Method for co-producing peptizing pseudo-boehmite and pseudo-boehmite

Abstract

The invention relates to the technical field of preparation of pseudo-boehmite, in particular to a method for co-producing peptizing pseudo-boehmite and pseudo-boehmite. The method comprises the following steps: introducing carbon dioxide into a sodium aluminate solution for carbonization reaction to obtain first neutralized slurry; performing first aging treatment on the first neutralized slurry, and filtering to obtain a first solid-phase material and a liquid-phase material; drying the first solid-phase material to obtain first pseudo-boehmite; aluminum sulfate and the sodium aluminate solution are subjected to parallel flow neutralization treatment and filtration, and a second solid-phase material is obtained; pulping the second solid-phase material and the liquid-phase material to obtain mixed slurry; carrying out second aging treatment on the mixed slurry, filtering and washing to obtain second pseudo-boehmite; and collecting the first pseudo-boehmite and the second pseudo-boehmite to obtain the peptizing pseudo-boehmite. According to the method, through a multi-layer and multi-step strategy, the regulation and control performance of the peptizing property of the pseudo-boehmite product is enhanced, and directional regulation and control of the pseudo-boehmite are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pseudo-boehmite preparation, and in particular to a method for co-producing gel-soluble pseudo-boehmite and pseudo-boehmite. BACKGROUND

[0002] Pseudo-boehmite can be widely used in core application fields such as catalyst carriers and binders in the broad field of industrial chemistry due to its unique physical and chemical properties. The key indicator of the application performance of pseudo-boehmite, i.e., gel solubility, can reflect the efficiency and quality level of pseudo-boehmite used in industrial production. In the case of meeting the gel solubility requirements of catalytic cracking catalysts, pseudo-boehmite with adjustable gel solubility can adjust the viscosity of the material, thereby significantly reducing the production consumption of the catalyst. However, the traditional pseudo-boehmite has high viscosity after gelation, and the high-viscosity pseudo-boehmite can seriously hinder the fluidity of the gelation system. At the present stage, in order to improve the gel solubility of pseudo-boehmite, water is additionally added in the industrial production stage of pseudo-boehmite to dilute the pseudo-boehmite system and improve the fluidity of the pseudo-boehmite. However, in the subsequent drying and calcination links of pseudo-boehmite, more energy consumption is required to remove the additional water, which not only increases the production cost, but also may affect the quality of the pseudo-boehmite product due to the physical and chemical effects of water evaporation removal.

[0003] In addition, the production of pseudo-boehmite is more common by carbon separation method, but the washing wastewater of the carbon separation method contains a large amount of soluble alkaline substances, which cannot be effectively utilized, not only causing resource waste, but also increasing the cost and difficulty of alkaline wastewater treatment. If the washing wastewater of the carbon separation method of pseudo-boehmite is used as the alkaline reagent of the neutralization method, not only the consumption of the alkaline reagent of the neutralization method can be reduced, but also the viscosity of the pseudo-boehmite can be diluted. However, the alkaline substances produced by the carbon separation method have many impurities, and it is difficult to accurately control the gel solubility of the pseudo-boehmite. SUMMARY

[0004] The present application provides a method for co-producing gel-soluble pseudo-boehmite and pseudo-boehmite to solve the technical problem of how to improve the controllability of the gel solubility of pseudo-boehmite.

[0005] In a first aspect, the embodiments of the present application provide a method for co-producing gel-soluble pseudo-boehmite, which comprises:

[0006] carbon dioxide is introduced into the sodium aluminate solution to perform carbonation reaction to obtain a first slurry;

[0007] The first neutralization slurry is subjected to first aging treatment to obtain a first aging slurry;

[0008] The first aging slurry is filtered to obtain a first solid-phase material and a liquid-phase material containing alkaline substances;

[0009] drying the first solid phase material to obtain a first pseudo-boehmite;

[0010] carrying out a parallel flow neutralization treatment on the aluminum sulfate and the sodium aluminate solution to obtain a second neutralization slurry;

[0011] filtering the second neutralization slurry to obtain a second solid phase material;

[0012] carrying out a beating treatment on the second solid phase material and the liquid phase material containing the alkaline substance to obtain a mixed slurry;

[0013] carrying out a second aging treatment on the mixed slurry to obtain a second aging slurry;

[0014] sequentially filtering and washing the second aging slurry to obtain a second pseudo-boehmite;

[0015] collecting the first pseudo-boehmite and the second pseudo-boehmite to obtain a peptizable pseudo-boehmite;

[0016] wherein the peptizability of the first pseudo-boehmite > the peptizability of the second pseudo-boehmite.

[0017] Optionally, the mass m1 of the second solid phase material and the volume V1 of the liquid phase material satisfy: m1:V1=(15 to 75):1000, if the unit of m1 is g, then the unit of V1 is mL.

[0018] Optionally, the temperature of the first aging treatment is 60°C to 95°C, and the duration of the first aging treatment is 2h to 5h; and / or

[0019] the temperature of the second aging treatment is 60°C to 95°C, and the duration of the second aging treatment is 2h to 5h.

[0020] Optionally, the temperature of the carbonization reaction is 25°C to 60°C, and the time of the carbonization reaction is 10min to 15min; and / or

[0021] the temperature of the parallel flow neutralization treatment is 40°C to 90°C.

[0022] Optionally, the pH of the first neutralization slurry is 10 to 12.

[0023] Optionally, the pH of the second neutralization slurry is 4.5 to 7.0.

[0024] Optionally, the alumina content of the mixed slurry is 15g / L to 70g / L.

[0025] In a second aspect, the embodiments of the present application provide a peptizable pseudo-boehmite, which is prepared by the method of the first aspect.

[0026] Optionally, the peptizable pseudo-boehmite comprises a first pseudo-boehmite and a second pseudo-boehmite, the peptizability of the first pseudo-boehmite is 62.34% to 97.18%, and the peptizability of the second pseudo-boehmite is 6.80% to 52.35%.

[0027] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0028] The method for co-producing peptizable pseudo-boehmite provided by the embodiments of the present application can first form a first solid-phase material containing pseudo-boehmite and a liquid-phase material containing alkaline substances through the carbonation reaction of carbon dioxide and sodium aluminate solution and the first aging treatment, and the first solid-phase material can be washed and dried to obtain a first pseudo-boehmite product with good peptizability; then the precursor of pseudo-boehmite is formed by aluminum sulfate and sodium aluminate, and the liquid-phase material containing alkaline substances is used as an alkaline reagent to control the dispersibility and stability of the precursor of pseudo-boehmite, so as to promote the precursor to form a second pseudo-boehmite product with certain peptizability in the second aging treatment stage, and different peptizability of pseudo-boehmite products can be formed between the first pseudo-boehmite product and the second pseudo-boehmite, thereby improving the controllability of the peptizability of pseudo-boehmite. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate preferred embodiments of the present application and, together with the description, serve to explain the principles of the present application.

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0031] Figure 1 A flowchart of a method for co-producing peptizable pseudo-boehmite is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0033] The range descriptions described in the present application, such as numerical range, ratio range, etc., all include all possible sub-ranges and single values within the range, for example, the range description of "1 to 6" or "1-6" covers all sub-ranges (such as 1 to 3, 2 to 5, etc.) and single numbers (such as 1, 2, 3, 4, 5, 6) between 1 and 6. Unless otherwise specified, the terms "comprise" and the like used in the present application mean "including but not limited to"; the relationship terms "first", "second", etc. are only used to distinguish different entities or operations, and do not imply actual sequence or relationship; "and / or" means that multiple cases can exist alone or simultaneously; "at least one", "multiple", "at least one" and the like refer to any combination of the corresponding objects, including single or multiple combinations of objects. The proportional relationship involved in the present application, such as mass ratio, molar ratio, etc., should be understood as the corresponding relationship between the front and the rear in the proportional form according to the description order. The raw materials, reagents, instruments and equipment used in the present application can be purchased or prepared by existing methods.

[0034] Figure 1 An exemplary flow chart of a method for co-producing peptizable pseudo-boehmite provided by the embodiments of the present application is shown;

[0035] As shown in Figure 1 , a method for co-producing peptizable pseudo-boehmite provided by the embodiments of the present application, the method comprises:

[0036] S1. Carbonation reaction is carried out by passing carbon dioxide into a sodium aluminate solution to obtain a first slurry;

[0037] S2. The first neutralized slurry is subjected to a first aging treatment to obtain a first aged slurry;

[0038] S3. The first aged slurry is filtered to obtain a first solid phase material and a liquid phase material containing alkaline substances;

[0039] S4. The first solid phase material is dried to obtain a first pseudo-boehmite;

[0040] S5. Aluminum sulfate is subjected to a parallel flow neutralization treatment with the sodium aluminate solution to obtain a second neutralized slurry;

[0041] S6. filtering the second neutralization slurry to obtain a second solid phase material;

[0042] S7. performing a beating treatment on the second solid phase material and the liquid phase material containing the basic substance to obtain a mixed slurry;

[0043] S8. performing a second aging treatment on the mixed slurry to obtain a second aged slurry;

[0044] S9. sequentially performing filtering and washing on the second aged slurry to obtain a second pseudoboehmite;

[0045] S10. collecting the first pseudoboehmite and the second pseudoboehmite to obtain a peptizable pseudoboehmite;

[0046] wherein the peptizability of the first pseudoboehmite > the peptizability of the second pseudoboehmite.

[0047] It should be noted that the carbonization reaction and the parallel flow neutralization treatment can be performed by stirring.

[0048] It should be noted that the embodiment of the present application provides a method for co-producing peptizable pseudoboehmite, which significantly improves the controllability of the peptizability of the final product by preparing two pseudoboehmites with different peptizabilities in steps. The specific mechanism is as follows:

[0049] 1. preparing two intermediate products with different properties:

[0050] (1) first pseudoboehmite (high peptizability): prepared by the route of neutralizing sodium aluminate with CO2. This route generally produces pseudoboehmite with relatively high crystallinity, large crystal grains, and more regular and compact structure. The peptizability of this step can be finely adjusted by controlling the CO2 feeding rate, temperature, concentration, end point pH, first aging treatment conditions (time, temperature), etc.

[0051] (2) second pseudoboehmite (lower peptizability): prepared by the traditional parallel flow neutralization route of aluminum sulfate and sodium aluminate. This method generally produces pseudoboehmite with lower crystallinity, smaller crystal grains, relatively loose structure, and more amorphous or disordered structure. This structural feature makes it have higher specific surface area and pore volume, and poor peptizability. The peptizability of this step can be adjusted by controlling the pH value, temperature, and additive modification of parallel flow neutralization.

[0052] 2. optimizing the second product with liquid phase material:

[0053] The liquid phase material (mainly containing sodium carbonate / sodium bicarbonate, etc.) obtained by filtering the first neutralization slurry is used for beating with the solid phase material obtained by the second neutralization (precursor of pseudoboehmite with lower peptizability).

[0054] The liquid phase material can form an alkaline environment, and the second solid phase material is beaten with the liquid phase material, which is equivalent to a mild reprocessing or surface modification of the second pseudoboehmite under alkaline conditions. This helps to dissolve some fine, unstable or impurity particles that may exist in the second solid phase material, and may activate the surface hydroxyl groups of the pseudoboehmite particles or cause a certain degree of phase transition through aging, improving its dispersibility and stability, and preparing for subsequent aging. Although its inherent peptization may still be lower than that of the first pseudoboehmite product, this step optimizes its physical state, enabling directional adjustment of its peptization.

[0055] 3. Second aging treatment step:

[0056] The mixed slurry is subjected to a second aging treatment. The aging conditions (temperature, time) of the second aging treatment can be independently optimized to ensure that the second pseudoboehmite reaches the desired peptization after being treated with the alkaline liquid phase material.

[0057] Therefore, the embodiments of the present application provide a method for co-producing peptizable pseudoboehmite, which realizes the regulation of the peptization of the pseudoboehmite product through the following mechanisms.

[0058] (1) Source differentiation: Two pseudoboehmites with significantly different intrinsic peptization are prepared through two completely different production processes (CO2 neutralization and acid-base parallel neutralization). This provides a basic variable for subsequent regulation.

[0059] (2) Independent optimization path: The key process parameters (neutralization conditions, aging conditions) of the two routes can be independently optimized to accurately control the peptization of the two pseudoboehmites, respectively. This provides the first layer of regulation dimension.

[0060] (3) Liquid phase reuse and optimization: The alkaline liquid phase material produced by the first route is used to optimize the treatment of the solid phase product of the second route, improving its dispersibility and processing performance, and paving the way for effective mixing. This is an indirect but important auxiliary regulation.

[0061] (4) Special aging stabilization: The mixed slurry is subjected to an independent second aging treatment. The aging conditions (temperature, time) of the second aging treatment are the second layer of regulation dimension, affecting the structure and stability of the final mixture.

[0062] In summary, the embodiments of the present application provide a method for co-production of colloidal solubility pseudo-boehmite, which greatly enhances the controllability of colloidal solubility of the final pseudo-boehmite product through multi-level and multi-step strategies such as preparation by quality (creating differences), independent optimization, liquid phase auxiliary treatment and special aging, so that it can more flexibly adapt to diversified application requirements. Compared with a single process route that can only adjust the colloidal solubility within a relatively limited range by changing process parameters, this co-production mixed strategy greatly widens the range and accuracy of regulation.

[0063] In some optional embodiments, the mass m1 of the second solid phase material and the volume V1 of the liquid phase material satisfy: m1:V1=(15 to 75):1000, if the unit of m1 is g, then the unit of V1 is mL.

[0064] In these embodiments, the second solid phase material and the liquid phase material with a mass ratio of (15 to 75):1000 can improve the surface morphology, dispersibility and stability of the pseudo-boehmite in the second solid phase material by using the alkaline substance of the liquid phase material as an alkaline reagent and combining with beating treatment, which is beneficial to obtaining the second pseudo-boehmite product with certain colloidal solubility through subsequent second aging treatment.

[0065] The value of the mass m1 of the second solid phase material can be 15, 30, 40, 60 or 75.

[0066] In some optional embodiments, the temperature of the first aging treatment is 60°C to 95°C, and the duration of the first aging treatment is 2h to 5h; and / or

[0067] The temperature of the second aging treatment is 60°C to 95°C, and the duration of the second aging treatment is 2h to 5h.

[0068] In these embodiments, the first aging treatment with a temperature of 60°C to 95°C and a duration of 2h to 5h can promote the pseudo-boehmite crystals of the first neutralized slurry to be fully converted into first pseudo-boehmite crystals with higher colloidal solubility. In addition, the second aging treatment with a temperature of 60°C to 95°C and a duration of 2h to 5h can effectively stabilize the mixed structure of the mixed slurry formed by the second solid phase material and the liquid phase material, so that the second solid phase material can be fully converted into the second pseudo-boehmite product with certain colloidal solubility.

[0069] The temperature of the first aging treatment can be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C.

[0070] The time of the first aging treatment can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h or 5h.

[0071] The temperature of the second aging treatment can be 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃, or 95℃.

[0072] The time of the second aging treatment can be 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, or 5h.

[0073] It should be noted that, in the case that the temperature of the first aging treatment is less than 60℃, the pseudo-boehmite formed by the first neutralized slurry will have a Bayerite impurity, and the presence of the Bayerite impurity will affect the peptization of the first pseudo-boehmite; in the case that the temperature of the first aging treatment is greater than 95℃, the demand for the aging treatment equipment is higher and the energy consumption cost is higher.

[0074] It should be noted that, in the case that the temperature of the second aging treatment is less than 60℃, the second aging slurry containing pseudo-boehmite formed by the mixed slurry will have an insufficient solid content, and it will be difficult to obtain a sufficient amount of second pseudo-boehmite with lower peptization in the subsequent process; in the case that the temperature of the second aging treatment is greater than 95℃, the second aging slurry containing pseudo-boehmite obtained by the second aging treatment will have a larger viscosity, and it will be extremely easy to be mixed with impurities, and it will be difficult to be washed in the subsequent process, affecting the purity of the pseudo-boehmite.

[0075] In some optional embodiments, the temperature of the carbonization reaction is 25℃ to 60℃, and the time of the carbonization reaction is 10min to 15min; and / or

[0076] The temperature of the parallel flow neutralization treatment is 40℃ to 90℃.

[0077] In these embodiments, the carbonization reaction with a temperature of 25℃ to 60℃ and a time of 10min to 15min can promote the reaction between carbon dioxide and the sodium aluminate solution to form a pseudo-boehmite product with higher peptization; in addition, the parallel flow neutralization treatment with a temperature of 40℃ to 90℃ can promote the mixing of aluminum sulfate and sodium aluminate, and obtain a second neutralized slurry with a stable mixed structure, which is conducive to the second aging treatment, so as to facilitate the subsequent obtaining of

[0078] The temperature of the carbonization reaction can be 25℃, 30℃, 40℃, 50℃, or 60℃.

[0079] The time of the carbonization reaction can be 10min, 11min, 13min, 14min, or 15min.

[0080] The temperature of the parallel flow neutralization treatment can be 40℃, 55℃, 65℃, 80℃, or 90℃.

[0081] In some alternative embodiments, the first neutralized slurry has a pH of 10 to 12.

[0082] In these embodiments, the first neutralized slurry having a pH of 10 to 12 can have sufficient alkaline substances, which is beneficial for the subsequent beating treatment stage, and guarantees the peptization of the second pseudo-boehmite.

[0083] The pH of the first neutralized slurry can be 10, 10.5, 11.0, 11.5, or 12.0.

[0084] In some alternative embodiments, the second neutralized slurry has a pH of 4.5 to 7.0.

[0085] In these embodiments, the second neutralized slurry having a pH of 4.5 to 7.0 can contain a large amount of pseudo-boehmite precursor coarse products and promote the uniform distribution of the pseudo-boehmite precursor coarse products, which is beneficial for the subsequent beating treatment between the second solid phase material and the liquid phase material, and promotes the conversion of the pseudo-boehmite precursor coarse products into pseudo-boehmite products to form the second pseudo-boehmite products with a certain peptization.

[0086] The pH of the second neutralized slurry can be 4.5, 5.0, 5.5, 6.0, 6.5, or 7.0.

[0087] It should be noted that, in the case that the pH of the second neutralized slurry is less than 4.5, the decomposition efficiency of the second neutralized slurry is low, and it is difficult to obtain sufficient pseudo-boehmite precursor coarse products, resulting in a low yield of the final second pseudo-boehmite; in the case that the pH of the second neutralized slurry is greater than 7.0, the second neutralized slurry can directly decompose to form the second pseudo-boehmite products, but the peptization of the directly formed second pseudo-boehmite products is low.

[0088] In some alternative embodiments, the mixed slurry has an alumina content of 15 g / L to 70 g / L.

[0089] In these embodiments, the mixed slurry having an alumina content of 15 g / L to 70 g / L can have sufficient alumina substances, which can be converted into pseudo-boehmite products with a certain peptization in the second aging treatment.

[0090] The alumina content of the mixed slurry can be 15 g / L, 20 g / L, 25 g / L, 30 g / L, 35 g / L, 40 g / L, 45 g / L, 50 g / L, 55 g / L, 60 g / L, 65 g / L, or 70 g / L.

[0091] It should be noted that, in the case that the alumina content of the mixed slurry is less than 15 g / L, the pH of the mixed slurry is too high, and the viscosity of the mixed slurry is increased, which is not conducive to the subsequent washing, so that the purity of the second pseudo-boehmite product is low; in the case that the alumina content of the mixed slurry is greater than 70 g / L, the pH of the mixed slurry is too low, which will affect the aging effect of the subsequent second aging treatment, and may promote the formation of amorphous alumina or low peptization pseudo-boehmite product from the mixed slurry.

[0092] Based on one overall inventive concept, the embodiments of the present application provide a peptized pseudo-boehmite, which is prepared by the method.

[0093] The peptized pseudo-boehmite is prepared based on the above method, and the specific steps of the method can be referred to the above embodiments. Since the peptized pseudo-boehmite adopts part or all of the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0094] In some optional embodiments, the peptized pseudo-boehmite includes a first pseudo-boehmite and a second pseudo-boehmite, the peptization of the first pseudo-boehmite is 62.34% to 97.18%, and the peptization of the second pseudo-boehmite is 6.80% to 52.35%.

[0095] In these embodiments, the first pseudo-boehmite with a peptization of 62.34% to 97.18% and the second pseudo-boehmite with a peptization of 6.80% to 52.35% can indicate that the method provided by the embodiments of the present application can effectively prepare two pseudo-boehmite products with different peptizations.

[0096] The present application will be further described in conjunction with specific embodiments. The experimental methods in the following embodiments without specific conditions are generally determined according to national standards / industry standards; if there is no corresponding national standards / industry standards, the international standards, conventional conditions or the conditions suggested by the manufacturers are used.

[0097] Example 1

[0098] A sodium aluminate solution with an alumina content of 50 g / L is used. The specific operation is as follows:

[0099] As shown in Figure 1 A method for co-producing peptized pseudo-boehmite, comprising:

[0100] S1. Carbonation reaction is carried out by introducing carbon dioxide into the sodium aluminate solution to obtain a first neutralization slurry;

[0101] S2. The first neutralized slurry is subjected to a first aging treatment to obtain a first aged slurry;

[0102] S3. The first aged slurry is subjected to filtration to obtain a first solid-phase material and a liquid-phase material containing alkaline substances;

[0103] S4. The first solid-phase material is subjected to drying to obtain a first pseudo-boehmite;

[0104] S5. Aluminum sulfate and sodium aluminate solution are subjected to parallel flow neutralization treatment to obtain a second neutralized slurry;

[0105] S6. The second neutralized slurry is subjected to filtration to obtain a second solid-phase material;

[0106] S7. The second solid-phase material and the liquid-phase material containing alkaline substances are subjected to beating treatment to obtain a mixed slurry;

[0107] S8. The mixed slurry is subjected to a second aging treatment to obtain a second aged slurry;

[0108] S9. The second aged slurry is subjected to filtration and washing in sequence to obtain a second pseudo-boehmite;

[0109] S10. The first pseudo-boehmite and the second pseudo-boehmite are collected to obtain a peptizable pseudo-boehmite.

[0110] The mass m1 of the second solid-phase material and the volume V1 of the liquid-phase material satisfy: m1:V1=15g:1000mL.

[0111] The temperature of the first aging treatment is 75℃, and the duration of the first aging treatment is 3h;

[0112] The temperature of the second aging treatment is 90℃, and the duration of the second aging treatment is 2h.

[0113] The temperature of the carbonization reaction is 25℃, and the time of the carbonization reaction is 10min;

[0114] The temperature of the parallel flow neutralization treatment is 40℃.

[0115] The pH of the first neutralized slurry is 11.5.

[0116] The pH of the second neutralized slurry is 4.5.

[0117] The alumina content of the mixed slurry is 15g / L.

[0118] Example 2

[0119] Compared with Example 1, the differences of the present example are as follows, and the rest are the same:

[0120] The mass m of the second solid-phase material and the volume V of the liquid-phase material satisfy: m:V=30:1000.

[0121] The temperature of the first aging treatment is 65℃, and the duration of the first aging treatment is 3h;

[0122] The temperature of the second aging treatment is 80℃, and the duration of the second aging treatment is 3h.

[0123] The temperature of the carbonization reaction is 30℃, and the duration of the carbonization reaction is 14min;

[0124] The temperature of the concurrent neutralization treatment is 55℃.

[0125] The pH of the first neutralization slurry is 11.5.

[0126] The pH of the second neutralization slurry is 4.5 to 7.0.

[0127] The alumina content of the mixed slurry is 15g / L to 70g / L.

[0128] Example 3

[0129] Compared with Example 1, the differences of the present example are as follows, and the rest are the same:

[0130] The mass m1 of the second solid-phase material and the volume V1 of the liquid-phase material satisfy: m1:V1=40g:1000mL.

[0131] The temperature of the first aging treatment is 85℃, and the duration of the first aging treatment is 3h;

[0132] The temperature of the second aging treatment is 70℃, and the duration of the second aging treatment is 4h.

[0133] The temperature of the carbonization reaction is 40℃, and the duration of the carbonization reaction is 11min;

[0134] The temperature of the concurrent neutralization treatment is 80℃.

[0135] The pH of the first neutralization slurry is 11.5.

[0136] The pH of the second neutralization slurry is 6.5.

[0137] The alumina content of the mixed slurry is 45g / L.

[0138] Example 4

[0139] Compared with Example 1, the differences of the present example are as follows, and the rest are the same:

[0140] The mass m of the second solid-phase material and the volume V of the liquid-phase material satisfy: m:V=75:1000.

[0141] The temperature of the first aging treatment is 95℃, and the duration of the first aging treatment is 3h;

[0142] The temperature of the second aging treatment is 60℃, and the duration of the second aging treatment is 5h.

[0143] The temperature of the carbonization reaction is 60℃, and the time of the carbonization reaction is 15min;

[0144] The temperature of the parallel flow neutralization treatment is 90℃.

[0145] The pH of the first neutralized slurry is 11.5.

[0146] The pH of the second neutralized slurry is 4.5.

[0147] The alumina content of the mixed slurry is 60g / L.

[0148] Comparative Example 1

[0149] The differences of the present comparative example compared with Example 1 are as follows, and the rest are the same:

[0150] Without using liquid phase materials, directly using the mixed slurry as raw material to directly prepare pseudoboehmite, the specific steps are as follows:

[0151] Using a peristaltic pump to perform parallel flow neutralization treatment on the aluminum sulfate and the sodium aluminate solution to obtain a second neutralized slurry;

[0152] The second neutralized slurry is sequentially filtered and washed to obtain a second pseudoboehmite.

[0153] Comparative Example 2

[0154] The differences of the present comparative example compared with Example 1 are as follows, and the rest are the same:

[0155] The temperature of the first aging treatment is 50℃, and the duration of the first aging treatment is 6h.

[0156] Comparative Example 3

[0157] The differences of the present comparative example compared with Example 1 are as follows, and the rest are the same:

[0158] The temperature of the first aging treatment is 100℃, and the duration of the first aging treatment is 1h.

[0159] Comparative Example 4

[0160] The differences of the present comparative example compared with Example 1 are as follows, and the rest are the same:

[0161] The temperature of the second aging treatment is 50℃, and the duration of the second aging treatment is 6h.

[0162] Comparative Example 5

[0163] The difference between the present comparative example and Example 1 is as follows, and the rest is the same:

[0164] The temperature of the second aging treatment is 100℃, and the duration of the second aging treatment is 1h.

[0165] Comparative Example 6

[0166] The difference between the present comparative example and Example 1 is as follows, and the rest is the same:

[0167] The pH of the second neutralization slurry is 3.

[0168] Comparative Example 7

[0169] The difference between the present comparative example and Example 1 is as follows, and the rest is the same:

[0170] The pH of the second neutralization slurry is 8.0.

[0171] Related experiments and effect data:

[0172] The peptization of the pseudoboehmite in each example and comparative example is counted respectively (peptization index), and the results are shown in Table 1.

[0173] Table 1 Peptization of pseudoboehmite in each example and comparative example

[0174]

[0175]

[0176] As can be seen from Table 1, the method for co-producing pseudoboehmite provided by the present application greatly enhances the controllability of the peptization of the final pseudoboehmite product through multi-level and multi-step strategies such as preparation by quality difference (creating differences), independent optimization, liquid phase auxiliary treatment, mixed specific aging, and possible physical mixing ratio control. The first pseudoboehmite product with a peptization of 62.34% to 97.18% and the second pseudoboehmite product with a peptization of 6.80% to 52.35% can be obtained, and different pseudoboehmites can be flexibly selected according to different needs to meet the application needs of different pseudoboehmites.

[0177] Compared with Example 1, Comparative Example 1 does not use liquid material as an alkaline reagent, and the pseudoboehmite formed by direct and concurrent neutralization treatment has no peptization.

[0178] Compared with Example 1, the lower temperature and longer time of the first aging treatment used in Comparative Example 2 makes the pseudo-boehmite in the first neutralized slurry difficult to be shaped, which finally results in the worst peptization of the first pseudo-boehmite. The higher temperature and shorter time of the first aging treatment used in Comparative Example 3 makes the peptization of the final first pseudo-boehmite lower.

[0179] Compared with Example 1, the lower temperature and longer time of the second aging treatment used in Comparative Example 4 makes the pseudo-boehmite in the second neutralized slurry difficult to be shaped, which finally results in the lower yield of the second pseudo-boehmite. The higher temperature and shorter time of the second aging treatment used in Comparative Example 5 makes the peptization of the final second pseudo-boehmite lower.

[0180] Compared with Example 1, the lower pH of the second neutralized slurry in Comparative Example 6 makes the yield of the pseudo-boehmite precursor in the second neutralized slurry lower, which finally affects the yield of the second pseudo-boehmite; the higher pH of the second neutralized slurry in Comparative Example 7 makes the second pseudo-boehmite directly decompose from the second neutralized slurry, but the peptization of these second pseudo-boehmites is lower.

[0181] In summary, the method for co-producing peptizable pseudo-boehmite provided in the embodiments of the present application greatly enhances the controllability of the peptization of the final pseudo-boehmite product by using multi-level and multi-step strategies such as separate preparation (producing differences), independent optimization, liquid-phase auxiliary treatment, mixing of specific aging, and possible control of the physical mixing ratio, so that the method can more flexibly adapt to diversified application requirements.

[0182] In addition, the method for co-producing peptizable pseudo-boehmite provided in the embodiments of the present application can form the first pseudo-boehmite product while generating sufficient liquid-phase materials containing alkaline substances based on the carbonation reaction of carbon dioxide and sodium aluminate solution, which can replace the alkaline additives of the mixed slurry of sodium aluminate and aluminum sulfate in the traditional carbon separation method, can improve the resource utilization rate in the pseudo-boehmite preparation stage, and can also reduce the overall preparation cost of the pseudo-boehmite.

[0183] In addition, the method for co-producing peptizable pseudo-boehmite provided in the embodiments of the present application can convert the amorphous aluminum gel without peptization formed by the carbonation reaction of carbon dioxide and sodium aluminate solution into pseudo-boehmite, and by adjusting the process parameters of each stage, the peptization of the pseudo-boehmite can be directionally controlled, so that the pseudo-boehmite can meet different use requirements.

[0184] The foregoing detailed description of the application has been presented for purposes of illustration and description. Various modifications to the description will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the spirit or scope of the application. Accordingly, the application is not intended to be limited to the implementations described herein but is to be accorded the widest scope consistent with the principles and novel features to the application.

Claims

1. A method for co-producing pectin-soluble pseudoboehmite, the method comprising: Carbon dioxide is passed into a sodium aluminate solution to carry out a carbonization reaction, resulting in the first slurry. The first neutralized slurry is subjected to a first aging treatment to obtain a first aged slurry; The first aging slurry is filtered to obtain a first solid phase material and a liquid phase material containing alkaline substances. The first solid material is dried to obtain the first pseudoboehmite; Aluminum sulfate and sodium aluminate solution are subjected to co-current neutralization treatment to obtain a second neutralized slurry; The second neutralized slurry is filtered to obtain the second solid phase material; The second solid material and the liquid material containing alkaline substances are pulped to obtain a mixed slurry; The mixed slurry is subjected to a second aging treatment to obtain a second aged slurry; The second aged slurry was filtered and washed sequentially to obtain the second pseudoboehmite; The first and second pseudoboehmite were collected to obtain colloidal pseudoboehmite. The colloidal solubility of the first pseudoboehmite is greater than that of the second pseudoboehmite.

2. The method according to claim 1, characterized in that, The mass m1 of the second solid phase material and the volume V1 of the liquid phase material satisfy the following condition: m1:V1=(15 to 70):1000. If the unit of m1 is g, then the unit of V1 is mL.

3. The method according to claim 1, characterized in that, The temperature of the first aging treatment is 60°C to 95°C, and the duration of the first aging treatment is 2 hours to 5 hours; and / or The temperature of the second aging treatment is 60°C to 95°C, and the duration of the second aging treatment is 2 hours to 5 hours.

4. The method according to claim 1, characterized in that, The carbonization reaction is carried out at a temperature of 25°C to 60°C for a duration of 10 to 15 minutes; and / or The temperature of the parallel flow neutralization process is 40°C to 90°C.

5. The method according to claim 1, characterized in that, The pH of the first neutralized slurry is 10 to 12.

6. The method according to claim 1, characterized in that, The pH of the second neutralized slurry is 4.5 to 7.

0.

7. The method according to claim 1, characterized in that, The alumina content of the mixed slurry is from 15 g / L to 70 g / L.

8. A colloidal pseudoboehmite, said colloidal pseudoboehmite being prepared by the method according to any one of claims 1 to 7.

9. The colloidal pseudoboehmite according to claim 8, characterized in that, The colloidal boehmite includes a first boehmite and a second boehmite, wherein the colloidal solubility of the first boehmite is 62.34% to 97.18% and the colloidal solubility of the second boehmite is 6.80% to 52.35%.

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