work well with bumpy products, such as peppers and paprika. The advantage of this method is that, unlike machine learning, it doesn't require large amounts of data. The proposed method could be applied to a screening system using X-rays and used not only in agricultural product screening systems but also in manufacturing processes such as processed food and parts manufacturing, so that it can be actively used to select defective products.

• 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.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.289-302
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• 2007

Separation process of heavy minerals was performed with sand from Dunjang beach of Jaeundo, Shinangun, Chonnam, and the feasibility study separating heavy minerals was carried out, and their properties were studied. Samples were selected in three parts, which were upper part, middle part and lower part, with depth. Samples of heavy mineral groups separated with the spiral separator were chosen as starting materials, and they were separated with 3 times of table separation. Heavy minerals presenting in this area were ilmenite, zircon, rutile, anatase, monazite, and xenotime. In the results of 3 times of table separation, minor content of quartz, orthoclase, albite and muscovite were existed as gangue minerals. Accordingly, we concluded that additional specific gravity separation was needed. In the results of separation of heavy minerals by hand picking, it was confirmed that heavy minerals had various genesis because of their various roundness and color.

• Resources Recycling
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• v.5 no.4
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• pp.25-31
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• 1996

The wastes ot l~mestone mines have been cause the extrar.ngance of the valuablz m e r a l s and destruction of the environment. Therefore, \\-c tied ta separation of calcite illid clay from the limestone mine wastes by rotntmg screen type separator made by ourselves in order to recyding such us a raw matcriala for cement maimfacture. CaO amtents in the separated coarse products increased from 37.36 wt% to 42+2 wt% at the condition ihat water content in wastes was lzss than 6wt%, the passing time of specimen in &amber was 15 semnds and the rotation speed was 6OLl qm. A process in order lo separate wastes effectively to having wide range aI part~dcs ize was cstablishcd and CaO contents of coarsc products through this process increased to 46.85 wt%. Tbis rcsult is insuEiicient to directly rcusing as a raw malerials for cement. However, it is supposed that coarse products would be able to be reuscd as a raw materials uf cement, if only it rs sclected dolomite in wastes, and really it may be possible in fields Othenvise, undcrsize products(less than 20 mm) would be able to recycling as a raw of cement bccause chcmicrl campasitions of thosc is kept almost constant v&cs on the overall process.

• Resources Recycling
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• v.8 no.3
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• pp.9-17
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• 1999

The study investrgated the properti es of lh$\xi$ dust~ from felToalloy manufacture, The chemical composition, composItron material, particle size and shapes of the bulk dust, sized dust and magnetically separated dust were llivestigated. As the result, we s suppose that the dust from HLgh Carbon Fenomauganesc Manufacturing Process is not sufficient as soource material of Mn because of the low Mn conteut (13.5%) aud complicated composition material The dust from Bag Filter of AOD Process is m mainly made up of $0.2~2\mu\textrm{m}$ $Mn_3O_4$ (Hausmatmite) particle in spherical shape and the Mn content is 63.1%. The dust from Cooler of AOD Process is mainly made up of coarse $Ca(OH)_2$ Mn, $Fe_yO_2$ $SiO_2$ and fine $Mn_3O_1$.

• Clean Technology
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• v.27 no.1
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• pp.24-32
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• 2021

Unburned carbon (UC) was successfully separated from fly ash by up to 85.8% in weight via froth flotation using soybean oil as a collector. An 18 wt% yield of microceramics (CM) could be achieved by employing a hydro cyclone separator located immediately after the flotation equipment. UC and CM were tested as alternatives to weight-adding material and polymer (especially polypropylene in this study) filler, respectively. Large particles of UC were broken down into smaller ones via ball milling to have an average particle diameter of 10.2 ㎛. When crushed UC was used as an alternative to clay as a rubber weight-adding material, a somewhat lower tensile strength and elongation rate than the allowed values were unfortunately obtained. In order to satisfy the standard limits, further treatment of UC is required to enhance surface energy for more intimate bonding with rubber. CM was observed in spherical forms with an average diameter of 5 ㎛. The surface of the CM particles was modified with phenol, polyol, stearic acid, and oleic acid so that the surface modified CM could be used as a polypropylene-filling agent. The flowability was good, but due to the lack of coupling forces with polypropylene, successful impact strength and flexural strength could not be obtained. However, when mixing the surface-modified CM with 1% silane by weight, a drastic increase in both the impact strength and flexural strength were obtained.

• Resources Recycling
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• v.11 no.2
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• pp.20-27
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• 2002

This study was to develop the triboelectrostatic separation technique to recycle the coal from about 20% of mill reject products remained by grinding process in the coal thermoelectric power plant. In this study, we get a test results that can product the cleaned coal of 15% ash content and 66.23% recovery from mill reject of 47% ash content. And then, from the result of the releases analysis, we proved the excellence of treatment method, after showing the treament processing which is able to get 80% of recovery of coal from 20% of ash content demanded in the power plant.

• Resources Recycling
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• v.33 no.2
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• pp.24-36
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• 2024

The lithium-ion battery recycling process has been classified into direct recycling, hydrometallurgical process, and pyrometallurgical process. The commercial process based on the hydrometallurgical process produces black mass through pretreatment processes consisting of dismantling, crushing and grinding, heat treatment, and beneficiation, and then each metal is recovered by hydrometallurgical processes. Since all lithium-ion battery recycling processes under development conducts hydrometallurgical processes such as leaching, after the pretreatment process, to produce precursor raw materials, this article suggests a classification method according to the pretreatment method of the recycling process. The processes contain sulfation roasting, carbothermic reduction roasting, and alloy manufacturing, and the economic feasibility of the lithium-ion battery recycling process can be enhanced using unused by-products in the pretreatment process.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.217-218
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• 2015

주석은 최근 첨단 전기, 전자 제품의 핵심 소재로써 지속적인 수요 증가가 예상되는 전략 금속이다. 국내의 수요량은 2011년 기준 약 17,000톤 으로 99% 이상 수입에 의존하고 있는 실정이다. 그러나, 국내의 주석 제련 산업은 전무한 상태이며 폐자원에서 재활용하는 회수 기술도 초보 단계이다. 이러한 폐자원 발생량은 12,000톤/year이며, 약 1200억원에 달하는 규모이다. 다양한 폐자원의 선별적 전처리 요소 기술 개발 및 회수 공정 시스템 개발이 절실히 요구된다. 본 연구에서는, 주석 폐자원 중 solder 용융물 및 공정 스크랩 Lead solder, Lead-free solder 등 뿐만 아니라, ITO target 제조 시 발생하는 ITO sludge 등의 고상 폐자원으로부터 페자원의 물성을 파악하여 금속/산화물과의 파/분쇄 및 분급공정을 통하여 고품위의 주석 금속을 회수하였다. 뿐만 아니라, 고순도 주석시 발생하는 양극 슬라임 침출액 등의 액상 폐자원으로부터 희소금속의 추출 및 회수를 위해 습식 전처리 공정을 수행하였다. 침출액은 주석, 구리, 납 등의 유가금속이 이온형태로 존재하고 있으며, Chlorine이 다량 함유되어 있다. 고품위의 주석 산화물을 회수하기 위하여 침출액 내의 구리 제거 공정, Chlorine 제거 공정 등을 순차적으로 수행하여 고품위의 산화물 회수를 수행하였다.