阅读说明：本技术 一种小颗粒氧化铝粉和大颗粒氧化铝粉的混合双性剂及工艺流程 (Mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder and process flow ) 是由 薛德运 崔巍 于 2020-12-18 设计创作，主要内容包括：本发明属于氧化铝粉末技术领域,具体涉及一种小颗粒氧化铝粉和大颗粒氧化铝粉的混合双性剂及工艺流程,这种小颗粒氧化铝粉和大颗粒氧化铝粉的混合双性剂及工艺流程包括：第一氧化铝粉末和第二氧化铝粉末；所述第一氧化铝粉末的粒径为2-2.2微米；所述第二氧化铝粉末的粒径为50-60纳米。所述第一氧化铝粉末为40-50wt％；所述第二氧化铝粉末为50-60wt％。所述第一氧化铝粉末内掺有0.2-0.5wt％磁粉。所述第二氧化铝粉末内掺有0.2-0.5wt％磁粉。这种小颗粒氧化铝粉和大颗粒氧化铝粉的混合双性剂及工艺流程具有增加氧化铝粉末热收缩性和致密性的效果。(The invention belongs to the technical field of alumina powder, and particularly relates to a mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder and a process flow, wherein the mixed amphiprotic agent of the small-particle alumina powder and the large-particle alumina powder comprises the following steps: first and second alumina powders; the grain size of the first aluminum oxide powder is 2-2.2 microns; the particle size of the second aluminum oxide powder is 50-60 nanometers. The first aluminum oxide powder is 40-50 wt%; the second aluminum oxide powder is 50-60 wt%. The first alumina powder is doped with 0.2-0.5 wt% of magnetic powder. The second aluminum oxide powder is doped with 0.2-0.5 wt% of magnetic powder. The mixed amphiprotic agent of the small-particle alumina powder and the large-particle alumina powder and the process flow have the effect of increasing the heat shrinkage and compactness of the alumina powder.)

1. A mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder is characterized by comprising the following components in percentage by weight:

first and second alumina powders;

the grain size of the first aluminum oxide powder is 2-2.2 microns;

the particle size of the second aluminum oxide powder is 50-60 nanometers.

2. The mixed binary agent of small-particle alumina powder and large-particle alumina powder according to claim 1,

the first aluminum oxide powder is 40-50 wt%;

the second aluminum oxide powder is 50-60 wt%.

3. The mixed binary agent of small-particle alumina powder and large-particle alumina powder according to claim 2,

the first alumina powder is doped with 0.2-0.5 wt% of magnetic powder.

4. The mixed binary agent of small-particle alumina powder and large-particle alumina powder according to claim 3,

the second aluminum oxide powder is doped with 0.2-0.5 wt% of magnetic powder.

5. A mixed amphiprotic agent process flow of small-particle alumina powder and large-particle alumina powder is characterized by comprising the following steps:

the method comprises the following steps: calcining industrial alumina raw material at high temperature;

step two: coarse grinding the alumina raw material by a coarse grinding machine to obtain alumina with the grain diameter of less than 50 mm;

step two: finely grinding the alumina raw material by a fine grinding machine to obtain first alumina powder with the particle size of 2-2.2 microns;

step three: taking out part of the first aluminum oxide powder, grinding the part of the first aluminum oxide powder by a special fine grinding device (1) into first aluminum oxide powder with the particle size of 50-60 nanometers or less;

step four: primarily filtering the first alumina powder through a coarse filtration screen to remove alumina with a particle size of 2.2 microns or more, and filtering the first alumina powder through the coarse filtration screen again to remove alumina powder with a particle size of 2 microns or less.

6. The mixed binary agent process of claim 5, wherein the small-particle alumina powder and the large-particle alumina powder are mixed together,

the specially-made fine powder device comprises a driving motor (101) and a grinding cavity (2) sleeved with a driving shaft of the driving motor (101), wherein the driving shaft of the driving motor (101) is provided with a grinding rod (102), a magnetic rod (201) is arranged in the grinding cavity (2), a pushing assembly (3) for pushing the magnetic rod (201) is arranged in the grinding cavity (2) and used for enabling the magnetic rod (201) to abut against the grinding rod (102), and the grinding rod (102) is suitable for grinding the magnetic rod (201) together when the aluminum oxide powder is ground, so that micro magnetic powder is generated.

7. The mixed binary agent process of claim 6, wherein the small-particle alumina powder and the large-particle alumina powder are mixed together,

pusher is including setting up pushing spring (301) on grinding chamber (2), the inboard that pushes up spring (301) is provided with secondary and promotes spring (302), the end that pushes up spring (301) sets up bar magnet (201), the both sides that push up spring (301) are provided with clamp plate (303), clamp plate (303) are provided with the spout that supplies to promote spring (301) shrink and stretch out.

Technical Field

The invention belongs to the technical field of alumina powder, and particularly relates to a mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder and a process flow.

Background

A "lithium battery" is a type of battery using a nonaqueous electrolyte solution with lithium metal or a lithium alloy as a positive/negative electrode material. Because the chemical characteristics of lithium metal are very active, the requirements on the environment for processing, storing and using the lithium metal are very high. Lithium batteries can be broadly classified into two types: lithium metal batteries and lithium ion batteries. Lithium ion batteries do not contain lithium in the metallic state and are rechargeable. In the process of manufacturing the lithium battery, the anode and the cathode need to be separated by the separator, and the separator needs to be covered with a layer of alumina as a heat insulation layer.

Alumina, formula Al2O3, is a high hardness compound, an ionic crystal that has a melting point of 2054 ℃ and a boiling point of 2980 ℃ and is ionizable at high temperatures, and is commonly used in the manufacture of refractory materials.

The lithium battery diaphragm is a film (PE, PP, PE-PP composite film) with a microporous structure, and is used as a key structural component which has the most technical barrier in the lithium battery industry, and the performance of the lithium battery diaphragm directly influences the battery capacity, internal resistance, cycle performance, current density and safety performance. The lithium battery has the biggest potential safety hazard that the battery randomly generates internal short circuit, and in order to solve the potential safety hazard, a thin aluminum oxide coating needs to be coated on a lithium battery diaphragm. The method is used for preparing the lithium battery ceramic membrane alumina, generally requires that the purity is more than or equal to 99.9 percent, the particle size distribution is uniform, the particles are monodisperse particles, and the maximum particle size is less than 3 mu m.

The patent technology of 'a production process of alumina micropowder' (CN103028482A) discloses a sorting process of alumina powder, which adopts a sedimentation method and an overflow method to extract the alumina powder with two particle sizes, and then carries out mixing overflow treatment to obtain the alumina powder for the abrasive material, and has the characteristics of designable particle size and obviously reduced scratch in the grinding process. However, the method has the disadvantages of complex process, low production efficiency and high cost. The patent technology of "an active calcined alumina micropowder and its preparation method" (CN104108923A) uses industrial alumina, aluminium hydroxide as main materials, grinding aid and compound mineralizer as auxiliary materials, all the raw materials are mixed and ball-milled, then pelletized, dried and slowly calcined in a shaft kiln at low temperature to obtain an active calcined alumina micropowder. The patent technology only analyzes the calcining process, but does not control the particle size distribution of the alumina powder, and the prepared alumina micropowder cannot improve the performance of the castable to the maximum extent. The patent technology of the preparation method of the alumina powder (CN103351012A) is that anhydrous aluminum chloride and ammonia water are used as raw materials, the anhydrous aluminum chloride is firstly sublimated and desublimated and purified, then the anhydrous aluminum chloride is prepared into solution, the solution is neutralized with the ammonia water under stirring to obtain the aluminum hydroxide powder, and the aluminum hydroxide powder is dried and calcined at high temperature to obtain the high-purity alumina powder. The prepared alumina powder has the characteristic of high purity, but the granularity of the alumina powder is not adjusted and optimized, so that the fluidity, the density and the mechanical strength of the castable are not improved, and the production cost is higher.

The patent technology of 'a preparation method of nano-scale alumina powder' (CN102849762A) adopts the reaction of aluminum powder and solvent n-hexanol to prepare an aluminum alkoxide compound, and then the nano-scale alumina powder product is prepared by the processes of hydrolysis, distillation, separation and roasting. The product produced by the method has the advantages of low impurity content, large pore volume, large specific surface area and reasonable pore size distribution, and is used as an industrial catalyst carrier. A process for preparing the ultrapure nano-class alumina powder (CN1374251A) includes such steps as reaction between pure aluminium and low-carbon alcohol to generate aluminium alkoxide, vacuum complexing, rectifying, purifying to obtain high-purity aluminium alkoxide, dissolving it in high-purity non-polar solvent, hydrolyzing with ultrapure water to generate aluminium hydroxide, ageing, washing, filtering, and high-temp heat treating. The ultrapure nanometer alumina powder prepared by the method can be applied to the fields of fluorescent materials, catalyst carriers, artificial crystals, electronic elements, grinding materials and the like. However, the technical schemes disclosed in the two patents have high production cost and concentrated particle size of alumina powder, are mostly used for high-end ceramic products such as catalyst carriers and are not suitable for being used as a matrix of castable.

In conclusion, most of the alumina micro powder in the prior art is in unimodal distribution and concentrated in particle size, so that the alumina micro powder only has single characteristic.

Disclosure of Invention

The invention aims to provide a mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder, so as to achieve the purpose that the alumina on a lithium battery diaphragm can have more characteristics.

In order to solve the technical problem, the invention provides a mixed binary agent of small-particle alumina powder and large-particle alumina powder, which comprises the following components in part by weight: first and second alumina powders; the grain size of the first aluminum oxide powder is 2-2.2 microns; the particle size of the second aluminum oxide powder is 50-60 nanometers.

Preferably, the first alumina powder is 40 to 50 wt%; the second aluminum oxide powder is 50-60 wt%.

Preferably, the first alumina powder is doped with 0.2 to 0.5 wt% of magnetic powder.

Preferably, 0.2 to 0.5 weight percent of magnetic powder is doped in the second aluminum oxide powder.

The lithium battery interlayer has the beneficial effects that the lithium battery interlayer has different characteristics due to the two-grain-size aluminum oxide, when the lithium battery is charged, the temperature of the lithium battery rises, the first aluminum oxide powder with thicker grains can have good thermal shrinkage, and when the lithium battery is at high temperature, the first aluminum oxide powder shrinks, the density is increased, the texture is hardened, and the influence of the high temperature of the lithium battery on the sealing performance of the aluminum oxide interlayer is reduced. Due to the finer particles of the finer alumina powder, gaps between the alumina particles are smaller when the alumina particles are arranged, and the alumina powder has good compactness.

In another aspect, the present invention further provides a mixed binary agent process flow of small-particle alumina powder and large-particle alumina powder, comprising the following steps: the method comprises the following steps: calcining industrial alumina raw material at high temperature; step two: coarse grinding the alumina raw material by a coarse grinding machine to obtain alumina with the grain diameter of less than 50 mm; step two: finely grinding the alumina raw material by a fine grinding machine to obtain first alumina powder with the particle size of 2-2.2 microns; step three: taking out part of the first aluminum oxide powder, grinding the part of the first aluminum oxide powder by a special fine grinding device into first aluminum oxide powder with the particle size of 50-60 nanometers or less;

step four: primarily filtering the first alumina powder through a coarse filtration screen to remove alumina with a particle size of 2.2 microns or more, and filtering the first alumina powder through the coarse filtration screen again to remove alumina powder with a particle size of 2 microns or less.

Preferably, purpose-built fine powder device includes that driving motor and cover are located the chamber of polishing of driving motor's drive shaft, driving motor's drive shaft is provided with the stick of polishing, it is provided with the bar magnet to polish the intracavity, it is provided with the propelling movement subassembly of propelling movement bar magnet to polish the intracavity for with the bar magnet butt in the stick of polishing, be suitable for the stick of polishing and polish the bar magnet together when polishing alumina powder, produce micro magnetic.

Preferably, the pushing device comprises a pushing spring arranged on the grinding cavity, a secondary pushing spring is arranged on the inner side of the pushing spring, a magnetic rod is arranged at the tail end of the pushing spring, clamping plates are arranged on two sides of the pushing spring, and sliding grooves for the pushing spring to contract and stretch out are formed in the clamping plates.

The method has the beneficial effects that the aluminum oxide powder with proper specification can be screened in the processing step, so that the aluminum oxide powder with double-peak characteristics can be prepared, and meanwhile, the magnetic powder can be added in the grinding process through the magnetic rod in the grinding cavity.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic view of the structure of the special fine grinding device of the present invention.

In the figure:

1. specially manufacturing a fine grinding device; 101. a drive motor; 102. grinding a rod;

2. grinding the cavity; 201. a magnetic bar;

3. a push assembly; 301. a push spring; 302. a secondary pushing spring; 303. and (5) clamping the plate.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

a mixed binary agent of small-particle alumina powder and large-particle alumina powder comprises: first and second alumina powders; the particle size of the first aluminum oxide powder is 2-2.2 microns; the particle size of the second alumina powder is 50-60 nm. In this example, the first alumina powder is 40 to 50 wt%; the second alumina powder is 50-60 wt%. The thermal shrinkage and compactness of the alumina powder are improved by the alumina powder with two grain sizes.

In this embodiment, 0.2 to 0.5 wt% of magnetic powder is doped in the first alumina powder. The second alumina powder is doped with 0.2-0.5 wt% of magnetic powder. The compactness of the alumina powder is improved by the added magnetic powder, and the alumina powder has micro adsorption force by the magnetic powder, so that scrap iron or other iron products in the positive electrode and the negative electrode are adsorbed, and the positive electrode and the negative electrode are purified. In this embodiment, the magnetic powder has a particle size of 1 to 1.2 μm, and can fill gaps between the first alumina powder particles, and does not easily affect the denseness of the second alumina, and assists in enhancing the denseness of the second alumina.

In summary, the two particle sizes of alumina enable the lithium battery interlayer to have different characteristics, when the lithium battery is charged, the temperature of the lithium battery rises, the first alumina powder with thicker particles can have good thermal shrinkage, and when the lithium battery is at high temperature, the first alumina powder shrinks, the density is increased, the texture is hardened, and the influence of the high temperature of the lithium battery on the sealing performance of the alumina interlayer is reduced. Due to the finer particles of the finer alumina powder, gaps between the alumina particles are smaller when the alumina particles are arranged, and the alumina powder has good compactness.

Example 2:

a mixed double-performance agent of small-particle alumina powder and large-particle alumina powder adopts 44.5 wt% of first alumina, 0.5 wt% of magnetic powder and 55 wt%, and experiments show that compared with alumina particles with single particle size, the heat shrinkage of twenty percent is improved, and the heat resistance of an alumina interlayer is improved; the compactness of twenty percent is improved, and the isolation performance of the alumina interlayer is improved.

Example 3: a process flow of a mixed amphiprotic agent of small-particle alumina powder and large-particle alumina powder comprises the following steps: the method comprises the following steps: calcining industrial alumina raw material at high temperature; step two: coarse grinding the alumina raw material by a coarse grinding machine to obtain alumina with the grain diameter of less than 50 mm; step two: finely grinding the alumina raw material by a fine grinding machine to obtain first alumina powder with the particle size of 2-2.2 microns; step three: taking out part of the first aluminum oxide powder, grinding the part of the first aluminum oxide powder by a special fine grinding device 1 into first aluminum oxide powder with the particle size of 50-60 nanometers or less;

step four: primarily filtering the first alumina powder through a coarse filtration screen to remove alumina with the particle size of more than 2.2 microns, and filtering the first alumina powder through the coarse filtration screen again to remove alumina powder with the particle size of less than 2 microns, wherein the rest is the first alumina powder with the particle size of 2-2.2 microns.

As shown in FIG. 1, the special fine powder device comprises a driving motor 101 and a grinding chamber 2 sleeved on a driving shaft of the driving motor 101, wherein the driving shaft of the driving motor 101 is provided with a grinding rod 102. The driving motor 101 drives the driving shaft to rotate, and drives the polishing rod 102 to polish the alumina.

In this embodiment, a magnetic rod 201 is disposed in the polishing cavity 2, and a pushing assembly 3 for pushing the magnetic rod 201 is further disposed in the polishing cavity 2, so as to push the magnetic rod 201 against the polishing rod 102, and the polishing rod 102 is adapted to polish the magnetic rod 201 together when polishing alumina powder, thereby generating micro magnetic powder.

As shown in fig. 1, the pushing device includes a pushing spring 301 disposed on the grinding chamber 2, a secondary pushing spring 302 is disposed inside the pushing spring 301, a magnetic rod 201 is disposed at the end of the pushing spring 301, clamping plates 303 are disposed on two sides of the pushing spring 301, and the clamping plates 303 are provided with sliding grooves for the pushing spring 301 to contract and extend.

In conclusion, the processing steps of the present invention can screen alumina powder with proper specification to prepare alumina powder with bimodal characteristics, and simultaneously, magnetic powder can be added during the grinding process by grinding the magnetic rods 201 in the cavity 2.

All the components selected in the application are general standard components or components known by those skilled in the art, and the structure and the principle of the components can be known by technical manuals or by routine experiments.

In the description of the embodiments of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some communication interfaces, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment. In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.