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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 23, Issue 6 - Dec 2014
Volume 23, Issue 5 - Oct 2014
Volume 23, Issue 4 - Aug 2014
Volume 23, Issue 3 - Jun 2014
Volume 23, Issue 2 - Apr 2014
Volume 23, Issue 1 - Feb 2014
Selecting the target year
Grinding Effects of Coal-Fired Pond Ash on Compressive Strength of Geopolymers
Lee, Sujeong ; Kang, Nam-Hee ; Chon, Chul-Min ; Jou, Hyeong-Tae ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 3~11
DOI : 10.7844/kirr.2014.23.6.3
Bottom ash from coal fired power plants is not widely used due to a broad range of particle sizes and a high carbon content for producing geopolymers. The effect of mechanical activation on compressive strength of bottom ash- based geopolymers was examined by rod and planetary-ball milling to encourage full-fledged recycling of bottom ash, the main component of pond ash. The amount of amorphous component in the milled ash samples did not change significantly after the mechanical activation. It is presumably because needle-shaped mullite crystals, which is a major crystalline phase and grown in a glassy matrix, possess high strength and toughness, and therefore, they could endure external shocks and remain almost intact. Milling operation, however, decreased the particle size and improved the homogeneity of ash, thereby leading to increase reactivity of milled ash with alkali activators. Rod milling produced a relatively narrow particle size distribution of the milled ash particles; however, it was less effective in reducing the particle size. Nevertheless, it was interesting to observe that rod milling had equal effect on improving the compressive strength of geopolymers up to about 37%, as that of planetary ball milling. Rod milling is believed to be suitable process for enhancing the reactivity of bottom ash for large-scale recycling of bottom ash and producing geopolymers.
A Study on Separation of Limonite and Saprolite from Nickel Laterite Ores
Kim, Kee-Seok ; Seo, Joo-Beom ; Bea, In-Kook ; Bae, Kwang-Hyun ; Yoo, Kwang-Suk ; Lee, Jae-Young ; Kim, Hyung-Seok ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 12~21
DOI : 10.7844/kirr.2014.23.6.12
Nickel oxide ores are composed of two kinds of minerals; one is saprolite that is processed by smelting to obtain nickel products, and the other is limonite that is used in hydrometallugical processes. It is not efficient economically to process the mixture of limonite and saprolite, so the processes to saparate the ore mixture should be developed. In the present study, the mixture was separated by dry-classification after liberationg using grindability difference between limonite and saprolite. Consequently, it is possible to obtain the limonite with less than 10% of Mg+Si contents, which could be treated by hydrometallurgical processes, when the limonite contain less than 30% of saprolite.
Preparation of Iron Nano-particle by Slurry Reduction Method from Leaching Solution of Spent Nd magnet
Ahn, Jong-Gwan ; Gang, Ryunji ; You, Haebin ; Yoon, Ho-Sung ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 22~29
DOI : 10.7844/kirr.2014.23.6.22
Recycling process of iron should be developed for efficient recovery of neodymium (Nd), rare metal, from acid-leaching solution of Nd magnet. In this study,
solution as iron source was used for preparation of iron nano particles with the condition of various factors, such as, reductant, and surfactant.
and Polyvinylpyrrolidone (PVP) as surfactants,
as reductant, and palladium chloride (
) as a nucleation seed were used. Iron powder was analyzed by using XRD, SEM for measuring shape and size. Iron nano particles were prepared at the ratio of 1:5 (Fe (III) :
). Size and shape of iron particles were round-form and 50 ~ 100 nm size. Zeta-potential of iron at the 100 mg/L of
was negative value, which was good for dispersion of metal particle. When
(100 mg/L), PVP(
= 1 : 4, w/w) and Pd(
= 1 : 0.001, w/w) were used, iron nano particles which were round-shape, well-dispersed and near 100 nm-sized range. In this condition,
solution changed with spent Nd leachate solution, and then it is possible to be made round-formed iron nano particles at pH 9 and at the reaction bath over 20 L which is not include any surfactant.
Simulation on the PCB Particle Trajectories in Corona-discharge Electrostatic Separator
Han, Seongsoo ; Park, Seungsoo ; Kim, Seongmin ; Park, Jaikoo ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 30~39
DOI : 10.7844/kirr.2014.23.6.30
The trajectories of PCB(Printed Circuit Board) particles in the corona discharge electrostatic separation was simulated. The PCB particles are prepared by crushing bare board, which disassembled from electronic components, consist mostly of copper and FR-4(Flame Retardant Level-4) Firstly, a model was established for calculating of detachment points of PCB particles from the rotating electrode in separator. The model of detachment points was derived from equilibrium of force such as gravity force, centrifugal force, electrostatic force. The trajectories of particles after detachment was calculated by acceleration derived from time-integrating method of motion equation. In this simulation, particle size, supplied voltage, rotation speed of rotating roll electrode and angle of induction electrode were adopted as variables. While the trajectories of FR-4 particles were affected by all variables, rotation speed of rotating roll electrode was dominant variables affecting trajectories of copper particles.
Evaluation on Reaction Kinetics of Cow Manure in Carbonization Process
Kim, Jae-Kyung ; Lee, Min-Seok ; Rhee, Seung-Whee ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 40~46
DOI : 10.7844/kirr.2014.23.6.40
Through the study of the basic characteristics of cow manure and the characteristics of carbonization residue, carbonization degree, conversion rate, kinetic reactions, and activation energy for cow manure were examined. Since the heating value of cow manure was very low, it was converted to carbonization residue as a fuel with heating value of 4,300 kcal/kg by carbonization processes. Conversion rate was increased rapidly up to 10 minutes of the initial reaction stage and was increased with increasing temperature. The carbonization of cow manure could be described by the 1st order reaction. Frequency factor(A) of reaction rate for cow manure was evaluated to be
, the activation energy was estimated to be 5,196.4 cal/mol. As carbonization temperature increased from
, the kinetic reaction was increased from
. From the result of the carbonization for cow manure, it can be determined that the optimal conditions of the carbonization process were 20 minutes in carbonization time and
for carbonization temperature.
A Kinetic Studies of Pyrolysis and Combustion of Sewage Sludge
Roh, Seon Ah ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 47~53
DOI : 10.7844/kirr.2014.23.6.47
Effective treatment and energy conversion technologies are necessary due to the ban of the dumping of organic waste including the sewage sludge. In this study, the kinetics of pyrolysis and combustion were derived in a TGA and thermobalance reactor, which is essential for thermal conversion of sewage sludge to energy. Three steps are shown for the pyrolysis in TGA and the different pre-exponential factors and activation energies are derived depending on the temperature range. Three models of gassolid reaction were applied to the reaction kinetics analysis for the combustion of sewage sludge char and shrinking core model was an appropriated model. Apparent activation energy and pre-exponential factor were evaluated and the effect of oxygen partial pressure was examined.
Standard Process Design of Remanufacturing of LPG Vaporizer by using FMEA
Mok, Hak-Soo ; Song, Hyun-Su ; Kim, Deuk-Jung ; Hong, Jin-Eui ; Lee, Seung-Min ; Ahn, Jung-Tae ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 54~62
DOI : 10.7844/kirr.2014.23.6.54
This paper present a improved process for remanufacturing of LPG vaporizer through Failure Mode and Effect Analysis(FMEA). Based on the failure causes analysis and classification of faults that occur after the initial failure of LPG vaporizer remanufacturing, suggests improvements for high R.P.N. Derive the improvement for higher cumulative frequency of each process, proposes the overall improvement of a current process for establish a standard LPG remanufacturing process.
Method for Making High Purity Gallium by Electrowinning
Choi, Young-Jong ; Hwang, Su-Hyun ; Jeon, Deok-Il ; Han, Kyu-Sung ;
Journal of the Korean Institute of Resources Recycling, volume 23, issue 6, 2014, Pages 63~67
DOI : 10.7844/kirr.2014.23.6.63
Gallium is an important material and is used by industry of oxide semi-conductor and LED chip. However, the most of the gallium-containing waste resources became outflow abroad and the most of which is imported from oversea by following technical problem and low circulation rate. In this research, the recovery of high purity Gallium metal from Gallium scrap, which containing about 30% of Gallium, was investigated by using hydro-metallurgical process. As pretreatment, the Gallium scrap was pulverized and leached by strong acid such as hydro chloric acid. At the leached solution, Indium was separated as an Indium sponge by substitution reaction and then Gallium and Zinc hydroxide separated and filtrated using strong alkaline solution such as sodium hydroxide by precipitation method. Also, Gallium metal and Zinc metal was recovered by electrowinning method. To make an electrolytic solution, Gallium and Zinc hydroxide was leached by strong alkaline solution. Finally, High purity Gallium metal was recovered by vacuum refining process to remove the Zinc impurity.