JP2005058932A - Minute spherical inorganic oxide molded body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a minute spherical inorganic oxide molded body having a high compression strength even if the body has a high pore volume or a small particle size. <P>SOLUTION: This minute spherical inorganic oxide molded body has a mean particle size (D) of 0.3 to 5 mm, the pore volume (PV) of pores with pore sizes of 30 to 500 nm of 0.1 to 0.6 ml/g, the mean compression strength (N) of 2 to 30 N and a mean compression strength index (C) represented by the formula, C=N×PV/D, of 0.3 to 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inorganic oxide microspherical molded article having high compressive strength even when the pore volume is large or the particle diameter is small, and a method for producing the molded article.

  It is well known that inorganic oxide particles are used industrially as adsorbents, catalysts, catalyst carriers and the like. Inorganic oxide particles are rarely used as fine powders, and are often used after being formed into pellets or spheres. However, the size and shape of the molded body are appropriately selected and used depending on the purpose of use, use conditions, etc., but the pellets may be crushed due to breakage or wear of the edges, and may be filled uniformly. In some cases, there are problems such as difficulty and low filling efficiency.

  For this reason, use of a spherical molded body is desired, but it has been difficult to obtain a spherical molded body having sufficient strength, wearability and the like. In particular, it was difficult to obtain a fine spherical molded body having a particle diameter of 5 mm or less, and even if it was obtained, there was a problem in economic efficiency such as low yield and production efficiency.

  Therefore, in order to produce such a spherical molded body, specifically, an inorganic oxide fine particle dispersion or a hydrogel slurry and / or an inorganic oxide binder such as an inorganic oxide sol or clay mineral is used as necessary. Addition of a molding aid such as cellulose to adjust the water content, heat concentration, kneading, kneading, etc., and then pelletizing with an extrusion molding machine, etc., this is properly formed into a spherical molded body with a malmerizer, rolling granulator, etc. It was done. Furthermore, when making pellets spherical, larger particles were formed while adding inorganic oxide fine powder adjusted for moisture.

As a method for producing a millimeter-order spherical molded body from fine crystal particles such as zeolite, a method disclosed in JP-A-6-64916 (Patent Document 1) is known. In this publication, a) granulation core particles composed of a zeolite and an inorganic binder are charged into a rolling granulator, and the moisture is adjusted in advance. B) a zeolite fine powder and an inorganic binder. A method is disclosed in which a fine powder for granulation is supplied at a constant rate, and the fine powder for granulation is adhered to the core particles using water as a granulation medium to obtain a spherical zeolite compact.
JP-A-6-64916

  However, it has been difficult to obtain a satisfactory spherical molded body by the above method.

  For example, in the above-described method, extrusion molding is easy when there is a lot of moisture depending on the level of moisture adjustment, but the resulting pellets may be too long or non-uniform in length, so the spherical size is It was non-uniform or it was difficult to obtain a spherical molded body. Furthermore, there is a problem that the pellets adhere to each other and aggregate. Such a problem was conspicuous when trying to obtain a microspherical molded product having a particle size of 5 mm or less, particularly a particle size of 2 mm or less.

  On the other hand, when moisture is low, extrusion molding is difficult, even if extrusion molding is possible, the pellets may be too short, and the length may also be non-uniform. Or spherical.

  Even if a spherical molded body is obtained as described above, if the pore volume is increased or the size of the molded body is decreased, the compressive strength and wear resistance of the particles are reduced. There were restrictions.

Moreover, in the method disclosed in Patent Document 1,
1) It is necessary to prepare and use dense particles as core particles,
2) If the ratio of the size of the product particles to the core particles is increased too much, the amount of fine powder for granulation must be increased, and therefore the size varies widely and the particle size distribution becomes wide.
3) For this reason, there was a problem that the yield decreased when classification was performed.

  In addition, if the ratio of the size of the product particles to the core particles is small, in order to obtain the desired large particles, the particles are originally excellent in sphericity, have a uniform particle size distribution, etc. It is required to make core particles having the required particle size and other performances in advance. However, it has been difficult to obtain such core particles.

  The spherical molded body produced in this way also usually has a limit in terms of performance, as the pore volume increases or the size of the molded body decreases, the compressive strength and wear resistance of the particles decrease. There were many restrictions in terms of use.

  Under such circumstances, the present inventors have intensively studied, and as a result, by pelletizing a molding precursor having a low water content with a specific molding machine, the particle diameter is small or the pores are small. The inventors have found that an inorganic oxide microspherical molded article having excellent compressive strength and wear resistance and having a uniform particle size distribution can be obtained even with a large volume molded article, and has completed the present invention.

  That is, the inorganic oxide microspherical molded body according to the present invention has an average particle diameter (D) in the range of 0.3 to 5 mm, and a pore volume (PV) in the range of the pore diameter of 30 to 500 nm of 0. 1 to 0.6 ml / g, average compressive strength (N) is in the range of 2 to 30 N (Newton), average compressive strength index (C) represented by the following formula is 0.3 to 5 Is in range.

C = N × PV / D
Such a microspherical molded body has excellent compressive strength and wear resistance even when the particle diameter is small or the pore volume is large, and an inorganic oxide microspherical molded body having a uniform particle size distribution can be obtained. The present invention is excellent in compressive strength and wear resistance and has a uniform particle size distribution.

The inorganic oxide is composed of I-B, II-A, II-B, III-A, III-B, IV-A, IV-B, V-A, V-B, VI-A in the periodic table. An oxide or composite oxide of one or more elements selected from Group VII-A and Group VIII is preferable.

Examples of the inorganic oxide include SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , V ₂ O ₅ , CrO ₃ , MoO ₃ , WO ₃ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO, CuO, ZnO, GaO, the _{GeO 2, SnO 2, P 2} O 5, AsO 2, Sb 2 O 3, Sb 2 O 5, Bi 2 O 1 or more _{oxides 3} selected from the group consisting of two or more oxides A composite oxide is preferable.

  The inorganic oxide constituting the microspherical shaped body is an inorganic oxide fine particle obtained from an inorganic oxide hydrogel, further includes a binder component (sol, clay mineral), and the content of the inorganic oxide fine particle is 50 as a solid content. It is preferable that the content of the binder component is in the range of 2 to 50% by weight as solid content.

The ratio of the major axis (D _L ) to the minor axis (D _S ) (spherical coefficient (D _L ) / (D _S ) of the inorganic oxide microspherical molded body is preferably in the range of 1 to 1.5.

  In the inorganic oxide microspherical molded body, the proportion of the inorganic oxide microspherical molded body whose particle diameter is in the range of average particle diameter (D) × (1 ± 0.3) is preferably 80% by weight or more. .

The method for producing an inorganic oxide microspherical molded body according to the present invention is characterized by comprising the following steps (a) to (d);
(A) Step of preparing an inorganic oxide fine particle molding precursor having a moisture content in the range of 35 to 60% by weight (b) Molding with a down-press molding machine and a diameter (D) in the range of 0.3 to 5 mm Step (c) for forming a pellet-shaped formed body in step (d), Step (d) for forming a spherical formed body with a spheroid machine, and then drying and / or firing step The inorganic oxide fine particle forming precursor in step (a) is: A precursor obtained by spray-drying the inorganic oxide hydrogel slurry and then adjusting the water content is preferred.

  The inorganic oxide fine particle molding precursor preferably contains a binder.

  The powder obtained by spray drying preferably has an average particle diameter in the range of 20 to 150 μm.

  In the step (a), the inorganic oxide fine particle molding precursor preferably contains a molding aid.

  According to the manufacturing method according to the present invention as described above, the above-described inorganic oxide microspherical molded body according to the present invention is obtained.

  According to the present invention, it comprises an inorganic oxide and, if necessary, a binder. Even if the pore volume is large or the particle diameter is small, the compression strength is high and the wear resistance is excellent, and the spherical coefficient is 1. Thus, it is possible to provide an inorganic oxide microspherical molded body that can be suitably used as and a method for producing the inorganic oxide microspherical molded body.

  Hereinafter, the inorganic oxide microspherical molded body according to the present invention will be specifically described.

[Inorganic oxide microspheres]
The inorganic oxide microspherical molded body according to the present invention has an average particle diameter (D) in the range of 0.3 to 5 mm, and a pore volume (PV) in the range of the pore diameter of 30 to 500 nm of 0.1 to 0.1 mm. In the range of 0.6 ml / g, the average compressive strength (N) is in the range of 2 to 30 N (Newton), and the average compressive strength index (C) represented by the following formula is in the range of 0.3 to 5 It is characterized by being.

C = N × PV / D
Inorganic oxide The inorganic oxide microspherical molded body according to the present invention is composed of an inorganic oxide. Inorganic oxide microspherical molded products include IB, II-A, II-B, III-A, III-B, IV-A, and IV of the periodic table.
An oxide of one or more elements selected from the group consisting of -B, VA, VB, VI-A, VII-A and VIII or 2
It is preferably a composite oxide of more than one kind of oxide.

Examples of such oxides and composite oxides include CuO, AgO, MgO, CaO, BaO, ZnO, La ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , GaO, TiO ₂ , ZrO ₂ , SiO ₂ and GeO _2. , SnO ₂ , V ₂ O ₅ , V ₂ O ₅ , Nb ₂ O ₅ , P ₂ O ₅ , Sb ₂ O ₃ , Sb ₂ O ₅ , Bi ₂ O ₃ , CrO ₃ , MoO ₃ , WO ₃ , MnO ₂ , Fe ₂ O ₃ , CoO, NiO and other oxides, SiO ₂ —Al ₂ O ₃ , SiO ₂ —TiO ₂ , SiO ₂ —ZrO ₂ , Al ₂ O ₃ —MgO, Al ₂ O ₃ —CuO, Al ₂ Examples thereof include composite oxides such as O ₃ —ZnO and Al ₂ O ₃ —NiO.

Among them, the inorganic oxide is _{SiO 2, Al 2 O 3,} TiO 2, ZrO 2, V 2 O 5, CrO 3, MoO 3, WO 3, MnO 2, Fe 2 O 3, CoO, NiO, CuO, ZnO, GaO, is preferably _{GeO 2, SnO 2, P 2} O 5, AsO 2, Sb 2 O 3, Sb 2 O 5, Bi 1 or more oxides selected from ₂ O ₃ or a composite oxide .

  Such oxides and composite oxides can be used as adsorbents, catalysts, catalyst supports, etc. in addition to large oxides and composite oxides having a large pore volume and specific surface area. It is possible to obtain a fine spherical molded body having excellent wear and fluidity.

  Such oxides and composite oxides can be obtained, for example, by neutralizing an aqueous solution of the elemental compound by adding an acid or alkali, or by mixing mixed aqueous solutions of the elemental compound (salt or complex) with each other. A precipitate (sometimes referred to as an inorganic oxide hydrogel) obtained by mixing or neutralizing by adding an acid or an alkali can be obtained by washing, drying, firing, or the like. Moreover, white carbon obtained by drying these can also be used.

  Such oxides and composite oxides usually exist as a porous material.

Binder The inorganic oxide microspherical molded body of the present invention preferably contains a binder in addition to the inorganic oxide.

  The binder is not particularly limited as long as it can be bonded to the inorganic oxide, and a conventionally known binder can be used. For example, particulate alumina, silica, zirconia, titania, silica / alumina, silica / zirconia, etc. are mentioned, and these sols such as alumina sol, silica sol, zirconia sol, titania sol, silica / alumina sol, silica / zirconia sol are usually used. The These fine particles preferably have an average particle diameter in the range of about 5 to 100 nm.

  Moreover, clay minerals, such as kaolin, montmorillonite, bentonite, allophane, and sepiolite, are mentioned.

  The clay mineral preferably has a particle diameter in the range of about 0.1 to 10 μm, and the shape is not particularly limited, and may be any of spherical, fibrous, amorphous, and the like. .

  Furthermore, the sol and clay mineral can be used in combination as necessary.

  The content of such a binder is preferably in the range of 2 to 60% by weight, more preferably 5 to 50% by weight as a solid content in the inorganic oxide microspherical molded body.

  When the content of the binder is less than 2% by weight as the solid content in the inorganic oxide microspherical molded body, the moldability may be inferior depending on the type of the inorganic oxide.

  When the content of the binder exceeds 60% by weight as the solid content in the inorganic oxide microspherical molded article, the characteristics of the inorganic oxide may not be sufficiently exhibited when used as a catalyst, a catalyst simple substance, an adsorbent or the like.

  In the above, when a sol is contained as a binder, the inorganic oxide is bonded, the plasticity at the time of molding is increased and the moldability is improved, and the compressive strength and abrasion resistance of the resulting inorganic oxide microspherical molded body Can be increased.

  Moreover, when a clay mineral is contained, moldability can be improved, strength and wear resistance can be improved, and pore volume, pore diameter, particle density, bulk specific gravity and the like can be adjusted.

  Among the clay minerals used in the present invention, among others, fibrous fillers such as bentonite are excellent in moldability, and thus have a uniform particle size distribution, are spherical, and are inorganic oxide microspheres that are excellent in compressive strength and wear resistance. A molded body can be obtained.

  The inorganic oxide microspherical shaped product according to the present invention preferably has an average particle diameter (D) in the range of 0.3 to 5 mm, more preferably 0.5 to 3 mm.

  The inorganic oxide microspherical molded article having an average particle diameter (D) of less than 0.3 mm is because the pore diameter of the die is small as will be described later in the method for producing an inorganic oxide microspherical molded article of the present invention. It cannot be extruded and is therefore difficult to obtain.

  When the average particle size (D) of the inorganic oxide microspherical molded body exceeds 5 mm, such a large spherical molded body is possible by other methods without using the method of the present invention, or when used as a catalyst. In some cases, the effective coefficient may decrease, and the activity may be inferior to that of the inorganic oxide microspherical molded article having an average particle diameter (D) in the above range.

  In addition, the inorganic oxide microspherical molded body has a pore volume (PV) in the range of 30 to 500 nm and a pore volume (PV) in the range of 0.1 to 0.6 ml / g, and further in the range of 0.2 to 0.5 ml / g. It is preferable that it exists in. In such a range, the activity and adsorption performance are high, the compressive strength of the green form is high, and the body wear resistance is also excellent.

  When the pore volume (PV) in the pore diameter range of 30 to 500 nm of the inorganic oxide microspherical compact is less than 0.1 ml / g, the activity and the adsorption performance tend to be insufficient.

  If the pore volume (PV) in the range of 30 to 500 nm of the pore size of the inorganic oxide microspherical molded body exceeds 0.6 ml / g, the compressive strength of the inorganic oxide microspherical molded body decreases and the wear resistance Also decreases.

The above pore volume in the present invention is measured by a pore distribution measuring device (manufactured by QUANTA CHROME: AUTOSCAN-60 POROSOMETER, mercury contact angle 130 ° C., mercury surface tension 473 Dyn / cm ² , measurement range “high pressure”). Can be measured.

  It is preferable that the average compressive strength (N) of the inorganic oxide microspherical molded product is in the range of 2 to 30 N (Newton), more preferably 4 to 20 N.

  If the average compressive strength (N) of the inorganic oxide microspherical molded product is less than 2N, it will break when it is filled or withdrawn, and depending on the conditions of use, a differential pressure may be produced and the reaction performance will be reduced. Or difficult to use repeatedly.

  It is difficult to obtain an inorganic oxide microspherical molded article having a high compressive strength when the average compressive strength (N) of the inorganic oxide microspherical molded article exceeds 30N.

  The average compressive strength (N) used in the present invention was determined by measuring the compressive strength of 20 inorganic oxide microspherical molded bodies with a Kiyama hardness tester (manufactured by Fujiwara Seisakusho).

  Next, the inorganic oxide microspherical molded body according to the present invention has a compressive strength index (C) represented by the following formula in the range of 1.0 to 5, preferably 1.5 to 5.

C = N x PV / D
This compressive strength index (C) is obtained by calculating the average compressive strength (N) of the inorganic oxide microspherical shaped product, multiplying this by the pore volume (PV), and dividing by the average particle size (D).

  Usually, since the compressive strength is proportional to the particle diameter and inversely proportional to the pore volume, the compressive strength index (C) means a compressive strength independent of the particle diameter and pore volume.

  When the compressive strength index (C) of the inorganic oxide microspherical molded body is less than 1.0, it is broken when it is filled in or pulled out regardless of the particle size, and the differential pressure depends on the usage conditions. Will occur, resulting in poor reaction results and difficulty in repeated use.

  It is difficult to obtain an inorganic oxide microspherical molded article having a high compressive strength index when the compressive strength index (C) of the inorganic oxide microspherical molded article exceeds 5.

The ratio of the major axis (D _L ) to the minor axis (D _S ) (spherical coefficient: (D _L ) / (D _S )) of the inorganic oxide microspherical compact is 1 to 2, and further 1 to 1.5. In particular, it is preferably in the range of 1 to 1.2.

If this spherical coefficient exceeds 2, the packing density may be lowered and the reproducibility of the filling may be inferior. For this reason, the performance may not be sufficiently exhibited or the reproducibility may be inferior, and the fluidity may be reduced. In some cases, the effect of forming a spherical molded body may not be sufficiently obtained.
The average particle diameter and spherical coefficient in the present invention are obtained by taking an optical photograph of particles, obtaining the long and short diameters of the particles with a caliper, and determining the average value as the particle diameter. The value was defined as the average particle diameter (D), and the average value of the ratio between the long diameter and the short diameter was defined as the spherical coefficient (D _L ) / (D _S ).

  Next, in the inorganic oxide microspherical molded body, the proportion of particles having a particle diameter in the range of (D) × (1 ± 0.3) is 80% by weight or more, and further 90% by weight or more. preferable.

  In the particle size distribution of the inorganic oxide microspherical shaped product, when the proportion of particles in the range of (D) × (1 ± 0.3) is less than 80% by weight, depending on the type of reaction, Because there are differences in activity and selectivity due to differences, it may be difficult to obtain optimal performance or cause differential pressure.

  Further, the bulk specific gravity of such a molded article is desirably in the range of 0.3 to 1.6 g / ml, preferably 0.4 to 1.5 g / ml. In the present invention, the bulk specific gravity is measured as follows. Fill a 100 cc graduated cylinder with about 100 cc of microsphere zeolite fuel treatment agent, measure the volume of the treatment agent after applying moderate vibration, and divide the weight (g) of the filled treatment agent by the treatment agent volume. Can be obtained.

  Such an inorganic oxide microspherical molded body according to the present invention can be produced, for example, by the following method.

Method for Producing Inorganic Oxide Microspherical Molded Body The method for producing an inorganic oxide microspherical molded body according to the present invention is not particularly limited as long as the above-described inorganic oxide microspherical molded body is obtained. The manufacturing method of the inorganic oxide microspherical shaped body comprising steps (d) to (d) can be suitably employed.

The method for producing an inorganic oxide microspherical molded body according to the present invention is characterized by comprising the following steps (a) to (d).
(A) Step of preparing an inorganic oxide fine particle molding precursor having a moisture content in the range of 30 to 60% by weight (b) Molding with a down-press molding machine and a diameter (D) in the range of 0.3 to 5 mm Step (c) for forming a pellet-shaped molded body in step (b), Step (d) for forming a spherical molded body with a spheroid machine, and then drying and / or firing
[Process (a)]
The same inorganic oxide as described above can be used.

  Specifically, for example, by adding an acid or alkali to an aqueous solution of the elemental compound to neutralize, or by mixing an aqueous mixed solution of the elemental compound with each other or adding an acid or alkali or the like An inorganic oxide hydrogel slurry such as an oxide (hydroxide) or a composite oxide (composite hydroxide) obtained by washing and aging as necessary is suitably used. be able to.

As the binder, the same sol and / or clay mineral as described above can be used.

  As the sol, sols such as alumina sol, silica sol, zirconia sol, titania sol, silica / alumina sol and silica / zirconia sol can be preferably used. When a sol is used, the solid concentration is preferably 1 to 50% by weight, preferably 2 to 40% by weight.

  The sol at this time preferably has an average particle diameter in the range of about 5 to 100 nm.

  In addition, clay minerals such as kaolin, montmorillonite, bentonite, allophane, and sepiolite can also be suitably used.

  The clay mineral preferably has a particle diameter in the range of about 0.1 to 5 μm, and the shape is not particularly limited, and may be any of spherical, fibrous, amorphous, and the like.

  Furthermore, the sol and clay mineral can be used in combination as necessary.

  The content of such a binder is preferably in the range of 2 to 60% by weight, more preferably 5 to 50% by weight as a solid content in the inorganic oxide microspherical molded body.

  When the content of the binder is less than 2% by weight as the solid content in the inorganic oxide microspherical molded body, the moldability may be inferior depending on the type of the inorganic oxide.

  When the content of the binder exceeds 60% by weight as the solid content in the inorganic oxide microspherical molded article, the characteristics of the inorganic oxide may not be sufficiently exhibited when used as a catalyst, a catalyst simple substance, an adsorbent or the like.

  In the method for producing an inorganic oxide microspherical molded body according to the present invention, the inorganic oxide hydrogel slurry described above, a binder, if necessary, a pulverized powder described later, and a molding aid are mixed to form an inorganic oxide microspherical molding precursor. Prepare the body. The amount of water in the precursor is adjusted to be in the range of 35 to 60% by weight, preferably 37 to 58% by weight, although it varies depending on the type of the inorganic oxide.

  When the water content of the inorganic oxide fine particle molding precursor is less than 35% by weight, extrusion molding becomes difficult, and when the water content of the mixture powder exceeds 60% by weight, the length of the extruded pellets becomes long. It tends to be non-uniform or long, and it becomes difficult to form spherical particles in the granulation process, and thus it is necessary to cut the pellet to the length (L) described later. In addition, pellets may adhere to each other and form a molded body.

  The method for adjusting the moisture is not particularly limited as long as the amount of moisture described above is reached, and a conventionally known method can be adopted. For example, the mixture can be a mixture of an inorganic oxide hydrogel slurry and a binder, and further a pulverized powder. It can be adjusted by adding a predetermined amount of water or by dehydrating and drying.

Spray Drying In the present invention, in the step (a), it is preferable to use a spray-dried powder obtained by spray-drying a mixed slurry in which an inorganic oxide hydrogel slurry is mixed with a binder as necessary.

  The concentration of the slurry at this time is preferably in the range of 1 to 40% by weight, more preferably 2 to 35% by weight as the solid content.

  When the concentration of the slurry is less than 1% by weight as the solid content, not only the spray drying thermal efficiency is low, but also a spray dried powder having a desired particle size described later may not be obtained.

  When the concentration of the slurry exceeds 40% by weight as the solid content, the viscosity of the slurry becomes high and stable spray drying may not be possible.

  In addition, the mixing ratio when the inorganic oxide hydrogel slurry and the binder are mixed and used varies depending on the type and particle size of the inorganic oxide and the binder, but the binder content in the mixture is 2 to 40 as the solid content. It is preferable to be in the range of wt%, more preferably 5 to 30 wt%.

  When the content of the binder in the mixture is less than 2% by weight as a solid content, the moldability is lowered due to insufficient plasticity, and the compression strength and resistance of the finally obtained inorganic oxide microspherical molded body are reduced. Abrasion may be insufficient.

  When the content of the binder in the mixture exceeds 40% by weight as a solid content, the performance of the finally obtained inorganic oxide microspherical molded body as a catalyst or an adsorbent may be insufficient.

  As the spray drying method, a spray-dried powder having an average particle size in the range of 20 to 150 μm, preferably 30 to 120 μm, and a moisture content in the range of 3 to 40% by weight, preferably 5 to 30% by weight. If it is obtained, there is no particular limitation, and a conventionally known spray drying method can be employed.

  For example, although it depends on the solid content concentration of the slurry, a method of spraying the slurry using a disk or a nozzle in a hot air stream usually at 70 to 500 ° C. can be suitably employed.

  When the average particle size of the spray-dried powder is less than 20 μm, the particles obtained by spray-drying are aggregated when adding water to adjust the moisture content for extrusion molding. In some cases, the pellets adhere to each other and agglomerate during granulation, and an inorganic oxide microspherical molded product having a uniform particle size may not be obtained.

  When the average particle size of the spray-dried powder exceeds 150 μm, it is necessary to increase the pressure at the time of extrusion molding, and when the extrusion molding is performed at a pressure comparable to that of particles having an average particle size in the above range, the resulting inorganic oxidation Compressive strength and wear resistance of the product microsphere shaped product may be insufficient.

  In addition, when the moisture content of the spray-dried powder is less than 3% by weight, the moldability during extrusion molding can be improved even if the moisture content of the resulting inorganic oxide fine particle molding precursor is adjusted to the above range. It tends to decrease, the length of the pellets becomes non-uniform, the yield of spherical particles decreases, and the particle size of the spherical particles tends to become non-uniform.

  When the moisture content of the spray-dried powder exceeds 40% by weight, the effect of using the spray-dried powder, that is, the moldability is improved, the length of the pellet is close to the extrusion diameter and uniform, and the spherical coefficient is 1. The effect of obtaining a near-spherical microspherical molded body is insufficient.

Milling powder addition, the inorganic oxide fine particles molded precursor (by firing After or ground) ground to the inorganic oxide fine spherical green body obtained in later-described step (d) the average particle size obtained In the range of 10 to 100 μm, more preferably 20 to 80 μm, so that the total solid content is 2 to 40% by weight, further 5 to 30% by weight. preferable. That is, when the inorganic oxide microspherical molded product obtained through the steps (a) to (d) is included, the reason is not clear, but the improvement in moldability, inorganic oxide microspherical molded product Compressive strength and wear resistance can be improved.

  When the content in the total solid content of the powder obtained by pulverizing the inorganic oxide microspherical molded body obtained in step (d) is less than 2% by weight, the powder obtained by pulverization The effects of mixing the body, that is, the improvement of moldability, the compression strength of the inorganic oxide microspherical molded body, and the improvement of wear resistance may not be sufficiently obtained.

  When the content in the total solid content of the powder obtained by pulverizing the inorganic oxide microspherical molded body exceeds 40% by weight, extrusion molding becomes difficult, or powdered when spheroidized or spherical molded body May not be obtained.

  In addition, when the average particle size of the powder obtained by pulverizing the inorganic oxide microspherical molded body is less than 10 μm, the effect of mixing the powder obtained by pulverization, that is, improvement of moldability, In some cases, the compression strength and wear resistance of the spherical molded body cannot be sufficiently improved.

  When the average particle size of the powder obtained by pulverizing the inorganic oxide microspherical molded body exceeds 100 μm, although it depends on the content, extrusion molding becomes difficult or the powder tends to be pulverized when spheroidized. .

Molding aid Further, as the inorganic oxide fine particle molding precursor, a molding aid (sometimes referred to as a plasticizer) can be used as necessary.

  Examples of the molding aid include crystalline cellulose, methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, starch, and lignin.

  When such a molding aid is added, the allowable range of the moisture content at the time of extrusion molding described later may be widened. For example, in the case of an inorganic oxide having a moldable water content in the range of 40 to 52% by weight when no molding aid is added, if the crystalline cellulose is used as a molding aid at 3% by weight of the solid content, The range is 38 to 55% by weight, good moldability, no adhesion during granulation, and an inorganic oxide microspherical molded body having sufficient compressive strength and wear resistance can be obtained. Furthermore, although the reason is not clear, when the extrusion molding described later, the pellet is folded so that the ratio L / D of the length (L) and the diameter (D) of the pellet is approximately in the range of 1-2. Granulate without artificially cutting.

  The addition amount of the molding aid at this time is preferably in the range of 0.5 to 15% by weight, more preferably 1 to 10% by weight of the total solid content (inorganic oxide, binder, filler, pulverized powder). .

  When the addition amount of the molding aid is less than 0.5% by weight of the total solid content, the effect of adding the molding aid cannot be sufficiently obtained, and the addition amount of the molding aid is 15% of the total solid content. If it exceeds wt%, it tends to be pulverized when it is spheroidized, and the compression strength and wear resistance of the resulting inorganic oxide microspherical molded product tend to be reduced.

The moisture-adjusted inorganic oxide fine particle molding precursor can be extruded immediately after kneading as necessary, but it is allowed to mature while maintaining the moisture content for an appropriate time, and then extrusion molding. can do. When such aging is performed, the compressive strength and abrasion resistance of the resulting inorganic oxide microspherical molded body may be improved.
[Step (b)]
Next, the inorganic oxide fine particle molding precursor obtained in the step (a) is extruded using a molding machine, and the diameter (D) is in the range of 0.3 to 5 mmφ, preferably 0.5 to 3 mmφ. And As the molding machine, a bottom push roll type extruder having a pellet discharging die is used. The diameter of the formed body is controlled by the diameter of the die.

  When the diameter (D) of the pellet is less than 0.3 mmφ, it is difficult to extrude because the hole diameter of the die is small, and when the diameter (D) of the pellet exceeds 5 mmφ, the resulting molded article has a particle size of Pellets having a diameter in the above range may exceed 5 mmφ, and such a large spherical shaped body may be produced by other methods without using the method of the present invention, or when used as a catalyst, the effectiveness factor may decrease. The activity may be inferior to that of the inorganic oxide microspherical molded body obtained from the above.

  At this time, it is preferable to extrude at least once with a die having a diameter larger than the desired diameter, and then extrude with a die having a desired diameter. The reason is not necessarily clear, but it tends to be easy to extrude with a die having a desired diameter and to improve the compressive strength of the finally obtained inorganic oxide microspherical molded body.

  Examples of the extrusion molding machine include a front pressing screw type, a side pressing screw type, a front pressing ram type, a horizontal pressing roll type, a lower pressing roll type, a horizontal pressing basket type, and a lower pressing screen type. The above-described lower pressing roll mold can extrude a mixture powder with less moisture compared to other molding machines, so that the pellets do not adhere to each other when spheroidizing, and it is uniform in high yield. An inorganic oxide microspherical shaped product having a particle size distribution can be obtained.

  The length (L) of the pellet varies depending on the hole diameter of the die of the extrusion molding machine (or the diameter (D) of the obtained pellet), but is in the range of 0.3 to 10 mm, preferably 0.4 to 7.5 mm. Therefore, it is preferable that the diameter (D) of the pellet is approximately the particle diameter of the desired inorganic oxide microspherical shaped body. At this time, the ratio L / D between the length (L) of the pellet and the diameter (D) of the pellet is preferably in the range of 1 to 2, more preferably 1 to 1.5. It is difficult for L / D to be less than 1, and even if it is possible, it tends to be difficult to be spherical. When the L / D exceeds 2, the resulting particles are unlikely to be spherical, and even if it can be produced, it takes a long time to spheroidize, and production efficiency may be reduced. For this reason, L / D can be cut to 2 or less, but there is still a problem that the production efficiency is lowered.

As described above, since the particle diameter of the inorganic oxide microspherical molded body obtained by the method of the present invention depends on the hole diameter of the die of the extrusion molding machine, it has a very uniform particle size distribution.
[Process (c)]
Next, the pellet prepared in the above step (b) is formed into a spherical molded body with a high-speed rolling sphere forming machine.

A conventionally known rolling granulator (sometimes referred to as a Malmerizer) or the like can be used as the high-speed rolling sphere forming machine. When using a rolling granulator, it is made spherical by filling the pellets obtained in step (b) and rotating the granulator, or filling the rotated rolling granulator with pellets. The spheroidizing conditions at this time, for example, the rotational speed, the peripheral speed, the granulation time, and the like vary depending on the size of the spheroid machine, the size of the pellets to be filled, the degree of sphericalness, etc., and are preferably selected and set as appropriate. In the present invention, the water content is adjusted to a predetermined value in the step (a) and is extruded to a predetermined size in the step (b), so that the pellets do not adhere to each other and agglomerate. It is not necessary to dry the pellets to prevent aggregation before spheroidization or at the time of spheroidization, and there is no deterioration in moldability due to drying.
[Process (d)]
The resulting spherical shaped body is then dried and / or fired.

  When the spherical molded body is dried, the degree of drying may be appropriately set depending on the application. However, it is preferable to dry the particles having a large particle diameter slowly, although the drying speed can be set relatively early for the particles having a small particle diameter. The drying temperature is preferably 50 to 200 ° C, more preferably 80 to 150 ° C. Moreover, although drying time changes also with drying temperature, it is preferable that it exists in the range of 10 minutes-48 hours, Furthermore, 30 minutes-24 hours.

  When firing, the temperature is preferably in the range of 200 to 1000 ° C, more preferably 300 to 800 ° C. When the firing temperature is less than 200 ° C., the strength of the obtained particles may be insufficient, or powdering due to wear may be remarkable. Even when the calcination temperature exceeds 1000 ° C., the strength of the particles is not further improved, and depending on the type of inorganic oxide, crystallization occurs, the specific surface area decreases, and the performance as a catalyst, catalyst carrier, or adsorbent is poor. May be sufficient.

  In the present invention, either drying or firing may be performed, or both may be performed.

  The inorganic oxide microspherical molded body obtained by the above steps (a) to (d) has an average particle size in the range of 0.3 to 5 mm.

  Those having an average particle diameter of less than 0.3 mm are difficult to obtain due to the difficulty of extrusion molding, and those having an average particle diameter exceeding 5 mm can be obtained by other methods regardless of the method of the present invention. When used as a catalyst, the effectiveness factor may decrease, and the activity may be inferior to that of an inorganic oxide microspherical molded article having an average particle diameter in the above range.

In addition, the spherical shape referred to in the present invention is not necessarily a true spherical shape, and may be a shape having moderate fluidity and a curvature with no corners to such an extent that powdering does not occur. At this time, the ratio (D _L ) / (D _S ) (sometimes referred to as a spherical coefficient) of the major axis (D _L ) and the minor axis (D _S ) of the spherical particles is 1-2, and further 1-1. Preferably, it is in the range of 5, especially 1 to 1.2. If it is in such a range, since it has a shape close to a sphere, it is excellent in fluidity, can be filled uniformly easily, and can be suitably used as a catalyst, a catalyst carrier, an adsorbent and the like.

The average particle diameter and spherical coefficient of the obtained inorganic oxide microspherical molded article were obtained by taking an optical photograph of the particles, obtaining the major axis and minor axis of the particles with a caliper, and setting the average value as the particle diameter. For each particle, the average value was defined as the average particle diameter (D), and the average value of the ratio of the major axis to the minor axis was defined as the spherical coefficient (D _L ) / (D _S ).

  In addition, the obtained inorganic oxide microspherical shaped product has a particle size in the range of (D) × (1 ± 0.3) of 80% by weight or more, more preferably 90% by weight or more. Is preferred. If it is in such a range, the particle size distribution is uniform, and therefore, pulverization is suppressed, excellent fluidity, and can be easily and uniformly filled, and catalyst, catalyst carrier, adsorbent, etc. can be pulverized. It is suppressed, excellent in fluidity, can be filled easily and uniformly, and can be suitably used as a catalyst, a catalyst carrier, an adsorbent and the like.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited to an Example by these.
[Example 1]
85 g of white carbon (SiO ₂ content 94% by weight) is mixed with 1000 g of silica sol (catalyst conversion Co., Ltd .: SI-350, SiO ₂ concentration 20% by weight, average particle size 8.5 nm) at a high speed stirring powder mixer (( After thorough mixing with Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type, 30 g of cellulosic molding aid (Asahi Kasei Kogyo Co., Ltd .: Avicel RC-591) and 370 g of water were added. The mixture was sufficiently mixed to prepare an inorganic oxide fine particle molding precursor (1) having a moisture content of 55% by weight.

  The inorganic oxide fine particle molding precursor (1) was molded into pellets using a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). . At this time, extrusion was first performed with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 2.0 mmφ to form pellets. At this time, the length of the pellets was relatively uniform, and the average length was 2.5 mm.

  The obtained pellets having a diameter of 2.0 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 2 minutes.

  The obtained spherical molded body was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded body (1).

  Yield of inorganic oxide microspherical molded body (1) (desired particle diameter is D, weight of microspherical molded body in which particle diameter is in the range of D ± 0.3D) / total raw material content for molding × 100 (% )), Average short diameter, average long diameter, average particle diameter, spherical coefficient, pore volume, compressive strength were measured to obtain an average compressive strength index, and the results are shown in Table 1. Moreover, abrasion resistance was measured and the results are shown in Table 1.

  The compressive strength was measured with a compressive strength meter (manufactured by Fujiwara Seisakusho Co., Ltd .: Kiyama-type hardness meter, max 5 kg), and the wear resistance was measured based on the abrasion strength measurement method (JIS No. K1464). The pore volume was determined by a mercury intrusion method and indicated as a pore volume in a pore diameter range of 50 to 500 nm.

  The average minor axis and the average major axis were measured with respect to 100 particles by taking an optical micrograph, and the average particle diameter was expressed as (average minor axis + average major axis) / 2.

Further, the bulk density (CBD) was measured by the method described above and is shown in Table 1.
[Example 2]
First, a bamato alumina gel which is gelled aluminum hydroxide was prepared as follows. Sodium aluminate aqueous solution (Al ₂ O ₃ concentration: 5.0% by weight, Na ₂ O concentration: 3.86% by weight) 50 Kg With sufficient stirring, an aluminum sulfate aqueous solution (Al ₂ O ₃ concentration: 2.5% by weight, H ₂ An alumina hydrogel slurry was prepared by adding 25 kg (SO ₄ concentration 7.2 wt%) in 10 minutes. The alumina hydrogel slurry had a pH of 8.5 and an Al ₂ O ₃ concentration of 3.75% by weight. Next, the alumina hydrogel slurry was filtered and washed to prepare a boehmite alumina gel slurry. At this time, the pH was 8.1 and the Al ₂ O ₃ concentration was 13.6% by weight.

This boehmite alumina gel slurry was spray-dried with a spray dryer (hot air inlet temperature 280 to 310 ° C., outlet temperature 118 to 128 ° C.) to be powdered. The obtained spray-dried powder had an average particle size of 67 μm, an Al ₂ O ₃ content of 75% by weight, and a water content of 25% by weight.

1.13 Kg of this spray-dried powder is put into a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), and then alumina sol (Catalyst Chemical Industries Co., Ltd .: Cataloid-AP, Al ₂ O ₃ content 69.5 wt%, average particle size 7.6 nm) 220 g, Avicel 30 g and water 980 g were mixed well and mixed to prepare inorganic oxide fine particle molding precursor (2) having a moisture content of 57 wt%. did.

  This inorganic oxide fine particle molding precursor (2) is molded into pellets using a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). did. At this time, first, extrusion was performed twice with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 1.5 mmφ to form pellets. At this time, the length of the pellets was relatively uniform, and the average length was 2.1 mm.

  The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 2 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (2).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the obtained inorganic oxide microspherical molded body (2), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Example 3]
In the same manner as in Example 2, a spray-dried powder of boehmite alumina gel having a water content of 25% by weight was prepared.

  1.13 Kg of this spray-dried powder is put into a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), and then powdered bentonite (Nihon Bentonite Co., Ltd .: containing solids) 92.8 wt%, particle size of about 1 μm) 162 g, cellulosic molding aid (Yureken Kogyo Co., Ltd .: Serander, YB-154) 25 g and water 790 g were mixed well and the water content was 52 wt%. An inorganic oxide fine particle molding precursor (3) was prepared.

  This inorganic oxide fine particle molding precursor (3) is molded into pellets with a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). did. At this time, first, extrusion was performed once with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 1.5 mmφ to form pellets. At this time, the length of the pellet was relatively uniform, and the average length was 1.9 mm.

  The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 4 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (3).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (3), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Example 4]
Metatitanic acid (manufactured by Ishihara Sangyo Co., Ltd.) was thoroughly washed with water, and a part thereof was dried at 110 ° C. The obtained powder had a TiO ₂ content of 92.0% by weight and a water content of 8% by weight.

  Separately, nitric acid was added to part of the washed metatitanic acid to adjust the pH to 2 to prepare a titanium oxide sol (TiO 2 content 20.0 wt%, average particle diameter 5 nm).

  Put 924 g of metatitanic acid powder in a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), then add 750 g of titanium oxide sol and 30 g of Avicel, and mix well. An inorganic oxide fine particle molding precursor (4) was prepared.

  This inorganic oxide fine particle molding precursor (4) is molded into pellets using a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). did. At this time, first, extrusion was performed three times with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 0.5 mmφ to form pellets. The length of the pellet at this time was relatively uniform, and the average length was 0.8 mm.

  The obtained pellets having a diameter of 0.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 2 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (4).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (4), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in the table.
[Example 5]
635 g of copper nitrate (Cu (NO ₃ ) ₂ · 3H ₂ O), 945 g of nickel nitrate (Ni (NO ₃ ) ₂ · 6H ₂ O), 1557 g of zinc nitrate (Zn (NO ₃ ) ₂ · 6H ₂ O), aluminum nitrate 449 g of (Al (NO) ₃ .9H ₂ O) was dissolved in 10 L of water. While this was stirred, a sodium carbonate aqueous solution having a concentration of 5.44% by weight was gradually added until the pH reached 7.2, and stirring was continued for 2 hours. The precipitate was filtered and washed with 100 L of water. The obtained washed cake was dispersed again in water to prepare a composite oxide hydrogel slurry. At this time, the solid content concentration was 20.5 wt.

  This composite oxide hydrogel slurry was spray-dried with a spray dryer (hot air inlet temperature 280 to 310 ° C., outlet temperature 118 to 128 ° C.). The resulting spray-dried powder had an average particle size of 54 μm, a solid content concentration of 81.7% by weight, and a water content of 18.3% by weight.

  Place 1000g of spray-dried powder of complex oxide into a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), then gradually add 570g of water, mix well, and contain water An inorganic oxide fine particle molding precursor (5) having an amount of 41.2% by weight was prepared.

  This inorganic oxide fine particle molding precursor (5) is molded into pellets with a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). did. At this time, first, extrusion was performed twice with a nozzle diameter of 2 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 0.7 mmφ to form pellets. The length of the pellet at this time was relatively uniform, and the average length was 0.9 mm.

  The obtained pellets having a diameter of 0.7 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 6 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (5).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (5), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Example 6]
Metatitanic acid (TiO ₂ content 36% by weight) 2834g and silicic acid liquid obtained by treating sodium silicate with a cation exchange resin (SiO ₂ content 4.8% by weight) 14160g were mixed well to metatitanium. A mixture dispersion of acid and silicic acid solution was prepared.

  This mixture dispersion was spray-dried with a spray dryer (hot air inlet temperature 280 to 310 ° C., outlet temperature 118 to 128 ° C.). Subsequently, it was calcined at 400 ° C. for 3 hours to obtain a powder composed of silica / titania. The average particle size of the powder was 58 μm, the solid content concentration was 95.8% by weight, and the water content was 4.2% by weight.

887 g of silica-titania spray-dried powder was put into a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), and then titanium oxide sol (TiO) prepared in the same manner as in Example 4. ₍₂ ) 20.0 wt%, average particle diameter 5 nm) 750 g, Avicel 30 g, and 324 g of water were mixed well to prepare an inorganic oxide fine particle molding precursor (6) having a water content of 49 wt%.

  The inorganic oxide fine particle molding precursor (6) was molded into pellets using a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). . At this time, first, extrusion was performed twice with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 1.5 mmφ to form pellets. At this time, the length of the pellet was relatively uniform, and the average length was 1.9 mm.

  The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 5 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (6).

Measure the yield, average minor axis, average major axis, average particle size, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (6), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Example 7]
Ammonium water having a concentration of 15% by weight was gradually added to 2226 g of an aqueous cerium nitrate solution (CeO ₂ content: 5% by weight) until the pH reached 8.5 to obtain a cerium hydroxide precipitate. The stirring was further continued for 1 hour, and then the precipitate was filtered with a filter and washed with 10 L of water. 263 g of this cerium hydroxide hydrogel (concentration as CeO ₂ ) was 6620 g of alumina boehmite gel slurry (Al ₂ O ₃ concentration 13.6 wt%, pH 8.1) obtained in the same manner as in Example 2. Were mixed well.

  This mixture dispersion was spray-dried with a spray dryer (hot air inlet temperature 280 to 310 ° C., outlet temperature 118 to 128 ° C.). The average particle size of the spray-dried powder was 75.2 μm, the solid content concentration was 65% by weight, and the water content was 35% by weight.

  1540 g of ceria / alumina powder is put into a high-speed stirring powder mixer (Mitsui Mining Co., Ltd .: Henschel mixer, FM-20C type), then 25 g of Avicel and 543 g of water are put in and mixed well, and the water content is 48 A 1% by weight inorganic oxide fine particle molding precursor (7) was prepared.

  The inorganic oxide fine particle molding precursor (7) was molded into pellets with a down roll type extruder (Fuji Paudal Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). . At this time, first, extrusion was performed twice with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 1.5 mmφ to form pellets. At this time, the length of the pellets was relatively uniform, and the average length was 2.1 mm.

  The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 5 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (7).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (7), determine the average compressive strength index, Shown in the table. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Example 8]
The inorganic oxide microspherical molded body (2) obtained in Example 2 was pulverized to prepare a pulverized powder having an average particle diameter of 69 μm. 104 g of this pulverized powder (solid content: 96% by weight), 960 g of spray-dried powder of boehmite alumina gel having a water content of 25% by weight obtained in the same manner as in Example 2, and alumina sol (manufactured by Catalyst Kasei Kogyo Co., Ltd.) : Cataloid-AP, Al ₂ O ₃ content 69.5 wt%, average particle size 7.6 nm) 260 g and high speed stirring powder mixer (Mitsui Mine Co., Ltd .: Henschel mixer, FM-20C type) Then, 25 g of cellulose-based molding aid (Yureken Kogyo Co., Ltd .: Selander, YB-154) and 900 g of water are mixed and mixed thoroughly to form an inorganic oxide fine particle molding precursor (8) having a moisture content of 55% by weight. Was prepared.

  This inorganic oxide fine particle molding precursor (8) is molded into pellets using a down roll type extruder (manufactured by Fuji Powder Co., Ltd .: disk pelleter, F-5 (PV-S) / 11-175 type). did. At this time, first, extrusion was performed once with a nozzle diameter of 3 mmφ of the extruder, and then extrusion was performed once with a nozzle diameter of 1.5 mmφ to form pellets. At this time, the length of the pellets was relatively uniform, and the average length was 2.0 mm.

  The obtained pellets having a diameter of 2.0 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 4 minutes.

  The obtained spherical molded product was dried at 130 ° C. for 24 hours and then calcined at 670 ° C. for 3 hours to obtain an inorganic oxide microspherical molded product (8).

Measure the yield, average minor axis, average major axis, average particle diameter, spherical coefficient, pore volume, compressive strength of the resulting inorganic oxide microspherical molded body (8), determine the average compressive strength index, It is shown in Table 1. The abrasion resistance and CBD were measured and the results are shown in Table 1.
[Comparative Example 1]
625 g of alumina boehmite gel (pH 8.1, Al ₂ O ₃ concentration 13.6 wt%) prepared in the same manner as in Example 2 and alumina sol (manufactured by Catalyst Kasei Kogyo Co., Ltd .: Cataloid-AP, containing Al ₂ O ₃ ) 69.5 wt%, average particle size 7.6 nm) 220 g and put into a steam heating concentrator (manufactured by Toshin Co., Ltd.), and after mixing well, the moisture becomes about 60 wt% while heating through the steam through the jacket. The solution was concentrated to adjust the water content, and then cooled. The moisture of this moisture adjusted product was 61.1% by weight.

  Pellets were molded from the moisture-adjusted product using an extruder (Honda Tetsuko Co., Ltd .: DE-75 type, front screw type) using a 1.5 mmφ die. At this time, the length of the pellets was uneven and long, and the average length was 4.2 mm.

The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 5 minutes. Since the pellets are long, it is difficult to form a sphere, and even when the pellets adhere to each other and agglomerate to form a part of a sphere, the sphericity is low, the particle size is not uniform, and a spherical molded body with a desired particle size The yield of was about 15%.
[Comparative Example 2]
In Comparative Example 1, pellets were molded and spheroidized in the same manner except that the water content was adjusted by adjusting the water content to 50% by weight. However, it was difficult to extrude, and it was difficult to obtain a spherical molded body by pelletizing the partially extruded pellet. (Therefore, the molded product is not evaluated.)
[Comparative Example 3]
A composite oxide hydrogel slurry (solid content concentration 20.5 wt%) prepared in the same manner as in Example 5 was placed in a steam heating concentrator and mixed thoroughly, and then the moisture was reduced to about 45 wt% while being heated through steam in the jacket. Concentrated until cooled, then cooled. The water content of this concentrated product was 45.3% by weight.

I tried to mold this moisture-adjusted product with an extruder (Honda Tekko Co., Ltd .: DE-75 type, front screw type) using a 0.7mmφ die, but the die was clogged and extruded. It was difficult. (Therefore, the molded product is not evaluated.)
[Comparative Example 4]
2500 g of the composite oxide hydrogel slurry (solid content concentration 20.5% by weight) prepared in the same manner as in Example 5 was placed in a steam-heated concentrator, 75 g of Avicel was added and mixed well, and then the jacket was heated through steam. The solution was concentrated until the water content was about 45% by weight, and then cooled. The water content of this concentrated product was 46.5% by weight. (Therefore, the molded product is not evaluated.)
I tried to mold this moisture-adjusted product with an extruder (Honda Tekko Co., Ltd .: DE-75 type, front screw type) using a 0.7mmφ die, but the die was clogged and extruded. It was difficult.
[Comparative Example 5]
1470 g of a powder composed of silica and titania (spray-dried product, solid content concentration: 76.3% by weight) prepared in the same manner as in Example 6 was dispersed in 1100 g of water, and this was heated with a steam heat concentrator (manufactured by Toshin Co., Ltd.). The mixture was thoroughly mixed and then heated with steam through the jacket until the water content was about 60% by weight to adjust the water content, and then cooled. The moisture of this moisture adjusted product was 56.8% by weight.

  Pellets were molded from the moisture-adjusted product using an extruder (Honda Tetsuko Co., Ltd .: DE-75 type, front screw type) using a 1.5 mmφ die. The length of the pellet at this time was uneven and long, and the average length was 3.9 mm.

  The obtained pellets having a diameter of 1.5 mmφ were formed into spherical particles using a spherical machine (Fuji Paudal Co., Ltd .: Malmerizer, QJ-400). The rotational speed of the spherical machine at this time was 600 rpm, the external heat temperature was 60 ° C., and the treatment time was 5 minutes. Since the pellets are long, it is difficult to form a sphere, and even when the pellets adhere to each other and agglomerate to form a part of a sphere, the sphericity is low, the particle diameter is non-uniform, and a spherical molded body with a desired particle diameter The yield of was 9.2%.

  The molded bodies obtained in Comparative Examples 1 and 5 were evaluated in the same manner as in the Examples. The results are shown in Table 1.

Claims (13)

The average particle diameter (D) is in the range of 0.3 to 5 mm, the pore volume (PV) in the range of 30 to 500 nm is in the range of 0.1 to 0.6 ml / g, and the average compressive strength is (N) is in the range of 2 to 30 N (Newton), and the average compressive strength index (C) represented by the following formula is in the range of 0.3 to 5. .
C = N × PV / D The inorganic oxide is IB, II-A, II-B, III-A, III-B, IV-A, IV-B, V-A, V-B, VI-A, VII in the periodic table. The inorganic oxide microspherical molded article according to claim 1, which is an oxide or composite oxide of one or more elements selected from -A and VIII groups. Wherein the inorganic oxide is _{SiO 2, Al 2 O 3,} TiO 2, ZrO 2, V 2 O 5, CrO 3, MoO 3, WO 3, MnO 2, Fe 2 O 3, CoO, NiO, CuO, ZnO, GaO , GeO ₂ , SnO ₂ , P ₂ O ₅ , AsO ₂ , Sb ₂ O ₃ , Sb ₂ O ₅ , Bi ₂ O _3, one or more oxides or a composite of two or more oxides It is an oxide, The inorganic oxide microsphere molded object of Claim 1 or 2 characterized by the above-mentioned. The ratio of the major axis (D _L ) to the minor axis (D _S ) of the inorganic oxide microspherical compact (spherical coefficient (D _L ) / (D _S ) is in the range of 1 to 1.5. The inorganic oxide microspherical molded body according to claim 1 to 3. In the inorganic oxide microspherical molded body, the proportion of the inorganic oxide microspherical molded body having a particle diameter in the range of average particle diameter (D) × (1 ± 0.3) is 80% by weight or more. The inorganic oxide microspherical molded article according to claim 1. The manufacturing method of the inorganic oxide microsphere molded object characterized by including the following process (a)-process (d).
(A) Step of preparing an inorganic oxide fine particle molding precursor having a moisture content in the range of 35 to 60% by weight (b) Molding with a down-press molding machine and a diameter (D) in the range of 0.3 to 5 mm Step (c) for forming a pellet-shaped molded body in step (b), Step (d) for forming a spherical molded body with a spheroid machine, and then drying and / or firing The inorganic oxide fine particle forming precursor in the step (a) is a precursor obtained by spray-drying an inorganic oxide hydrogel slurry, and then adjusting water content. Manufacturing method of a product microsphere molded object. The method for producing an inorganic oxide microspherical shaped product according to claim 6 or 7, wherein the inorganic oxide fine particle shaped precursor contains a binder. The method for producing an inorganic oxide microspherical shaped product according to claim 7, wherein the powder obtained by spray drying has an average particle size in the range of 20 to 150 µm. In the said process (a), an inorganic oxide microparticle shaping | molding precursor contains a shaping | molding adjuvant, The manufacturing method of the inorganic oxide microsphere molded object in any one of Claims 6-9 characterized by the above-mentioned. The obtained inorganic oxide microspherical molded article has an average particle diameter (D) in the range of 0.3 to 5 mm, and a pore volume (PV) in the range of the pore diameter of 30 to 500 nm of 0.1 to 0. The average compressive strength (N) is in the range of 2 to 30 N (Newton), and the average compressive strength index (C) represented by the following formula is in the range of 0.3 to 5. The manufacturing method of the inorganic oxide microsphere molded object in any one of Claims 6-10 characterized by the above-mentioned.
C = N × PV / D The ratio of the major axis (D _L ) to the minor axis (D _S ) of the inorganic oxide microspherical compact (spherical coefficient (D _L ) / (D _S ) is in the range of 1 to 1.5. The manufacturing method of the inorganic oxide microsphere molded object of Claims 7-11 to do. In the inorganic oxide microspherical molded body, the proportion of the inorganic oxide microspherical molded body having a particle diameter in the range of average particle diameter (D) × (1 ± 0.3) is 80% by weight or more. The manufacturing method of the inorganic oxide microsphere molded object of Claim 7-12.