• Resources Recycling
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• v.10 no.3
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• pp.51-59
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• 2001

Impurities removal from waste carbon black was carried out to produce high-grade carbon black. A large amount of hydrophilic carbon black is produced as a byproduct of the hydrogen production process by flame decomposition of water. Due to its impurities content such as sulphur, iron, ash, etc., it can only be used as low-grade carbon or burnt out. High-grade hydrophilic carbon black is 3~5 times more expensive than oil-based carbon black because of high production cost associated with process complexly and pollutant treatment. Hydrophilic carbon is normally used for conductive materials for batteries, pigment for plastics, electric wire covering, additives for rubber, etc. In these applications, impurity content must be blow 1 fe. In this study, magnetic separation, froth flotation and ultrasonic treatment were employed to remove impurities from the low-grade hydrophilic carbon black. Results showed that the ash, iron and sulphur content of product decreased to less than 0.01 wt.%, 0.01 wt.% and 0.3 wt % respectively and the surface area of product was about 930 $m^2$/g for conductive materials.

• Resources Recycling
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• v.19 no.3
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• pp.24-32
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• 2010

In the present work, a new separation system with rotating rakes has been developed to separate the film-based plastics from the recyclable materials, and environment assessment is also carried out during operation of the device. Capacity of the device was about 5.3 ton/hr at a rakes rotation speed of 26.0 rpm (the number of rakes in the 1st, 2nd and 3rd trials were 39, 52 and 48, respectively) and a belt conveyor speed of 38.5m/min, which satisfied the initial design capacity (5.0 ton/hr). Recovery ratio and purity of the plastic films were 92.6% and 96.5%, respectively at a rotation speed of 28 rpm. The levels of noise, vibration and particulate emission were below material standard regulatory limits. Plastic refused fuel (RPF) was also prepared with the recovered films. The calorific value and chlorine content of the prepared RPF were 9,740 kcal/kg and 0.18%, respectively which satisfy the first grade quality specification of the Korean RPF standard. As a result of this work, recovery of energy resources from the municipal solid waste is possible by adopting the developed separation device.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.112-120
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• 2004

In this study, the physico chemical characteristic of MSW and sludge in west area of Kangwondo was investigated for database, managing the waste and waste treatment facility. The sampling sites were selected as 6 different MSW generation area and 2 sludge generation area. it is necessary to measure the characteristics of MSW to build the data-base. The year of 2000, 197.4ton/day of MSW which was generated in this area. This MSW was composed of 26.6% food wastes, 24.2% of papers, 22.8% of plastics & vinyls, 9.6% of textiles, 3.80% of wood, 2.8% of rubbers & leathers and others, respectively. Most of MSW are composed of food, paper and plastic waste and combustible waste is more than 89%. The generation of papers and vinyls are almost same for different seasons For 3-components of MSW, moisture is 40.2%, combustible component is 52.1% and ash is 7.7% and for 3-components of sludge, moisture is 83.3%, combustible component is 7.7% and ash is 9%. The chemical element has the high order of carbon(51.6%), oxygen(38.6%), hydrogen(7%) on the dry basis of wastes. And the high heating value of MSW is 4989.4 Kcal/kg sludge is 4428.04 Kcal/kg and low heating value of the MSW which is measured by calorimeter is 2032.88kcal/kg. From the leaching test of wastes, there is no heavy metals.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.222-222
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• 2011

Plastic product is increasing by the growth of its demand and most of refused plastics are incinerated or reclaimed. However, the refused plastic is not easily decomposed and has the environmental problem with its various toxic gas in case of incineration. Therefore, many countries such as USA, Japan, Germany and other developed industrial countries as well as Korea are interested in studying the recyclable resource of refused plastic. The macromolecular waste pyrolysis has the advantage of collecting of raw materials in high price and can at least get fuel gas or oil with high heat capacity. It also discharges low waste gas and low toxic gas including SOx, NOx and HCl heavy metals. However, pyrolyzed oil includes enough excess unsaturated hydrocarbons to form tar, which can cause the nozzle of engines to plug when pyrolyzed oil is used as fuel. Activated carbon was proven to have prominent adsorption capability among the other adsorbents that were mainly composed of carbon. This study examined the possibility of application in activated charcoal of its solid formation by analysing the feature of pyrolysis which is one of the chemical recycling methods and getting chemical analysis of the product and activated energy. Analyze the element of the oil produced by pyrolysis using GC-MS. The experiment of tar adsorption using fly-ash showed that fly-ash improved the optical intensity of pyrolyzed oil and decreased oxygen compounds in the pyrolyzed oil.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.483-486
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• 2005

The polymer concrete is drawing a strong interest as high-performance materials in the construction industry. Resins using recycled PET offer the possibility of a lower source cost of materials for making useful polymer concrete products. Also the recycling of PET in polymer concrete would help solve some of the solid waste problems posed by plastics and save energy. Polymer concrete beams using unsaturated polyester resins based on recycled polyethylene terephthalate (PET) plastic waste were used in our study for grasping its structural behavior of static and fatigue. As a result of static test, Compression stress distribution of Polymer concrete indicates linear behavior such as triangles. Although polymer concrete is high strength materials, its ductility capacity is excellent. From the fatigue test results, There was almost no difference on flexural characteristics between before and after fatigue loading. Therefore, recycled PET polymer concrete remains excellent structural ability after fatigue loading.

• Composites Research
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• v.35 no.4
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• pp.242-247
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• 2022

This study has a different direction from the existing technology of applying recycled carbon fiber obtained by recycling waste CFRP to CFRP again. A study was conducted to utilize recycled carbon fiber as a raw material for manufacturing a carbon/carbon (C/C) composite material comprising carbon as a matrix. First, it was attempted to recycle a commonly used epoxy resin composite material through a thermal decomposition process. By applying the newly proposed oxidation-inert atmosphere conversion technology to the pyrolysis process, the residual carbon rate of 1~2% was improved to 19%. Through this, the possibility of manufacturing C/C composite materials utilizing epoxy resin was confirmed. However, in the case of carbon obtained by the oxidation-inert atmosphere controlled pyrolysis process, the degree of oxygen bonding is high, so further improvement studies are needed. In addition, short-fiber C/C composite material specimens were prepared through the crushing and disintegrating processes after thermal decomposition of waste CFRP, and the optimum process conditions were derived through the evaluation of mechanical properties.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.3
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• pp.76-85
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• 2004

Anaerobic decomposition of municipal solid waste (MSW) had potential adverse impacts such as the production of methane and long-term post closure on human health and the environment. It was demonstrated that aerobic degradation of MSW resulted in the reduction of a methane yield and the enhancement of stabilization of MSW. Excavated solid wastes were both aerobically and anaerobically treated in order to evaluate the effects of air injection on the stabilization of landfill site. The municipal solid waste (MSW) samples were excavated from a 10-year old landfill (operation period: 1991. 11~1994. 11), Jeonju, Korea. Excavated municipal solid wastes are primarily composed of soils and vinyl/plastics. For the two aerobic simulated lysimeters, the levels of $O_2$ ranged 1.6~23.1% and the levels of $CO_2$ ranged 1.5~15.1%, which confirmed the aerobic decomposition. Aeration did prevent methane formation. For the anaerobic simulated lysimeter, the $CO_2$ rose as $O_2$ was consumed and low levels of CH4 were produced. The pH levels ranged from 7.7 to 8.9 for anaerobic lysimeter and from 7.3 to 8.5 for aerobic lysimeters. As expected, aerobic treatment proved to enhance the removal of biodegradable materials in the excavated solid wastes when monitoring the concentration of BOD, COD, $NH_4-N$, and $NO_3-N$ in the leachate.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.3
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• pp.55-61
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• 2018

This study evaluated if the selected samples meets the Solid Refuse Fuel quality criteria in Korea. Biomass and plastic wastes generated in D City were mixed in diverse ratio. When the biomass content was about 40%, the moisture content was close to the SRF criteria and was measured to be 9.8%. The ash contents were analyzed up to 4.19%, and the lower calorific values based on Steuer, Dulong Equation and Bomb Calorimeter were at least 4,851, 4,181 and 3,847 kcal/kg, respectively. As a result of the elemental analysis, sulfur and chloride content were measured up to 0.05%. Those values satisfied the SRF criteria. Also, heavy metals(Hg, Cd, Pb, As) were analyzed to be below the SRF criteria. This makes it possible to use efficiently the wood byproducts abandoned in the woods, and the physical properties of wood being weak to moisture can be supplemented with plastics. Consequently, if plastic and biomass were well mixed and made into SRF, it would overcome the problem of shortening the life span of incineration facilities due to the high temperature of plastic wastes in the incinerator.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.4
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• pp.383-388
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• 2019

The present study evaluated experimentally the effects of the type and content of plastic fine aggregates on cement mortar in order to utilize waste platics as raw materials of concrete. The two kinds of plastics, LLDPE and HDPE were used, and the mixing rate of plastic fine aggregates was increased 0, 25, 50, 75, 100%. The mortar of LLDPE fine aggregate and HDPE fine aggregate showed similar tendency in flow and material separation resistance, density and water absorption, compressive strength and flexural strength by age. The flowability of mortar mixed with plastic fine aggregates was increased up to 50% but decreased at 75% or more. The material separation resistance of mortar with plastic fine aggregates was also dramatically decreased. On the other hand, due to the low density of plastics, the density of mortar decreased with the mixing of plastic fine aggregates. Due to the low adhesion between plastic fine aggregates and cement, the compressive strength by age was decreased in proportion to the mixing ratio of plastic aggregate, but the flexural strength of each age decreased with maintaining a certain level at 50% or more of plastic fine aggregate content.

• Resources Recycling
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• v.17 no.4
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• pp.47-56
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• 2008

The aim of this study is to produce cokes which can be used for the production of ferroalloy, for this purpose, domestic anthracite mixed with plastic was sintered at various condition. The combustion and physical properties of anthracite and plastic, coal separation, and the influence of factors on the strength of coke were investigated. The results of this study are as follows: 1. The three kinds of anthracite from the Samcheok region contained 25 to 30% ash of $100{\mu}m$ over size, and have the caloric value of 5,205 cal/g(TaeAn), 4,893 cal/g(JangSung), 4,873cal/g(KyongDong). 2. The recommendable conditions for heavy-fluid separation of the Samcheok coal are to set the specific gravity of heavy fluid to 2.4 and control the size of coal to $35{\sim}140mesh$. 3. It is concluded that phenolic resin powder, liquefied phenolic resin, SAN, and melamine resin can be used as a binder for the anthracite cokes, from the thermal analysis of various plastics. Especially, the liquefied phenolic resin was considered as the most suitable binder as it would simplify the process.