To enable effective regeneration or recovery in a method and an apparatus that regenerate a treatment liquid containing hydrofluoric acid that processes a silicon substrate, a glass substrate or other silicon-containing materials.
The regeneration apparatus includes: a storage tank 1 that stores a treatment liquid containing hydrofluoric acid after use; a concentration measuring apparatus 11 that measures the concentration of hexafluoro silicic acid in the liquid in the storage tank 1; a precipitation reaction tank 2 in which the liquid accepted from the storage tank 1 can be left at rest; a precipitation chemical solution supply parts 7, 8 and 15 that add a prescribed amount of a potassium salt aqueous solution in the precipitation reaction tank 2 based on a theoretical calculation amount obtained from a measured concentration; solid-liquid separation mechanisms 3-6 and 9 in which the suspension of an insolubility potassium salt that has precipitated is left at rest, a supernatant liquid being removed, and is filtered by necessity to be separated to a clarified liquid and a precipitated solid material; the concentration measuring apparatus 11 that measures the concentrations of hydrofluoric acid and nitric acid in the clarified liquid; and mechanisms 13, 14, and 23 that add hydrofluoric acid and nitric acid based on the concentration measurement result.
O AKIHIKO
| JP2000239001A | 2000-09-05 | |||
| JP4363494B2 | 2009-11-11 | |||
| JP2011126720A | 2011-06-30 | |||
| JP2003275747A | 2003-09-30 |
| WO2010004925A1 | 2010-01-14 |
Masato Tsuda
Tetsuji Nakamura
Katsuyuki Tomita
Husband