• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.130-134
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• 1995

To investigate the influence of coal fly ash treatment on the heavy metal content in the infilteration water, 12t/10a/year of fly ash(Anthracite and Bituminous) were applicated at two paddy fields of different textured soils, clay loam and sandy loam, for 3 and 2 years, respectively. The infilteration waters were collected 30, 60 and 100cm of soil depth and the heavy metal contents were measured. In the paddy field of clay loam, the content of Zn in the infilteration water were increased with fly ash treatment and increasing soil depth, but it didn't show any significance. In the clay loam soil, successive application of fly ash for 3 years brought to increase Pb, Zn content in the infilteration water, Pb content was the highest at 100cm of soil depth, but the content of others were lower than non-treatment. In the paddy field of sandy loam, successive application of fly ash for 2 years increased Cd, Ni and Mn content in the infilteration water at anthracite ash application, but the contents of other elements were similar or lower than non-treatment.

• Journal of the Korean GEO-environmental Society
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• v.11 no.5
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• pp.25-34
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• 2010

In this study characteristics for reclaimed ash was studied to enlarge the usage of reclaimed ash which is reaching to 72 million ton producted from whole thermal power plants in South Korea. Fly ash and bottom ash are reclaimed separately at some of thermal power plants. However, typically bottom ash and fly ash are mixed when they are buried at most of the thermal power plant, as a result the engineering characteristics of ponded ash are not investigated properly. In order to investigate the engineering characteristics of the ponded ash, laboratory tests were performed with ponded ash and fly ash from youngheung and samcheonpo thermal power plants. Specific gravity, unit weight, and grain size analysis test were fulfilled to evaluate the physical characteristics and triaxial permeability test, direct shear test, unconfined compressive strength test, compaction test were performed to evaluate the mechanical characteristics. And also engineering characteristics of coal ash from anthracite and Bituminous thermal power plants were compared and studied respectively. As a result of the study, it was confirmed that using coal ash from Bituminous thermal power plants can be effective in the place where lightweight materials are required and using coal ash from anthracite thermal power plants can be effective as backfill material which require higher permeability. Finally, it was confirmed that fly ash from youngheung thermal power plants which has the lowest permeability among the tested material is suitable for a field requiring impermeable material.

• Journal of the Korean Society of Combustion
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• v.10 no.3
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• pp.1-9
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• 2005

The characteristics of co-combustion of Korean anthracite and bituminous coal was determined in a TGA and a lab-scale CFB reactor. The combustion reactivity of Korean anthracite (E = 51.2 kcal/mol) was much lower than that of bituminous coal (E = 14.5 kcal/mol). As the addition amount of the bituminous coal into the anthracite was increased, the reactivity of the anthracite was found to be improved. The effluent rate of the emission gases from the CFB reactor was not changed appreciably when each coal burned. As the bituminous coal was added, however, the effluent rate of the emissions was increased. The unburned carbon in fly ash from the CFB reactor was decreased with increasing the ratio of bituminous coal in co-combustion. But as the ratio of the bituminous coal was larger than 40 %, the combustion reactivity was not increased any more.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.279-284
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• 1999

Fly ash is the fine ash particles that are flying out of chimney of the thermoelectric power plant where coals are used as fuel. There are two kinds of fly ashes from anthracite and bituminous coal. By scanning electron microscope(SEM) morphological feature of fly ash was confirmed to the exact spherical particles with the diameter variation from the fine to the largest about $50{\mu}m$(mainly silty particle). Surface of anthracite ash particle was very smooth but that of bituminous was somewhat coarse. To find the utilization of fly ash for improving soil permeability, soils of 4 kinds of different texture, clay, clay loam, sandy clay loam and sand mere applied with 7 levels of fly ash: 0, 10, 20, 40, 60, 80, 100%(w/w) and their saturated hydraulic conductivity(Ks) were determined at each application by constant head method. In clay soil with low water permeability, Ks value was increased about 10 times from $10^{-8}$ to $10^{-7}m\;s^{-1}$ level with application of 10% fly ash and it was slightly increased with increasing fly ash application from 40 to 80%. In clay loam Ks value was about $10^{-7}m\;s^{-1}$ level and its value was not influenced by the fly ash application. In sandy clay loam with relatively high permeability, Ks value was decreased about 10 times from $10^{-5}$ to $10^{-6}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 50 times from $10^{-5}$ to $5.0{\times}10^{-7}m\;s^{-1}$ with application of more than 20% fly ash. In sand with very high permeability, Ks value was decreased about 10 times from $10^{-4}$ to $10^{-5}m\;s^{-1}$ level with application of 10% fly ash and also decreased about 100 times from $10^{-4}$ to $10^{-6}m\;s^{-1}$ level with application of 20% fly ash and continuously decreased about 500 times from $10^{-4}$ to $5.0{\times}10^{-7}m\;s^{-1}$ level with application of more than 40% fly ash. In conclusion by fly ash application saturated hydraulic conductivity was increased in clay soil, on the contrary it was decreased in sandy soils. Fly ash may be used as a material for amelioration of soil permeability.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.373-379
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• 1998

Fly ash application with a rate 0, 50, 100, $150Mg\;ha^{-1}$ in clay loam paddy, which had properties of pH 5.3 and low contents of silicate, gave a positively residual effects on the growth of rice crop subsequent to malting barley. The responses of rice yields to fly ash application were in the order of bituminous coal fly ash(BCFA) 100 > 150 > 50 > anthracite fly ash(AFA) 50 > 100 > none > AFA $150Mg\;ha^{-1}$. As a result, yields responses of milled rice were ranged from $6.2(50Mg\;ha^{-1}){\sim}14.4%(100Mg\;ha^{-1})$ by BCFA and from $-0.6(150Mg\;ha^{-1}){\sim}6.6%(50Mg\;ha^{-1})$ by AFA showing maximum yields of 5.084 and $4.738Mg\;ha^{-1}$ by the former and the latter, respectively. Rice plant showed lodging indices ranging from $20(50Mg\;ha^{-1}){\sim}40%(150Mg\;ha^{-1})$ by BCFA and from $1.3(150Mg\;ha^{-1}){\sim}15%(50Mg\;ha^{-1})$ by AFA at harvesting stage. In especial, soils applicated with BCFA contained a good fertility in terms of pH, available $P_2O_5$ and $SiO_2$, and exchangeable Ca and Mg etc. so that possibly harbored 3yr-residual effects of the fly ash on crop subsequent to this rice.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.1
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• pp.177-186
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• 1992

In this study, the proper mixing ratio of fly ash to bottom ash is evaluated and bearing capacity of this mixed ash is examined for use of highway embankment and subgrade materials in large quantities. Independently of the mixing ratio of fly ash to bottom ash or the method of compaction test, maximum dry density ${\gamma}_{dmax}$ and CBR value of anthracite mixed coal ash is greater than that of bituminous mixed coal ash. The mixed ashes to contain more fly ash than that of which the ratio of fly ash to bottom ash is 8 : 2, are slaked readily when the water contents of compaction are greater than optimum moisture content O.M.C. The proper mixing ratios of fly ash to bottom ash are about 5 : 5 to 6 : 4. Coal ashes mixed with these ratios exhibit proper physical and geotechnical properties for use of highway embankment and subgrade materials, and enable coal ashes to be used in large quantities.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.2
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• pp.143-148
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• 1992

Fly ash treatment on soil had a strongly positive effect on the growth of soybean. Treatment of fly ash to the soil made soil pH improved and available phosphate content increased. Consequently yield of soybean increased. From germination to early growth stage, growth status and weight of the plant were unfavorably affected by fly ash and its effects on the leaf was quite serious specially in the plots treated with more than 10 MT/10a of bituminous fly ash. However after early stage, plant growth became vigorous in the order of 0 (control plot)<15<5<10 MT/10a. But at the late maturing stage, deteriorative symptoms such as leaf burn and drying were appeared from the plant treated with 10MT/10a and its symptoms were more serious with 15MT/10a. By anthracite fly ash treatment, the plant growth was greatly improved. As a result plant height and dry matter were in the order of 0<5<10<15MT/10a. Grain yield was in the order of 0<15<5< 10MT/10a treatment with bituminous fly ash and 0<5<10<15MT/10a treatment with anthracite fly ash. As a conclusion, recommandable amount of fly ash treatment for soybean would be 5-10 MT/10a with anthracite fly ash and 5 MT/10a with bituminous fly ash.

• Applied Chemistry for Engineering
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• v.21 no.5
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• pp.553-558
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• 2010

To solve the problems of the low combustion activity of Korean anthracite and the abundant loss of unburned carbon in fly ash, pellet coal was fabricated from coal fines and fly ash, and the mixed combustion of coarse coal with the pellet coal was examined in the circulating fluidized bed combustor of a 0.1 MW scale test unit. In the combustion of the raw coal only, the significant amount of coal fines was entrained, resulting in overheat at the top of the combustor. With the coarse coal that most fines were eliminated, however, the combustion temperature was maintained stable. The mixed combustion of coarse and raw coals was also feasible even though it often went unstable. The mixed combustion of the coarse coal with the pellet coal was as stable as the coarse coal combustion, showing a promise that the combustion of the Korean anthracite in commercial circulating fluidized bed boilers could be further enhanced.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.72-77
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents of the arable soil. Rice was cultivated on the two types of paddy field clay loam and sandy loam with 0, 12ton/10a of anthracite fly ash and bituminous coal fly ash application. And soybean was cultivated at the same type of upland fields with those ashes of 0, 9ton/10a, yearly for three years. At the harvest time, the heavy metal contents in the different layer were investigated. The results were summarized as follows : 1. The contents of some heavy metal were increased in the surface soils but didn't show the tendency in the deeper layer or soil texture. 2. In the paddy fields, the contents of Cd, Cu, Zn, Cr were increased. Meanwhile and the upland fields, the contents of Cd and Cr were increased with the successive application of Anthracite fly ash, but the others didn't show those tendency. 3. The contents of Cd, Cu and Zn in the paddy field, were increased but the upland field, the contents of Cd, Cr and Ni were increased by the successive application of bituminous coal fly ash.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.249-254
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• 1992

This research was conducted to investigate the effects of fly ash applications on growth and yield parameters of corn (Zea mays L.), and soil chemical properties. Corn height at silking stage, and height and dry matter ratio at harvesting stage were enhanced by applications of fly ashes derived from bituminous coal and anthracite, respectively. Effects of fly ash treatment on growth parameters of corn were varied with kinds and levels of fly ash application and growth periods, but relatively small without revealing a major negative effect as compared to the control. Yield of corn was increased by applying fly ash of anthracite origin, but other yield components were not influenced negatively by fly ash treatment. Soil total carbon contents, cation exchange capacity, and phosphorus contents of soils sampled after harvest of corn were significantly increased by fly ash treatment, although there were slightly different effects according to kinds and levels of fly ash application. Exchangeable cations of soils were varied within an experimental error range. Phosphorus taken up by corn was enhanced by treating fly ash of the bituminous coal to the soil and there were a positive correlation between phosphorus uptake and soil Phosphorus level. Cation uptake by corn was changed a little, but no significant reduction was observed in cation uptake due to fly ash treatment. It seems to be difficult to figure out the mechanism of fly ash effects on growth and nutrient uptake by corn with one year field experiment, however treatment of fly ash enhanced some parameters of growth and yield, and nutrient uptake by corn without revealing any major negative effects. To determine the value of fly ash as a fertilizer source, continuous researches under various soil and crop conditions were considered to be necessary.