JP2590431B2 - Method for producing Bi5O7 (NO3) - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to Bi ₅ O ₇ (NO ₃ )
And a method for producing the same. More specifically, the present invention relates to a novel Bi ₅ O ₇ (NO ₃ ) which can produce a compound represented by the general formula Bi ₅ O ₇ (NO ₃ ) by chemical synthesis, not by thermal decomposition of a raw material. It relates to a manufacturing method.

Compound represented by the Prior Art and Its Problems] Formula Bi ₅ O ₇ (NO ₃₎ are ion-exchange, as being useful in various applications such as adsorption, e.g. processing such as nuclear power waste and industrial waste, It is expected to be applied to adsorption removal of harmful ions in gas, adsorption solidification, and the like. Conventionally, such Bi ₅ O ₇ (NO ₃ ) has been conventionally used for bismuth nitrate pentahydrate [Bi (NO ₃ ) ₃ .5H ₂ O] and basic bismuth nitrate [4Bi (NO ₃ ) (OH) _2.・ BiO (O
H)] and the like. However, this production method is substantially based on a thermal decomposition reaction of a bismuth compound containing a nitrate group, and is not a method of chemically synthesizing Bi ₅ O ₇ (NO ₃ ). For this reason, the selection range of the substance as the raw material is very limited to bismuth compounds containing a nitrate group, and as a result, there is a problem that the production cost rises. Further, in the conventional method, extra NO ₃ is generated in the production process, so that it cannot be said that it is preferable in terms of environmental conservation. The present invention has been made in view of the above circumstances, and solves the drawbacks of the conventional method for producing Bi ₅ O ₇ (NO ₃ ). Instead of the thermal decomposition method, the general formula Bi _{5 is obtained} by chemical synthesis. It is an object of the present invention to provide a new production method capable of producing a compound represented by O ₇ (NO ₃ ).

According to the present invention, in order to solve the above-mentioned problems, the inventor of the present invention has proposed that a nitrate group (NO
₃₎ the raw material composition of the bismuth compound with an adjustment to the results which were intensively studied how to proceed chemical reaction as a raw material, the first time succeeded in synthesizing _{Bi 5 O 7 (NO 3)} , has been completed based on this finding Things. That is, the present invention hydrothermally reacts a raw material mixture obtained by mixing an oxygen-containing bismuth compound and a nitrate-containing bismuth compound in a molar ratio of Bi and NO ₃ of 5: 1 to obtain a general formula Bi _Five
Method for producing _{O 7 Bi 5 O 7 (NO} 3) , characterized in that to produce the compound that represented by (NO ₃₎ there is provided a. In the method for producing Bi ₅ O ₇ (NO ₃ ) of the present invention, a bismuth compound having oxygen is used as a raw material component in addition to a bismuth compound having a nitrate group, and these are used as Bi.
And NO _{3 in} a molar ratio of 5: 1.
This mixture is used as starting material. Since these ingredients are produced by the reaction Bi ₅ O ₇ (NO ₃₎ are likely to react with the contains no ions, Bi ₅ O
_It is suitable for chemical synthesis of ₇ (NO ₃ ). As a combination of such raw material components, for example, bismuth oxide (Bi
₂ O ₃₎ and bismuth nitrate pentahydrate [Bi (NO _{3) 3} · 5H
₂ O], bismuth oxide (Bi ₂ O ₃ ) and basic bismuth nitrate [4Bi (NO ₃ ) (OH) ₂ .BiO (OH)], bismuth hydroxide [Bi (OH) ₃ ] and bismuth nitrate pentahydrate things _{[Bi (NO 3) 3 · 5H} 2 O ], bismuth hydroxide [B
i (OH) ₃ ] and basic bismuth nitrate [4Bi (NO ₃ )
(OH) ₂ · BiO (OH)], bismuth oxide, bismuth hydroxide and bismuth nitrate pentahydrate, bismuth oxide and bismuth hydroxide and basic bismuth nitrate, bismuth oxide and bismuth nitrate pentahydrate and basic nitric acid Specific examples include bismuth, bismuth hydroxide, bismuth nitrate pentahydrate, and basic bismuth nitrate, or bismuth oxide, bismuth hydroxide, bismuth nitrate pentahydrate, and basic bismuth nitrate. For example, bismuth oxide (Bi ₂ O ₃ )
And bismuth nitrate pentahydrate [Bi (NO _{3) 3} · 5H
_In the case where ₂ O] is selected, for example, bismuth oxide (Bi ₂ O ₃ ) and bismuth nitrate pentahydrate [Bi (NO ₃ ) ₃ .5H ₂ O] may be used in a molar ratio of 7: 1. When mixed in proportions, the proportion of Bi and NO ₃ in the mixture is 5: 1 in molar ratio. The chemical reaction using this mixture as a starting material can be represented by the following equation (1).

Embedded image In addition, bismuth oxide (Bi ₂ O ₃ ) and basic bismuth nitrate [4Bi (NO ₃ ) (OH) ₂ .BiO (O
H)], bismuth oxide and basic bismuth nitrate are mixed at a molar ratio of 15: 2,
The molar ratio of Bi and NO ₃ in the mixture can be 5: 1. The chemical reaction in this case can be represented by the following equation (2).

Embedded image Similarly, when using a raw material component other than the above two examples, the mixing ratio may be determined so that the molar ratio of Bi and NO ₃ in the raw material mixture is 5: 1. Although the chemical reactions represented by these formulas (1) and (2) do not proceed even when the raw material mixture is left at room temperature, the raw material mixture is considerably dissolved in water or a suitable solution such as an aqueous potassium nitrate solution at room temperature. Heating at a high temperature for a certain time or more facilitates the progress. Such a synthesis reaction is generally called a hydrothermal reaction or a hydrothermal reaction.
Bi ₅ O ₇ (NO ₃ ) is easily chemically synthesized. The heating temperature can be set in an appropriate range according to the starting material used as a starting material, and the heating time can be set in an appropriate range according to the heating temperature and the like. There is no special limitation. Bi ₅ O ₇ produced by the production method of the present invention
The X-ray diffraction patterns measured for each of the (NO ₃ ) powder sample and the sample prepared by the conventional pyrolysis method are shown in FIG. A in FIG. 1 is an X-ray diffraction pattern of a sample prepared by pyrolysis, and B is an X-ray diffraction pattern of a sample chemically synthesized by the method of the present invention.
As is evident from the results of FIG. 1, the two show a very good agreement. Table 1 shows the measured values (d) and the relative reflection intensity (I) of the interplanar spacing obtained from the above powder X-ray diffraction pattern. (H k l) in Table 1 is
The surface index is shown.

[Table 1] In Table 1, d ₁ and I ₁ are for samples prepared by a conventional pyrolysis method, and d ₂ and I ₂ are for samples chemically synthesized by the method of the present invention. As is clear from Table 1, it is confirmed that the samples prepared by any of the methods are crystals belonging to the orthorhombic system. The lattice constant of the sample chemically synthesized by the method of the present invention is a = 16.300 °, b = 5.520 °, c = 23.332 °, and the sample obtained by the conventional thermal decomposition method has a = 16.280 ° and b = 5.
548 ° and c = 23.301 ° show a good match.

The following examples are provided to illustrate the Bi ₅ O ₇ (N
The method for producing O ₃ ) will be described in more detail. Example 1 Bismuth oxide and bismuth nitrate pentahydrate were well mixed in a molar ratio of 7: 1, and about 0.2 g of the mixture was put in a platinum capsule, about 0.2 ml of pure water was added thereto, and the platinum capsule was added. Sealed. Next, the platinum capsule was placed in a pressure vessel and pressurized to about 500 to 1000 kg / cm ² to prevent the solution in the platinum capsule from evaporating during the subsequent heat treatment and destroying the capsule. Thereafter, the pressure vessel was heated in an electric furnace at 50 to 500 ° C. shown in Table 2 at a constant temperature for 24 hours. After the heating, the sample was taken out by rapid cooling, dried, and identified by a powder X-ray diffraction pattern. Bi ₅ O ₇ (NO ₃ ) could be produced by chemical synthesis. In order to obtain pure Bi ₅ O ₇ (NO ₃ ), in the case of the raw material components in this example, the heating temperature is set at 20.
Table 2 confirms that it is effective to set the temperature around 0 ° C. or higher. Example 2 In the same manner as in Example 1, bismuth oxide and bismuth nitrate pentahydrate were well mixed in a molar ratio of 7: 1, and about 0.2 g of the mixture was placed in a platinum capsule. Was added and the platinum capsule was sealed. Then, the platinum capsule was placed in a pressure vessel and pressurized to about 500 to 1000 kg / cm ² , and then the pressure vessel was kept constant at 200 and 350 ° C. shown in Table 3 in an electric furnace. Heated. In Example 2, the chemical synthesis was performed by changing the heating time variously as shown in Table 3. After the heating, the sample was taken out by rapid cooling, dried, and identified by a powder X-ray diffraction pattern. Bi ₅ O ₇ (NO ₃ ) could be produced by chemical synthesis. As is clear from Table 3, it is confirmed that the time required for completing the hydrothermal reaction varies depending on the reaction temperature. When heated to 200 ° C., it takes about 24 hours to complete the reaction, but it can be seen that heating to 350 ° C. completes the reaction even in 1 hour. From this, it is estimated that the higher the reaction temperature, the shorter the reaction time may be. Example 3 Bismuth oxide and basic bismuth nitrate were mixed well in advance at a molar ratio of 15: 2 using raw material components. This raw material mixture was hydrothermally reacted in the same manner as in Example 1.
In addition, as shown in Table 4, the heating temperature was set in the range of 200 to 500 ° C., and each temperature was kept constant, and heating was performed for 24 hours. Bi ₅ O ₇ (NO ₃ ) could be produced by chemical synthesis. It is confirmed from Table 4 that in order to obtain pure Bi ₅ O ₇ (NO ₃ ), it is effective to set the heating temperature to around 300 ° C. or higher in the case of the raw material components in this example. Example 4 Each mixture of bismuth hydroxide and bismuth nitrate pentahydrate, bismuth hydroxide and basic bismuth nitrate was mixed in a molar ratio such that the molar ratio of Bi and NO ₃ in the mixture was 5: 1. The mixture was mixed at a ratio of 14: 1 and 15: 1, respectively, and hydrothermally reacted in the same manner as in Example 1. In these cases, Bi ₅ O ₇ (NO ₃ ) could be produced by chemical synthesis. Of course, the present invention is not limited by the above examples. It goes without saying that various aspects are possible for the details of the reaction conditions such as the heating temperature and the heating time.

As described above in detail, according to the present invention, Bi ₅ O ₇ useful for various applications such as ion exchange and adsorption is provided.
(NO ₃ ) can be produced by chemical synthesis instead of thermal decomposition of the raw material. The range of selection of the material to be a raw material is expanded, and a cheaper raw material can be selected. This contributes to a reduction in manufacturing costs. Further, in the manufacturing process, no extra NO ₃ is generated unlike the related art, which is preferable for environmental protection.

[Brief description of the drawings]

FIG. 1 is a diffraction pattern diagram showing an X-ray powder diffraction pattern of Bi ₅ O ₇ (NO ₃ ) prepared by the method of the present invention and conventional pyrolysis.

[Table 2]

[Table 3]

[Table 4]

Claims (2)

(57) [Claims] 1. A raw material mixture obtained by mixing an oxygen-containing bismuth compound and a nitrate-containing bismuth compound in a molar ratio of Bi and NO ₃ of 5: 1 is subjected to a hydrothermal reaction to obtain a compound of the general formula Bi ₅ method for producing _{O 7 Bi 5 O 7 (NO} 3) , characterized in that to produce the compound that represented by (NO _3). 2. The oxygen-containing bismuth compound is one of bismuth oxide (Bi ₂ O ₃ ) and bismuth hydroxide [Bi (OH) ₃ ] or a mixture thereof, and the nitric acid-containing bismuth compound is bismuth nitrate. Pentahydrate [Bi (NO ₃ ) ₃
.5H ₂ O] or basic bismuth nitrate [4Bi (NO ₃ )]
(OH) ₂ .BiO (OH)] or a mixture thereof.