Method and apparatus for purifying ultra-high purity hydrogen fluoride
AssigneeRam Technology Co., Ltd.
InventorsJune-Ing Kil, Young-Su Jang, Hwan-Pyoung Lee
Life of this patent
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Abstract
The present invention discloses a method and apparatus for purifying ultra-high purity hydrogen fluoride, which purify it through a continuous distillation process by putting crude hydrogen fluoride instead of hydrogen fluoride into a multi-stage distillation column as it is, and remove impurities in hydrogen fluoride through a contact with fluorine gas having the concentration of the F2 gas automatically controlled depending on the content of arsenic fluoride that is an impurity.
Claims7
A method for purifying ultra-high purity hydrogen fluoride, the method including steps of:
- providing crude hydrogen fluoride produced by a reaction between fluorspar and sulfuric acid and not having undergoine a pretreatment process from a raw material supply unit;
- performing a continuous distillation process of supplying crude hydrogen fluoride to a multi-stage distillation column to extract and remove impurities in the distillation column after fractional distillation, and transfer distilled hydrogen fluoride to a next multi-stage distillation column;
- and
- injecting a gas stream containing an F2 gas and an inert gas for removal of AsF3 in impurities into the multi-stage distillation column into which crude hydrogen fluoride is put,
- wherein the gas stream is a gas stream whose concentration is adjusted according to the content of AsF3 contained in hydrogen fluoride gas that passed through the multi-stage distillation column, and
- wherein the gas stream containing the F2 gas and the inert gas is also injected into another multi-stage distillation column into which crude hydrogen fluoride is not put.
An apparatus for purifying ultra-high purity hydrogen fluoride, the apparatus including:
- a raw material supply unit for supplying a crude hydrogen fluoride produced by a reaction between fluorspar and sulfuric acid and not having undergone a pretreatment process;
- a distillation purification unit equipped with a plurality of multi-stage distillation columns for performing a continuous distillation process;
- a gas supply unit for supplying a gas stream containing an F2 gas and an inert gas into the multi-stage distillation columns;
- a recovery unit for recovering ultra-high purity hydrogen fluoride;
- an advanced process control unit for process control to enable continuous process,
- wherein a gas stream whose concentration is adjusted according to the content of AsF3 contained in hydrogen fluoride gas that has passed through the multi-stage distillation columns by the advanced process control unit is supplied to the multi-stage distillation columns into which crude hydrogen fluoride is put, and
- wherein the gas stream containing the F2 gas and the inert gas is also injected into another multi-stage distillation column into which crude hydrogen fluoride is not put.
Dependencies are inferred from the claim text.