Resources Recycling (자원리싸이클링)

The Korean Institute of Resources Recycling (한국자원리싸이클링학회)
권호 표지
DOI QR코드

DOI QR Code

Formation Behavior of Precipitated Calcium Carbonate Polymorphs by Supersaturation

과포화도에 의한 침강성 탄산칼슘 다형체의 생성거동

  • Ahn, Young jun (Department of Chemical Engineering, Kwangwoon University) ;
  • Jeon, ong Hyuk (Department of Chemical Engineering, Kwangwoon University) ;
  • Lee, Shin Haeng (Department of Chemical Engineering, Kwangwoon University) ;
  • Yu, Young Hwan (Department of Chemical Engineering, Kwangwoon University) ;
  • Jeon, Hong Myeong (Department of Chemical Engineering, Kwangwoon University) ;
  • Ahn, Ji Whan (Mineral Resources Research Division, Korea Institute of Geoscience and Mineral Resources) ;
  • Han, Choon (Department of Chemical Engineering, Kwangwoon University)
  • Received : 2015.04.13
  • Accepted : 2015.05.29
  • Published : 2015.08.31
Download PDF
⟨ Previous Next ⟩

Abstract

From results obtained by adjusting experimental variables based on the kinetic, the nucleation rate for formation of precipitated calcium carbonate (PCC) was investigated. Formation behavior of PCC was investigated for various concentrations of NaOH solution and $Na_2CO_3$ addition methods in the $Ca(OH)_2$ slurry. The range of nucleation rate was investigated for dissolution rates of major ion concentrations, $Ca^{2+}$ and $CO{_3}^{2-}$. In case of high concentration of major ions, vaterite and calcite were synthesized. The high nucleation rate was achieved for lower either $Ca^{2+}$ or $CO{_3}^{2-}$ ion concentration, calcite was mainly synthesized and when concentration of major ions was low, aragonite was synthesized. Furthermore, the formation of calcite was decreased with increasing concentration of NaOH. homogeneous aragonite could be obtained by addition 5 M NaOH. Therefore, in this study, specific shape of polymorphs could be prepared through controlling supersaturation.

속도론적인 관점에서 실험변수를 조절하여 얻어진 결과로부터 침강성 탄산칼슘(precipitated calcium carbonate, PCC)의 생성을 핵생성속도로 규명하였다. 반응온도 $80^{\circ}C$에서 $Ca(OH)_2$ slurry, $Na_2CO_3$ 수용액 및 다양한 농도의 NaOH를 첨가하여 침강성 탄산칼슘의 생성거동을 관찰하였다. 핵생성속도는 주 반응물인 $Ca^{2+}$ 이온과 $CO{_3}^{2-}$ 용해속도를 조건으로 나누어 진행하였다. 두 이온의 농도가 고농도일경우에는 vaterite와 calcite가 혼재되어 나타났다. $Ca^{2+}$ 이온과 $CO{_3}^{2-}$ 이온농도 중 어느 하나만을 낮게 하여 반응시킨 경우에는 주로 calcite가 생성되었으며 두 이온농도가 모두 낮을 경우에는 aragonite가 형성되었다. 또한 NaOH 농도를 증가시킴에 따라 calcite의 생성은 감소하였으며 5M NaOH 수용액 내에서 단일상의 aragonite를 얻을 수 있었다. 따라서 본 연구에서는 과포화도 조절을 통해 다형체(polymorphs) 중 특정 형태를 합성할 수 있었다.

Keywords

References

  1. Sohnel, O., Mullin, JW., 1982 : Precipitation of calcium carbonate, J. Crystal Growth, 60, pp. 239-250. https://doi.org/10.1016/0022-0248(82)90095-1
  2. Wray, JL., Daniels, F., 1957 : Precipitation of calcite and aragonite, J. Am. Chem. Soc., 79, pp. 2031-2034. https://doi.org/10.1021/ja01566a001
  3. Maciejewski, M., Oswald, HR., Reller, A., 1994 : Thermal tranformation of vaterite and calcite, Thermochimica Acta, 234, pp. 315-328. https://doi.org/10.1016/0040-6031(94)85155-7
  4. Tanaka, H., Horiuchi, H., Ohkubo, T., 1988 : Synthesis of whisker aragonite $CaCO_3$, Gypsum & Lime, 216, pp. 314-321.
  5. Kitamura, M., Konno, H., 2002 : Controlling factors and mechanism of reactive crystallization of calcium carbonate polymorphs from calcium hydroxide suspensions, J. Crystal Growth, 236, pp. 323-332. https://doi.org/10.1016/S0022-0248(01)02082-6
  6. Konno, H., Nanri, Y., 2003 : Effect of NaOH on aragonite precipitation in bath and continuous crystallization in causticizing reaction, Powder Technology, 129, pp. 15-21. https://doi.org/10.1016/S0032-5910(02)00275-9
  7. Kojima, Y., Sadotomo, A., 1992 : Control of crystal shape and modification of calcium carbonate prepared by precipitation from calcium hydrogencarbonate solution, J. Ceram. Soc. Japan Int, 100, pp. 1128-1135.
  8. Nyvlt, J., 1985 : The kinetics of industrial crystallization, Elsevier, Amsterdam, 284, pp. 68.
  9. Shindler, PW., 1967 : Heterogeneous Equilibria involving oxides, hydroxides, carbonated and hydroxide carbonates, Adv. Chem. Ser., 67, pp. 196. https://doi.org/10.1021/ba-1967-0067.ch009
  10. Nielsen, AE., Davis, JA., Hayes, KF., 1986 : Mechanism and rate laws in electrolyte crystal growth from aqueous solution in geochemical processes at mineral surfaces, Am. Chem. Soc. Symp. Ser., 323, pp. 600-614.
  11. Kim, JH., Ahn, JW., Park, HS., Park, CH., 2004 : Synthesis Peculiarity of the precipitated calcium carbonate polymorphs following variation of supersaturation in $Ca(OH)_2$ and $Na_2CO_3$ reaction system, J. Geosystem Engineering., 7, pp. 95-102. https://doi.org/10.1080/12269328.2004.10541227

Cited by

  1. Improving the Yield of Sonochemical Precipitated Aragonite Synthesis by Scaling up Intensified Conditions vol.203, pp.12, 2016, https://doi.org/10.1080/00986445.2016.1230105