63 results about "Peptization" patented technology

The invention relates to high-peptization pseudo-boehmite and a preparation method thereof, and belongs to the technical field of porous aluminum oxide preparation. The method comprises the following steps: obtaining slurry containing pseudo-boehmite colloidal particles; mixing the slurry containing the pseudo-boehmite colloidal particles with an alkaline auxiliary agent to obtain a mixed solution; and aging the mixed solution at a set temperature so as to enable the alkaline additive to perform surface modification on the pseudo-boehmite colloidal particles, thereby obtaining the high-peptizing-solubility pseudo-boehmite. According to the invention, the alkaline auxiliary agent acts on the colloidal particle surface of the pseudo-boehmite at a proper temperature, so that the pore structure of the pseudo-boehmite is maintained, and meanwhile, the pseudo-boehmite with high peptizing property is constructed.

The present invention provides a method for preparing large-pore spherical alumina, and relates to the technical field of spherical alumina. The preparation method of the present invention comprises the following steps: mixing pseudo-boehmite powder with water to obtain a suspension, adding a peptizing agent for peptization to prepare an aluminum hydroxide sol; adding cross-linking molecules to the aluminum hydroxide sol to form a system to be cross-linked; adding a cross-linking agent to the system to be cross-linked to obtain a sol containing a prepolymer; and subjecting the sol to oil-ammonia column molding, drying and roasting to obtain large-pore spherical alumina. The present invention adopts an oil-ammonia column molding method, which does not require the addition of a pore-expanding agent or new equipment, and the preparation process is simple and does not introduce new impurities, so it is suitable for industrial production. The large-pore spherical alumina prepared by the present invention has a pore volume of up to 0.60cm 3 / g or more, and can be used as a propane dehydrogenation catalyst carrier.

The invention provides a preparation method of pseudo-boehmite with high bulk specific gravity, and belongs to the field of pseudo-boehmite. The method comprises the following steps: carrying out a low-temperature neutralization reaction on an aluminum salt solution and a sodium metaaluminate solution, and keeping the pH value of a neutralized material at 6-6.5 in the reaction process to obtain amorphous precursor slurry; carrying out solid-liquid separation on the amorphous precursor slurry to obtain first mixed slurry; performing high-temperature aging crystal transformation reaction on the first mixed slurry and sodium carbonate to obtain macroporous pseudo-boehmite slurry; performing solid-liquid separation on the macroporous pseudo-boehmite slurry to obtain second mixed slurry; carrying out modification treatment on the second mixed slurry and acid or acid aluminum salt so as to re-agglomerate the non-peptized macroporous pseudo-boehmite to obtain third slurry; performing solid-liquid separation on the third slurry to obtain fourth mixed slurry; and carrying out spray drying on the fourth mixed slurry to obtain the pseudo-boehmite. Therefore, the bulk density of the pseudo-boehmite is improved.

The present invention provides a method for preparing spherical alumina, and relates to the technical field of spherical alumina. The preparation method of the present invention comprises the following steps: mixing pseudo-boehmite powder with water to obtain a suspension, then adding a peptizing agent for peptization to obtain an aluminum sol; adding a cross-linking substrate and a cross-linking agent to the aluminum sol to obtain a sol containing a prepolymer, and then adding a coagulant to obtain a mixed sol; dripping the mixed sol into a hot oil column for molding, and obtaining spherical alumina after aging, washing, drying, and roasting. The present invention adopts a hot oil column molding method, which does not require the addition of a pore expanding agent or new equipment, and the preparation process is simple and does not introduce new impurities, so it is suitable for industrial production. The pore volume of the spherical alumina prepared by the present invention reaches 0.60cm 3 / g or more, and can be used as a propane dehydrogenation catalyst carrier.

This invention discloses a catalytic cracking co-catalyst with high resistance to thermal abrasion, comprising a molecular sieve, a matrix, a binder, and a binder modifier. The molecular sieve has an MFI structure, and the molecular sieve with a pore diameter less than 0.7 nm accounts for 50 wt% to 100 wt% of the total molecular sieve. The matrix is ​​composed of a γ-alumina precursor with a colloidal index ≤ 50% and clay. The binder is prepared from phosphorus-containing and aluminum-containing compounds. The raw materials for the binder modifier include multi-chelate ligands, precursors of at least two coordination metals, alcohols, and organic acids. The binder, binder modifier, and matrix are all mixed in a high-shear emulsifier. Compared with existing catalytic cracking co-catalysts for propylene and octane number, the catalytic cracking co-catalyst provided by this invention has higher resistance to thermal abrasion, larger pore volume, and higher molecular sieve content.

The invention discloses a recovery method of peptization of modified pseudo-boehmite and application thereof, and the recovery method of peptization of modified pseudo-boehmite comprises the following steps: (1) uniformly mixing pseudo-boehmite and a modifier, and carrying out solid-phase reaction to obtain an alumina precursor sample; (2) putting the aluminum oxide precursor sample into a closed container, adding deionized water, fumigating at 60-110 DEG C for 12-30 hours, and drying; or (1) uniformly mixing pseudo-boehmite and a modifier, carrying out solid-phase reaction to obtain an aluminum oxide precursor, and roasting the aluminum oxide precursor; and (2) putting the roasted sample into a closed container, adding deionized water, fumigating at 60-110 DEG C for 12-30 hours, and drying. According to the method disclosed by the invention, the modified pseudo-boehmite has a developed pore structure while the peptizing property is recovered, and the method disclosed by the invention is green, environment-friendly, simple in process and relatively low in cost.

This invention provides a sulfur transfer aid, its preparation method, and its application. The sulfur transfer aid comprises 30%-70% magnesium oxide, 15%-60% aluminum oxide, 10%-15% cerium oxide, and 2%-5% vanadium pentoxide. The magnesium oxide is provided by a first magnesium source and a magnesium-aluminum matrix material, and the aluminum oxide is provided by a first aluminum source and a magnesium-aluminum matrix material. On a dry basis, the mass of the magnesium-aluminum matrix material is 5%-30% of the total mass of the raw materials of the sulfur transfer aid. The magnesium-aluminum matrix material is obtained by crystallizing a mixture of a second magnesium source and a second aluminum source after sol-treatment, and the magnesium-aluminum matrix material comprises magnesium oxide and aluminum oxide in a mass ratio of 0.2-0.8:1. This invention also provides a preparation method for the above-mentioned sulfur transfer aid and its application in catalytic cracking processes. This sulfur transfer aid can efficiently desulfurize and is suitable for industrial production.

The invention relates to a low-carbon alkane dehydrogenation olefin preparation catalyst, which comprises an alumina carrier and an active component, and is characterized in that the alumina carrier is a millimeter-scale sulfur-containing theta-alumina pellet, the particle size is 1.6-2.5 mm, the specific surface area is 80-150m < 2 > / g, the pore volume is 0.40-0.75 mL / g, the crushing strength is greater than 50N / pellet, the bulk density is 0.55-0.80 g / mL, the length-diameter ratio b / l value is more than 0.95, and the sulfur content is 0.05-0.50%. The theta-alumina pellets are prepared by the following steps: adding an acid solution into an alumina suspension of at least two kinds of hydrated alumina, wherein the acid peptizing index DI of at least one kind of hydrated alumina is 50-85%, peptizing to obtain alumina sol, then dropwise adding the alumina sol into an oil ammonia column through a dropper, pelletizing, drying and roasting. When the catalyst is used for an alkane dehydrogenation reaction, the alkane conversion rate and olefin selectivity are high, and the carbon deposition resistance is strong.

This invention relates to the field of catalytic cracking additives, providing a catalytic cracking additive, its preparation method, its application in catalytic cracking, and a method for improving the selectivity of C4 olefins. The additive, based on a dry weight basis, contains 15-40 wt% β-zeolite, 10-50 wt% highly colloidal macroporous boehmite, and 10-75 wt% clay; wherein the highly colloidal macroporous boehmite has an alumina content of 98-100 wt%; the pore volume V1 of the highly colloidal macroporous boehmite is 0.45-0.7 mL / g, and the colloidal index DI is 95-100%; the pore volume V2 of the highly colloidal macroporous boehmite after colloidal dissolution is 0.4-0.55 mL / g. When applied to the catalytic cracking process, this additive can significantly improve the yield and selectivity of C4 olefins.

A method for preparing a cracking catalyst includes combining a zeolite, an alumina binder, and phosphoric acid to form an extrusion mixture. The phosphoric acid acts as a peptizing agent. The extrusion mixture comprises from 0.000271 weight percent to 0.1 weight percent phosphoric acid based on the total weight of the extrusion mixture. The method further includes extruding the extrusion mixture to produce an extrudate. During the extruding, the phosphoric acid peptizes the alumina binder in the extrudate. The method further includes drying and calcining the extrudate to produce the cracking catalyst.

The application discloses a high-strength, large-pore-volume phosphorus-containing binder, characterized in that the binder comprises a glue, a curing agent and a modifier; the glue comprises a phosphorus-containing compound and an aluminum-containing compound; the curing agent comprises a gamma-aluminum oxide precursor, an acid and an alkylammonium salt, and the modifier is a metal chelate; wherein the colloidal solubility index of the gamma-aluminum oxide precursor is less than or equal to 50%; and the modifier is reacted with the glue in a high-shear dispersion emulsifier. The phosphorus-containing binder provided by the application, in combination with a conventional method, can obtain a catalytic cracking catalyst which, on the basis of high molecular sieve content and large pore volume, still has high wear resistance.

The invention discloses a catalytic cracking catalyst carrier and a preparation method and application thereof, and relates to the technical field of petrochemical engineering, the preparation method comprises the following steps: adding pseudo-boehmite into deionized water, uniformly stirring, then adding a nitric acid solution, and stirring to obtain gel; adding pseudo-boehmite and deionized water into the gel, stirring for peptization, heating and uniformly stirring to obtain sol; adding a silicon-aluminum material, deionized water and modified cellulose into the sol, mixing and pulping, and carrying out spray forming and drying to obtain microspheres; and roasting the microspheres to obtain the catalytic cracking catalyst carrier, the carrier has relatively large pore volume and specific surface area, also has excellent wear-resistant property, can keep the structure stable for a long time at high temperature, can tolerate the temperature and hydrothermal conditions of catalytic cracking reaction, can maintain the carbon containing performance of the carrier in the thermal conversion process for a long time, and can effectively improve the yield of low-carbon olefin.

The invention provides a desulfurization, denitrification and combustion-supporting triple-effect additive as well as a preparation method and application thereof. The triple-effect additive comprises 30%-60% of magnesium oxide, 20%-50% of aluminum oxide, 8%-15% of cerium oxide, 2%-5% of vanadium pentoxide, 2%-10% of modified metal components in terms of oxide and 0.01%-0.1% of noble metal elements in terms of elementary substances. The magnesium oxide is provided by the first magnesium source and the magnesium-aluminum matrix material, and the aluminum oxide is provided by the first aluminum source and the magnesium-aluminum matrix material; the mass of the magnesium-aluminum matrix material is 5-30% of the total mass of the raw materials of the triple-effect additive; the magnesium-aluminum matrix material is obtained by mixing and crystallizing a second aluminum source and a second magnesium source which are subjected to peptizing treatment, and the magnesium-aluminum matrix material comprises magnesium oxide and aluminum oxide in a mass ratio of (0.2-0.8): 1. The invention also provides a preparation method and application of the triple-effect auxiliary agent. The triple-effect auxiliary agent has catalytic cracking flue gas sulfur transfer, denitration and CO combustion-supporting effects.

This invention discloses a method for rapidly detecting the gel solubility index of pseudoboehmite, comprising: weighing a weight of m 1 The pseudoboehmite was calcined in a high-temperature furnace, then transferred to a desiccator to cool to room temperature, and weighed. m 2 The mass fraction of Al2O3 is calculated according to... W The value of Al2O3 content was determined by weighing it on a balance. m 3 The pseudoboehmite was placed in a beaker, deionized water was added, and the mixture was mechanically stirred. Nitric acid solution was added dropwise, and stirring continued until a gel was formed. The gel was then transferred to a centrifuge tube and centrifuged. After centrifugation, the supernatant was discarded, the inner wall of the centrifuge tube was rinsed with water, and the washing liquid was discarded. The insoluble matter at the bottom of the centrifuge tube was removed and rinsed with water. The insoluble matter and washing water were poured into a weighing bottle, dried, and then transferred to a desiccator to cool to room temperature before weighing and recording the weight. m 4 The gel solubility index of boehmite is calculated. This invention has the advantages of short testing cycle, simple operation, high accuracy, economic practicality, and strong adaptability.

The application belongs to the technical field of inorganic functional material preparation, and discloses an energy-saving preparation method of high-purity and high-crystallinity aluminum sol. First, pseudo-boehmite powder prepared by an alcoholate method is mixed with deionized water, and hydrothermal crystallization treatment is performed to enrich the hydroxyl group on the surface of the pseudo-boehmite and improve the peptization performance of the pseudo-boehmite, so that high-crystallinity pseudo-boehmite slurry is obtained; then, an acid peptizing agent is added to the obtained slurry, and hydrothermal peptization treatment is performed, and the high-purity and high-crystallinity aluminum sol is obtained after cooling. The application adopts a two-step hydrothermal process of 'hydrothermal crystallization-hydrothermal peptization', and the drying step in the previous process is omitted, so that the energy consumption is greatly reduced. The particle size of the obtained aluminum sol is less than 100 nm, the Zeta potential is stably maintained at more than 30 mV, the colloidal stability is excellent, and no precipitation is generated after being placed for 6 months. The application has a wide process window, high controllability and high product purity, and is suitable for the fields of catalysis, ceramics, coating and lithium batteries.

The present invention provides a preparation method of an integrated shielding foam with two-sided anisotropy, comprising: obtaining a reinforced polyimide foam with a sheet stack structure by subjecting the polyimide foam to isothermal gradient compression treatment; performing surface colloidal palladium activation, peptization treatment, and electroless plating conductive treatment on the reinforced polyimide foam to form a first metal layer; performing electro-deposition on one side of the first metal layer to obtain a second metal layer with a thickness gradient, wherein the first metal layer uniformly adheres to the inner and outer surfaces of the reinforced polyimide foam to form a three-dimensional continuous conductive structure, and the second metal layer grows on one side of the outer surface of the first metal layer; this integrated shielding foam has good bending resistance while achieving a good shielding effect; due to the inconsistent metal layer structures on both sides, the loss modes and paths of electromagnetic waves are also inconsistent, which can well meet the requirements of some special devices for materials with two-sided anisotropic shielding performance.

The invention relates to the field of preparation of pseudo-boehmite, and discloses pseudo-boehmite as well as a preparation method and application thereof, the content of sodium oxide in the pseudo-boehmite is lower than 0.3 wt%, the peptization index DI is 95-99.5%, the pore volume is 0.5-0.7 mL / g, and the retention rate of the pore volume after peptization is greater than 70%. The pseudo-boehmite has the advantages of high peptizing property, high pore volume retention rate after peptizing, large pore volume, small washing water consumption and low sodium oxide content.

A process for preparing C2 to C5 hydrocarbons includes introducing a feed stream including hydrogen gas and a carbon-containing gas selected from the group consisting of carbon monoxide, carbon dioxide, and mixtures thereof into a reaction zone of a reactor, and converting the feed stream into a product stream including C2 to C5 hydrocarbons in the reaction zone in the presence of a formed hybrid catalyst. The formed hybrid catalyst includes a metal oxide catalyst component comprising gallium oxide and zirconia, a microporous catalyst component that is a molecular sieve having 8-MR (Membered Ring) pore openings, and a binder including alumina, where the alumina binder is prepared as a colloidal solution, suspension, or gel by peptization of a binder precursor comprising oxides or hydroxides of aluminum with an organic carboxylic acid solution.

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.

The application discloses a high-strength, large-pore-volume and high-solid-content catalytic cracking catalyst and a preparation method thereof. The raw material of the catalytic cracking catalyst comprises a zeolite molecular sieve, a matrix and a binder. The matrix is composed of a gamma-alumina precursor with a peptization index of less than or equal to 50% and clay. The binder comprises a phosphorus-containing compound, an aluminum-containing compound and a multi-metal chelate. The catalytic cracking catalyst is prepared in a high-shear emulsifier. Compared with existing catalytic cracking catalysts, the catalytic cracking catalyst provided by the application has higher wear resistance, a large pore volume, a high molecular sieve content, a high solid content and excellent reaction performance.

This invention discloses a method for preparing an alumina support, belonging to the field of catalyst support technology. Addressing the shortcomings of existing alumina supports, such as difficulty in synergistically improving pore volume and strength, and poor hydrothermal stability, this invention uses boehmite as raw material and silk fibroin as a biomimetic template. The process involves solution preparation, sol-gel, template addition, molding, drying, and segmented calcination to obtain the product. The core innovation lies in utilizing the dual-structure characteristics of β-sheet crystalline and amorphous regions of silk fibroin, combined with the synergistic effect of selective β-sheet induction treatment and segmented calcination, to construct a hierarchical pore structure and strengthen the support framework. The resulting support has a pore volume of 1.2-1.8 mL / g, a lateral compressive strength of 220-350 N / cm, and after aging in steam at 800℃ for 12 h, a specific surface area and pore volume retention rate of ≥80% and ≥85%, respectively, overcoming the limitations of traditional techniques. This method is simple, compatible with existing production lines, and the product is suitable for harsh conditions such as heavy oil hydrogenation, showing broad application prospects.

This application discloses a method for preparing a rare-earth composite solid electrolyte coating material, relating to the field of solid-state battery technology, comprising the following steps: Step 1, modifying solid high-purity, highly colloidal alumina powder with rare-earth-based precursor powder to obtain a modified mixture; Step 2, subjecting the modified mixture to sequential acidification and high-speed stirring dispersion to obtain a slurry; Step 3, adding LATP solid electrolyte powder to the slurry and mixing and beating to obtain a coating material; wherein the modified mixture is obtained through surface coating modification or doping modification. This application has the effect of enhancing the ion transport capability of the coating material in solid-state batteries and improving chemical and thermal stability.

This invention provides a highly active catalytic cracking catalyst with low coke yield and its preparation method. The catalytic cracking catalyst comprises, by mass percentage, 26%–45% molecular sieve (dry basis), 20%–30% inorganic oxide binder (oxide basis), 0%–4% rare earth additive (oxide basis), 3%–10% magnesium-aluminum matrix material (dry basis), and 20%–50% clay (dry basis). The magnesium-aluminum matrix material is obtained by reacting boehmite with magnesium oxide via crystallization after solubilization. This catalytic cracking catalyst can increase the conversion depth and reduce coke yield. By reducing the coke yield of the catalytic cracking unit and increasing the yield of high-value-added products, it achieves a balance between the economic benefits of catalytic cracking and the goal of low-carbon and environmentally friendly development.

The present application relates to a kind of preparation methods of high-strength alumina pellets with large pore volume, by the hydrolysis of aluminium alcohol in the organic solvent containing only hydrogen bond donor is transferred to kettle and is aged to obtain pseudo-boehmite, the prepared pseudo-boehmite is made into aluminium sol, add gelling agent, drop into hot oil column and form, then after washing, drying, calcination is prepared.The pseudo-boehmite prepared in the present application has the characteristics of large pore volume and high peptization, and the specific surface area of the alumina pellets prepared after hot oil column forming is 158~289 m 2 / g, the pore size distribution is 2~46 nm, the pore volume is 0.50~0.88 cm 3 / g, and the strength is 43~73 N / grain.

The invention discloses a preparation method of spherical aluminum oxide. The preparation method comprises the following steps: mixing a proper amount of pseudo-boehmite and basic aluminum chloride sol to obtain mixed sol; adding the mixed sol into a balling column, and sequentially aging and roasting to obtain spherical aluminum oxide; wherein the upper layer in the column cavity of the balling column is an oil phase, and the lower layer is a salt phase. The method of mixing and peptizing the pseudo-boehmite and the basic aluminum chloride is used, so that the flowability and the solid content of a balling solution are increased, and the hydrothermal stability is improved. In the balling process, a mixed solution of inorganic ammonium salt and organic amine is adopted as a forming solution, and compared with ammonia water, poison and pollution can be remarkably reduced, so that the production process is safer, green and environmentally friendly. The spherical alumina carrier prepared by the method disclosed by the invention is uniform in particle size distribution (1.6-1.8 mm), large in surface area, suitable in pore structure, high in mechanical strength and good in hydrothermal stability.

The application discloses a high-strength and large-pore catalytic cracking aid and a preparation method thereof. The catalytic cracking aid comprises a molecular sieve, a substrate, a binder and a metal chelate. The substrate is composed of a gamma-alumina precursor with a peptization index of less than or equal to 50% and clay. The binder is prepared from a phosphorus-containing compound and an aluminum-containing compound. The molecular sieve has an MFI structure, and the molecular sieve with a pore diameter less than 0.7 nm accounts for 50 wt% to 100 wt% of the total amount of the molecular sieve. The binder, the metal chelate and the substrate are mixed in a high-shear emulsifier. The catalytic cracking aid provided by the application can keep excellent wear resistance and strength under the premise of high molecular sieve content and large pore volume through the cooperation between the components and the dispersion and emulsification of the components in the high-shear emulsifier in the preparation process. When used as a propylene aid and an octane aid, the catalytic cracking aid can not only make the device run smoothly, but also improve the propylene and octane content.

The preparation method comprises the following steps: firstly, impregnating organic amine or organic amine salt on a molecular sieve matrix by adopting an equivalent-volume impregnation method to prepare a modified molecular sieve, and then carrying out hydrothermal treatment on the modified molecular sieve by adopting an alkaline solution to prepare an active component, and finally, uniformly mixing the active component and the binder, acidifying and peptizing, kneading, extruding and molding, drying and roasting to obtain the mixed xylene olefin removal catalyst. The catalyst prepared by the invention can effectively remove trace olefin in mixed xylene under a non-hydrogen condition; the catalyst can reduce the bromine index of the raw material by at least 70%, has the advantages of high activity, long service life, high hydrothermal stability and less aromatic loss, and prolongs the service life of the olefin removal catalyst to the greatest extent.

The application discloses a preparation method of GO / Al2O3 composite ceramic ultrafiltration membrane, and comprises the following steps: step one, weighing graphene oxide into a container, adding distilled water, stirring and dispersing on a constant-temperature water bath magnetic stirrer, and then using an ultrasonic dispersing instrument for ultrasonic dispersion to obtain a graphene oxide dispersion liquid; step two, weighing pseudoboehmite, dissolving the pseudoboehmite in the graphene oxide dispersion liquid, stirring and dispersing on the constant-temperature water bath magnetic stirrer, then using a constant-pressure dropping funnel to drop a calculated amount of nitric acid, continuing to stir and gelatinize, and obtaining a GO / AlOOH mixed sol; step three, weighing a PVA solution and the GO / AlOOH mixed sol with a mass ratio of 1:1, stirring, and obtaining a coating solution; and step four, using an immersion method to coat the coating solution on the surface of a substrate. The preparation method of the GO / Al2O3 composite ceramic ultrafiltration membrane is simple in technological process, friendly to the environment, smaller in ceramic membrane pore size, and stronger in permeability.

The application relates to an alumina powder and a preparation method thereof, and the method comprises the following steps: stirring pseudo-boehmite, an acid solution and an ammonium salt to obtain an alumina sol; wherein the pseudo-boehmite has set crystallization parameters; aging the alumina sol, and then drying and crushing the alumina sol to obtain the alumina powder. The application selects the pseudo-boehmite with the set crystallization parameters as a main raw material to realize the characteristics of good peptization, fast peptization rate, high peptization rate and low peptization viscosity of the pseudo-boehmite, hydrogen ions in the acid solution are used to break the oxygen bridge bonds in the pseudo-boehmite to generate a sol body with alumina hydrate (Al2O3.xH2O) as a gel nucleus, and the ammonium salt is used to reduce the sol viscosity, increase the alumina content in the slurry, and then obtain the alumina powder through aging, drying and crushing. The powder can be dissolved in water to obtain a transparent or translucent sol, so that the technical problem of poor water solubility of the existing alumina product is solved.

The invention relates to the technical field of industrial production of titanium dioxide by a sulfuric acid method, in particular to a high-activity rutile calcination seed crystal preparation method based on acid dissolution parameter optimization. A high-activity rutile calcined seed crystal preparation method based on acid dissolution parameter optimization comprises the following steps: reacting a preheated metatitanic acid solution with an alkali solution, and filtering to obtain a sodium titanate filter cake; adding desalted water into the sodium titanate filter cake for pulping to obtain sodium titanate slurry; adding hydrochloric acid into the sodium titanate slurry to obtain orthotitanic acid slurry; heating the orthotitanic acid slurry, adding hydrochloric acid to carry out peptization reaction, and continuously mixing after the hydrochloric acid is completely added and the temperature is raised to obtain rutile calcined seed crystals; according to the method, the activity of the rutile calcined seed crystal is effectively improved by adjusting the secondary acid adding temperature, the acid-titanium ratio and the speed of heating to boiling after secondary acid adding in the acid dissolution process, so that the specific surface area of the rutile calcined seed crystal is larger than or equal to 85 m < 2 > / g, and the rutile conversion rate of the rutile calcined seed crystal is larger than or equal to 98.5%.