Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Institute of Resources Recycling
Journal Basic Information
Journal DOI :
The Korean Institute of Resources Recycling
Editor in Chief :
Volume & Issues
Volume 16, Issue 6 - Dec 2007
Volume 16, Issue 5 - Oct 2007
Volume 16, Issue 4 - Aug 2007
Volume 16, Issue 3 - Jun 2007
Volume 16, Issue 2 - Apr 2007
Volume 16, Issue 1 - Feb 2007
Selecting the target year
Preparation of Alum and Poly Aluminum Chloride Using Waste Aluminum Dross
Park, Hyung-Kyu ; Lee, Hoo-In ; Choi, Young-Yoon ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 3~7
Waste aluminum dross was processed to prepare alum with sulfuric acid, and poly aluminum chloride(PAC) with hydrochloric acid. Metallic aluminum remained in the waste dross was dissolved into the sulfuric acid solution, and the solution could be used as alum for water treatment chemicals after adjusting the required alumina concentration and pH of the solution. Also, it was dissolved into the hydrochloric acid solution and processed to make PAC solution. Compared with the conventional method for preparation of alum and PAC using aluminum hydroxide, material cost could be saved in this method. Also, there is an additional merit in view of recycling of the waste aluminum dross by reducing the amount of waste disposed to landfill.
Dehydration characteristics of Magnesium Chloride Hydrate
Eom, Hyoung-Choon ; Yoon, Ho-Sung ; Park, Hyung-Kyu ; Kim, Chul-Joo ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 8~12
Anhydrous magnesium chloride, dehydration product from magnesium chloride hydrate is a general raw material to prepare electrolytic magnesium. However, the dehydration is not trivial and can be accompanied by hydrolysis leading to the production of undesirable hydroxy chloride compounds of magnesium. Therefore, dehydration process is actually the most complicated and hardest in the electrolysis methods for the production of magnesium. In this work, the influence of dehydrating temperature has been studied at the temperature range from
in air and HCl gas atmosphere individually to compare the results. With increasing of dehydration temperature MgOHCl and MgO were obtained in air. On the other hand, when the temperature was increased above
anhydrous magnesium chlorides were prepared in HCl gas atmosphere. Anhydrous magnesium chloride was formed at near
and completely crystallized at about
. All of the HCl used as atmosphere gas in the dehydration was recovered as hydrochloric acid solution at a water vessel up to 41% by weight at
Separation of Recycled Aggregates from Waste Concrete by Heavy Medium Separation
Lee, Myung-Gyu ; Kwon, Ki-O ; Gayabazar, Ganbileg ; Kang, Heon-Chan ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 13~18
The recycled aggregates produced from waste concrete by crushing and granularity adjusting processes only can't be used for structural aggregates because they display low density and high abrasion rate by including lots of mortar and cement paste. However, the recycled aggregates include a lot of aggregates for concrete. Using the heavy medium separation method that is one of the specific gravity separation methods, about 45% of the waste concrete could be converted to the recycled aggregates.
Development and Commercialization of Artificial Reefs from Waste Mulch Plastic Films
Kim, Hea-Tae ; Shon, Sang-Jin ; Kim, Myoung-Ho ; Choi, Mi-Ran ; Baek, Wook-Jin ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 19~24
Reefs are the marine structure that can give resting, inhabiting, feeding and nursing spaces for a variety of fishes. Usually artificial reefs are made of cement and steels respectively in Japan as well as in Korea. However since resources deficiency has been getting serious, other materials are taken into consideration for the basic bodies of artificial reefs. About 300 thousand tons of waste agricultural plastic films are generated every yew in Korea, but no effective recycling techniques have been developed. In this sense, artificial reefs made of waste agricultural plastic films are the most representative symbol of the recycled products in the Resource Recycling Era. In particular, since these reefs could be made of the semi-cleaned waste agricultural plastic films that still contain high portion of soil, it is very environmentally friendly not only in manufacturing process but also in using under water. Furthermore they have some evident advantages as follows; 1) high fish swarming effect 2) good initial attachment of the marine growths 3) extremely low corrosion to brine 4) easy adjustment of the gravity 5) economical manufacture, transportation and jettison 6) excellent safety to ecosystem caused by lower elution of toxic substances 7) good recyclable property after application and so on.
Development of Recycled Aggregate Producing Circuit Using Autogenous mill
Kim, Kwan-Ho ; Lee, Duck-Jae ; Cho, Hee-Chan ; Ahn, Ji-Whan ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 25~30
In Korea, reutilization of construction waste is gaining attention as construction waste generated increases continuously. Currently, the concrete waste is simply crushed and used as a low value application such as paving, back filling, etc. To meet the demand of aggregate for construction and the resource efficiently, production of high quality recycled aggregate is necessary. Therefore, in this study, a better process for production of high quality recycled aggregate was developed using combination of heat pretreatment and autogenous milling. Test results showed that the recycled aggregate has a density of
and a water absorption ratio of 3.0%, which meet the specification of the first class of KS F 2573. Currently, a pilot scale autogenous mill is being constructed and tests will be further conducted to develop a commerce-scale process.
Preparation and Growth of Silica Sol from Sodium Silicate
Yoon, Ho-Sung ; Kim, Chul-Joo ; Kim, Sung-Don ; Jang, Hee-Dong ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 31~35
The formation of silica sol from sodium silicate solution and the growth of silica sols were investigated in this study. The
content of 2% in sodium silicate solution was proper to oxidize sodium silicate with sulfuric acid. After the removal of sodium ions in sodium silicate solution, the pH of silicate solution had to be controlled above 9 for a stable silicate solution. The silica sol, which size is about 10 nm, could be prepared by heating the mixed solution of sodium silicate and silicate solution removed sodium ions at pH 10 and 80. And the silica sol grew into about 50 nm as silicate solution was added to silica sol solution.
Preparation of Nano-sized Pt Powders by Solution-phase Reduction
Kim, Chul-Joo ; Yoon, Ho-Sung ; Cho, Sung-Wook ; Sohn, Jung-Soo ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 36~40
Platinum plays an important role in many applications because of its extraordinary physical and chemical properties. All these applications require the use of platinum in the finely divided state. Therefore the preparation of platinum nanoparticles by reducing platinum-surfactant salt with reducing agent in the solution was investigated in this study. The net interaction between C14TABr and
in aqueous solution results in the formation of
. The concentration of C14TABr and the concentration of
has to be above cmc and 0.32 mM, respectively in order to obtain complex-micelle aggregation for mono dispersed Pt particles. Pt particle size increases with increasing
and C14TABr concentration. And the shape of Pt particles was well controlled with increasing surfactant concentration.
Synthesis of Tetramethylorthosilicate (TMOS) and Silica Nanopowder from the Waste Silicon Sludge
Jang, Hee-Dong ; Chang, Han-Kwon ; Cho, Kuk ; Kil, Dae-Sup ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 41~45
Tetramethylorthosilicate (TMOS) and silica nanopowder were synthesized from the waste silicon sludge containing 15% weight of silicon powder. TMOS, a precursor of silica nanopowder, was firstly prepared from the waste silicon sludge by catalytic chemical reaction. The maximum recovery of the TMOS was 100% after 5 hrs regardless of reaction temperature above
. But the initial reaction rate became faster while the reaction temperature was higher than
. As the methanol feedrate Increased from 0.8 ml/min to 1.4 ml/min, the yield of reaction was not varied after 3 hrs. Then, silica nanopowder was synthesized from the synthesized TMOS by flame spray pyrolysis. The morphology of as-prepared silica nanopowder was spherical and non-aggregated. The average particle diameters ranged from 9 nm to 30 nm and were in proportional to the precursor feed rate, and precursor concentration.
ion co-doping in
Bartwal, Kunwar Singh ; Ryu, Ho-Jin ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 46~50
Blue phosphor calcium aluminate,
was prepared by solid state synthesis method. Phosphor materials with 1 mol%
and varying compositions of
show high brightness and long persistent luminescence. The synthesized phosphor materials were investigated by powder x-ray diffraction (XRD), SEM, TEM, photoluminescence excitation and emission studies. Broad band UV excited luminescence of the
was observed in the blue region (
) due to transitions from the
configuration of the
ion doping in the phosphor results in long afterglow phosphorescence when the excitation light is cut off.
Recovery of PET from Final Plastic Wastes using HDPE Cyclone Charger
Jeon, Ho-Seok ; Park, Chul-Hyun ; Baek, Sang-Ho ; Kim, Byoung-Gon ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 51~56
Plastics are widely used in everyday life as very useful material. In Korea, about 4 million tons of plastic wastes are generated annually. However, recycling ratio is below 30%, and most of plastic wastes are disposed by landfill and incineration. Hence, the development of material separation technique that can recycle plastic wastes is a necessary situation. In this study, Triboelectrostatic separation for recovery of PET from final plastic wastes obtained from the sink product after wet-type gravity separation has been carried out. In the charging properties, the charge polarity and charge density of PET and PVC were very effective with the tirbo-charger made of PP and HDPE with the decrease in relative humidity. In material separation using HDPE cyclone charger, a PET grade of 96.80% and a recovery of 85.0% were achieved at 30 kV and the splitter position -2cm from the center. In order to obtain PET grade of 98.5%, PET recovery should be sacrificed by 24% with moving the splitter from the center to -6cm position.
Triboelectrostatic Separation of Mixed Three Kinds of Plastics by a Two-stage Separation Process
Park, Chul-Hyun ; Jeon, Ho-Seok ; Baek, Sang-Ho ; Park, Jai-Koo ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 57~64
Triboelectrostatic separation of mixed three kinds of plastics, PVC, PET and PMMA, in the range of similar gravity has been performed through a two-stage separation process. Polypropylene (PP) and high-impact polystyrene (HIPS) were found to be the most effective materials for a tribo-charger in the separation of PVC, PET and PMMA. In the 1st stage using the PP cyclone charger, PVC grade and recovery depended considerably on the air velocity (10 m/s), the relative humidity (<30%), the electric field (>200 kV/m) and the splitter position (+2 cm from the center) in the triboelelctrostatic separator unit. At an optimum condition a PVC grade of 99.6% and a recovery of 97.5% was achieved. In the 2nd stage using the HIPS cyclone charger, a PMMA grade of 98.3% and a recovery of 97.0% was obtained under the conditions of 10m/s air velocity, over 250 kV/m electric field, central splitter position and less than 40% relative humidity.
Development of RTD Model of the Mixer-Settler-Type Extractor Using the Stimulus-Response Method
Lee, Jin-Young ; Kim, Joon-Soo ; Lee, Hoo-In ; Sohn, Jeong-Soo ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 65~70
This study presents the findings of the experiments that were conducted on single- and multi-stage solvent extractors using the stimulus-response method, with the am of identifying flow characteristics of the material inside the mixer-settler-type extractor. The results of this study show that the response characteristics of a single-stage mixer is the same as that of a completely stirred tank reactor (CSTR), and that the lag time of a mixer-settler-type extractor increases with the number of its extraction stages. The experimental data for the single- and multiple-stage extractors were analyzed using K-RTD, a response analysis program, to obtain a retention time distribution (RTD) model of one-stage and four-stage extractors. The correlation coefficient between the calculated values and the experimental data was 0.963 for the one-stage extractor and 0.995 for the four-stage extractor, showing quite a good correlation.
Removal of PVC from Mixed Plastic Waste by Combination of Air Classification and Centrifugal Process
Choi, Woo-Zin ; Yoo, Jae-Myung ;
Journal of the Korean Institute of Resources Recycling, volume 16, issue 5, 2007, Pages 71~76
The mixed plastic waste generated from households after hand-picking and/or mechanical sorting processes amounts to 1,750,000 ton in 2006, and most of these waste are finally end up with landfill and/or incineration due to the lacks of separation technologies and economical reasons. The mixed plastic wastes can not be used as raw materials for chemical and/or thermal recycling processes because of their high content of PVC(upto 4.0 wt.%). In the present research, gravity separation system has been developed to remove PVC from the mixed plastic waste and to recover the PO-type plastics. This system mainly consists of air classification, magnetic separation, one-step crushing, feeding system at fixed rate and wet-type gravity separation system. The gravity system based on centrifugal separation has been developed at capacity of 0.5 ton/h and it consists of mixing, precleaning, separation, dewatering, recovery system and wastewater treatment system, etc. The main objective of this process is to achieve high separation efficiency of polyolefins with less than 0.3 wt.% PVC content and less than 10% moisture content in the final products. In addition, a crushing unit of with 8 rotor system is also developed to improve the crushing efficiency of soft-type plastics. The system with a capacity of 1.0 ton/h is developed and operational results are presented.