Patents Assigned to Hi-Silicon Co., Ltd.
  • Process for cleaning silicon mass and the recovery of nitric acid
    Patent number: 5346557
    Abstract: In a process for cleaning a silicon mass with a acid washing solution, a waste solution containing a mixed acid composed of nitric acid and hydrofluoric acid is introduced to a distillation step, and hydrofluoric acid is introduced to a distillation cooling portion to prevent precipitation of silicon dioxide. The waste cleaning liquor is distilled to recover nitric acid.
    Type: Grant
    Filed: October 28, 1992
    Date of Patent: September 13, 1994
    Assignee: Hi-Silicon, Co., Ltd.
    Inventors: Hideo Ito, Mitsutoshi Narukawa, Kazuhiro Sakai
  • Method and apparatus for cutting polycrystalline silicon rods
    Patent number: 4955357
    Abstract: A method and apparatus for cutting polycrystalline silicon rods which comprise applying pressing forces at at least two positions on a plane perpendicular to the longitudinal axis of a polycrystalline silicon rod at a plurality of positions symmetrical to said axis.
    Type: Grant
    Filed: January 22, 1988
    Date of Patent: September 11, 1990
    Assignee: Hi-Silicon Co., Ltd.
    Inventors: Masakatsu Takeguchi, Takashi Yamamoto, Mamoru Nakano