JPH05341B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improved alumina particles useful as catalyst supports, improved methods of making such particles, and improved hydroprocessing catalysts containing such particles as catalyst supports. The catalyst support particles of the present invention are made from partially dehydrated, rehydratable alumina produced by flash calcination of hydrated alumina, such as Bayer process alumina. In a method of forming shaped alumina particles, partially dehydrated alumina is rehydrated to solidify and harden the particles, and then calcined to convert the alumina to essentially anhydrous alumina, such as gamma and eta alumina. . A method for forming spherical bead-shaped particles of rehydrated alumina from an aqueous slurry of partially dehydrated alumina is described in U.S. Pat.
Described in No. 4065407. Partially dehydrated alumina is crushed and dispersed in water to approximately 50-60%
% solids aqueous slurry, the droplets of the aqueous slurry are introduced into a modeling medium where the drops are shaped, heated, shaped, rehydrated, and cured. In one embodiment, the drops are formed by forcing the slurry through an orifice, from which the drops of the slurry fall into a hot oil bath, in which the drops are shaped into spheres; Cured at a temperature suitable for rehydration. After curing in a hot oil bath for several hours to complete rehydration, the spherical alumina beads were separated, dried, and calcined to produce finished alumina particles. The described prior art method of introducing drops of alumina slurry into a hot oil shaping and curing medium is very suitable for making beads with an average particle size of 1 to 5 mm, but very small diameter tubes. or limited by the ability to pass slurry through the orifice. As a practical matter, for producing beads smaller than 1 mm in diameter, such techniques are unsuitable due to the low throughput per orifice. Additional difficulties are the frequent plugging of the required small diameters and waste due to particle agglomeration on the surface of the hot oil bath. This prior art is very suitable for producing beads of large diameter, ie between 1 mm and 5 mm in diameter. According to the present invention, a volume of aqueous alumina slurry is combined with a large volume of immiscible hot oil, and the slurry and oil are stirred together with sufficient shear to mix the aqueous slurry into a continuous phase of hot oil. The method was improved by dispersing it as small droplets. When drops of aqueous slurry are suspended in an immiscible oil phase, interfacial surface tension forces the drops to be shaped into spherical beads. The beads are hardened in hot oil to at least partially rehydrate the alumina and harden. The average particle size of the beads is determined by the droplet size, which in turn is determined by the degree of agitation used to disperse the droplets of the aqueous slurry into the oil phase. Excellent yields of beads within a selected, rather narrow particle size range can be obtained by this method, and this method is useful for forming rehydratable alumina spherical beads with a diameter of less than 1 mm. Especially preferred. Dispersion of the aqueous slurry droplets in the continuous oil phase can be accomplished by several agitation means, such as a rotating blade agitation mixer. However, it is preferred to use an in-line static mixer placed on-line in a conduit immediately downstream from the point of the conduit into which separate streams of immiscible aqueous slurry and oil components are introduced in selected ratios.
Static mixers of several different designs are commercially available. Several types of in-line static mixers are well described in European Patent Application Publication No. 0005619 (Application No. 793008251). 2
A combined stream of two immiscible components is fed through a conduit to an in-line static mixer at a sufficient linear velocity so that the agitation of the components within the mixer provides sufficient shear to cause the liquid to reach the desired magnitude as it traverses the mixer. Drops of the aqueous slurry are dispersed into a continuous oil phase. The two-phase dispersion is led from an in-line mixer into a relatively still hot oil bath. Aqueous droplets in a hot oil bath gradually settle to the bottom when held by interfacial tension in the desired spherical particle shape. The droplets harden rapidly in hot oil due to rehydration of the alumina in the droplets. Thus, the spherical shape of each formed particle is fixed by rehydration as the dispersed droplets harden in hot oil. The advantage of this is that, with a given mixer, the average bead size can be varied within a valid range of sizes by adjusting the flow rate of the fluid through the mixer, and by controlling the flow rate, the average bead size can be varied within a range of sizes. This means that it can be maintained at a certain size. The size of the beads decreases as the flow rate through the mixer increases. Other factors that influence bead size are the diameter of the mixer, the number of mixing elements in the mixer, the slurry to oil ratio, and the viscosity, density and interfacial surface tension properties of the selected fluid. A suitable slurry of partially dehydrated, rehydratable alumina powder is prepared by mixing the powder with water. The rehydratable alumina powder preferably has a loss on ignition of about 7-15% at 650°C and a median particle size of 5-15 microns. It can contain 0.1-0.8% by weight _Na2O . Such powders are known from previous U.S. Pat.
It can be prepared by flash calcination of hydrated alumina, such as Bayer process alumina, as detailed in US Pat. No. 4,065,407. When it is necessary to reduce the sodium content of the finished beads for a particular application, soda can be easily leached from the powder before the beads are formed or from the beads after they are formed. The level of soda in the powder can be reduced by leaching the sodium with cold water, dilute acid, or by the use of ion exchange resins, as described in the patent. If the soda has not been extracted from the powder, the slurry should preferably be neutralized with a small amount of acid. An aqueous slurry of rehydrated alumina powder can be prepared at low temperatures (e.g., 15
℃) for several hours. The concentration of alumina solids in the slurry used in the present invention is within the range of about 40 to about 60%, preferably about 42 to 55% by weight solids in the slurry. The advantage of this method is that the total pore volume and macropore volume (i.e., the volume of pores with a pore radius greater than 105 angstroms) of the finished alumina beads can be reduced over a range by varying the concentration of solids in the slurry. and that the desired pore volume can be obtained by selecting the appropriate slurry concentration.
To obtain large pore volumes and low densities, choose solids concentrations at the lower end of this range. The microporosity of the bead product, i.e., the volume of pores with a pore radius smaller than 105 angstroms, is largely unaffected by variations in the solids concentration of the slurry and is generally within the range of about 0.3-0.6 ml/g. , while macroporosity will be affected by changes in solids concentration in the slurry. A preferred slurry with 47.5% solids has a total pore volume of about 1 ml/g and a pore volume in the range of macropores, i.e., pores with a radius greater than 105 angstroms, of about 1 ml/g.
It was found that 0.6 ml/g of alumina beads were produced. To produce spherical alumina beads with a diameter smaller than 1 mm, the method of the present invention uses a method of the present invention that introduces drops of slurry into hot oil by dropping them from an orifice plate or hollow needle above the hot oil bath. It has been found that such beads can be manufactured effectively with reduced mechanical difficulty, high production rates, and reduced waste. In-line mixers, preferably used to disperse the slurry droplets in the continuous immiscible phase, are commercially available in a variety of sizes. Essentially such a mixer is a tube whose interior is lined with a series of several radial helical blade stators fixed along the axis of the tube;
The pitch of each stator blade is opposite the pitch of the next adjacent stator blade in-line.
The two-phase liquid stream across the length of the mixer is directed by opposing blades in constantly changing directions, creating strong shear agitation that disperses the aqueous phase as droplets into the continuous oil phase. Other mixers can be used to disperse the water phase into the oil. For feeding two components into the mixer, the ratio of oil to water phase is always greater than 2 volumes to 1, preferably about 5
ranges from ~20. Water-immiscible components are necessarily immiscible with the aqueous slurry. Other properties of the immiscible liquids, such as viscosity, density and interfacial tension, should be within ranges that produce the desired slurry droplet size and spherical shape. Various mineral oils could be used effectively. Although not necessary, it is most convenient to use the same oil components for the mixing step and the hot oil bath so that the composition of the oil bath does not change when the dispersion is fed from the mixer to the bath. Also, when the oil component is preheated and then introduced into the mixer and the dispersion is supplied from the mixer to the bath,
It is most convenient to facilitate maintenance of the desired operating temperature in a hot oil bath. The temperature preferably used for hot oil curing baths is the highest temperature that can be maintained without boiling the water in the aqueous droplets, and one seeks to maintain the bath temperature at about 90-95°C. At lower temperatures, hydration and therefore hardening of the spherical beads will take a long time. The beads can be removed from the hot oil bath as soon as they are sufficiently cured to retain their spherical shape, or the beads can be cured in the hot oil bath for a sufficient time to complete hydration. If the beads are removed before hydration is complete, a subsequent curing step using steam or hot water should be used. Oil can be largely removed from the beads before calcination by simple filtration or centrifugation, or by washing with steam or hot water. A small amount of residual oil will burn off during the subsequent firing process. When removal of sodium ions is required, this can be done by leaching the spherical beads with water or dilute acid before or after calcination. Example 1 A flash-calcined alumina powder having a median particle size of about 10 microns, a loss on ignition (LOI) of 7.8%, a rehydration index (RHI) of 63, and about 0.15% _Na2O was 13.2 lbs (6.0Kg) rehydratable alumina/16 lbs (7.3Kg) ice chips plus 24 lbs (10.9Kg) water/76ml concentrated HNO ₃ (70%) in dilute nitric acid In the ratio of
Make slurry. The terms LOI and RHI are
As defined in US Pat. No. 4,065,407.
After 1.5 hours of leaching, the alumina was separated by filtration.
Wash away residual salts with deionized water. The filter cake containing about 57% solids is re-thickened in water using 20 pounds (9.1 Kg) of cake to about 3 pounds (1.4 Kg) of pure water to create a slurry with a solids content of 47.5%. . Store this slurry at 15°C until use. One part mineral oil (Sontex 35) and one part polyterpene resin (Zonarey 7070) were heated to 95°C and poured into 1 inch (2.5 cm) diameter Ke-nics 12
Approximately 3 gallons/minute through an elemental static mixer
Pump at GPM (11.4/min). About this
The 15 °C aqueous slurry is introduced at the inlet of the mixer into the oil stream at a rate of approximately 0.3 GPM (1.1/min) and dispersed as droplets with an average diameter of approximately 500 microns into the oil phase during passage through the mixer. . The conduit from the mixer contains 95% of the same composition as the oil phase used to disperse the drops.
Directly into an oil bath heated to ℃. When the drops harden in the bath, they solidify rapidly. After curing in a hot oil bath for 0.5 h, the beads are dispersed from the oil by sieving and hydrothermally treated with hot water. During this process,
Strength is improved, additional soda is removed, and adhering oil is washed off the surface of the beads. The beads are dried, calcined at 650°C for 3 hours, and then classified to obtain the desired mesh size. Classification yield from a typical sample is 20 to 50%
40 meshes, 6% +20 meshes, and 44% -40 meshes. Compressed bulk density (CBD)
was 0.48g/ml. The beads have a pore volume of 0.99 ml/g water. The pore size distribution, determined by mercury injection porosimetry, was 0.96 ml/g total pore volume, 0.39 ml/g micropore volume and 0.57 ml/g
The volume of the giant pore is g. Example 2 Substantially as described in Example 1, but
Beads are manufactured using different rehydratable alumina powders and varying the fixed concentration of the slurry introduced into the Kenics mixer in several experiments, as shown in Table 1. In all cases, the finished alumina beads have a micropore volume of 0.44-0.48 ml/g determined by mercury A injection. This is a property derived from the selected alumina powder. The total pore volume varied as shown in Table 1. Although other similar products were found to have micropore volumes that were substantially unaffected by solids concentration, substantially the same relationship existed between total pore volume and slurry solids concentration. I understood. This relationship is expressed schematically by the following equation: Total pore volume in the final alumina beads (by mercury inclusion) = 0.9 {100 - % solids in slurry/% solids in slurry} ml/g Thus, ml The total pore volume in the final alumina beads, expressed as /g, is approximately 90% of the volume of water in the precursor slurry drop (ml) divided by the mass of alumina solids in the slurry drop (g). be equivalent to. Thus, the total pore volume can be controlled between about 0.75 and about 1.3 ml/g by controlling the slurry concentration between about 42% and 55% solids.

[Table] Example 3 6.77 Kg of rehydratable alumina powder with a median particle size of 11.4 microns, 0.25 wt% Na ₂ O, and 1.02% LOI was mixed with 3 Kg of ice, 3 Kg of water and 85 ml of acetic acid. A bead-forming slurry is prepared by mixing with: This slurry
It has a specific gravity of 1.54 g/ml, a solids content of 47.1% and a viscosity of 17 seconds in a Zahn #2 cup. This cooled slurry was mixed with a 1 inch (2.5 mm) diameter
cm) x 18 element Kenics in-line mixer, add 1 part by volume of slurry to 10 parts by volume of heated (95°C) mineral oil (Sontex 35) to the oil stream.
at a total flow rate of 2.2 gallons per minute (8.3 per minute). This mixture of slurry drops in hot oil is collected in a heated container and cured overnight at 90°C. After removing the oil from the beads in a perforated basket centrifuge, the beads are calcined at 650° C. for 2 hours. Here, the soda is washed away in acidic water. Repeating the same procedure and using different flow rates reveals how the bead size changes as a function of the total flow rate through the static mixer;
See table. The pore size distribution is independent of the flow rate through the mixer. In all cases, the total pore volume is approximately 1.0 ml/g and the micropore volume is approximately
0.42ml/g, and the macropore volume is about 0.58
ml/g.

Table: The pore volume and pore size characteristics of the rehydrated and calcined alumina beads described above are suitable for use as a support for catalysts used in various methods of catalytic hydroprocessing of hydrocarbon liquids. These beads are particularly suitable. petroleum fractions or residues or other hydrocarbons in the presence of alumina-supported catalysts for hydrodesulphurization, removal of nitrogen compounds, or removal of metals, or for conversion of hydrocarbons, such as reforming or cracking, or A number of methods have been described for contacting a combination of functions with hydrogen under suitable conditions. Most such catalysts consist of at least one catalytic metal selected from a group of the periodic table, usually molybdenum, and also at least one promoter metal selected from a group of the periodic table, usually cobalt or Can contain nickel. As catalyst support particles for such catalysts, the spherical beads of the present invention offer several advantages. They are particularly suitable for use in countercurrent ebullated bed processes of the type described in, for example, US Pat. No. 3,622,500.
Easy to manufacture with very small and uniform particle size. Due to the aforementioned particle size and pore size distribution, these catalysts are suitable for extended use in processes for hydrotreating heavy petroleum residues, such as those described in US Pat. No. 3,630,888.
In addition to catalytic hydrogen treatment of petroleum fractions or residues,
The hydrotreating catalyst of the present invention can be used with other hydrocarbon liquids, such as coal-derived residues by the method described in U.S. Pat. Can be used to hydrotreat hydrogen. Example 4 Shaped from rehydratable alumina slurry drops as described in Example 1 above, solidified in a hot oil bath, then steam cured, and calcinated at 650°C. The spherical alumina beads produced in this way are impregnated to produce catalyst beads. Use a 20/40 mesh fraction. To impregnate 1700 g of these calcined carrier particles, the impregnating solution is prepared in two parts. The first part is 40g
of citric acid dissolved in water, 116.4g of Co(No ₃ )
_{2.6H 2} O and 116.4 g of Ni(NO ₃ ) _{2.6H 2} O. In the second part, molybdenum oxide (grade L) was dissolved in an aqueous ammonium hydroxide solution to obtain a molar ratio of MoO ₃ :NH ₄ OH of 1:1.
It is prepared by adjusting the concentration of MoO ₃ in 1 ml of the solution to 0.232 g. Immediately before impregnation, remove the first part.
Combine with a second portion of 1034 ml with stirring and dilute this mixture with water to make 1785 ml of impregnating solution. Spray this amount of solution onto 1700 g of beads to impregnate. The wet beads are aged for 1-2 hours, then dried and calcined at 650°C for 1 hour. The calcined catalyst was analyzed to contain 1.5% CoO, 1.5%
of NiO and 12.8% _MoO3 . The measured water pore volume is 0.86 ml/g. The impregnated and calcined catalyst has a macropore volume of macropores with radius greater than 105 angstroms measured by mercury injection.
0.57ml/g, and the micropore volume is 0.31ml/g.
It is g. The macropore volume is relatively large compared to other hydroprocessing catalysts and is particularly advantageous for hydroprocessing heavy oil fractions. The catalyst is calcined again at 450° C. for 1 hour and then loaded into a graded density trickle bed reactor using sand as a diluent to help maintain an isothermal bed. The catalyst in this reactor was heated to 400℃ for 75 minutes.
Using a 10% by volume gaseous solution of H ₂ S in hydrogen,
Pre-sulfurize. After sulfidation, the oil feed blend of light cycle oil fraction and virgin distillate having a 27° API gravity and a distillation end point of 350°C is transferred to a reactor at 330°C and 500 psip at a gravimetric hourly space velocity of 500 SCF. /BBL flow rate together with hydrogen. Sulfur in the feedstock ranges from 1.4% by weight in a single pass through the reactor
It decreased to 0.40% by weight. Example 5 A 285 c.c. stainless steel cylindrical locking autoclave equipped with an inlet and a thermowell is charged with 150 g of residual oil and 2 g of bead catalyst prepared as in Example 4 above. This catalyst has a surface area of 150 m ² /g, a total pore volume of 0.86 ml/g, a macropore volume of 0.57 ml/g and a particle size of 20-40 mesh. The reactor is flushed with hydrogen to remove air and then pressurized to 750 psi with hydrogen. The reactor is brought to operating temperature of 380°C over approximately 2 hours and the pressure is increased to and then controlled to 1500 psi. The temperature of the reactor is
When 380°C is reached, the gas in the reactor is purged by venting to reduce the internal pressure to 500 psi. The pressure is then restored to 1500 psi with hydrogen. The reactor is maintained at 380°C and continuously rocked in a 60° arc at a frequency of approximately 60 cycles/min. After operating for 1 hour at operating temperature, the gas is vented again to 500 psi and the reactor is repressurized with hydrogen as before. This is also repeated at the end of the second, third and fourth hours. At the end of the 20.5 hour working time, the heating was stopped and the reactor was heated to about 200 ml for about 1 hour.
Cool to °C and vent gas. The reactor is opened and the liquid contents are separated from the solids and analyzed for sulfur, metals and asphaltenes. The analytical values of the products are shown in the table. The procedure just described is repeated in a series of experiments, but in the experiments used, the catalyst used, the residual oil treated and the reaction time are varied as shown in the table. Control experiments are carried out without catalyst and with Alundum brand crystalline aluminum oxide particles of comparable size. These particles are
It has a surface area of less than 10 m ² /g, a pore volume of less than 0.1 ml/g and a size of 20 to 40 meshes. Comparative experiments are performed using a commercially available hydrodesulfurization catalyst, Aero HDS1442B brand catalyst, with a comparable catalytic metal supported on support particles of alumina extract. This commercial catalyst was ground to a comparable size (20-40 mesh) and it had a comparable total pore volume (0.85 ml/g) but a lower macropore volume (0.31
ml/g) and large surface area (more than 250m ² /g)
has. The content of catalytic metals in the Aerocatalyst is 15% by weight MoO ₃ and 3% CoO. In the bead catalyst, the content of catalytic metal is 12% by weight
MoO ₃ , 1.5% CoO and 1.5% NiO. The two Persian Gulf residual oils (untreated) used in the experiments are shown in the table. Safaniya Resid residue boils at 642〓 (339 °C) when 20% is distilled and 995〓 (535 °C) when 50% is distilled.
The distillation residue has an API gravity of 13.9°C. Kuwait Resid
Resid) is 793〓 (423℃) when 10% is distilled.
When boiled and distilled 30%, it becomes 981
It is a heavy oil that boils at (527°C) and has an API gravity of 9.3°.

Table: As evident from the data in the table, the rehydrated alumina-supported catalyst is comparable to the catalyst supported on an extrudate alumina support, which is known to be effective, for the hydrodesulfurization of resid oils. Has activity.
The bead catalyst had significantly less surface area and equal effectiveness. The beaded alumina support has a relatively large macropore pore volume, which allows more metal to be absorbed from the resid being processed before the catalyst is deactivated by the metal. Thus, the lifetime of the catalyst in continuous processing of resid oils and other metal-containing feedstocks is longer than known catalysts. Example 6 A beading slurry is prepared as in Example 1 by suspending rehydratable alumina powder in ice water containing about 1 part concentrated nitric acid per 100 parts alumina. After steeping for 1 hour,
The slurry is filtered and washed with four changes of deionized water. 47% by re-slurrying the excess cake
to a solid concentration of Molybdenum oxide (Amax purity grade L) is added to this slurry, 6 parts by weight MoO to ₃ parts alumina, and blended with stirring. Adjust the pH to 6-7 with ammonia. Drops of slurry approx.
Beads are formed by pipetting into hot mineral oil at 90°C. This mineral oil is Sonte 35 mineral oil
A 30:70 mixture with Zonarez 7070 polyterpene resin in which the beads are slowly settled and then cured overnight at 90°C. After dripping with oil, the beads are fired at 650℃. Instead of molybdenum oxide, silica was added in the proportion of 5 parts by weight _SiO2 per 100 parts alumina and as an additive Linde HNa-Y-1
Beads are similarly prepared using molecular sieves at a ratio of 10 weight sieves per 100 parts alumina and without additives. In all cases beads of very uniform size were produced. As evident from the physical properties listed in the table, strong beads with large total pore volumes are produced by incorporating additives prior to bead formation. 70
Beads similarly made using ~100 parts by weight of partially dehydrated rehydrated alumina and up to 30 parts by weight of other solids (which can include other alumina and other solid fillers) , can be made by the method described herein.

[Table] Monster

[Table] In the foregoing description and claims,
The term "spherical" is used to define the shape formed by surface tension forces in a two-phase fluid system. The term encompasses shapes that may vary from a true sphere, such as pear-shaped, flattened spheres, etc. In a variation of the bead formation method described herein,
Drops of the slurry are dispersed in a low-melting hot paraffin wax, liquefied, and the paraffin is then cooled as in other water-immiscible oils.
Bring to a low temperature where the paraffin solidifies sufficiently to keep the drops suspended indefinitely. In this state, the droplet holds its shape long enough to harden by rehydration (which is slow at this low temperature). To remove the hardened beads, the paraffin is heated again and separated by filtration. In addition to rehydratable alumina, other aluminas in aqueous dispersions can be formed into spherical beads by the method of the present invention. There are several types of known aluminas that have properties suitable for use in the present invention in aqueous dispersions. An aqueous alumina slurry (the term slurry as used herein encompasses a sol or other dispersion of alumina in water) must be dispersed into droplets by stirring with a water-immiscible liquid and must be sufficiently The oil must be fluid and the droplets must be shaped into beads by interfacial surface tension in the oil bath. Additionally, the alumina must be able to harden sufficiently in the bath to retain the particle shape it formed in the bath, so that the particles either remain in the bath or after removal from the bath.
Must not clump and stick. In an aqueous dispersion with non-rehydratable alumina, these properties may be affected, for example, by adding a base to bring the pH of the aqueous dispersion to a range of about 4 to 7, where the alumina thickens and solidifies. Therefore, you can get it. The basic substance can be added by using an ammoniated oil bath from which the droplets absorb the basic ammonia when dispersed in the oil, or the base decomposes with the heat of the bath to form the base. can be generated by adding a compound that liberates, for example hexamethylenetetramine, to an aqueous slurry. U.S. Pat. No. 4,179,408 describes a method for forming spherical particles from drops of alumina slurry,
These droplets fall into a bath of water-immiscible liquid and, as they descend through the ammonia-containing bath, shape and solidify in the water-immiscible bath. The shaped and solidified particles are then further hardened in an aqueous alkaline bath. The present invention can be used in place of the oil drop method to dump drops of the same aqueous alumina slurry into the same continuous phase of ammoniated oil. During this dispersion, the droplets are shaped and solidify as they settle out of the dispersion. Aqueous alumina droplets are produced by feeding an alumina slurry and a water-immiscible liquid (kerosene) together into an in-line mixer to distribute the aqueous phase as a dispersed aqueous phase (droplets) into the continuous phase immiscible liquid. Then, it is dispersed. The dispersion immediately flows into an ammoniated kerosene bath in which the droplets gradually settle downwards. The kerosene can be ammoniated in the bath or preferably before being fed to the mixer. US Pat. No. 4,250,058 further describes another method of producing spherical alumina particles by oil drop method. An alumina hydrogel containing an ammonia precursor that hydrolyzes or decomposes to ammonia upon heating is prepared in a slurry and dripped from a nozzle dropwise into an oil bath heated to a temperature of about 95-100°C. Prepared by At this temperature, the ammonia precursors react and liberate ammonia, which increases the PH of the droplets, thereby causing them to harden while still in the oil bath. Instead of dispersing the slurry droplets into an oil bath by dropping the slurry from a nozzle, the present invention disperses the alumina slurry droplets into the oil with a stirring mixer. Example 7 An alumina sol is prepared by aging alumina pellets in dilute hydrochloric acid at 102°C. The sol is cooled and combined with a hexamethylenetetramine solution to form a thermoset alumina hydrosol containing about 8% aluminum by weight of about 12% hexamethylenetetramine. By combining the slurry stream with the oil stream and feeding the lump mixture through a static in-line mixer,
Disperse as drops in kerosene. The slurry to oil ratio is 1:10 volume/volume. The flow rate through this mixer is 18
5 through the element Kenics mixer
Adjust to produce approximately 500 micron diameter beads at gallons per minute (18.9/min). No significant gelation occurs before the dispersion leaves the mixer. The dispersion of aqueous droplets in oil is fed to an oil-filled shaping column maintained at about 95° C., at which temperature gelation of the droplets into beads is induced by the decomposition of the tetramine to ammonia. The beads are further aged in a 100°C oil bath for 19 hours, then in a buffered ammonium chloride solution at 95°C for 15 minutes, and finally in an aqueous ammonia solution for 7 hours. beads
Dry in air at 650°C for 2 hours and bake.
The spherical particles are ready for use.

[Claims]

1. A beta-double prime alumina or gallium analog characterized by having a sensitive amount of at least one trivalent or higher cation inserted therein and exhibiting a sensitive fluorescence, phosphorescence or laser action. 2. The beta double prime alumina according to claim 1, further comprising one or more monovalent or divalent cations. 3. Beta double prime alumina according to claim 1, which is in the form of a single crystal. 4. A method for producing a beta double prime alumina or gallium analog having a sensitive amount of at least one trivalent or higher cation inserted therein and exhibiting a sensitive fluorescence, phosphorescence or laser action, comprising: 1 or more beta double primes

Claims (1)

heating the beads to sufficiently cause at least partial rehydration and hardening of the rehydratable alumina in the dispersed droplets; heating the beads with sufficient heat to rehydrate the alumina; curing to complete rehydration of the alumina in the dispersion or in another contact with steam or water;
and calcining the rehydrated alumina beads to transform the alumina into substantially anhydrous alumina;
The particles have an average particle size in the range of about 0.1 to about 1 mm and a total pore volume of about 0.75 to about 1.3 ml/g.
from about 0.3 to about 0.6 of the pore volume in the pores.
ml/g has a pore radius smaller than 105 angstroms, and about 0.3 to about 0.95 ml/g in the pores has a pore radius of less than 105 angstroms.
A method for producing spherical alumina beads having a pore radius of angstroms or more. 3. The method of claim 2, wherein the aqueous slurry droplets are dispersed in the oil phase by an in-line static mixer. 4. Disperse droplets of aqueous slurry of alumina in a continuous phase of water-immiscible liquid, and while dispersing in said continuous phase, shape the droplets into spherical alumina beads; The beads contain 70-100% by weight of alumina and are sufficiently hardened while the beads are dispersed in the continuous phase so that the beads retain their spherical shape when removed from the miscible liquid. The particles have an average diameter of approximately 0.1
~1 mm, and the total pore volume is approximately
0.75 to about 1.3 ml/g, about 0.3 to about 0.6 ml/g of the pore volume in the pores has a pore radius of less than 105 Angstroms, and about 0.3 ml/g of the pore volume in the pores has a pore radius of less than 105 Angstroms;
~0.95 ml/g has a pore radius greater than or equal to 105 angstroms. In a process for producing spherical alumina beads, an aqueous slurry of alumina and a water-immiscible liquid are stirred together and fed into a mixer; forming a droplet dispersion as described above by agitating the mixed feed sufficiently to disperse as a discrete phase of droplets of an aqueous slurry in a continuous phase of an aqueous slurry. 5. The agitating mixer is an in-line mixer with opposing stators in the tube, and the mixed stream of immiscible liquids is fed through the in-line mixer at a sufficient velocity to cause stirring of the flow by the stators in the tube. A method according to claim 4, wherein an aqueous slurry is dispersed in a water-immiscible phase. 6. The method of claim 5, wherein the droplets of aqueous alumina slurry are thermally hardened into said shape while being formed into spherical beads in a water-immiscible continuous liquid phase. 7. The method of claim 5, wherein the droplets of aqueous alumina slurry are shaped into spheres in the water-immiscible liquid while being hardened to said shape by ammonia in the water-miscible liquid phase. . 8. A claim in which the ratio of water-immiscible liquid to aqueous slurry of alumina and water-immiscible liquid fed to the stirring mixer is at least 2 volumes of water-immiscible liquid to 1 volume of aqueous alumina slurry. The method described in item 5. 9. The method of claim 8, wherein said ratio is 5 to 20 volumes to 1 volume.