CN1123383C - Amorphous silica-alumina and its preparing method - Google Patents

Abstract

This invention relates to a macroporous amorphous silica-alumina with high acidity and high specific surface area, having a silica content of 10-50 wt%, a specific surface area of 350-600 ^m² /g, a pore volume of 0.8-1.5 ml/g, and an infrared acidity of 0.25-0.55 mmol/g. This amorphous silica-alumina not only possesses the acidic properties required for cracking reactions but also exhibits a typical carrier physicochemical structure, thus making it an excellent catalytic material.

Description

A kind of amorphous silicon aluminum and preparation method thereof

The invention relates to a high pore volume, high specific surface acidic amorphous silicon aluminum and a preparation method thereof.

Amorphous silica-alumina, as one of the important carrier components of the catalyst, requires that it must have a large enough specific surface and pore volume to support the active metal components. On the other hand, in order to carry out the reaction effectively, the amorphous silica-alumina generally needs to provide a certain acidic cracking function. However, none of the disclosed prior art can fully embody this dual function. As the acidic component, the amorphous silicon-alumina needs to be dispersed on a matrix such as amorphous alumina with a higher specific surface and pore volume. As a catalyst carrier, the amorphous silica-alumina prepared by the prior art is limited by the preparation method. If it is required to have a pore structure that can be directly used as a catalyst carrier, it cannot introduce enough silica to make the number of acid centers too high. Low; if enough silicon oxide is added to increase the number of acid centers, the pore structure will inevitably be destroyed.

GB2166971 discloses a method for preparing amorphous silicon-alumina, which is prepared by mixing alkali metal aluminate and silicate at high pH (12-12.5), and then reacting with aluminum sulfate. From the implementation of this patent For example, it can be seen that when the SiO ₂ content of its product silicon aluminum is less than 35w%, the specific surface area is 277m ² /g, and the pore volume is 0.31ml/g. Although it has cracking activity, its disadvantage is still that the pore volume and specific surface are not high, and it is not enough to be used as a carrier component alone when carrying a relatively high amount of metal components. The patented method is a kind of gelation by using the rapid mixing method of the pump, which requires high equipment, is difficult to produce, and has certain production limitations.

US4758338 uses the pH swing method to swing the alumina sol at a pH value of 2-10, and then adds silicon compounds to form amorphous silicon aluminum, but the process is complicated to operate and difficult to control, and _the SiO of the product is not high, the highest is no more than 8.7 w%, mainly used as a carrier for hydrorefining catalysts that do not require acidic cracking function. The specific surface of this product is 308m ² /g, and the pore volume can reach 1.78ml/g, but the pore volume of 3-10nm is only 0.31ml/g. Mainly on large pores of 10-100nm. EP0788270 is a kind of aluminum oxide treated with water glass or silica sol, and then hydrothermally treated to improve the properties of amorphous silicon aluminum products. The final amorphous silicon aluminum contains SiO ₂ at 6-12w%. The product has the highest surface specific surface with silica sol The specific surface of the 12w% hydrothermally treated amorphous silica-alumina obtained from the treatment is only 214m ² /g. The preparation method of this product has harsh conditions, and the hydrothermal treatment consumes a lot of energy.

The purpose of the present invention is to provide an amorphous silica-alumina that can be directly used as a catalyst carrier, which not only has a suitable specific surface and pore volume, but also has sufficient silicon oxide content to ensure the acidic function required by chemical reactions. Another object of the present invention is to provide a method for preparing the above-mentioned amorphous silicon-alumina, which simplifies the preparation process and reduces material consumption and energy consumption.

In order to improve the pore structure properties of amorphous silica-alumina, the amorphous silica-alumina of the present invention adopts the co-current fixed pH method, not only the process is easy to control, but also the product has better property indicators, and the amorphous silica-alumina of the present invention has a pore volume of at least 0.8-1.5 ml/g, the specific surface area is at least 350-600m ² /g, and the pore volume with a pore diameter of 40-150×10 ^-10 m accounts for more than 50% of the total pore volume.

The physical and chemical properties of the amorphous silicon-alumina of the present invention are characterized by silicon oxide content of 10-50w%, specific surface area of 350-600m ² /g, generally 400-550m ² /g, preferably 450-500m ² /g, and pore volume of 0.8- 1.5ml/g, generally 0.9-1.4ml/g, preferably 1.0-1.3ml/g. The pore volume of the amorphous silicon-alumina of the invention with a pore diameter of 40-150×10 ^-10 m accounts for more than 50% of the total pore volume. Infrared acidity 0.3-0.55mmol/g, generally 0.35-0.50mmol/g, preferably 0.40-0.45mmol/g.

The preparation principle of amorphous silicon-alumina in the present invention is to form the pre-alumina matrix first, and control the aforementioned neutralization conditions to obtain a certain characteristic crystal form, and then make silicon atoms replace the positions of aluminum atoms, which is different from the use of silicon source impregnation in the prior art Alumina and silicon atoms are simply deposited, that is, the acidity cannot be greatly increased, and the pores of the carrier will also be damaged. The characteristic of the amorphous silicon-alumina of the present invention is that silicon attacks and replaces aluminum atoms at a dominant concentration, thereby forming a large number of original acid center structures, which mainly reflect the presence of free aluminum and subsequent amorphization The characteristics of the L acid are shown in Table 1. The infrared acid results show this. Then the substituted aluminum atoms enter the sol system again, together with the excess aluminum atoms in the system, continue to form new colloidal particles and interact with the formed Al ₂ O ₃ , SiO ₂ and the initially formed silicon aluminum, deposit or aggregate to form more Large colloidal particles; under certain aging conditions, it destroys the growth tendency of the crystalline form and promotes the transformation to the amorphous form. Due to the above-mentioned characteristics of the amorphous silicon-alumina of the present invention, the amorphous silicon-alumina not only has high acidity, but also has a high degree of amorphization, and has a high specific surface area and pore volume. Compared with the prior art, the amorphous silica-alumina of the present invention not only has higher acidity, but also has a high specific surface and pore volume due to the low degree of crystallization and high degree of amorphization, so the amorphous Si-alumina does not require hydrothermal treatment or other methods to expand the pores.

The amorphous silicon aluminum of the present invention is prepared according to the following process:

(a) Add an acidic aluminum salt solution and an alkaline precipitant into a reaction vessel with a small amount of deionized water in parallel, form a sol at a pH value of 7.0-9.0 and a temperature of 50-70°C, and neutralize the reaction time for 1-2 hours.

(b) stabilizing the material obtained in step (a) for 0-60 minutes under the condition of pH 8-9.

(c) adding a silicon compound to the material obtained in step (b) within 5-10 minutes.

(d) Aging the material obtained in step (c) at a temperature of 50-70° C. for 10-60 minutes at a pH value of 7.5-9.5.

(e) filtering and washing the material obtained in step (d).

(f) drying and pulverizing the material obtained in step (e) to obtain a product.

In the preparation process of amorphous silicon-alumina of the present invention, (a) the acidic aluminum salt can be one of Al ₂ (SO ₄ ) ₃ , AlCl ₃ , Al(NO ₃ ) ₃ , and the alkaline precipitant can be NaOH, NH One of ₄ OH and NaAlO ₂ . However, in industrial applications, Al ₂ (SO ₄ ) ₃ is widely used due to its low price; and different alkaline precipitants will cause differences in the alumina matrix obtained in (a), and generally different precipitants obtain The size order of alumina colloidal particles is: NaOH<NaAlO ₂ <NH ₄ OH, and the silicon compound involved in (c) can be water glass, silica sol or organic silicon. The amorphous silica-alumina preparation process or method of the present invention can use different precipitants to prepare amorphous silica-alumina within the scope of the physical and chemical properties of the present invention, and the difference in pore size and pore distribution can make it applicable to different catalytic reactions on the substance or on the type of reaction.

In the process of the present invention, the pH value in (a) is generally at 7.0-9.0, preferably 7.5-8.5; the temperature is 50-70°C, preferably 55-65°C; the stabilization time in (b) is generally 0-60 minutes , preferably 15-45 minutes. The above-mentioned condition setting within the condition range of the present invention can obtain the acidic amorphous silica-alumina with high specific surface and large pore volume within the scope of the physical and chemical properties of the present invention, and the difference in pore size and pore distribution caused by the change of conditions can make Their respective application to different catalytic reactants or reaction types are included within the limits of the present invention.

Due to different application purposes, there are different requirements for the acidic cracking function of amorphous silicon aluminum, and the acidity or cracking activity of the amorphous silicon aluminum prepared by the process of the present invention can be appropriately changed by adjusting the addition of silicon compound through step (c). And the preparation process of the amorphous silicon-alumina of the present invention will not be like some prior art, how much the amount of silicon introduced will strongly affect the specific surface and pore volume of the final product, the amorphous silicon-alumina of the present invention is in a very wide silicon oxide Within the content range, amorphous silicon-alumina with high specific surface and large pore volume can still be obtained. Due to the aforementioned preparation characteristics and mechanism of the present invention, the time for the silicon compound to be added to step (b) to obtain the product should be added in a relatively short period of time to ensure the dominant concentration of silicon ions in the reaction system for a period of time to attack and form alumina matrix. Of course, due to the efficiency of stirring and mass transfer, the time should not be too short. The addition time is generally 5-10 minutes, preferably 5 minutes.

After the silicon source is introduced, the pH value of the reaction system will have a changing process or trend, which shows that the formation process of amorphous silicon-alumina has begun on the alumina substrate, which is different from the silicon-coated aluminum method of the prior art. It is silicon ions attacking the formed alumina matrix and accompanied by various interactions of silicon ions, free aluminum ions, primary silica particles formed after introduction into the system, and primary amorphous silica-alumina particles. After the reaction reaches equilibrium, continue to control certain conditions to complete the (d) process. This process should be a generalized aging process, which includes the process of forming amorphous silicon-alumina by reaction, and also includes the subsequent amorphization of the product. process. In this process, pH value, temperature, and aging time are all important control parameters. Generally, pH value is 7.5-9.5, preferably 8.0-9.0; temperature is 50-70°C, preferably 55-65°C; time is generally 0-60°C minutes, preferably 15-45 minutes.

After the aging, processes (e) and (d) can be obtained by washing the obtained amorphous silicon-alumina product in a conventional way to remove impurities such as iron ions, sodium ions, sulfate radicals, chloride ions, etc., drying and pulverizing to obtain Amorphous silicon aluminum of the present invention. The purpose of removing impurities is to prevent the impurity level from affecting the activity or stability of the catalyst when the amorphous silica-alumina of the present invention is used as the carrier or acidic component of the catalyst. The drying of the amorphous silica-alumina of the present invention can be oven-dried or spray-dried, generally oven-dried at 110°C for 6-10 hours, so that the dry basis of the final amorphous silica-alumina product reaches 60-80w%. The dried amorphous silica-alumina product is sieved, and the particle size is below 150 mesh, preferably below 200 mesh.

The amorphous silica-alumina of the present invention may also contain 1-5w% phosphorus, the purpose is to improve the distribution of pore size, which may also have a subtle influence on the properties of the catalyst in the future. The method is to beat the amorphous silicon-aluminum again, add metered phosphoric acid to make the amorphous silicon-aluminum of the present invention contain 1-5w% of phosphorus, and then filter, dry and pulverize to obtain the phosphorus-containing amorphous silicon-aluminum product.

The application feature of the amorphous silica-alumina of the present invention is that it can be used as the acidic component and the carrier component of the catalyst at the same time, and besides providing the bearing area and reaction space for the active metal component, it also has a certain acid cracking activity. The amorphous silica-alumina of the present invention is especially suitable for catalysts required for the catalytic processing of petroleum and its derivative products, such as hydrotreating catalysts including hydrocracking and hydrofining catalysts, catalytic cracking catalysts, as carrier components and part or all acidic components. At the same time, the above-mentioned range does not constitute a limit to the application of the amorphous silica-alumina of the present invention. In other words, the amorphous silica-alumina of the present invention can be applied to any carrier that requires a higher specific surface and pore volume and requires a certain acidic function. aspect.

Since the amorphous silicon aluminum of the present invention has a _SiO2 content in the range of 10-50w%, the specific surface area is generally ^400-550m2 /g, the pore volume is generally 0.9-1.4ml/g, and the pore volume of 40-150× ^10-10 m pore diameter Accounting for more than 50% of the total pore volume, it also has high acidity, the infrared acidity is generally 0.35-0.50mmol/g. Therefore, the amorphous silica-alumina of the present invention can be directly used as a carrier component with large pore volume and high specific surface area, and has a certain acid cracking function at the same time. The amorphous silicon-alumina of the present invention adopts step-by-step precipitation instead of the impregnation method or the pH value swing method, and does not require other post-treatment processes such as hydrothermal treatment, but can make the amorphous silicon-alumina have a high pore volume and specific surface. When used as a carrier component or as a catalyst component, it can also provide higher acidity, which is beneficial to the entry and exit of reactants and products and satisfies better product selectivity. On the other hand, the method of the present invention has a simple process, is easy to control, has low energy consumption, and does not require special equipment.

Instance 1

Add 4000g of solid aluminum sulfate to 7.5 liters of distilled water, while heating and stirring until dissolved to obtain aluminum sulfate solution (a), with _{an Al2O3} concentration of about 4g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. 10 liters of distilled water is added in the strong water glass of 4.8 liters of a kind of industrial grade modulus 3.0, obtains dilute water glass solution (c). Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that have aluminum sulfate and ammonia respectively, and set according to the preparation of 600g amorphous silicon-alumina product (a ) to keep the neutralization reaction time within one hour, and quickly adjust the flow of (b) to keep the pH value of the system at 7-8, and control the temperature of the system at about 65°C. After the aluminum sulfate reaction is completed, stop adding ammonia water, and after the generated alumina sol is stable for 15 minutes, start to add and measure (c) 3.3 liters according to the final _SiO2 content, and finish adding within 10 minutes, start the aging process of the system, and maintain the pH value At 8.0, the temperature is 60-65°C. After aging for 50 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain amorphous silica-alumina product S-1.

Example 2

Add 8000g of solid aluminum sulfate into about 7.5 liters of distilled water, while heating and stirring until _dissolved , to obtain aluminum sulfate solution (a2), with an _Al2O3 concentration of 8g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that have aluminum sulfate and ammonia respectively, and set according to the preparation of 600g amorphous silicon-alumina product (a2 ) so that the neutralization reaction time is two hours, and quickly adjust the flow of (b) to keep the pH value of the system at 7.0, and control the temperature of the system at 70°C. After aluminum sulfate has reacted, stop adding ammoniacal liquor and start to add (c) 1.6 liters in metering example 1 by final SiO _Amount , after adding in 5 minutes, start the aging process of system, keep pH value at about 7.5, temperature 65-70°C. After aging for 60 minutes, filter the colloidal solution to obtain a wet filter cake, wash the filter cake with water, and then filter to obtain the filter cake (d). After beating (d) again, add 17.6ml of phosphoric acid, continue to stir for 30 minutes and then filter to obtain filter cake (e), dry (e) at 110°C for 8 hours, crush and sieve to obtain amorphous silica-alumina product S -2.

Example 3

Add 3.2 liters of an industrial-grade aluminum sulfate concentrated solution into 4.2 liters of distilled water, while heating and stirring until dissolved to obtain an aluminum sulfate solution (a3), with _{an Al2O3} concentration of about 6g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that respectively store aluminum sulfate and ammonia water at the same time, set according to the preparation of 600g amorphous silicon-alumina product (a3 ) to keep the neutralization reaction time at 40 minutes, and quickly adjust the flow of (b) to keep the pH of the system at 9.0, and control the temperature of the system at 50-55°C. After the aluminum sulfate reaction was completed, stop adding ammoniacal liquor, and after the alumina sol of generation was stable for 30 minutes, start to add 1.4 liters of (c) in metered example ₁ according to the final SiO amount, after adding in 10 minutes, start the system During the aging process, keep the pH value at about 9.0 and the temperature at 55-60°C. After aging for 30 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain the amorphous silica-alumina product S-3.

Example 4

Add 3.5 liters of an industrial-grade aluminum sulfate _concentrated solution into 4.0 liters of distilled water, while heating and stirring until dissolved to obtain an aluminum sulfate solution (a4), with an _Al2O3 concentration of 8g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. 5 liters of distilled water was added to 2.4 liters of industrial-grade modulus 3.0 concentrated water glass to obtain dilute water glass solution (c). Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that have aluminum sulfate and ammonia respectively, and set according to the preparation of 600g amorphous silicon-aluminum product (a4 ) so that the neutralization reaction time is 1.5 hours, and quickly adjust the flow of (b) to keep the pH value of the system at 8.5, and control the temperature of the system at 55°C. After the aluminum sulfate reaction was completed, stop adding ammoniacal liquor, and after the alumina sol of generation was stable for 15 minutes, start adding 6.2 liters of (c) in metered example ₁ according to the final SiO amount, and after adding in 5 minutes, start the system During the aging process, keep the pH value at 8.5 and the temperature at 60-65°C. After aging for 15 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). After beating (d) again, add 31.5ml of phosphoric acid, continue to stir for 30 minutes and then filter to obtain filter cake (e). After drying (d) at 110°C for 8 hours, crush (e) and sieve to obtain Shaped silicon aluminum product S-4.

Example 5

Add 9800g of solid aluminum sulfate into 6.2 liters of distilled water, while heating and stirring until dissolved to obtain aluminum sulfate solution (a5), with an _Al2O3 concentration of 10g/100ml _. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Take a 10-liter steel reaction tank, add 2 liters of distilled water to the tank, stir and heat to 70°C, open the valves of the containers containing aluminum sulfate and ammonia respectively, and set the flow rate of (a) to neutralize the reaction The time is one hour, and the flow rate of (b) is quickly adjusted to keep the pH value of the system at 8.0, and the temperature of the system is controlled at 60°C. After the aluminum sulfate reaction is completed, stop adding ammonia water. After the generated alumina sol is stable for 40 minutes, start adding 2.0 liters of (c) in the metering example according to the final _SiO content. After adding within 10 minutes, start the aging process of the system , keep the pH value at around 8.5, and the temperature at 50-55°C. After aging for 40 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain the amorphous silica-alumina product S-5.

Example 6

Add 4000g of solid aluminum sulfate to 7.5 liters of distilled water, while heating and stirring until dissolved to obtain aluminum sulfate solution ( _a6 ), with an _Al2O3 concentration of 4g/100ml. Add an appropriate amount of distilled water to dilute industrial-grade 40% concentrated NaOH to form a dilute solution (b) of about 15%. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that respectively store aluminum sulfate and NaOH, set according to the preparation of 600g amorphous silicon-aluminum product (a6 ) so that the neutralization reaction time is 110 minutes, and quickly adjust the flow of (b) to keep the pH value of the system at 7.0, and control the temperature of the system at 70°C. After the aluminum sulfate reaction was completed, stop adding ammoniacal liquor and start to add (c) 4.2 liters in the metering example 1 by the final SiO ₂ amount, after adding in 5 minutes, start the aging process of the system, keep the pH value at 7.5, temperature 65 -70°C. After aging for 60 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain amorphous silica-alumina product S-6.

Example 7

Add the industrial-grade concentrated sodium aluminate solution into 6 liters of distilled water while heating and stirring until dissolved to obtain a sodium _aluminate solution (a7) with an _Al2O3 concentration of 18g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that have aluminum sulfate and ammonia respectively, and set according to the preparation of 600g amorphous silicon-alumina product (a7 ) to keep the neutralization reaction time in one hour, and quickly adjust the flow of (b) to keep the pH value of the system at 8.0, and control the temperature of the system at 60°C. After the aluminum sulfate reaction is completed, stop adding ammoniacal liquor, and after the alumina sol of generation is stable for 40 minutes, start to add (c) 3.3 liters in metering example 1 according to the final _SiO2 amount, after adding within 10 minutes, start the aging of the system During the process, keep the pH value at 8.5 and the temperature at 50-55°C. After aging for 40 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain the amorphous silica-alumina product S-7.

Example 8

Add 3.0 liters of concentrated aluminum chloride solution to 4 liters of distilled water while heating and stirring until dissolved to obtain aluminum chloride solution (a8), with _{an Al2O3} concentration of 4g/100ml. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers with aluminum sulfate and ammonia respectively at the same time, set according to the preparation of 600g amorphous silicon-aluminum product (a8 ) to keep the neutralization reaction time at 40 minutes, and quickly adjust the flow of (b) to keep the pH of the system at 9.0, and control the temperature of the system at 50-55°C. After the aluminum sulfate reaction is completed, stop adding ammoniacal liquor, and after the alumina sol of generation is stable for 30 minutes, start to add (c) 2.0 liters in metering example 1 according to the final _SiO2 amount, after adding within 10 minutes, start the aging of the system During the process, keep the pH value at 9.0 and the temperature at 55-60°C. After aging for 30 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain amorphous silica-alumina product S-8.

Example 9

Add 3.2 liters of concentrated aluminum nitrate solution into 7 liters of distilled water while heating and stirring until dissolved to obtain dilute aluminum nitrate solution (a9), with an _Al2O3 concentration of 6g/100ml _. Dilute the concentrated ammonia water into about 10% dilute ammonia water (b) by adding appropriate amount of distilled water. Get a 10-liter steel reaction tank, add 2 liters of distilled water in the tank and stir and heat to 70 ° C, open the valves of the containers that have aluminum sulfate and ammonia respectively, and set according to the preparation of 600g amorphous silicon-alumina product (a9 ) so that the neutralization reaction time is 1.5 hours, and quickly adjust the flow of (b) to keep the pH value of the system at 8.5, and control the temperature of the system at 55°C. After the reaction of aluminum sulfate, stop adding ammoniacal liquor, after the alumina sol of generation is stable for 15 minutes, start to add 1.0 liters of (c) in metering example 1 according to the final _SiO2 amount, after adding within 5 minutes, start the aging of the system During the process, keep the pH value at 8.5 and the temperature at 60-65°C. After aging for 15 minutes, filter the colloidal solution to obtain a wet filter cake, re-add distilled water to the filter cake for beating and washing, and then filter to obtain the filter cake (d). (d) was dried at 110° C. for 8 hours, crushed and sieved to obtain the amorphous silica-alumina product S-9.

Table 1. Properties of amorphous silica-alumina products Amorphous silica-alumina SiO ₂ (w%) Specific Surface(m2/g) Pore volume (ml/g) Aperture (×10 ^-10 m) Infrared acidity (mmol/g) i acid B acid L acid S-1 30 530 1.44 111 0.48 0.08 0.40 S-2 20 504 1.30 110 0.44 0.07 0.37 S-3 15 390 0.91 94 0.36 0.05 0:31 S-4 45 452 1.15 102 0.54 0.11 0.43 S-5 25 433 1.12 98 0.45 0.07 0.38 S-6 35 355 0.89 89 0.28 0.08 0.20 S-7 30 403 1.01 97 0.31 0.06 0.25 S-8 20 483 1.22 106 0.36 0.06 0.30 S-9 10 471 1.19 102 0.26 0.06 0.20 Reference alumina 0 390 1.05 94 0.22 0.04 0.18 Reference Amorphous Si-Al 60 280 0.65 71 0.55 0.12 0.43

Note: The reference alumina in the table is an industrial product produced by Fushun Petroleum No. 3 Plant, and the reference amorphous silica-alumina is an industrial product produced by Lanzhou Oil Refinery.

Claims (18)

1. a macropore amorphous aluminum silicide is characterized in that silicon oxide-containing 10-50w%, the specific surface 350-600m of described amorphous aluminum silicide ²/ g, pore volume 0.8-1.5ml/g, infrared acidity 0.25-0.55mmol/g.

2. amorphous aluminum silicide as claimed in claim 1 is characterized in that silicon oxide-containing 20-40w%.

3. amorphous aluminum silicide as claimed in claim 1 is characterized in that specific surface 400-550m ²/ g.

4. amorphous aluminum silicide as claimed in claim 1 is characterized in that specific surface 450-500m ²/ g.

5. amorphous aluminum silicide as claimed in claim 1 is characterized in that pore volume 0.9-1.4ml/g.

6. amorphous aluminum silicide as claimed in claim 1 is characterized in that pore volume 1.0-1.3ml/g.

7. amorphous aluminum silicide as claimed in claim 1 is characterized in that infrared acidity 0.30-0.50mmol/g.

8. amorphous aluminum silicide as claimed in claim 1 is characterized in that infrared acidity 0.35-0.45mmol/g.

9. amorphous aluminum silicide as claimed in claim 1, it is characterized in that can phosphorous 1-5w%.

10. the preparation method of amorphous aluminum silicide as claimed in claim 1 is characterized in that preparing according to the following steps:

(a) a kind of acid aluminium salt solution and a kind of alkaline precipitating agent and stream are joined in the reaction vessel that fills low amounts of water, at pH value 7.0-9.0, form colloidal sol under the temperature 50-70 ℃ of condition, the neutralization reaction time is 0.5-2 hour;

(b) material that step (a) is obtained was stablized under the condition of pH8-9 0-60 minute;

(c) in 5-10 minute, a kind of silicon compound joined in the material that step (b) obtains;

(d) at pH value 7.5-9.5,50-70 ℃ of material 10-60 minute of descending aging step (c) to obtain;

(e) filter and material that washing step (d) obtains;

(f) dry materials that step (e) is obtained is pulverized and the acquisition product.

11. the method as claim 10, the acid aluminium salt that it is characterized in that (a) step are selected from a kind of in aluminum sulfate, aluminium chloride and the aluminum nitrate.

12. the method as claim 10 is characterized in that the acid aluminium salt concentration 4-12g/100ml of (a) step.

13. the method as claim 10, the alkaline precipitating agent that it is characterized in that (a) step are to be selected from a kind of in NaOH, sodium metaaluminate and the ammoniacal liquor.

14. the method as claim 10 is characterized in that the pH value of (a) step is 7.5-8.5.

15. the method as claim 10, the temperature that it is characterized in that (a) step is 55-65 ℃.

16. the method as claim 10, be 15-45 minute stabilization time that it is characterized in that (b) step.

17. the method as claim 10 is characterized in that the pH value of (d) step is 8.0-9.0, temperature is 55-65 ℃, and the time is 15-45 minute.

18. the method as claim 10 is characterized in that the silicon compound of (c) step is selected from a kind of of waterglass or Ludox.