JPH0292802A - Extraction of fluorine and/or chlorine from inorganic substance - Google Patents

Abstract

PURPOSE:To enable easy and perfect extraction of fluorine and/or chlorine in inorganic substance by admixing a reaction accelerator to the inorganic substance, heating them in a steam at a specific temperature and collecting the formed HF and/or HCl in an alkaline solution. CONSTITUTION:An inorganic substance containing fluorine and/or chlorine such as a silicate salt containing magnesium fluoride and chloride is prepared. The inorganic substance is mixed with a reaction accelerator such as ferric oxide and the mixture is placed on a platinum boat, then inserted from the inlet 7 into the reaction tube 9. Then, the steam generated in the flask 1 is sent to the reaction tube 9 and the inorganic substance and the reaction accelerator is heated over 1,100 deg.C in the reaction tube 9 with an electric heater 6 so that the inorganic substance reacts with the reaction accelerator and the generated HF and/or HCl is cooled down with the cooling tube 8 and collected into an alkaline solution. This process enables accurate determination of fluorine and/or chlorine in inorganic substances.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for extracting and separating fluorine and/or chlorine in inorganic substances such as silicates and alumina by pyrohydrolysis (thermal hydrolysis). It is.

(Prior art) In general, the determination of fluorine and/or chlorine in inorganic substances is performed by extracting and separating fluorine and/or chlorine in advance by distillation or pyrohydrolysis, and then using spectrophotometry, ion electrode method, or ion chromatography. This was done using the graphic method, etc.

Among these, one example of a method for extracting and separating fluorine and/or chlorine by pyrohydrolysis is ``thermal hydrolysis using ferric oxide as a reaction accelerator'' (Kakuzo Tada,
The method disclosed in Japanese Society of Analytical Chemistry, Analytical Chemistry Forum, pages B73 to B74, IB 12 (1970)) is known. This method uses ferric oxide as a reaction accelerator to treat inorganic substances such as opal glass.
Fluorine was extracted and separated by reaction at a temperature of 050 to 1100°C.

(I1 Problem to be Solved by the Invention) The above-mentioned method is effective for opal glass, spodium mica, etc., but it is also effective for treating opal glass, sulfur mica, etc., but it also applies to silicates containing aluminum and magnesium lumps and/or chlorides, among other inorganic substances. When trying to quantify fluorine in alumina, fluorine and/or chlorine could not be completely extracted, making accurate analysis impossible in some cases.

The purpose of the present invention is to solve the above-mentioned problems, and to make it possible to accurately extract and separate fluorine and/or chlorine in silicates and alumina containing aluminum ram and magnesium chloride and/or chloride. /Or to provide a method for extracting chlorine.

(Means for Solving the Problems) The method for extracting fluorine and/or chlorine of the present invention is a method for extracting fluorine and/or chlorine from an inorganic substance, in which a reaction accelerator is mixed with an inorganic substance, It is characterized by heating at a temperature exceeding 1100° C. and collecting generated hydrogen fluoride and/or hydrogen chloride in an alkaline solution.

(Function) In the above-mentioned configuration, by setting the reaction temperature between the inorganic substance to be extracted and the reaction accelerator at a temperature higher than 1100°C than the conventional one, the conventional reaction temperature of 1100°C or lower can not be used completely. This is based on the discovery that it is possible to completely extract and separate fluorine and/or chlorine in silicates and alumina containing aluminum and magnesium fragments and/or chlorides, which could not be extracted. Aluminum and magnesium have strong bonds with fluorine and/or chlorine, and by increasing the heating temperature, these bonds can be decomposed and extracted as hydrogen fluoride and/or hydrogen chloride.

Here, the reason why the reaction temperature was specified as a temperature exceeding 1100'C is that by exceeding 1100'C, silicon containing aluminium or magnesium chloride and/or This is because fluorine and/or chlorine in acid salts and alumina can be completely extracted and separated. In actual use, the heating temperature is preferably 1200 to 1300'C, subject to restrictions such as the fact that the material of the reaction tube is transparent quartz glass.

In addition, as a reaction accelerator, conventionally known U3011
+ WOi+ V2O5+ (X -A jl! 20
31 Fe2O3 and the like can be used, but from the viewpoint of handling etc., it is preferable to use Fe2O3.

(Example) FIG. 1 is a diagram showing the configuration of an apparatus for carrying out the extraction method of the present invention. In Fig. 1, there is shown a steam supply device 5 consisting of a flask 1, a mantle heater 2, an introduction funnel (with a cock) 3, and a cock 4, and an electric furnace 6, which is installed in an electric furnace 6 and has a sample insertion lower at one end and cooling at the other end. A reaction tube 9 made of transparent quartz glass having a tube 8 constitutes an apparatus for carrying out the extraction method of the present invention.

When extracting fluorine and/or chlorine using the above-mentioned apparatus, the procedure is as follows. First, a mixture of an inorganic substance to be extracted and a reaction accelerator such as ferric oxide or α-alumina is placed on a platinum boat, inserted into the reaction tube 9 through the sample insertion lower, and the sample insertion lower is closed. Next, the cock 4 is closed, and while the water vapor generated in the flask 1 is flowing into the reaction tube 9,
The temperature of the inorganic substance and reaction promoter in the reaction tube 9 is maintained at a predetermined temperature exceeding 1100"C by the electric furnace 6.

Then, the inorganic substance and the reaction accelerator react to generate hydrogen fluoride and/or hydrogen chloride, which is distilled out through the cooling pipe 8.
Can be collected in alkaline solution.

The extracted and separated hydrogen fluoride and hydrogen chloride are quantified by known ion chromatography, spectrophotometry, etc., making it possible to quantitatively analyze fluorine and/or chlorine.

Hereinafter, a method of extracting and separating fluorine and/or chlorine by the method of the present invention and analyzing it by ion chromatography will be explained.

In addition, when quantifying fluorine and/or chlorine by ion chromatography, the sodium hydroxide solution used for collection should be adjusted to an extent that does not result in a large excess after collecting fluorine and/or chlorine, since sodium ions will interfere. A concentration of is preferred. Specifically, the sodium hydroxide concentration after collection is preferably 0.1 g/100d, and 0.025
g/100 mR, is more preferred.

16 Reagents and Equipment 1.1. Reagents Unless otherwise specified, JIS reagents are on sale.

(1) Sodium hydroxide solution (5-Haχ) (2) Standard fluorine solution (10 kgF/store): Sodium fluoride 2.210 dried at 105°C for 2 hours and left to cool in a desiccator
0. Dissolve g in water to make 11 and store in a polyethylene container. 20ml of this solution each time you use it! Dilute with water to make 22.

(3) Standard chlorine solution (10μg/d): 105
1.6489 g of sodium chloride, which had been dried at ℃ for 2 hours and left to cool in a desiccator, was dissolved in water, and II! , and store in a polyethylene container. 20 minutes of this solution before each use.
Dilute m1 with water to make 21.

(4) Eluent (1, OmM/Na) ICOz solution) Dissolve 0.050 g of sodium bicarbonate in water to obtain 11.

(5) Ferric oxide: γ-Fe2O3 with a purity of 99.9% is used.

(6) Alumina standard sample: manufactured by Sumitomo Chemical Co., Ltd., guaranteed value S-2; 51 ± 5 μg F/g, S-4; 220
±16 μg P/g.

(7) Cement standard sample: NBS SRM 633
Portland cement, guaranteed value FO, 08%.

(8) Nepheline syenite standard sample: 5ABS SARM3
LUSAVRITE guaranteed value Cl3 0.12% 1.2. Apparatus (1) Ion chromatograph (2) Electric furnace 2, quantitative operation (1) Sample 0.220 g and ferric oxide 0.440 g
Mix in an agate mortar, then take 0.600 g and transfer to a platinum port.

(2) Approximately 5 m of water in the receiver (250++f! volumetric flask)
fl.

Pour 0.5 ml of sodium hydroxide solution, immerse the tip of the cooler in the solution, and then insert the platinum boat up to the center of the core tube.

(3) After adjusting the electric furnace to the specified temperature, reduce the distillation rate to 8/min.
Adjust the volume to ~9 ml and generate water vapor until the distillate volume reaches 2.
50++4! Collect until

(4) Take a portion of the distillate and determine the amount of fluorine ions using an ion chromatograph.

(5) For a blank test, place 0.400 g of ferric oxide on a platinum board, follow steps (2) to (4), and test at the specified temperature.
Collect up to 250 ml.

Creating a calibration curve Standard fluorine solution and standard chlorine solution from 0 to
50mfl, as fluorine and chlorine (O~500μg)
Stepwise take the solution into a 250 ml volumetric flask, add 0.5-ml of sodium hydroxide solution, and dilute with water.

Specified temperature Nijirikar Magnesia minerals, cement and alumina: 1300℃ 1 Others: 1200℃ 0 3. Experiments and results 3.1 Effect of heating temperature in pyrohydrolysis Heating using various silicate and alumina raw materials temperature to 95
Fluorine and/or chlorine were determined by varying the temperature from 0 to 1300'C to examine their effects. The results are shown in Tables 1 (a) and (b). Conditions other than heating temperature followed this quantitative operation.

From the results in Table 1 (a) and (b), the extraction of fluorine from silica-magnesia minerals, cement, and alumina is 950.
At 1300°C, the value was the highest and almost constant, although it was incomplete, and at 1200'C the other values were constant.

3.2 Distillate Volume Table 1 (Table 1) where the heating temperature has a large effect on the fluorine quantitative value
a) Using the silica-magnesia mineral-2 in
Table 2 shows the results of investigating the relationship between the amount of distillate up to 0 ml and the amount of distillate every 50 ml and the fluorine quantitative value for 200 ml or more.

From the results in Table 2, in the case of silica-magnesia mineral, it is 13
The extraction was completed when 250 ml was distilled at 00°C. On the other hand, when the pyrohydrolysis temperature is 750°C, the recovery rate is 46.1% even if the distillate volume is increased to 450 ml.
It is. Even at 1050″C, the recovery rate was 94.4% when the distillate volume was 250mf, and fluorine extraction continued.

3.3 Results of repeated analysis of actual samples Table 3 shows the quantitative values of fluorine according to its nature. In Table 3, alumina and cement were subjected to pyrohydrolysis at 1300°C, and ceramic-1 was subjected to pyrohydrolysis at 1200°C, and then fluorine was determined by ion chromatography.

The present invention is not limited only to the embodiments described above, and numerous modifications and changes are possible. For example, in the embodiments described above, ferric oxide (r F ez
ch) was used, but other known reaction accelerators such as α-
It goes without saying that the same effects of the present invention can be obtained with alumina, U:1O11, etc.

(Effect of the invention) As is clear from the above explanation, the fluorine and/or
Or, according to the chlorine extraction method, the sample and reaction accelerator are separated into 11
By reacting at temperatures exceeding 00'C, it is possible to completely extract and separate fluorine and/or chlorine from silicates and alumina, which were difficult to extract using conventional methods among inorganic substances. As a result, accurate determination of fluorine and/or chlorine can be performed.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an apparatus for implementing the fluorine extraction method of the present invention. 1...Flask 2...Mantle heater・
...Introduction funnel (with conch) ...Cook ...Wisteria air supply device ...Sample insertion port ...Reaction tube 6 ...Electric furnace 8 ...Cooling pipe

Claims (1)

[Claims] 1. A method for extracting fluorine and/or chlorine from inorganic substances, in which a reaction accelerator is mixed with the inorganic substance and 11
A method for extracting fluorine and/or chlorine from inorganic substances, which comprises heating at a temperature exceeding 00°C and collecting generated hydrogen fluoride and/or hydrogen chloride in an alkaline solution.