Dispersion Characteristics of Carbon Black Particles in a High Viscous Simulated Solution

고점성 모사용액 내 Carbon Black 입자의 분산특성

  • 정경채 (한국원자력연구원 차세대핵연료개발부) ;
  • 엄성호 (한국원자력연구원 차세대핵연료개발부) ;
  • 김연구 (한국원자력연구원 차세대핵연료개발부) ;
  • 조문성 (한국원자력연구원 차세대핵연료개발부)
  • Published : 2013.04.10

Abstract

An external gelation method in place of an internal gelation method applied to the fabrication process of an intermediated compound of Uranium Oxy-Carbide (UCO) kernel spheres for Very High Temperature Reactor (VHTR) fuel preparation is under development in Korea. For the preliminary experiments of the UCO kernel sphere preparation using an external gelation method, the carbon black dispersion experiments were carried out using a simulated broth solution. From the selection experiments of various kinds of carbon black through dispersion experiments in a viscous metal salt solution, Cabot G carbon black was selected owing to its dispersion stability, and the homogeneous dispersing state of carbon black particles in our system. For the effective dispersion of nano-size aggregated carbon black particles in a high viscous liquid, the carbon black particles in a metal salt solution were first de-aggregated with ultrasonic force. The mixed solution was then dispersed secondly by the use of the extremely high-speed agitation with a mechanical mixer of 6000 rpm after feeding the Poly Vinyl Alcohol (PVA) in the solution. This results in the broth solution with good stability and homogeneity alongside no further changes in physical properties.

초고온가스로 핵연료 구형 UCO (uranium oxycarbide) 입자 제조과정 중 중간화합물 제조에서 적용하고 있는 내부겔화공정을 대체하기 위해 외부겔화공정을 도입하는 연구가 진행 중에 있다. 외부겔화공정을 이용해서 구형 UCO입자를 제조하기 위한 사전실험으로, 중간화합물인 ADU (ammonium di-uranate) 겔 입자를 제조하기 위한 원료용액인 모사 broth 용액을 제조하여 카본블랙 입자를 분산시키는 실험이 수행되었다. 다양한 종류의 카본블랙 입자를 사용해서 모사 broth 용액에 분산실험을 수행한 결과, Cabot G 제품이 용액상에서 분산안정성과 균일한 분산상태를 나타내고 있어서, 본 연구의 카본블랙으로 선정되었다. 또한 나노크기 입자로 응집된 카본블랙 입자를 고점성 액상물질에 효율적으로 분산시키기 위해서는, 금속염용액에 카본블랙 입자를 투입하고 ultrasonic force를 이용해서 응집입자를 해체한 다음, 고점성 물질인 PVA (poly vinyl alcohol)를 투입하여 강력한 기계식혼합기를 이용해서 6000 rpm으로 2차 분산 혼합시키는 경우, ultrasonic force에 의한 broth 용액의 물성이 유지되면서 카본블랙 입자의 분산안정성과 분산상태가 양호한 broth용액을 얻을 수 있었다.

Keywords

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