A tank rotating vacuum furnace for producing silicon oxide and preparation method thereof

Abstract

A tank rotating vacuum furnace and preparation method for producing silicon 2 oxide, comprising at least one tank, the tank comprising a reaction part and a collection part, the tank being provided with a sealing connector so that the reaction part and the collection part in the tank are tightly connected. The reaction part is used to place raw materials, and the collection part is used to collect products. The reaction part is arranged in a heating furnace, and the collection part and the sealing connector are arranged outside the heating furnace. The tank is evacuated through an interface, and the tank is opened or closed by a sealing connector; a cooling device is provided on the collection part; the tank is assisted by external force applied by a hanging ring and a ball to realize the transfer of the tank from inside and outside the heating furnace; the device method adopts the manufacturing device. The problem of high energy consumption and low efficiency caused by the inability of previous silicon 2 oxide manufacturing equipment and preparation methods to produce continuously is solved.

Description

Technical Field

[0001] The invention relates to the technical field of silicon oxide production, and in particular to a tank rotating vacuum furnace for producing silicon oxide and a preparation method thereof. Background Art

[0002] Lithium-ion batteries have the characteristics of high voltage, high specific energy, long cycle life and environmental friendliness, and are ideal supporting power sources for portable electronics, mobile products and electric vehicles. As electronic products, especially smart phones, develop in the direction of miniaturization and portability, lithium-ion batteries are required to have higher and higher energy density. The key to improving the performance of lithium-ion batteries lies in increasing the energy density and cycle life of lithium-intercalated materials. However, the theoretical capacity of lithium-ion batteries with graphite and other materials as negative electrodes is only 375 mAh g -1 , which is far from meeting the requirements of energy storage devices in people’s daily lives. The development of new high-performance negative electrode materials has become a top priority.

[0003] Silicon monoxide is an important raw material for negative electrode materials of lithium-ion batteries. At present, most of the domestic silicon monoxide production equipment is a single vacuum furnace, which has low output and high energy consumption. At the same time, the sealing of the single vacuum furnace in the prior art is poor, and the batch stability is very poor. In addition, the heating time of the single vacuum furnace is long, and the waiting time for cooling is also long, which cannot achieve mass production of one furnace at the same time. The large demand of the industry is very weak, especially the development of silicon-based negative electrode materials for lithium-ion batteries cannot be met. Therefore, there is an urgent need for a multi-chamber horizontal vacuum furnace for producing silicon monoxide and a method for preparing silicon monoxide that can solve the above problems.

[0004] CN109210930A proposes a multi-chamber horizontal vacuum furnace for producing silicon monoxide and a method for preparing silicon monoxide. The multi-chamber horizontal vacuum furnace for producing silicon monoxide and the method for preparing silicon monoxide are provided. Multiple vacuum furnaces are integrated in a system for simultaneous heating and collection, which can play a role in reducing energy consumption to a certain extent. However, since the material replacement process takes a long time, it causes huge energy loss.

[0005] CN107249726B proposes a manufacturing device for silicon oxide compounds, in which the reaction part is arranged in a heating furnace, the collecting part and the opening are arranged outside the heating furnace, the collector is taken out by opening the opening, a new collector is put in and the opening is closed, and the heating furnace can work continuously without cooling the whole device. However, due to the limited reaction materials, large-scale continuous production cannot be achieved, and a large amount of energy loss occurs during the replacement of the collector.

[0006] CN107597025A proposes to solve the problem of continuous feeding and discharging of silicon monoxide under high temperature and high vacuum by using a vacuum screw feeding device and a receiving device, which has the characteristics of simple design and convenient cleaning and maintenance. However, since the vacuum screw feeding device and the receiving device are difficult to implement in mass production, the vacuum degree of the equipment is unstable, and the performance of the produced silicon monoxide is poor. Summary of the invention

[0007] The present invention solves the deficiencies of the above-mentioned technologies and provides a tank rotating vacuum furnace for producing silicon oxide and a preparation method. The tank rotating vacuum furnace for producing silicon oxide adopts a rotating tank design to achieve fully continuous production with high output, and does not need to stop heating during the production process, and has strong stability. The preparation method adopts the steps of material filling and reaction which are completely separated and do not affect each other, and the material input and output are convenient, thereby achieving continuous operation of the equipment, improving production efficiency, and being able to better meet industry needs.

[0008] The technical solution adopted by the present invention to solve the first technical problem is as follows: a tank rotating vacuum furnace for producing silicon 2 oxide, comprising at least one tank 1 and a heating furnace 7 corresponding to the tank 1, the tank 1 comprising a reaction part 2 and a collecting part 3, the reaction part 2 and the collecting part 3 are respectively provided with cavities to form a reaction chamber for placing raw materials and a collecting chamber for collecting reaction products, the reaction part 2 and the collecting part 3 are connected through a sealing connector 4, the sealing connector 4 makes the reaction part 2 of the tank 1 detachably connected to the collecting part 3, the heating furnace 7 is provided with a heating chamber matching the size of the reaction part 2 of the tank 1, the reaction part 2 of the tank 1 is arranged in the heating chamber of the heating furnace 7, the collecting part 3 and the sealing connector 4 are arranged outside the heating chamber of the heating furnace 7, and the tank 1 is provided with an interface 8 for vacuuming.

[0009] In this embodiment, valves are installed on the inlet and outlet of the reaction part 2 or the collection part 3, and the valves control the connection or sealing between the reaction chamber and the collection chamber.

[0010] In this embodiment, the interface 8 is disposed on the collecting portion 3 and communicated with the collecting chamber.

[0011] In this embodiment, the collecting portion 3 is further provided with a cooling device 9 for cooling the product in the collecting cavity.

[0012] In this embodiment, the cooling device 9 includes a cooling jacket sleeved outside the collecting portion 3 and a circulating cooling medium arranged in the cooling jacket, and the cooling medium is a combination of one or more of water, air, and inert gas.

[0013] In this embodiment, a lifting ring 10 is fixed on the top of the outer side of the collecting part 3 for easy lifting.

[0014] In this embodiment, the contact surface between the heating furnace 7 and the reaction part 2 is in rolling connection.

[0015] In this embodiment, the heating furnace 7 is composed of two half furnace bodies hingedly connected by a rotating shaft 12 .

[0016] In this embodiment, the tank bodies 1 are provided in plurality, and the heating furnace 7 is provided with a plurality of heating chambers corresponding to the tank bodies 1 .

[0017] A method for preparing silicon oxide, using the above-mentioned tank rotating vacuum furnace for producing silicon oxide, comprises the following steps:

[0018] Step 1: Open the sealed connector, separate the reaction part and the collection part, mix Si powder and SiO2 powder as raw materials and place them in the reaction part, and connect the reaction part and the collection part through the sealed connector;

[0019] Step 2, evacuate the tank through the interface;

[0020] Step 3: Load the assembled cans filled with raw materials into the heating chamber of the heating furnace in sequence through the auxiliary device lifting ring, and start the heating furnace;

[0021] Step 4, turning on the cooling device;

[0022] Step 5: After the raw materials in the tank have reacted completely, keep the heating furnace and the cooling device running, take the tank out of the heating furnace, put a new tank filled with raw materials and evacuated, and start the next round of reaction.

[0023] In this embodiment, in step five, after taking out the tank body from the heating furnace, the tank body is opened after the reaction is completed, the remaining raw materials in the reaction part are emptied, and new raw materials are loaded, the silicon oxide product in the collection part is poured out, the sealing connector is closed, and the tank body is vacuumed through the interface to prepare for the subsequent connection and loading.

[0024] In this embodiment, the loading capacity of the tank body is 1-300KG, the temperature of the heating furnace is 1200-1500°C, the vacuum degree of the tank body is maintained between 0.01-1000Pa, and the temperature of the collecting part is 300-1000°C.

[0025] In this embodiment, in step 5, the interval time between two rounds of reaction is 1-20 minutes.

[0026] The beneficial effects of the present invention are as follows:

[0027] (1) The tank body and the heating furnace can be separated, and the heating furnace does not need to be cooled, thus achieving fully continuous production;

[0028] (2) The tank body is cooled outside the heating body, and the cooling speed is faster, which can reduce the corresponding low-temperature side reactions in the tank body and speed up the removal time of silicon oxide products, thereby improving production efficiency;

[0029] (3) During the heating production process, the tank body can be filled with materials, the product can be taken out, and vacuuming can be carried out outside the heating furnace in advance, thereby further shortening the production time on the basis of continuous production, improving production efficiency, and increasing product capacity.

[0030] In summary, the heating furnace does not need to be cooled during the production process of the method, thereby realizing fully continuous production; the tank body is cooled outside the heating body, and the cooling speed is faster, thereby reducing the corresponding low-temperature side reactions in the tank body and accelerating the time for removing the silicon oxide product, thereby improving production efficiency; during the heating production process of the tank body, the tank body material filling, product removal, vacuuming and other processes can be carried out in advance outside the heating furnace, thereby further shortening the production time on the basis of continuous production, improving production efficiency and increasing product capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of a first embodiment of a tank-type rotating vacuum furnace for producing silicon oxide according to the present invention;

[0032] Figure 2 For the present invention Figure 1 A cross-sectional view of a tank body;

[0033] Figure 3 This is a schematic diagram of the structure of a second embodiment of a tank-type rotating vacuum furnace for producing silicon oxide according to the present invention;

[0034] Figure 4 For the present invention Figure 3 A cross-sectional view of a tank body;

[0035] Figure 5 It is a structural schematic diagram of a combination arrangement of multiple tank-type rotating vacuum furnaces for producing silicon 2 oxide according to the present invention;

[0036] Figure 6 The figure is a top view of a combination arrangement of multiple tank-type rotating vacuum furnaces for producing silicon 2 oxide according to the present invention.

[0037] In the figure, 1, tank body; 2, reaction part; 3, collection part; 4, sealing connector; 5, raw material; 6, collection product; 7, heating furnace; 8, interface; 9, cooling device; 10, lifting ring; 11, ball; 12, rotating shaft. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with embodiments and drawings.

[0039] The following is a preferred implementation of the embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the embodiment of the present invention. These improvements and modifications are also within the scope of protection requested by this patent application.

[0040] In each embodiment, the raw materials used are common commercially available products. Example 1

[0041] like Figure 1 , 2 As shown, a tank rotating vacuum furnace for producing silicon 2 oxide comprises a tank 1, the tank 1 comprises a reaction part 2 and a collecting part 3, the reaction part 2 and the collecting part 3 are respectively provided with a reaction chamber for placing raw materials and a collecting chamber for collecting the reaction products, the reaction part 2 and the collecting part 3 are connected through a sealing connector 4, so that the reaction part 2 and the collecting part 3 in the tank 1 are sealed and connected, and a valve is installed on the inlet and outlet of the reaction part 2 or the collecting part 3, and the valve controls the connection or sealing between the reaction chamber and the collecting chamber. The heating furnace 7 is provided with a heating chamber matching the size of the reaction part 2 of the tank 1, the reaction part 2 of the tank 1 is arranged in the heating chamber of the heating furnace 7, the collecting part 3 and the sealing connector 4 are arranged outside the heating furnace 7, and the tank 1 is provided with an interface 8 for vacuuming that is connected with the reaction chamber and the collecting chamber. In this embodiment, the interface 8 is arranged in the collecting part 3, so as to ensure the vacuum degree in the tank 1. The collecting part 3 is also provided with a cooling device 9 for cooling the product in the collecting chamber; a hanging ring 10 is fixed on the collecting part 3, and the contact surface between the heating furnace 7 and the reaction part 2 is in rolling connection. This rolling connection can be achieved by arranging balls 11 on the opposite side of the heating furnace 7 or the reaction part 2, so that the tank body 1 can be transferred from the heating furnace 7 through the hanging ring 10 after the reaction is completed; the cooling device 9 of this embodiment includes a cooling jacket sleeved on the outside of the collecting part 3 and a circulating cooling medium in the cooling jacket, and the cooling medium is one or more of water, air, and inert gas. This embodiment adopts circulating water cooling, which is low in cost.

[0042] During the reaction, the tank body 1 is vented through the interface 8 to make the vacuum degree in the tank body 1 meet the requirements. The heating furnace 7 heats the raw material 5 in the reaction part 2. The raw material 5 undergoes a chemical reaction to generate product vapor, and the product vapor enters the collection cavity of the collection part 3. Since the collection part 3 is located outside the heating furnace 7, the air temperature outside the collection part 3 is much lower than that of the heating furnace 7. At the same time, under the action of the cooling device 9, the product vapor condenses on the lining of the collection part 3 to form a solid product 6. After a production cycle, the heating furnace 7 and the cooling device 9 are kept running, the tank body 1 is taken out, and a new tank body 1 containing raw materials 5 and vacuumed is placed to start the next round of reaction. Repeat the above steps until the preparation is completed. In this process, the heating furnace does not need to be cooled, thus achieving fully continuous production; the tank body is cooled outside the heating body, and the cooling speed is faster, thereby reducing the corresponding low-temperature side reactions in the tank body and speeding up the removal time of silicon oxide products, thereby improving production efficiency; during the heating production process, the tank body can be filled with materials, the product is removed, and vacuuming is carried out in advance outside the heating furnace, thereby further shortening the production time on the basis of continuous production, improving production efficiency, and increasing product capacity.

[0043] The heating furnace 7 can be connected to the air, so as to realize electric heating or combustion heating. Electric heating includes medium and high frequency induction heating, microwave heating and resistance heating. Resistance heating includes silicon carbon rods, silicon molybdenum rods and graphite resistance heating. The fuel used for combustion heating includes natural gas, coal gas, gas, biomass gas or artificial gas. Compared with electric heating, combustion heating saves energy to a great extent. Due to the vacuum state in the tank body 1, the atmospheric pressure will be detrimental to the service life of the tank body 1. To ensure the service life of the tank body 1, in this embodiment, the tank body 1 is made of one or more of heat-resistant steel, ceramics, corundum, silicon carbide and carbon materials. To ensure sealing, easy processing and processing cost, heat-resistant steel is preferred, and the diameter of the tank body 1 is preferably 100mm to 1000mm, and the length of the tank body 1 is preferably 300mm to 5000mm.

[0044] The method for preparing silicon oxide compounds using the manufacturing equipment proposed in this embodiment is:

[0045] Step 1, open the sealing connector 4, separate the reaction part 2 and the collection part 3, place the mixed Si powder and SiO2 powder as the raw material 5 in the reaction part 2, and connect the reaction part 2 and the collection part 3 through the sealing connector 4;

[0046] Step 2: Vacuum the tank 1 through the interface 8.

[0047] Step 3, repeating steps 1 and 2, thereby assembling a plurality of tanks 1 filled with raw materials 5 and evacuated;

[0048] Step 4: sequentially load the assembled tanks 1 filled with raw materials 5 into the heating chamber of the heating furnace 7 through the auxiliary device lifting ring 10, and start the heating furnace 7;

[0049] Step 5, start the cooling device 9;

[0050] Step 6, after the raw material 5 in the tank body 1 has reacted completely, keep the heating furnace 7 and the cooling device 9 running, take out the tank body 1 from the heating furnace 7, put in a new tank body 1 filled with raw material 5 and evacuated, and start the next round of reaction.

[0051] Step seven, repeat steps one to six until the preparation is completed.

[0052] Step eight, open the tank body 1 after the reaction is completed, empty the remaining raw material 5 in the reaction part 2, and load new raw material 5, pour out the silicon oxide product 6 in the collection part 3, close the sealing connector 4, and evacuate the tank body 1 through the interface 8.

[0053] In this embodiment, in order to achieve higher production efficiency and lower cost, the loading capacity of the tank body 1 is preferably not more than 300KG, the temperature of the heating furnace 7 is adjusted between 1200-1500°C, the vacuum degree of the tank body 1 is maintained between 0.01-1000Pa, and the cooling device 9 allows the temperature of the collecting part 3 to be adjusted between 300-1000°C; the interval time between the two rounds of reaction in step six is ​​1-20 minutes. Example 2

[0054] like Figure 3 , 4 As shown, the difference between this embodiment and embodiment 1 is that the heating furnace 7 is composed of two half furnace bodies hinged by a rotating shaft 12. When it is necessary to put in or take out the can body 1, the half furnace body is rotated to open or close the heating furnace 7, and the can body 1 is loaded into or taken out of the heating furnace 7 through the lifting ring 10. Under the premise of ensuring good sealing, this embodiment further improves the speed and production efficiency of preparing products. Example 3

[0055] like Figure 5 , 6 As shown, the difference between this embodiment and embodiment 1 is that this equipment includes 16 tank bodies 1. For those skilled in the art, the number of tank bodies 1 is reasonably set according to production needs and the size of the heating furnace 7. This number is not limited to this embodiment. This embodiment sets multiple tank bodies 1, which further improves the use efficiency of the heating furnace and the speed and efficiency of preparing products.

[0056] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A tank rotating vacuum furnace for producing silicon oxide, characterized in that: The invention comprises at least one tank body (1) and a heating furnace (7) corresponding to the tank body (1), wherein the tank body (1) comprises a reaction part (2) and a collection part (3), wherein the reaction part (2) and the collection part (3) are respectively provided with cavities to form a reaction chamber for placing raw materials and a collection chamber for collecting products after the reaction, wherein the reaction part (2) and the collection part (3) are connected via a sealing connection piece (4), wherein the sealing connection piece (4) enables the reaction part (2) of the tank body (1) to be detachably connected to the collection part (3), and wherein the heating furnace (7) is provided with a cavitation chamber corresponding to the reaction part (2) of the tank body (1). ) with a heating chamber of a matching size, the reaction part (2) of the tank body (1) being arranged in the heating chamber of the heating furnace (7), the collecting part (3) and the sealing connection part (4) being arranged outside the heating chamber of the heating furnace (7), the tank body (1) being provided with an interface (8) for evacuating a vacuum; a lifting ring (10) for facilitating lifting is fixed on the top of the outside of the collecting part (3), the contact surface between the heating furnace (7) and the reaction part (2) being in rolling connection, the tank body (1) being provided with a plurality of them, and the heating furnace (7) being provided with a plurality of heating chambers corresponding to the tank body (1).

2. The tank rotating vacuum furnace for producing silicon 2 oxide according to claim 1, characterized in that: A valve is installed on the inlet and outlet of the reaction part (2) or the collection part (3), and the valve controls the connection or sealing between the reaction chamber and the collection chamber.

3. The tank rotating vacuum furnace for producing silicon 2 oxide according to claim 1, characterized in that: The interface (8) is arranged on the collecting portion (3) and is in communication with the collecting chamber.

4. The tank rotating vacuum furnace for producing silicon oxide according to claim 1, characterized in that: The collecting portion (3) is also provided with a cooling device (9) for cooling the product in the collecting cavity.

5. The tank rotating vacuum furnace for producing silicon 2 oxide according to claim 4, characterized in that: The cooling device (9) comprises a cooling jacket sleeved outside the collecting portion (3) and a circulating cooling medium arranged in the cooling jacket, wherein the cooling medium is a combination of one or more of water, air and inert gas.

6. The tank rotating vacuum furnace for producing silicon 2 oxide according to claim 1, characterized in that: The heating furnace (7) is composed of two half furnace bodies hingedly connected via a rotating shaft (12).

7. A method for preparing silicon oxide, using the tank rotating vacuum furnace for producing silicon oxide according to claim 4 or 5, characterized in that: The steps include: Step 1: Open the sealed connector, separate the reaction part and the collection part, mix Si powder and SiO2 powder as raw materials and place them in the reaction part, and connect the reaction part and the collection part through the sealed connector; Step 2, vacuum the tank through the interface; Step 3: Load the assembled cans filled with raw materials into the heating chamber of the heating furnace in sequence through the auxiliary device lifting ring, and start the heating furnace; Step 4, turning on the cooling device; Step 5: After the raw materials in the tank have reacted completely, keep the heating furnace and the cooling device running, take the tank out of the heating furnace, put a new tank filled with raw materials and evacuated, and start the next round of reaction.

8. The method for preparing silicon 2 oxide according to claim 7, characterized in that: In step five, after taking the tank body out of the heating furnace, open the tank body after the reaction is completed, empty the remaining raw materials in the reaction part, load new raw materials, pour out the silicon oxide product in the collection part, close the sealing connector, and evacuate the tank body through the interface to prepare for subsequent connection and loading.

9. The method for preparing silicon 2 oxide according to claim 7, characterized in that: The loading capacity of the tank body is 1-300KG, the temperature of the heating furnace (7) is 1200-1500°C, the vacuum degree of the tank body (1) is maintained between 0.01-1000Pa, and the temperature of the collecting part (3) is 300-1000°C.

10. The method for preparing silicon 2 oxide according to claim 7, characterized in that: In step 5, the interval time between two rounds of reaction is 1-20 minutes.

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