• Journal of the Korean Wood Science and Technology
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• v.37 no.6
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• pp.537-545
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• 2009

The objective of this study was to investigate potential usage of environmentally friendly building materials, liquid mortar and dry cement mortar mixed with charcoal, based on the test of their physical and chemical properties. From the test results of physical and chemical properties of the liquid mortar mixed with charcoal, liquid mortar containing over 20% of charcoal, the consistency viscosity and the non-volatile content met a standard requirement. Drying time was delayed with increase in charcoal contents in the liquid mortar, however they were fully cured within 60 minutes in all treated levels. Other properties were acceptable at standard requirement. From the results, it was found that the proper charcoal addition level to the liquid mortar was 25%. In the results on dry cement, it was found that samples containing 5% of charcoal showed the maximum compressive strength, whereas samples containing over 20% of charcoal did not reach the minimum requirement of KS standard. Water retention ability constantly increased as the charcoal ratio increased. The conventional dry cement mortar adsorbed 59.5% of it, in the test of adsorption rate on ammonia gas, whereas cement mortar containing 10% of charcoal showed 71.6% of ammonia gas adsorption.

• Resources Recycling
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• v.17 no.5
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• pp.66-75
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• 2008

Using a pinus koraiensis and pinus rigida which are normally being discarded in South Korea, the optimal condition of producing charcoals has been studied to develop activated carbons which can be recycled as a higher value-added product. A study on manufacture of activated carbons from a discarded timber consists of two processes, the production process of charcoals from a discarded timber by low temperature pyrolysis process and the production process of activated carbons from the charcoals by chemical activation reaction. This study deals with the production process of charcoals from a discarded timber by low temperature pyrolysis process. As a results of experiment, it was investigated that charcoals produced through drying at $150^{\circ}C$ for 6hr and pyrolysis process at $500^{\circ}C$ for 1hr had the highest values in physical properties such as iodine number and BET surface area. Furthermore, through observing SEM images, the maximum development of porosity had been founded in this condition. It was confirmed that values of physical properties on using a pinus koraiensis are superior to the ones when using a pinus rigida. When charcoals were produced from a pinus koraiensis in this condition, BET surface area was approx. $640m^2/g$.

• Journal of Conservation Science
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• v.32 no.2
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• pp.109-121
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• 2016

Mother-of-pearl turtle shell lacquerware refers to a decoration made of a mother-of-pearl, a turtle shell and metal wires. This lacquerware features bright color tone as it is produced by sprinkling metal powder over its entire surface. This study aimed to find out its material properties and characteristics by using an optical microscopy and conducting a SEM-EDS analysis on the cross section of lacquer coating. As a result, it was found that charcoal powder and soil powder were mixed for undercoating. Then a mixture of cinnabar lacquer and monoclinic arsenic sulfide mineral ($As_2S_3$) was coated on the undercoating and brass powder was sprinkled on top of it. Especially, a little amount of pigment was found on the lacquer layer, which is distinguished from the colors used for conventional lacquer patterns. In addition, it was also found that the cinnabar lacquer and monoclinic arsenic sulfide mineral were mixed together.

• Resources Recycling
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• v.2 no.4
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• pp.10-16
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• 1993

Reduction behavior of stainless steelmaking dust by microwave heating process was investigated using coke and charcoal as reducing agents. Pellet dust and stanless steelmaking dust pelletized with reducing agent were reduced by the heating upto $1000^{\circ}C$ in microwave oven. The results showed that charcoal and coke seemed effective in the reduction of metals from stainless steelmaking dust by microwave heating and charocal was found to be better than coke. Degree of reduction seemed similar with the power of 500W and 700W in microwave oven. Dusts were rapidly reduced within 20 minutes. Reducing degree decreased in the order of Fe>Ni>Cr.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.93-100
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• 2008

For investigation of adsoption properties of cadmium elimination by wood charcoal, $25m{\ell}$ aqueous cadmium solutions in various concentrations were treated with 0.2 g wood charcoal of Red Oak (Quercus mongolica) for 280 minutes. Almost 100% of cadmium elimination ratio was obtained in the solutions with initial concentration of 20 and 40 ppm in the treatment, whereas they were 75 and 50% in those of 80 and 160 ppm. In the effect of treatment time, the highest amount of cadmium ions was eliminated during the first ten minutes in each solution so that the elimination ratio of each case was over 70% of the maximum elimination value. From the analysis of adsorptive cadmium adsorption mechanism using the Langmuir adsorption isotherm, it was suggested that cadmium ion molecules were adsorbed at the active sites on the charcoal particle in form of one layer. The Gibbs free energy of the adsorption process was calculated in negative value for each solution. This means the adsorption processes are spontaneous which do not require the extra input energy.

• Journal of Conservation Science
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• v.31 no.2
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• pp.125-130
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• 2015

Specific techniques and materials in conservation of traditional lacquer has not been transmitted. This study aims to compare the basic characteristics of the filler which used in the base layer of lacquer conservation. Tohoe(a mixture of lacquer and Clay) and the three kinds of additives which is mixed with Tohoe and Goksu(a mixture of lacquer, wood powder and rice starch) are estimated in drying rate, impact resistance, abrasion. Among those samples, the more amount of clay causes fast dryness speed and worse cracks on the surface. The impact resistance is weakened at high amount of clay. There is no significant differences of impact resistance between both additives that is mixed with the samples and additives. The samples that are mixed with Goksu and additives show high impact resistance. In the polishing test, the more amount of filling powders show higher grinding degree and the sample that are mixed with wood powder and charcoal show higher degree as well. The highest grinding degree is Maekchil and Goksu but the lowest one is the sample of the rooftile powder mixture.

• Journal of the Korean Wood Science and Technology
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• v.36 no.6
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• pp.69-76
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• 2008

To estimate removal ability of harmful gas by charcoal, we carbonized Red oak (Quercus mongolica Fischer) wood and Larch (Larix leptoepis) bark at $300^{\circ}C$, $600^{\circ}C$ and $900^{\circ}C$ for 1 hour. Gas removal ratios was increased with carbonization temperature but there is no difference between wood and bark charcoal. In the case of bad smell and VOC gas, woody charcoal including bark charcoal carbonized at $300^{\circ}C$ showed low removal ratio, less than 50%, whereas woody charcoals which was carbonized at more than $600^{\circ}C$ reached almost 100% removal ratio to bad smell gas such as trimethylamine, methymercaptan, hydrogen sulfide, and to VOC such as benzene, toluene, xylene in $5{\ell}$ tedler bag with each gas of 100 ppm. It was thought that because charcoals carbonized at high temperature, for example, $600^{\circ}C$ or $900^{\circ}C$ have enough specific surface area to adsorb gas of 100 ppm. Moreover these charcoals rapidly removed almost gas in 10 minutes. However, acetylene, $SO_2$ and $NO_2$, charcoals which was carbonized more than $600^{\circ}C$ and which showed high removal ratio had low gas removal ratio of 40% at even 4 hours adsorption. It was concluded that adsorptive ability of woody charcoal was mainly influenced with carbonizing temperature, so that different charcoals carbonized at different temperature brings different gas removal ratio because these charcoals have not only different physical factor such as specific surface area but different chemical characteristic such as functional group, expected.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.2
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• pp.218-224
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• 2008

Coal-, coconut- and wood-based activated carbons and anthracite were tested to evaluate adsorption and biodegradation performances of chloral hydrate. In the early stage of the operation, the adsorption was the main mechanism for the removal of chloral hydrate, however as increasing populations of attached bacteria, the bacteria played a major role in removing chloral hydrate in the activated carbon and anthracite biofilter. It was also investigated that chloral hydrate was readily subjected to biodegrade. The coal- and coconut-based activated carbons were found to be most effective adsorbents in adsorption of chloral hydrate. Highest populations and activity of attached bacteria were shown in the coal-based activated carbon. The populations and activity of attached bacteria decreased in the order: coconut-based activated carbon > wood-based activated carbon > anthracite. The attached bacteria was inhibited in the removal of chloral hydrate at temperatures below 10$^{\circ}C$. It was more active at higher water temperatures(20$^{\circ}C$ <) but less active at lower water temperature(10$^{\circ}C$>). The removal efficiencies of chloral hydrate obtained by using four different adsorbents were directly related to the water temperatures. Water temperature was the most important factor for removal of chloral hydrate in the anthracite biofilter because the removal of chloral hydrate depended mainly on biodegradation. Therefore, the main removal mechanism of chloral hydrate by applying activated carbon was both adsorption and biodegradation by the attached bacteria. The observation suggests that the application of coalbased activated carbon to the water treatment should be the best for the removal of chloral hydrate.

• Journal of the Korean Wood Science and Technology
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• v.37 no.1
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• pp.87-93
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• 2009

Properties and chemical bonding of wood charcoal were investigated to understand the chemistry occurring in wood carbonization. From the pH changes of wood charcoal, it is revealed that it becomes acidic to weakly basic for charcoal carbonized at about $300^{\circ}C$, whereas it turns to basic at higher carbonization temperature higher than $600^{\circ}C$. Also, the ratio of carbon atoms in the charcoal was increased with increasing the carbonization temperature, while those of oxygen and hydrogen atoms. This tendency was significant when the carbonization temperature was increased up to $600^{\circ}C$ and the ratio changes of the atoms became stable at above $600^{\circ}C$. In the changes of chemical bonding, the ratio of C-C bonding was increased and those of C-O-H and C-O-R bonding was decreased significantly. It is considered that bondings connected to oxygen atoms tends to be broken, and the ratio of C-C bonding increased. Consequently, it is expected that this change may causes occurrence of new functional groups. In addition to that, it seems to be that the chemical bondings undergo the partial decomposition, formation, and recombination steps, Because ratio of C=O bonding tended to be increased or decreased by increasing the carbonization temperature. This understanding of chemical bond changes in charcoal can be a compensative consideration on the knowledges made only by physical parameters in the properties of micro-pore which has limited to explain the phenomenon. Also, it is considered that this can be treated as a basic knowledge for upgrading and development of use of wood charcoal.

• Journal of the Korean Wood Science and Technology
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• v.35 no.1
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• pp.73-80
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• 2007

This study was carried out to separate the heavy toxic metals in eco-building materials by low-temperature pyrolysis, especially arsenic (As) compounds in CCA wood preservative as a solid in char. The pyrolysis was carried out to heat the CCA-treated Hemlock at $280^{\circ}C$, $300^{\circ}C$, $320^{\circ}C$, and $340^{\circ}C$ for 60 mins. Laboratory scale pyrolyzer composed of [preheater$\rightarrow$pyrolyzer$\rightarrow$1st water scrubber$\rightarrow$2nd bubbling flask with 1% $HNO_3$ solution$\rightarrow$vent], and was operated to absorb the volatile metal compound particulates at the primary water scrubber and the secondary nitric acid bubbling flask with cooling condenser of $4^{\circ}C$ under nitrogen stream of 20 mL/min flow rate. And the contents of copper, chromium and arsenic compounds in its pyrolysis such as carbonized CCA treated wood, 1st washing and 2nd washing liquors as well as its raw materials, were determined using ICP-AES. The results are as follows : 1. The yield of char in low-temperature pyrolysis reached about 50 percentage similar to the result of common pyrolytic process. 2. The higher the pyrolytic temperature was, the more the volatiles of CCA, and in particular, the arsenic compounds were to be further more volatile above $320^{\circ}C$, even though the more repetitive and sequential monitorings were necessary. 3. More than 85 percentage of CCA in CCA-treated wood was left in char in such low-temperature pyrolytic condition at $300^{\circ}C$. 4. Washing system for absorption of volatile CCA in this experiment required much more contacting time between volatile gases and water to prevent the loss of CCA compounds, especially the loss of arsenic compound. 5. Therefore, more complete recovery of CCA components in CCA-treated wood required the lower temperature than $320^{\circ}C$, and the longer contacting time of volatile gases and water needed the special washing and recovery system to separate the toxic and volatile arsenic compounds in vent gases.