• Journal of the Korea Concrete Institute
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• v.17 no.1 s.85
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• pp.141-147
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• 2005

The development of automobile, vessel, rail road, and machine industry leads an increase of foundry production used as their components, which cause a by-product, waste foundry sand (WFS). The amount of the WFS produced in Korea is over 700,000 tons a year, but most WFS has been buried itself and only $5{\~}6\%$ WFS is recycled as construction materials. Therefore, it is necessary for most WFS to research other ways which can be used in a higher value added product. The study on recycling it as a fine aggregate for concrete or green sand has been in progress in America and Japan since 1970s and 1980s respaectively. In this study, two types of WFS were used as a fine aggregate for concrete. Nine types of concrete aimed at the specified strength of 30 MPa were mixed with washed seashore coarse sand in which salt was removed, and WFS and then appropriate mixture proportion of concrete was determined. Moreover, basic properties such as air contents, setting time, bleeding, workability and slump loss of the fresh concrete with WFS were tested and compared with those of the concrete mixed without WFS. In addition, both compressive strength of hardened concrete at each ages and tensile strength of it at the age of 28 days were measured and discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.137-142
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• 2018

Recycled synthetic resin materials produced from waste vinyl and waste plastic contain many foreign substances. Plastic products made from this recycled resin materials containing foreign substances are of poor quality, with reduced the strength and rigidity. Foreign substances include heavy metals, cement, foil, dyed paper and dust. In this study, the scratch-Dies process; which remove foreign sbustances, with precision and automation, through a three-stage mesh filter, is designed. The process is evaluated with finite element analysis according to vibration loading and make. After installing the manufactured equipment, recycled resin was producde, and its heavy metal content was evaluated. Recycled synthetic resin materials were also used plastic products and evaluate their strength. In addition, the change in production was assessed.

• Advances in Energy Research
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• v.3 no.3
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• pp.167-179
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• 2015

This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

• Resources Recycling
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• v.16 no.2 s.76
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• pp.63-76
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• 2007

Typical examples as unrecycled materials in Korea were Zinc from the electric arc furnace dust (EAF Dust), and Moiybdenium and Vanadium from the desulfurizing spent catalyst of petrochemical industries. In the otherwise, though recovery of valuable metals from the waste electronic scrap such as printed circuit boards (PCBs) and platinum group metals (PGM) from the waste automobile catalyst have been interesting issues, it is difficult to collect the exact informations or statistics on their material flow system. In this article, The current domestic research trends for unrecycled or less recycled materials have been reviewed, and material flow and recycling technologies on the desulfurizing spent catalyst were surveyed.

• Resources Recycling
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• v.27 no.1
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• pp.22-30
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• 2018

In order to industrially recycle nickel, cobalt and rare earth elements included in waste NiMH batteries, electrode powder scraps were recovered by dismantle, crushing and classification from automobile waste battery module. As a result of leaching recovered electrode powder scrap with sulfuric acid solution, 99% of nickel, cobalt and rare earth elements were leached under reaction conditions of 1.0 M sulfuric acid solution, pulp density 25 g/L and reaction temperature $90^{\circ}C$ for 4 hours. In addition, the rare earth elements were able to separate from nickel / cobalt solution as cerium, lanthanum and neodymium precipitated under pH 2.0 using 10 M NaOH.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.279-284
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• 2009

Traditionally, so-called "industrial waste gases", such ad exhaust from boilers at industrial installations and a large quantity of soot discharged from power station, before their release into the atmosphere, have been on occasion subjected to an air cleaning process to remove fine particles that may pollute the atmosphere (such as mist and dust containing various powdery or oily substances and moisture from industrial waste gases). The release of industrial waste gases containing these particles directly into the atmosphere poses a serious threat to the earth environment; and recovery of these noxious substances is required by law in some countries and local governments. in urban areas, air pollution from automobile exhaust and others creates a serious condition. Some homes are equipped with and use indoor air purifiers. In many of the kitchens of restaurants, smoke generated during cooking and otherwise contaminated air are cleansed by air purifiers before being released outside or recycled inside. For the dust collecting devices to recover the fine particles contained in contaminated air, the cause for air pollution and how to purify air, many types based on various principles are known. Specifically, classified based on theories of particle collection, filtration, gravity, inertia, centrifugation, electricity, and cleaning types are cited as available processes. Among them, an appropriate type is selected according to the size or type of fine particles to be collected and conditions for installation. For the efficiency of dust collection, a filtration system (by using bag filters and others) and electric system are particularly outstanding and are therefore used widely in various areas of industry. In this research, rotary type high performance oil mist and smoke collecting system with self auto cleaning device equipped with the cleaning fluid spraying section is investigated.

• Journal of the Korean Institute of Gas
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• v.19 no.2
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• pp.66-73
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• 2015

The amount and quality of waste heat from a gas engine which is modified from an automobile gasoline engine is analyzed. Exhaust temperature is $573.8^{\circ}C$ and engine cooling water exit temperature is $85.7^{\circ}C$. The amount of waste heat of engine cooling water is double compared to that of exhaust gas. Organic Rankine cycle (ORC) system is designed for two different waste heat source of engine cooling water and engine exhaust and is thermodynamically analyzed.

• International Journal of Automotive Technology
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• v.6 no.4
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• pp.413-419
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• 2005

The United States automotive recycling infrastructure has successfully reduced the amount of automotive waste sent to landfills, especially since the introduction of shredders in the late 1950s. Shredders are necessary to process and recycle automotive hulks and other durable goods. However, this industry faces significant challenges as the automotive manufacturers are increasing the use of nonmetallic components which are difficult to recycle. Additionally, it is becoming obvious that automobiles contain hazardous materials which place heavy burdens on the environment. To address this growing concern, we propose a process planning model for automotive shredders to make tactical decisions regarding at what level to process and at what level to reprocess feed stock materials. The purpose of this paper is to test analytical models to help shredders improve the profitability and efficiency of the bulk recycling processes for end of life automobile returns. The work is motivated by an actual recycling problem that was observed at Capitol City Metals shredding facility in Indianapolis, Indiana.

• 대한예방의학회:학술대회논문집
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• 2002.10a
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• pp.568-570
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• 2002

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.246-246
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• 2010

In this study, the effect of wast heat-electric energy conversion according to temperature difference between two sides of a thermoelectric module was investigated as a way of electric energy conversion from waste heat generated in machinery system like automobile system.