Method for producing ultra-clean high-pure hydrofluoric acid

A technology of hydrofluoric acid and clean height, applied in the direction of fluorine/hydrogen fluoride, etc., can solve problems such as the difficulty of applying ultra-clean and high-purity hydrofluoric acid, incomplete separation of arsenic trifluoride, and difficult control of process parameters, so as to increase economic benefits and environmental protection Benefits, relieve environmental pressure, improve the effect of purity

Active Publication Date: 2009-11-04
DO FLUORIDE CHEM CO LTD
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  • Summary
  • Abstract
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  • Claims
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AI Technical Summary

Problems solved by technology

[0003] At present, the reaction of industrial anhydrous hydrofluoric acid and potassium permanganate is generally used, followed by direct rectification and purification to produce ultra-clean and high-purity hydrogen fluoride. The separation of arsenic is not complete, so the ultra-clean and high-purity hydrofluoric acid produced by this method is difficult to apply in VLSI (microelectronics industry), and at the same time, the process parameters in the production process are not easy to control

Method used

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Examples

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Effect test

Embodiment 1

[0026] The method in this embodiment specifically includes: purifying the system with nitrogen, emptying the air in the system, maintaining the room temperature at 22.2°C, the temperature at the operating site at 22.2°C, and maintaining the humidity at 40%. 350kg of liquid hydrogen fluoride raw material flows out from the storage bottle and is added to the crude still with heat exchanger. In the crude still, control the pressure in the crude still to be less than 0.2Mpa, add (NH 4 ) 2 S 2 o 8 , its add-on is 5.25kg, makes a large amount of sulfur dioxide and arsenic trifluoride contained in the liquid hydrogen fluoride generate the compound that is difficult to volatilize; Add the hydrogen peroxide of 30% (weight ratio) then, the add-on of hydrogen peroxide is 7kg. The gas distilled out at a temperature of 30-50°C in the crude still rises continuously, passes through the crude distillation tower, and then enters the water condenser directly installed on the top of the tower...

Embodiment 2

[0028] The method in this embodiment specifically includes: purifying the system with nitrogen, and emptying the air in the system. Keep the room temperature at 23.5°C, the operating site at 22.3°C, and the humidity at 40%. 250kg of liquid hydrogen fluoride raw material flows out from the storage bottle and is added to the crude still with a heat exchanger. In the crude still, control the pressure in the crude still to be less than 0.2Mpa, add 2.5kg KHF 2, making a large amount of sulfur dioxide and arsenic trifluoride contained in industrial anhydrous hydrogen fluoride generate difficult volatile compounds; then add 30% (by weight) hydrogen peroxide, hydrogen peroxide accounts for 5kg of industrial anhydrous hydrogen fluoride addition. The gas distilled out at a temperature of 30-50°C in the crude still rises continuously, passes through the crude distillation tower, and then enters the water condenser directly installed on the top of the tower, and repeatedly condenses, refl...

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Abstract

The invention relates to a method for producing ultra-clean high-pure hydrofluoric acid. The method comprises the following steps: (1), emptying air in a system; (2), adding a measured liquid hydrogen fluoride raw material to a rough distillation kettle with a heat exchanger for rough distillation; (3), controlling the inside pressure of the rough distillation kettle to be lower than 0.2MPa and adding an oxidant; (4), repeatedly condensing, refluxing and vaporizing in the rough distillation kettle; (5), pumping gas guided from a top outlet of a water condenser into the bottom of a spraying absorption tower so as to be absorbed by spraying absorption liquid which is sprayed in from the top of the absorption tower; (6), gasifying and pumping hydrofluoric acid into the absorption tower to be absorbed; (7), pumping the hydrofluoric acid at the outlet of the condenser into the absorption tower and using ultra-pure water to absorb into 48 percent to 49 percent of hydrous hydrofluoric acid solution; (8), secondarily rectifying the 48 percent to 49 percent of hydrous hydrofluoric acid solution; and (9), filtering the 48 percent to 49 percent of hydrous hydrofluoric acid solution after secondary rectification at two stages to prepare 48 percent of ultra-clean high-pure hydrofluoric acid finished product. The invention not only improves the purity of the ultra-clean high-pure hydrofluoric acid, but also increases the economic benefits and the environmental-protection benefits.

Description

technical field [0001] The invention relates to a method for producing ultra-clean and high-purity hydrofluoric acid, in particular to a method for producing ultra-clean and high-purity hydrofluoric acid with liquid hydrogen fluoride as the main raw material. Background technique [0002] Hydrofluoric acid (hydrofluoric, HF), relative molecular weight 20.1, colorless liquid or gas; has a strong pungent smell, below 20 ℃, it is a colorless and transparent fuming liquid, and metal oxides, sodium hydroxide and carbonic acid Salt reaction to generate metal fluorine salt, which has the property of dissolving silicon and silicate, generates fluorosulfonic acid with sulfur trioxide or chlorosulfonic acid, reacts with halogenated aromatic hydrocarbons, alcohols, alkenes, and hydrocarbons to generate fluorine-containing organic compounds, and is soluble in water This produces a very corrosive acid. Melting point -83.7°C, boiling point 19.5°C, easily soluble in water, relative densit...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B7/19
Inventor 皇甫根利李世江刘海霞刘晓霞张良
Owner DO FLUORIDE CHEM CO LTD
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