• Title, Summary, Keyword: $CaCO_3$ preparation

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Study on $CaCO_3$ Preparation from MSWI Fly Ash (생활쓰레기 소각(燒却)비산재로부터 $CaCO_3$ 제조(製造)에 관한 연구(硏究))

  • Choi, Woo-Zin;Park, Eun-Kyu
    • Resources Recycling
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    • v.15 no.5
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    • pp.47-51
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    • 2006
  • The total amount of ash generated from the municipal solid waste incineration(MSWI) in Korea was approximately 420,000 tons in 2005 including 68,000 tons of fly ash. Fly ash from MSWI generally contains high amount of CaO (upto ${\sim}50%$) due to the treatment of flue gas by spraying CaO-base materials. Currently, most of fly ash generated is finally ended up with specially designed landfill sites and only less then 20% of fly ash is recycled. In the present work, preparation of $CaCO_3$ from the MSWI ny ash was studied to promote the fly ash recycling. Fly ash obtained from the dust collector in stoker-type MSWI is used to selectively dissolve CaO by using the sugar solution. Then, $CO_2$ gas was passed through the dissolved solution to pro- duce $CaCO_3$ powder. The optimum conditions for CaO dissolution were solid content 10%, reaction time 15 minutes, sugar concentration $10{\sim}15%\;and\;pH\;10.5{\sim}11.0$. The high grade $CaCO_3$ powder was obtained and the experimental conditions are also discussed.

A Development of Nontoxic Composite Latex Using $CaCO_3$/PEMA ($CaCO_3$/Poly ethyl methacrylate를 이용한 무독성 혼합라텍스의 개발)

  • Seul, Soo-Duk;Lee, Sun Ryong;Lee, Nae-Woo
    • Journal of the Korean Society of Safety
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    • v.17 no.4
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    • pp.133-139
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    • 2002
  • Core-shell polymers of inorganic/organic pair, which are consisted of both core and shell component, were synthesized by sequential emulsion polymerization using ethyl methacrylate (EMA) as a shell monomer and ammonium persulfate as initiator. We found that $CaCO_3$ core should be prepared by adding 2.0wt% SDBS(sodium dodecyl benzene sulfonate), $CaCO_3$ core/PEMA shell polymerization was carried out on the surface of $CaCO_3$ particle during EMA shell polymerization in the core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring the degree on decomposition of $CaCO_3$ by HCI solution, thermal decomposition of polymer composite on thermogravimetric analyzer, glass transition temperature on differential scanning calorimeter, and morphology using scanning electron microscope.

Preparation and Properties of Cellulose Diacetate/$CaCO_3$ Composite (Cellulose Diacetate/$CaCO_3$ 복합체의 제조 및 물성)

  • Lim, Hwan-Kyu;Kye, Hyoung-San;Won, Sung-Ho;Nam, Jae-Do;Lee, Young-Kwan
    • Polymer(Korea)
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    • v.32 no.2
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    • pp.178-182
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    • 2008
  • Cellulose diacetate (CDA) and calcium carbonate ($CaCO_3$) biodegradable composites were prepared by melt mixing in a twin screw extruder and their physical properties were examined. In the melt processing, triacetine and epoxidized soybean oil were added to the composites as a plasticizer and lubricant, respectively. The optimal conditions for the preparation of the biodegradable composites were determined. Acetic acids ($CH_3COOH$) were made by pyrolysis acetyl group ($-OC (O)CH_3$) of CDA and TA in melt processing. Increasing the amount of $CaCO_3$ in the composites resulted in further enhancement of the $CH_3COOH$ absorption effects. The tensile strength and elongation were decreased, and Young's modulus and $T_g$ value increased with increasing amount of $CaCO_3$.

Preparation and Characteristics of Hydroxyapatite Power by Wet Method (습식법에 의한 Hydroxyapatite 분말제조와 그 분체특성)

  • Kim, Jong-Moon;Kim, Kyum;Lee, Seo-Woo
    • Journal of the Korean Ceramic Society
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    • v.28 no.1
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    • pp.46-52
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    • 1991
  • The hydroxyapatite powders were prepared by the reaction of Ca(CH3COO)2$.$H2O and H3PO4 in aqueous solution. Effect of Ca/P mole ration and pH value on the powder characteristics were investigated. For phosphoric acid was dissociated to PO43- ion above pH 10, the preparation condition of hydroxyapatite by H3PO4 solution had this value. Dried powders were agglomerated each other. The mean agglomerate particle diameter was minimum when the condition was pH 11, Ca/P=1.75 and its specific surface area was 97㎡/g. All powders had poor crystallinity and small CO2. It prevented CaCO3 from using aspirator in preparation and maturing time. In most cases, hydroxyapatite was decomposed into ${\beta}$-TCP at more than 800$^{\circ}C$, into ${\alpha}$-TCP at 1200$^{\circ}C$. However non-decomposed hydroxyapatite was remained in Ca/P=1.85.

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Preparation of PET Nanocomposites: Dispersion of Nanoparticles and Thermal Properties

  • Her, Ki-Young;Kim, Dae-Heum;Lim, Soon-Ho
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.4
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    • pp.71-73
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    • 2008
  • The development of polymer/inorganic nanocomposites has attracted a great deal of interest due to the improved hybrid properties derived from the two different components. Various nanoscale fillers have been used to enhance polymer mechanical and thermal properties, such as toughness, stiffness, and heat resistance. The effects of the filler on the final properties of the nanocomposites are highly dependent on the filler shape, particle size, aggregate size, surface characteristics, polymer/inorganic interactions, and degree of dispersion. In this paper, we describe the influence of different $CaCO_3$ dispersion methods on the thermal properties of polyethylene terephthalate (PET)/$CaCO_3$ composites: i.e., the adsorption of $CaCO_3$ on the modified PET surface, and the hydrophobic modification of the hydrophilic $CaCO_3$ surface. We prepared PET/$CaCO_3$ nanocomposites using a twin-screw extruder, and investigated their thermal properties and morphology.

A Study on the Environmental Fraternized Preparation of Inorganic/organic Core-shell Binder (환경친화적인 무기/유기 Core-Shell의 제조에 관한 연구)

  • Seoul, Soo-Duk;Lim, Jae-Keel;Lim, Jong-Min;Kwon, Jae-Beom;Lee, Nae-Woo
    • Journal of the Korean Society of Safety
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    • v.19 no.1
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    • pp.81-87
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    • 2004
  • Composite particles using inorganic and organic chemicals were synthesized and the results of those reaction were compared to variation of temperature and agitation speed in presence of $CaCO_3$ which was adsorbed SDBS. Also the synthesises were optimized according to conversion rate of composite particles. In inorganic/organic core-shell composite particle polymerization, $CaCO_3$ adsorbed by 0.5wt% surfactant SDBS was prepared initially and then core $CaCO_3$ was encapsulated by sequential emulsion polymerization using MMA at the addition of APS 3.16${\times}$$10^{-3}$mol/L to minimize the coagulated PMMA particle itself during MMA shell polymerization. Encapsulated PMMA on $CaCO_3$ as inorganic/organic core-shell particles was verified by FT-IR and DSC analysis. It was found that the $CaCO_3$ was very well encapsulated by PMMA as shell. The surfaces were distinctly found as spindle shape and broad particle distribution after capsulation.

Preparation of Silicone Rubber Membrane and its Porosity (Silicone Rubber Membrane의 제조 및 기공특성)

  • Lee, Seung-Bum;Kim, Hyung-Jin;Hong, In-Kwon
    • Elastomers and Composites
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    • v.30 no.3
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    • pp.185-194
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    • 1995
  • Membrane process has been employed to separate a specific substance from gas or liquid mixture, and treat wastewater. This is due to the fact that the substance of mixture can be permeated and separated selectively by membrane. Since Initial equipment and operation costs are not expensive, membrane process has been adopted in various fields such as petroleum Industry, chemistry, polymer, electronics, foods, biochemical industry and wastewater treatment. In this study, $CaCO_3$ particles impregnated in silicone rubber network were extracted by using supercritical carbon dioxide and pore distribution of silicone $rubber-CaCO_3$ was investigated with varying amount of extract. Silicone rubber has excellent mechanical properties such as heat-resistance, cold-resistance etc. and $CaCO_3$ has microporous structure. It is possible to make silicone $rubber-CaCO_3$ composite sheets via work-intensive kneading processes. In so doing $CaCO_3$ particles become distributed and impregnated in silicone rubber network. Supercritical carbon dioxide diffuse through composite sample, then sample is swollen. $CaCO_3$ in silicone rubber network Is dissolved in supercritical carbon dioxide, and its sites become pores. Pore distribution, pore shape and surface area are observed by SEM(scanning electron microscope) micrograph and BET surface area analyzer examination respectively. Pore characteristics of membrane suggest the possibilities that the membrane can be used for process of mixture separation and wastewater treatment.

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Synthesis of Inorganic/Organic Core-Shell Polymer (무기/유기 Core-Shell 에멀젼 고분자의 합성)

  • Kim, Nam-Seok;Kim, Duck-Sool;Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.19 no.4
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    • pp.265-272
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    • 2002
  • $CaCO_{3}$ absorbed sodium lauryl sulfate (SLS) surfactant was prepared, Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using styrene(St) as a shell monomer and potasium persulfate (KPS) as an initiator, We found that when $CaCO_{3}$; core prepared by adding 2,0 wt% SLS, $CaCO_{3}$ core/PSt shell polymerization was carried out on the surface of $CaCO_{3}$ particle without forming the new PSt particle during St shell polymerization in the inorganic/organic core-shell polymer preparation, The structure of core-shell polymer were investigated by measuring the degree of decomposition of $CaCO_{3}$ using HCl solution, thermal decomposition of polymer composite using thermogravimetric analyzer and morphology by scanning electron microscope.