CN102774813A - Method for preparing hydrofluoric acid - Google Patents
Method for preparing hydrofluoric acid Download PDFInfo
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- CN102774813A CN102774813A CN2011101295285A CN201110129528A CN102774813A CN 102774813 A CN102774813 A CN 102774813A CN 2011101295285 A CN2011101295285 A CN 2011101295285A CN 201110129528 A CN201110129528 A CN 201110129528A CN 102774813 A CN102774813 A CN 102774813A
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- hydrogen fluoride
- aqueous solution
- hydrofluoric acid
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- saturated aqueous
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Abstract
The invention discloses a method for preparing hydrofluoric acid, comprising the following steps: continuously adding unprocessed hydrogen fluoride and its included unprocessed impurities in an aqueous solution to dissolve partial unprocessed impurities in the aqueous solution and hydrofluoric acid generated by unprocessed hydrogen fluoride, after hydrofluoric acid in the aqueous solution reaches saturation, separating hydrogen fluoride that is insoluble in the saturated aqueous solution from the saturated aqueous solution to form processed hydrogen fluoride gas, simultaneously allowing the processed gaseous impurities that are insoluble in the aqueous solution and hydrofluoric acid to be removed from the saturated aqueous solution with the processed hydrogen fluoride gas, and taking the processed hydrogen fluoride gas and the gaseous impurities out and then putting them in purified water to generate a hydrofluoric acid aqueous solution with a raised purity, wherein the processed gaseous impurities are insoluble in the purified water and the hydrofluoric acid with a raised purity, so that a hydrofluoric acid aqueous solution with a raised purity can be obtained. According to the invention, the preparation process is simple, and the impurities are absorbed only by using water and hydrofluoric acid, thus the purposes of raising the production speed, reducing the production cost and producing the hydrofluoric acid aqueous solution which meets electronic-grade purity demand are achieved.
Description
Technical field
The invention provides a kind of hydrofluoric acid method of manufacture; Especially refer to utilize untreated hydrogen fluoride to add in the aqueous solution; The partial impurities that is comprised by the aqueous solution and the untreated hydrogen fluoride of hydrofluoric acid filtering that produced; Hydrogen fluoride gas after will handling again and gaseous impurities add pure water, obtain the high purity hydrofluoric acid aqueous solution.
Background technology
Press; Along with the continuous research and development and the technology of electronic installation progresses greatly; The trace of electronic installation is seen everywhere arround life; Since the increase of the market requirement, semi-conductor, liquid crystal and solar cell manufacturing industry just with development, also lid is many more more for its relevant factory building; But in process of production as clean, in the etch process (as the grinding attenuate cleaning of glass in the silicon that is attached to silica tube or the liquid crystal panel etc. is removed, removed to the oxide compound that is used for etching, the silicon face of cleaning, silicon and the silicon compound of assembly), just can use hydrofluoric acid (Hydrofluoruc Acid; HF (aq)), make the consumption of hydrofluoric acid increase year by year.
The pure hydrofluoric acid manufacture of tradition generates hydrogen fluoride gas for utilizing fluorite and sulfuric acid reaction, and its chemical formula is CaF
2(S)+H
2SO
4(1) → 2HF (g)+CaSO
4(s); Through collecting and lowering the temperature back generation hydrogen fluoride liquid (under the normal pressure; Liquefying-point is 19.5 ℃) because fluorite is the subsurface mineral that includes plurality of impurities (mainly contains silicon composition impurity and other like all kinds of impurity such as sulphur, phosphorus, chlorine, iron, aluminium, gallium, boron, bismuth, manganese, lead), the hydrogen fluoride that is produced also contains plurality of impurities; This kind hydrogen fluoride is called technical grade hydrogen fluoride, and general industry is used is technical grade hydrogen fluoride mostly.
Present hydrofluoric acid method of manufacture still exists disappearance to remain to be improved, as:
(1) after fluorite was made hydrogen fluoride, hydrogen fluoride liquid was again through repeatedly distillation, and let hydrogen fluoride be dissolved in to obtain hydrofluoric acid in the ultrapure water; But because of hydrogen fluoride liquid has impurity, cause also having impurity in the hydrofluoric acid (can combine to generate silicon tetrafluoride with fluorine like silicon), silicon tetrafluoride can be entrained in hydrogen fluoride; So must utilize repeatedly distillation mode to remove silicon compound; Yet the hydrogen fluoride that repeatedly distills output still contains the silicon compound of tens of ppm to hundreds of ppm, but industries such as general semi-conductor, liquid crystal and solar cell are when using hydrofluoric acid; Has the few high purity requirement of impurity; And along with the lifting of industrial technology and the research and development of volume micro, the hydrofluoric acid purity requirement of its use also with raising, concentration of metallic impurities requires to be increased to the ppb level from the ppm level in the hydrofluoric acid; Especially with the medicine that is used in state-of-the-art semi-conductor manufacturing the level requirement below the 5ppb is arranged, the hydrofluoric acid made in a conventional manner can't meet industry demand.
(2) technical grade hydrofluoric acid is mainly used in the semi-conductor relevant industries, but the group iii elements in the hydrofluoric acid impurities is (like ferric iron Fe
+ 3, aluminium Al
+ 3, gallium Ga
+ 3, boron
+ 3) or group-v element (arsenic As
+ 5, phosphorus P
+ 5) can disturb the semiconductor property of semiconductor subassembly; Because of metal residual at silicon wafer surface; Through letting behind some hot processing procedures metal diffusing get in the silicon wafer, make surperficial resistance descend and become defective products, so employed hydrofluoric acid must be avoided the interference of this type material; But the hydrogen fluoride that existing warp repeatedly distills output still contains the impurity (like sulphur, phosphorus, chlorine, iron, aluminium, gallium, boron, bismuth, manganese, lead etc.) of several ppb to hundreds of ppb, causes it to have the high disappearance of fraction defective.
(3) because traditional technology need be used distillation mode purifying hydrogen fluoride; Hydrofluoric gasification latent heat is 360 kilocalories/kilogram; And per kilogram aqueous vapor latent heat is about 500 kilocalories, when causing repeatedly distilling the mode purifying hydrogen fluoride, need expend the huge energy and heat; Not only let cost greatly improve, more do not meet the purpose of energy-conserving and environment-protective.
(4) because fluorine has reinforcing yin essence electrically (electromotive force is 2.87V); Thereby has a characteristic of easy attack metal; So distillation plant and pipeline can not use metal material and need with plastic material (like Teflon); But its heat-conductive characteristic of the equipment of plastic material and pipeline poor (the heat-conduction coefficient k like Teflon is merely 0.25W/M ℃) can't reach the effect of fast cooling when carrying, and the processing of need lowering the temperature in addition; Make to produce required consumed time and increase, so it is limited serious to distill hydrofluoric production capacity.
Above-mentioned known hydrofluoric acid method of manufacture, because of having problems and disappearance, this is the inventor and the target place of being engaged in this journey improvement that the dealer desires most ardently.
Summary of the invention
The object of the present invention is to provide the fast hydrofluoric acid method of manufacture of a kind of high purity, low cost and production rate.
Be the realization above-mentioned purpose, hydrofluoric acid method of manufacture provided by the invention, the flow process of its manufacturing comprises:
(A) the untreated hydrogen fluoride (HF) and the impurity that is untreated that comprises thereof add in the aqueous solution, make untreated hydrogen fluoride generation hydrofluoric acid soluble in water (HF (aq)), and in water-soluble solution of untreated partial impurities and the hydrofluoric acid;
(B) continue to add untreated hydrogen fluoride and impurity to the aqueous solution, the hydrofluoric acid in the aqueous solution is state of saturation;
(C) add untreated hydrogen fluoride gas and impurity again to saturated aqueous solution; Let in water-soluble solution of the untreated impurity of part and the hydrofluoric acid; And the hydrogen fluoride that is insoluble in the saturated aqueous solution just can leave the hydrogen fluoride gas after saturated aqueous solution forms processing, and the gaseous impurities after the processing in water insoluble solution and the hydrofluoric acid also leaves saturated aqueous solution with the hydrogen fluoride gas after handling simultaneously;
(D) hydrogen fluoride gas after the processing and gaseous impurities add in the pure water, and the hydrogen fluoride gas after the processing is dissolved in pure water and generates hydrofluoric acid (HF (the aq)) aqueous solution that purity improves, and the gaseous impurities after handling is insoluble in the hydrofluoric acid of pure water and purity raising;
(E) hydrofluoric acid aqueous solution that purity is improved takes out.
Described hydrofluoric acid method of manufacture, wherein, step (C) if in institute adds untreated hydrogen fluoride gaseous state, be insoluble to the hydrogen fluoride gas after hydrogen fluoride gas in the saturated aqueous solution just can leave saturated aqueous solution formation processing.
Described hydrofluoric acid method of manufacture; Wherein, Step (C) if in institute to add untreated hydrogen fluoride liquid, heat simultaneously, be insoluble to liquid hydrogen fluoride in the saturated aqueous solution hydrogen fluoride gas after producing hydrogen fluoride gas and leaving saturated aqueous solution formation processing that just can absorb heat.
Hydrofluoric acid method of manufacture of the present invention when reality is used, for having following advantage, as:
(1) manufacturing step is simple; Make production rate be improved; And, can pass through the aqueous solution and hydrofluoric acid absorption, thereby can obtain meeting the hydrofluoric acid aqueous solution of electronic-grade purity demand because of electrical the attracting each other and the difficult impurity that is untreated that utilizes distillation to remove of untreated hydrogen fluoride institute's tool reinforcing yin essence.
(2) only use water and hydrofluoric acid absorption impurity owing in the manufacturing processed, and at most only need carry out one time heat treated in the manufacturing processed,, not only can save consumes energy, can save temperature fall time and cooling system again compared to known heating for multiple times distillatory mode.
Description of drawings
Fig. 1 is a manufacturing flow chart of the present invention.
Embodiment
Main purpose of the present invention is; This untreated hydrogen fluoride and the impurity that comprises thereof continue to add in the aqueous solution; The hydrofluoric acid that lets the water-soluble solution of partial impurities and produced filters carrying out the second time in hydrogen fluoride after the resultant processing and the gaseous impurities adding pure water again, just can obtain the hydrofluoric acid that purity improves; Because manufacturing step is simple; And because of untreated hydrogen fluoride institute tool reinforcing yin essence electrically attracts each other and is difficult for the impurity that is untreated that utilizes distillation to remove, can absorb, thereby can reach and promote the purpose that production rate and production meet the hydrofluoric acid aqueous solution of electronic-grade purity demand through the aqueous solution and hydrofluoric acid.
Only use water and hydrofluoric acid absorption impurity in the manufacturing processed of the present invention; And it is maximum only when adding the liquid hydrogen fluoride of technical grade in the manufacturing processed; Just need carry out one time heat treated,, not only can save consumes energy because of the heating number of times reduces; Can save temperature fall time and cooling system again, and then reach and reduce production costs and the purpose of faster production.
Technique means that the present invention adopted and structure thereof explain that with regard to preferred embodiment of the present invention its characteristic and function are following in conjunction with accompanying drawing in detail, in order to understanding fully.
See also shown in Figure 1ly, be manufacturing flow chart of the present invention, find out that by knowing among the figure manufacturing process of hydrofluoric acid of the present invention comprises:
(100) the untreated hydrogen fluoride (HF) and the impurity that is untreated that comprises thereof add in the aqueous solution, make untreated hydrogen fluoride generation hydrofluoric acid soluble in water (HF (aq)), and in water-soluble solution of untreated partial impurities and the hydrofluoric acid.
(101) continue to add untreated hydrogen fluoride and impurity to the aqueous solution, the hydrofluoric acid in the aqueous solution is state of saturation, if untreated hydrogen fluoride is gaseous state, carries out step (102); If untreated hydrogen fluoride is liquid, then carry out step (103).
(102) add untreated hydrogen fluoride gas and impurity thereof again to saturated aqueous solution; Let in water-soluble solution of the untreated impurity of part and the hydrofluoric acid; And the hydrogen fluoride gas that is insoluble in the saturated aqueous solution just can leave the hydrogen fluoride gas after saturated aqueous solution forms processing; Processing rear impurity in water insoluble solution and the hydrofluoric acid also leaves saturated aqueous solution with the hydrogen fluoride gas after handling simultaneously, carries out step (104) again.
(103) add untreated liquid hydrogen fluoride and impurity again to saturated aqueous solution; Let in water-soluble solution of partial impurities and the hydrofluoric acid; Heat simultaneously; Be insoluble to liquid hydrogen fluoride in the saturated aqueous solution and just can absorb heat to produce hydrogen fluoride gas and leave saturated aqueous solution and form the hydrogen fluoride gas after handling, the gaseous impurities after the processing in water insoluble solution and the hydrofluoric acid also leaves saturated aqueous solution with the hydrogen fluoride gas after handling simultaneously.
(104) hydrogen fluoride gas after the processing and gaseous impurities add in the pure water, and the hydrogen fluoride gas after the processing is dissolved in pure water and generates hydrofluoric acid (HF (the aq)) aqueous solution that purity improves, and the gaseous impurities after handling is insoluble in the hydrofluoric acid of pure water and purity raising.
(105) hydrofluoric acid (HF (the aq)) aqueous solution that purity is improved takes out.
Can be learnt that by above-mentioned steps it mainly is to utilize hydrogen fluoride water-soluble and partial impurities is water-soluble and the characteristic of hydrofluoric acid, let untreated hydrogen fluoride and impurity add in the aqueous solution, hydrogen fluoride adds the reaction formula that produces hydrofluoric acid behind the aqueous solution and is:
HF+H
2O→HF(aq)
Untreated impurity is partly water-soluble solution and hydrofluoric acid then, generates silicofluoric acid after adding the aqueous solution like the silicon tetrafluoride in the impurity, and silicofluoric acid can water-soluble solution in, its reaction formula is:
SiF
4+2HF→H
2SiF
6
(NaF) is soluble in water like the Sodium Fluoride in the impurity, can be dissociated into sodium ion and fluorion, and its reaction formula is:
NaF+H
2O→Na
+ (aq)+F
- (aq)+H
2O
Be dissolved in hydrofluoric acid like the iron(ic)chloride in the impurity and generate the ferric fluoride aqueous solution, its reaction formula is:
FeCl
3+3HF→FeF
3(aq)+3HCl
(aq)
Be dissolved in hydrofluoric acid like the magnesium chloride in the impurity and generate the Sellaite aqueous solution, its reaction formula is:
MgCl
2+2HF→MgF
2(aq)+2HCl
(aq)
And continue to add untreated hydrogen fluoride and impurity to the aqueous solution; Hydrofluoric acid in the aqueous solution is saturated back (during as 20 ℃; Hydrofluoric acid saturation concentration in the aqueous solution is 35%); The hydrogen fluoride that adds again in the aqueous solution just can not dissolve in the aqueous solution, and forms the hydrogen fluoride after handling with bubble form come-up leaving water solution, simultaneously; Be untreated impurity because of partly water-soluble solution and hydrofluoric acid, gaseous impurities after the processing in water insoluble solution and the hydrofluoric acid only arranged along with the hydrogen fluoride leaving water solution after handling.
After hydrogen fluoride after the processing and gaseous impurities are collected; Add in the pure water again; Hydrogen fluoride after the processing just can generate hydrofluoric acid with pure water; And the gaseous impurities after handling so just can have less impurity in the hydrofluoric acid aqueous solution that takes out, just can reach the purpose that improves purity because be insoluble in pure water and the hydrofluoric acid.
Though and the hydrogen fluoride after handling has saturated vapor pressure because of the aqueous solution, and when leaving water solution, has aqueous vapor, because subsequent disposal is in the hydrogen fluoride adding pure water after will handling, so aqueous vapor can't influence the concentration of end product hydrofluoric acid aqueous solution.
This untreated hydrogen fluoride (HF) can be by fluorite (CaF
2) and sulfuric acid (H
2SO
4) the reaction generation, its reaction formula is: CaF
2(g)+H
2SO
4(1) → 2HF (g)+CaSO
4(g) because fluorite is the subsurface mineral that includes plurality of impurities (mainly contains silicon composition impurity and other like all kinds of impurity such as sulphur, phosphorus, chlorine, iron, aluminium, gallium, boron, bismuth, manganese, lead), generate untreated hydrogen fluoride (HF) just can produce untreated impurity simultaneously; Untreated hydrogen fluoride (HF) and impurity also can be obtained in the hydrogen fluoride raw material by technical grade, and the hydrogen fluoride raw material of technical grade can be gaseous state or liquid state.
If owing to obtain untreated hydrogen fluoride and impurity by the liquid hydrogen fluoride raw material of technical grade; Because untreated hydrogen fluoride is for being in a liquid state, the hydrofluoric acid in the aqueous solution be saturated after, if continue the untreated liquid hydrogen fluoride of adding; Also can't produce gaseous hydrogen fluoride; Just need heat this moment, and the heat energy that supply liquid hydrogen fluoride gasification is required just can let hydrogen fluoride in the aqueous solution float with the gaseous state mode and leave the water surface.
The present invention is for being primarily aimed at the hydrofluoric acid method of manufacture; And can continue to add untreated hydrogen fluoride and the impurity that is untreated that comprises thereof in the aqueous solution; Make untreated hydrogen fluoride generation hydrofluoric acid soluble in water, in water-soluble solution of the untreated impurity of part and the hydrofluoric acid, the hydrofluoric acid in the aqueous solution is state of saturation; The hydrogen fluoride that adds again forms the hydrogen fluoride gas after handling and leaves saturated aqueous solution; Hydrogen fluoride gas after the processing and gaseous impurities add and obtain the hydrofluoric acid that purity improves in the pure water, are main key protection point to reach the hydrofluoric acid aqueous solution that easy steps and equipment obtains meeting electronic-grade purity demand, only; The above is merely preferred embodiment of the present invention; Non-so promptly limit to claim of the present invention, so the simple and easy modification and the equivalent structure that use specification sheets of the present invention and accompanying drawing content to do such as change, all should in like manner be contained in the claim of the present invention.
Claims (3)
1. hydrofluoric acid method of manufacture, the flow process of its manufacturing comprises:
(A) the untreated hydrogen fluoride and the impurity that is untreated that comprises thereof add in the aqueous solution, make untreated hydrogen fluoride generation hydrofluoric acid soluble in water, and in water-soluble solution of untreated partial impurities and the hydrofluoric acid;
(B) continue to add untreated hydrogen fluoride and impurity to the aqueous solution, the hydrofluoric acid in the aqueous solution is state of saturation;
(C) add untreated hydrogen fluoride gas and impurity again to saturated aqueous solution; Let in water-soluble solution of the untreated impurity of part and the hydrofluoric acid; And the hydrogen fluoride that is insoluble in the saturated aqueous solution just can leave the hydrogen fluoride gas after saturated aqueous solution forms processing, and the gaseous impurities after the processing in water insoluble solution and the hydrofluoric acid also leaves saturated aqueous solution with the hydrogen fluoride gas after handling simultaneously;
(D) hydrogen fluoride gas after the processing and gaseous impurities add in the pure water, and the hydrogen fluoride gas after the processing is dissolved in pure water and generates the hydrofluoric acid aqueous solution that purity improves, and the gaseous impurities after handling is insoluble in the hydrofluoric acid of pure water and purity raising;
(E) hydrofluoric acid aqueous solution that purity is improved takes out.
2. hydrofluoric acid method of manufacture as claimed in claim 1, wherein, step (C) if in institute adds untreated hydrogen fluoride gaseous state, be insoluble to the hydrogen fluoride gas after hydrogen fluoride gas in the saturated aqueous solution just can leave saturated aqueous solution formation processing.
3. hydrofluoric acid method of manufacture as claimed in claim 1; Wherein, Step (C) if in institute add untreated hydrogen fluoride liquid state; Heat simultaneously, be insoluble to liquid hydrogen fluoride in the saturated aqueous solution and just can absorb heat to produce hydrogen fluoride gas and leave saturated aqueous solution and form the hydrogen fluoride gas after handling.
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|---|---|---|---|
| CN2011101295285A CN102774813A (en) | 2011-05-12 | 2011-05-12 | Method for preparing hydrofluoric acid |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011101295285A CN102774813A (en) | 2011-05-12 | 2011-05-12 | Method for preparing hydrofluoric acid |
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|---|---|
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|---|---|---|---|
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104828787A (en) * | 2015-04-09 | 2015-08-12 | 南通晨光石墨设备有限公司 | Process for separating and concentrating mixed acid |
| CN114146586A (en) * | 2021-12-30 | 2022-03-08 | 苏州金宏气体股份有限公司 | Device and method for preparing hydrofluoric acid solution |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2368441A1 (en) * | 1999-03-29 | 2000-10-05 | Honeywell Specialty Chemicals Seelze Gmbh | Method for producing high-purity solutions using gaseous hydrogen fluoride |
| CN101277899A (en) * | 2005-06-30 | 2008-10-01 | 日本顶点服务有限会社 | Hydrofluoric acid production apparatus and hydrofluoric acid production method |
| CN100546903C (en) * | 2007-08-06 | 2009-10-07 | 江阴市润玛电子材料有限公司 | Purifying method of ultrahigh pure hydrofluoric acid |
-
2011
- 2011-05-12 CN CN2011101295285A patent/CN102774813A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2368441A1 (en) * | 1999-03-29 | 2000-10-05 | Honeywell Specialty Chemicals Seelze Gmbh | Method for producing high-purity solutions using gaseous hydrogen fluoride |
| CN101277899A (en) * | 2005-06-30 | 2008-10-01 | 日本顶点服务有限会社 | Hydrofluoric acid production apparatus and hydrofluoric acid production method |
| CN100546903C (en) * | 2007-08-06 | 2009-10-07 | 江阴市润玛电子材料有限公司 | Purifying method of ultrahigh pure hydrofluoric acid |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104828787A (en) * | 2015-04-09 | 2015-08-12 | 南通晨光石墨设备有限公司 | Process for separating and concentrating mixed acid |
| CN114146586A (en) * | 2021-12-30 | 2022-03-08 | 苏州金宏气体股份有限公司 | Device and method for preparing hydrofluoric acid solution |
| CN114146586B (en) * | 2021-12-30 | 2023-11-21 | 金宏气体股份有限公司 | Device and method for preparing hydrofluoric acid solution |
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Application publication date: 20121114 |