CN100443398C

CN100443398C - Prepn process of high purity hydrofluoric acid

Info

Publication number: CN100443398C
Application number: CNB2006100965931A
Authority: CN
Inventors: 殷福华
Original assignee: 殷福华
Current assignee: Jiangyin Jianghua Microelectronic Material Co., Ltd.
Priority date: 2006-10-09
Filing date: 2006-10-09
Publication date: 2008-12-17
Anticipated expiration: 2026-10-09
Also published as: CN1931709A

Abstract

The preparation process of high purity hydrofluoric acid includes the following steps: 1. rectifying and purifying anhydrous hydrogen fluoride liquid at 19-35 deg.c via adding depurant KMnO4 solution of 1-3 wt% concentration in 1-5 wt% of anhydrous hydrogen fluoride liquid; 2. absorbing the purified hydrogen fluoride gas to obtain semi-finished hydrofluoric acid; and 3. ultraclean filtering the semi-finished hydrofluoric acid to obtain high purity hydrofluoric acid. The present invention has the advantages of effective elimination of arsenic trifluoride impurity, capacity of obtaining high purity hydrofluoric acid product meeting the requirement of SIME-C8 standard, low cost and great output.

Description

The preparation method of high-purity stage hydrofluoric acid

One, technical field

The present invention relates to a kind of preparation method of hydrofluoric acid, especially the preparation method of high purity hydrofluoric acid.

Two, technical background

Hydrofluoric acid (hydrofluoric, HF), relative molecular weight 20.1 is colourless transparent liquid, strongly-acid; It has intensive corrodibility to metal, glass, is severe toxicity.Hydrofluoric acid density (25 ℃) is 1.13g/ml (40 weight %).And high purity hydrofluoric acid is that strongly-acid cleans, etching reagent, can use with preparations such as nitric acid, glacial acetic acid, hydrogen peroxide and ammonium hydroxide, is mainly used in the production of super large-scale integration Technology.The high purity hydrofluoric acid main production methods is at present, the water absorption of anhydrous hydrogen fluoride elder generation is deployed into the hydrofluoric acid that concentration is 40 weight %, absorb by rectifying still rectifying and hydrogen fluoride again and make the hydrofluoric acid work in-process, filter by ultra-clean again and make high purity hydrofluoric acid; It is 106 ℃ that this production method is utilized the boiling point of 40 weight % hydrofluoric acid, the impurity that the great majority that it contained exist with the fluorochemical form has very high boiling point, most of impurity are separated goes out so make by rectifying still rectifying, but arsenous fluoride impurity is difficult to separate in the hydrofluoric acid, its easily and hydrofluoric acid together azeotropic come out, and arsenic is critical impurities in the ultra-clean and high pure chemical reagent, so the hydrofluoric acid of this method preparation is difficult to be suitable in super large-scale integration; Because hydrofluoric acid has severe corrosive, and rectifying device need be used platinum, gold and silver precious metal or polytetrafluoroethylmaterial material manufacturing, this equipment price is quite expensive, makes plant capacity not too large simultaneously, and output also suffers restraints thereupon, and production cost is very high; This production technique needs earlier hydrogen fluoride to be dissolved into hydrofluoric acid, and hydrofluoric acid is the loaded down with trivial details technology of two steps of rectifying again, needs the work-yard wider, is unfavorable for very much the management and the operation of these type of emphasis dangerization product of hydrogen fluoride.

Three, technology contents

At above-mentioned shortcoming, the object of the present invention is to provide and a kind ofly can effectively remove the preparation method that arsenous fluoride impurity, rectifying device low price and capacity are big, be suitable for mass-produced high purity hydrofluoric acid.

Technology contents of the present invention is, a kind of preparation method of high purity hydrofluoric acid, and it comprises the steps:

(1), carry out the rectifying purifying, add cleaner KMnO simultaneously with anhydrous hydrogen fluoride liquid ₄Solution, its concentration are 1～3 weight %, and add-on is 1～5 weight % of raw material anhydrous hydrogen fluoride liquid; Rectification temperature is 19～35 ℃;

(2), with ultrapure water rectifying is purified into hydrogen fluoride gas and absorbs, make the hydrofluoric acid work in-process;

(3), the hydrofluoric acid work in-process are carried out the ultra-clean filtration and make high purity hydrofluoric acid.

This production method has been cast out anhydrous hydrogen fluoride and has been absorbed into the hydrofluoric acid loaded down with trivial details operation of rectifying again, directly carry out the rectifying purifying with anhydrous hydrogen fluoride liquid, rectifying still is the titanium still, utilized the inert principle of pure hydrogen fluoride liquid, thereby reduced the expensive cost of equipment use precious metal or Teflon the titanium still.And this technology has been strengthened the arsenous fluoride separate impurities, adopts cleaner with tervalent arsenic complete oxidation, makes it to generate difficult evaporable compound, it is enriched in rectifying in the tower still and is removed.

The advantage that the present invention is compared with prior art had is:

1, can effectively remove arsenous fluoride impurity, make the high purity hydrofluoric acid of making meet the SIME-C8 standard, be applicable to the production of super large-scale integration Technology.

2, rectifying still does not need with precious metal or Teflon manufacturing, and manufacturing cost reduces, and the production cost of high purity hydrofluoric acid has been reduced.

3, the manufacturing cost of rectifying still reduces, and makes its volume can obtain increasing, and output is improved a lot

Four, specific embodiment

Example 1,300kg anhydrous hydrogen fluoride liquid is carried out the rectifying purifying, adding concentration simultaneously is the cleaner KMnO of 2 weight % ₄Solution, its add-on are 4.5kg; Its rectification temperature is 23 ℃; With ultrapure water rectifying is purified into hydrogen fluoride gas again and absorbs, make the hydrofluoric acid work in-process, its concentration 49 weight %, weight 480kg; The hydrofluoric acid work in-process are carried out the ultra-clean filtration make high purity hydrofluoric acid, weight 460kg.

Example 2,200kg anhydrous hydrogen fluoride liquid is carried out the rectifying purifying, adding concentration simultaneously is the cleaner KMnO of 2 weight % ₄Solution, its add-on are 2kg; Its rectification temperature is 25 ℃; With ultrapure water rectifying is purified into hydrogen fluoride gas again and absorbs, make the hydrofluoric acid work in-process, its concentration 50 weight %, weight 300kg; The hydrofluoric acid work in-process are diluted and ultra-clean filters and to make high purity hydrofluoric acid, weight 300kg.

Example 3,350kg anhydrous hydrogen fluoride liquid is carried out the rectifying purifying, adding concentration simultaneously is the cleaner KMnO of 2 weight % ₄Solution, its add-on are 5kg; Its rectification temperature is 34 ℃; With ultrapure water rectifying is purified into hydrogen fluoride gas and absorbs, make the hydrofluoric acid work in-process, concentration 49 weight %, weight 560kg; The hydrofluoric acid work in-process are carried out the ultra-clean filtration make high purity hydrofluoric acid, weight 550kg.

Example 4,100kg anhydrous hydrogen fluoride liquid is carried out the rectifying purifying, adding concentration simultaneously is the cleaner KMnO of 2 weight % ₄Solution, its add-on are 1.6kg; Its rectification temperature is 26 ℃; With ultrapure water rectifying is purified into hydrogen fluoride gas again and absorbs, make the hydrofluoric acid work in-process, concentration 49 weight %, weight 150kg; The hydrofluoric acid work in-process are carried out the ultra-clean filtration make high purity hydrofluoric acid, weight 130kg.

The physical index data such as the table 1 of example 1～4:

Physical index	Example 1	Example 2	Example 3	Example 4
Physical index	Example 1	Example 2	Example 3	Example 4	Silicofluoric acid (H ₂SiF ₆)，ppm；max	50	50	50	50
Ignition residue, max	2000	2000	2000	2000	Silicofluoric acid (H ₂SiF ₆)，ppm；max	50	50	50	50
Ignition residue, max	2000	2000	2000	2000	Muriate (Cl), max	2000	2000	2000	2000
Phosphoric acid salt (PO ₄)，max	500	500	500	500	Muriate (Cl), max	2000	2000	2000	2000
Phosphoric acid salt (PO ₄)，max	500	500	500	500	Vitriol (SO ₄)，max	1000	1000	1000	1000
Sulphite (SO ₃)，max	500	500	500	500	Vitriol (SO ₄)，max	1000	1000	1000	1000
Sulphite (SO ₃)，max	500	500	500	500	Aluminium (Al), max	≤1	≤1	≤1	≤1
Arsenic (As), max	≤1	≤1	≤1	≤1	Aluminium (Al), max	≤1	≤1	≤1	≤1
Arsenic (As), max	≤1	≤1	≤1	≤1	Calcium (Ca), max	≤1	≤1	≤1	≤1
Chromium (Cr), max	≤1	≤1	≤1	≤1	Calcium (Ca), max	≤1	≤1	≤1	≤1
Chromium (Cr), max	≤1	≤1	≤1	≤1	Copper (Cu), max	≤1	≤1	≤1	≤1
Gallium (Ga), max	≤1	≤1	≤1	≤1	Copper (Cu), max	≤1	≤1	≤1	≤1
Gallium (Ga), max	≤1	≤1	≤1	≤1	Iron (Fe), max	≤2	≤2	≤2	≤2
Plumbous (Pb), max	≤1	≤1	≤1	≤1	Iron (Fe), max	≤2	≤2	≤2	≤2
Plumbous (Pb), max	≤1	≤1	≤1	≤1	Magnesium (Mg), max	≤1	≤1	≤1	≤1
Manganese (Mn), max	≤1	≤1	≤1	≤1	Magnesium (Mg), max	≤1	≤1	≤1	≤1
Manganese (Mn), max	≤1	≤1	≤1	≤1	Nickel (Ni), max	≤1	≤1	≤1	≤1
Potassium (K), max	≤1	≤1	≤1	≤1	Nickel (Ni), max	≤1	≤1	≤1	≤1
Potassium (K), max	≤1	≤1	≤1	≤1	Silver (Ag), max	≤1	≤1	≤1	≤1
Sodium (Na), max	≤1	≤1	≤1	≤1	Silver (Ag), max	≤1	≤1	≤1	≤1
Sodium (Na), max	≤1	≤1	≤1	≤1	Tin (Sn), max	≤1	≤1	≤1	≤1

Table 1

Claims

1, a kind of preparation method of high-purity stage hydrofluoric acid, it comprises the steps:

(1), in rectifying still, carry out the rectifying purifying, add cleaner KMnO simultaneously with anhydrous hydrogen fluoride liquid ₄Solution, its concentration are 1～3 weight %, and add-on is 1～5 weight % of raw material anhydrous hydrogen fluoride liquid; Rectifying still is the titanium still, and rectification temperature is 19～35 ℃;

(3), the hydrofluoric acid work in-process are carried out the ultra-clean filtration and make finished product.

2, the preparation method of high-purity stage hydrofluoric acid according to claim 1 is characterized by cleaner KMnO ₄The concentration of solution is 2 weight %.