• KOREAN JOURNAL OF CROP SCIENCE
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• v.17
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• pp.143-148
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• 1974

Field and pot experiments were conducted for the split application of potash in paddy (Oryza sativa L. cultivar Jinheung.) Production and the experimental results were analysed with regard to the yield of paddy and its yield components. The absence of potash at the reproductive stages such as primodial and heading period but supplied most of the potash at the early growth stages, resulted in an increase of panicles but in a decrease of grain numbers per panicle and yield of paddy. On the other hand, however, the reduced amount of potash application at the earlystage of growth showed a decreased number of panicles and yield of paddy, particulary where lime and fresh rice straw were applied.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.273-284
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• 2005

Coagulation and precipitation process by using lime$(Ca(OH)_2)$ and calcium carbonate $(CaCO_3)$ were applied to remove heavy metals from groundwater in laboratory scale. From results of batch tests, by the addition of $0.3\;wt.\%$ lime, more than $90\%$ of As and Mn were removed and $70-80\%$ of Cd and Zn were removed by using $0.5\;wt.\%$ of lime. Removal efficiency of Pb almost reached $100\%$ with only $0.1\;wt.\%$ of calcium carbonate and more than $93\%$ of Cd were removed by the addition of $0.1\;wt.\%$of calcium carbonate. Pilot scale column experiments were performed to remove heavy metals in the separation process of precipitated Hoc to supernatant after the coagulation/ precipitation. For lime as a coagulant, more than $99\%$of As were removed from artificial groundwater and removal efficiencies of Cd, Mn, and Zn were over $80\%$. By using calcium carbonate, more than $95\%$ of Cd and Pb were removed in column experiment. Fe and Mn contaminated groundwater taken from a real landfill site, Ulsan was used for the column experiment and more than $99\%$ of Fe and Mn were removed by the addition of $1\;wt.\%$ lime in column experiment, suggesting that the coagulation/precipitation process by using lime and calcium carbonate have a great possibility to remove heavy metals from contaminated groundwater.

• Resources Recycling
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• v.3 no.3
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• pp.32-49
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• 1994

Hydration process is one of the basic carbonation system. Limestone sludge produced in Pohang Iron & Steel Co., Ltd. We tested for identify of hydration characteristics. The result obtained in this study can be summarized as follows; 1. The classify of limestone sludge is type of ground calcium carbonate(-3mm+325mesh)and the major mineral of calcite, and further more high grade(CaO 51%), fine powder(15~22$\mu\textrm{m}$). 2. Limestone sludge mixed two process sludge, first one is washing process sludge and the other one is wet collect kiln dust. The composition rate is about 8:2. Wet collect kiln dust is major mineral of calcite, too. But the sludge is assumed to one by quick lime, slaked lime and unreacted natural limestone. So, the ideal process is dividing of the washing process sludge and wet collect kiln dust. 3. We manufactured of slaked lime from limestone sludge. To investigate the effect of hydration reactor, the experiments was done with various reactor type as magnetic stirrer, shaking incubator and ultrasonic vibration reactor, respectively. Generally, ultrasonic vibration reactor is excellent hydration for limestone sludge and produced very fine slaked lime powder with ideal distribution. 4. The optimum condition is 10% pulp density, when the manufacture of fine slaked lime powder by ultrasonic vibration reactor. And hydration times to compare the results of the study with ultrasonic vibration reactor of generalized most short time(5~10 min). 5. Finally, the dispersive characteristics of slaked lime powder measured 1~5 $\mu\textrm{m}$ from limestone sludge were compared with those of natural limestone ones(10~20$\mu\textrm{m}$), in order to check applicability of slaked lime with hydration process from limestone sludge.

• Journal of the Mineralogical Society of Korea
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• v.22 no.3
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• pp.261-277
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• 2009

This study is aimed to emphasize the significance of ore selection in lime manufacturing through the evaluation of applied-mineralogical impact factors of crude ores controlling calcination characteristics for some domestic limestones used currently for lime manufacturing. To do this work, systematic characterization and determination were carried out for the limestone ores and their calcination products in a fixed calcining condition (target temperature: $1000^{\circ}C$, retention time: 30 minutes, 2, 4, 10, 16 hours), and the results were correlated and discussed. Selected high-Ca limestones in this study are as much as > 98 wt%, but they are somewhat diverse in crystallinity, texture, and impurity composition. Synthesized quicklimes are varied depending on such a difference in ore characters. The Pungchon limestone has relatively very low calcination rate, and the limestones from the Gabsan formation and the Jeongseon formation exhibit good quality in calcination rate and decrepitation. Among these samples, the limestone ore from the Jeongseon formation is evaluated to be the best for crude ore in manufacturing of highly-reactive quicklime. In addition, it is characteristic that the Gabsan limestone comparative rich in Fe-bearing mineral such as pyrite and goethite is more conspicuous in sintering effect.

• Journal of the Korean Geotechnical Society
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• v.20 no.3
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• pp.75-83
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• 2004

The Indiana Department of Transportation (INDOT) has permitted the use of Lime Kiln Dust (LKD) as a low-cost construction material in creating a workable platform for soil modification (not for soil stabilization) since the early 1990s on selected projects. However, the enhanced strength of soils with LKD has not been accounted for in the subgrade stability calculations in the design process. This study was initiated to evaluate how the lime kiln dust is a comparable material to hydrated lime. A series of laboratory tests were performed to assess the mechanical benefits of lime kiln dust in combination with various predominant fine grained soils encountered in the State of Indiana, such as A-4, A-6 and A-7-6. In the course of this study, several tests such as the Atterberg limits, standard Proctor, unconfined compression, CBR, volume stability, and resilient modulus were performed. As a result, mixtures of fine grained soils with 5% lime or 5% LKD substantially improve unconfined compressive strength up to 60% - 400%. CBR values for treated soils are in the range of 25 to 70 while those for untreated soils range from 3 to 18. In general, significant increase in resilient moduli of the soils treated with lime and LKD was observed. This indicates that lime kiln dust may be a viable, cost effective alternative to hydrated lime in enhancing the strength of fine grained soils.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.174-178
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• 2008

Nano-crystalline slaked lime was synthesized using design of experiment. In order to synthesize slaked lime, calcium chloride $(CaCl_2)$ and urea were used as starting materials. Calcium chloride solution and urea solution were mixed and heated in vessel that calcium carbonate was precipitated during heating. Precipitates were filtered, washed several times using D.I.water and ethanol and finally dried in oven. Slaked lime $(Ca(OH)_2)$ has been fabricated by the hydration of calcined $CaCO_3$. Design of experiment (Taguchi method) was used to optimize parameter, to minimize noise factors of experiment and to statistically analyze the results. Slaked lime having about 50 nm in optimized crystallite size could be obtained by calcination of $CaCO_3$ at $1000^{\circ}C$ for 0.5 h and hydration with D.I water containing ethanol and oxalic acid.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.1
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• pp.35-40
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• 1991

A laboratory column experiment was conducted to learn the desalinization effect of rice straw, fresh or predecayed in limed marine soil, compared with gypsum. One third of Ca equivalent to indigenous Na plus Mg of the soil was applied to the top 10g out of 80g of total column soil, mixing one half of it to the top soil and the rest spreading on the surface. 1. Pre-decaying of rice straw in limed marine soil promoted the permeability of column soil. but showed a less effectiveness in desalinization of sodium than lime alone or lime plus fresh rice straw treatemenents. 2. Gypsum and calcium carbonate treatments without rice straw fixed Mg in the limed top soil and washed it down disolving more from the layer immediatly be low the treated top soil But the treatment of calcium carbonate and rice straw both together washed out Mg more from lower layers than the upper's, showing only physical desalinization. 3. The desalinization of Na was also severe in the layer immediately below the $CaSO_4$ treated top soil, leauing more Na ilo the top soil, which seemed to be attributed to the peptisation of the top soil and retard peptisation of desalinization when washed the soil applying not enough amount or non of gypsum.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.159-166
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• 1999

This study was conducted to investigate the effects of application of the dolomite particle and the shell powder on soil characteristics, dry matter yield and nutritive value of forages in loam soil at the experimental field of National Livestock Research Institute, Suwon, from 1994 to 1996. Application treatments were control, lime, dolomite 0.5, 2.0, 4.0mm, and shell powder in mixed pasture. Rate of dust occurrence was greatly decreased according to dolomite application and the dissolving rate in soil was highest in shell powder application among treatments. Although there was no significant difference, average dry matter yield of forages for 3 years was slightly increased with the application of lime, shell powder, dolomite 0.5mm, 4.0mm, 2.0mm and control in order. Both Ca and Mg contents of forages were no differences among treatments in 1994. However, all treatments were higher than those of control in 1995. And K and Na contents of forages were no differences among treatments. Lime requirement was greatly increased from 2,630 to 6,150kg per ha with the lapse of time. Although soil hardness was optimum level at first, it was likely to become hard little by little after treatments. Solid phase of soil was lowered a little except for control. Organic matter and available $P_2O_5$ contents of soil were highest in shell powder application among treatments, and K, Ca and Mg contents of soil were no differences among treatments. Ca content was increased a little in 1995, but decreased a little in 1996 compared to that of soil before treatments in 1994. AIso, Mg content was lowered than that of soil before experiment in 1995 and 1996. The results demonstrated that use of dolomite and shell powder as lime substitutes could be reduced dust problem and coast pollution as well as soil improvement. Therefore, it is desirable to apply the dolomite and the shell powder every 3 years in loam soil.

• Journal of Ginseng Research
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• v.33 no.2
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• pp.139-142
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• 2009

The effect of calcium cyanamide (China-made) soil fumigation on the growth of the ginseng pathogen Rhizoctonia, Pythium), soil microbes, and seed germination of lettuce and radish was investigated. At twice the recommended level (2S0-ppm $CaCN_2$), the growth of Rhizoctonia and Pythium, and the seed germination, were not inhibited. Rather, the effective level was 10,000 ppm. The powder form was more effective than the granular form in inhibiting pathogen growth and seed germination. The lettuce seed was also more sensitive than the radish seed. Calcium cyanamide appearedto decrease the fungi population and to increase Actinomycetes in the soil.

• Applied Biological Chemistry
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• v.24 no.2
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• pp.112-119
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• 1981

The persistence of preemergence herbicides, butachlor [2-chloro-2,6-diethyl-N(butoxymethyl) acetanilide] and nitrofen(2,4-dichlorophenyl-4-nitrophenyl ether), at 10 ppm level in different soil conditions amended with organic matter and lime was studied under flooded and field moisture capacity. The microbial breakdown played a major role in the dissipation of the herbicides in soil. Nitrofen degradation in flooded soil was greatly accelerated, while it was slowed down in field moisture capacity as compared with butachlor. Increased amendment of rice straw to the soil shortened the half-life of butachlor under flooded condition, however it prolonged that of butachlor when the amendment was exceeded over 1% on dry weight basis. Liming the soil stimulated decomposition of the herbicides in the soil systems, which ap pears to be pH independent.