An integrated impregnation and roasting device and method

Abstract

The present invention relates to an integrated impregnation and roasting device and method, belonging to the technical field of graphite preparation. The integrated impregnation and roasting device of the present invention includes an integrated impregnation and roasting unit, which includes an integrated impregnation and roasting tank; an impregnating agent storage and melting unit, which includes an impregnating agent storage tank, and the impregnating agent storage tank is communicated with the integrated impregnation and roasting tank; a roasting medium circulation unit, which includes a roasting medium storage tank, and the roasting medium storage tank is communicated with the integrated impregnation and roasting tank; a heating and cooling unit, which is used to heat or cool the integrated impregnation and roasting tank, the impregnating agent storage tank and the roasting medium storage tank respectively; a vacuum pressurization unit, which is communicated with the integrated impregnation and roasting tank. The present invention realizes that both the impregnation process and the roasting process can be completed on the same device, and the roasting includes not only atmospheric pressure roasting but also pressure roasting, greatly reducing the manual operations of frequent loading and unloading.

Description

Technical Field

[0001] The present invention belongs to the technical field of graphite preparation, and particularly relates to an integrated impregnation and roasting device and method. Background Art

[0002] High-performance graphite (mainly high-strength and high-density graphite) is a new type of material with multiple uses and high added value, and has been widely used in industrial sectors such as metallurgy, machinery, electric engineering, petroleum, chemical industry, as well as atomic energy, aerospace and other high-tech fields. At present, due to market demand, especially the sharp increase in the demand of the photovoltaic industry and the semiconductor industry, the output of high-performance graphite materials has increased significantly.

[0003] The traditional production method of graphite products is to knead calcined coke and binder pitch into a shape, roll it into sheets, grind it into powder, roast it, impregnate it, perform secondary roasting, or perform multiple impregnations and multiple roastings, and then perform graphitization treatment. The preparation of high-performance graphite, especially high-strength and high-density graphite, mainly relies on multiple impregnations, multiple roastings or pressure roasting to improve the density and strength of the product. The main process of impregnation is to evacuate and pressurize the roasted semi-finished product, so that the impregnating medium coal tar pitch can be maximally immersed into the internal pores of the product, and effectively pyrolyzed to fill the pores, increasing the residual carbon rate, thereby improving the density and strength of the product. The roasting process is a process of heat-treating the formed green body in a protective medium in a heating furnace under airtight conditions at a certain heating rate.

[0004] There are mainly two problems in the preparation of graphite products, especially high-performance products, in the prior art: one is multiple impregnation and roasting. At least one impregnation and two roastings, and at most three impregnations and four roastings. Since the impregnation system and the roasting system are currently completely two independent devices, the impregnation process is completed in the impregnation system, while the roasting process is generally completed in an atmospheric furnace or a high-pressure furnace. The frequent loading and unloading between the impregnation system and the roasting system for the multiple impregnation and roasting process need to be operated manually, which not only increases the labor cost, but also reduces the production efficiency and increases the production cost of high-performance graphite; the other is that when roasting in an atmospheric roasting furnace or a high-pressure roasting furnace, resistance bands are used for heating and heat transfer is carried out through gas. In order to make the heating uniform and controllable, the roasting device needs to be provided with temperature control zones with different heating powers and a temperature equalizing system. The furnace body design is very complicated. At the same time, the roasted product also needs to be loaded into a roasting barrel and filled with yellow sand as a heat insulation filler. After roasting, the roasted product and the yellow sand filler are separated manually to complete the discharging from the barrel or a special suction device is used to complete the separation of the roasted product and the yellow sand filler, which increases the labor intensity and production cost.

[0005] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Invention

[0006] To solve the technical problems in the prior art that impregnation and roasting are carried out in two devices during the preparation process of graphite products, resulting in frequent loading and unloading, which is time-consuming and laborious, the present invention provides an integrated device and method for impregnation and roasting.

[0007] In a first aspect of the present invention, there is provided an integrated device for impregnation and roasting, characterized by comprising:

[0008] An integrated impregnation and roasting unit, which includes an integrated impregnation and roasting tank;

[0009] An impregnating agent storage and melting unit, which includes an impregnating agent storage tank, and the impregnating agent storage tank is communicated with the integrated impregnation and roasting tank;

[0010] A roasting medium circulation unit, which includes a roasting medium storage tank, and the roasting medium storage tank is communicated with the integrated impregnation and roasting tank;

[0011] A heating and cooling unit, which is used to heat or cool the integrated impregnation and roasting tank, the impregnating agent storage tank and the roasting medium storage tank respectively;

[0012] A vacuum pressurization unit, which is communicated with the integrated impregnation and roasting tank.

[0013] In some embodiments, the heating and cooling unit includes a heating furnace, a heat exchanger and heating coils connected in sequence at the head and tail. In order to increase the power of the heat transfer medium, a heat transfer medium circulation pump is arranged at the outlet of the heating furnace or the outlet of the heat exchanger; a heat transfer medium filter can also be arranged on the pipeline of the heat transfer medium to prevent impurities generated during the circulation of the heat transfer medium from entering the heating furnace, resulting in coking or other adverse reactions.

[0014] In some embodiments, the heating coils include a first heating coil, a second heating coil and a third heating coil, and the first heating coil, the second heating coil and the third heating coil are arranged in parallel. Flow valves for controlling the flow rate are respectively arranged on the inlet pipelines of each heating coil, and the temperature is controlled by controlling the opening degree of the flow valves.

[0015] In some embodiments, the first heating coil is wrapped around the outer wall of the impregnating agent storage tank, the second heating coil is wrapped around the outer wall of the integrated impregnation and roasting tank, and the third heating coil is wrapped around the outer wall of the roasting medium storage tank.

[0016] In some embodiments, the heat exchanger is also respectively provided with a cooling water inlet and a cooling water return port. After roasting, it is used to assist in cooling by circulating cooling water through the heat exchanger.

[0017] In some embodiments, the integrated impregnation and roasting unit, the impregnating agent storage and melting unit, the roasting medium circulation unit, and the heating and cooling unit are respectively provided with driving devices. Preferably, driving circulation pumps are respectively arranged on the outlet pipelines of the integrated impregnation and roasting tank, the outlet pipeline of the impregnating agent storage tank, and the outlet pipeline of the roasting medium storage tank to increase the circulation power of the corresponding liquids in the pipelines; in addition, filters can be respectively arranged on the inlet pipelines of the integrated impregnation and roasting tank, the inlet pipeline of the impregnating agent storage tank, and the inlet pipeline of the roasting medium storage tank to prevent impurities from being introduced into the integrated impregnation and roasting tank.

[0018] In some embodiments, a flue gas treatment unit is further included, and the flue gas treatment unit is respectively communicated with the integrated impregnation and roasting tank, the impregnating agent storage tank, the roasting medium storage tank, and the heating furnace. The flue gas treatment unit includes a blower and a flue gas treatment device, wherein one end of the flue gas treatment device is respectively communicated with the integrated impregnation and roasting tank, the impregnating agent storage tank, the roasting medium storage tank, and the heating furnace, and the other end is communicated with the blower. The flue gas treatment device can be an activated carbon adsorption device or an electrostatic purification device, etc.

[0019] In some embodiments, the impregnating agent is a lubricant;

[0020] and / or, the melting point temperature of the roasting medium is below 100 °C, and the temperature can reach above 900 °C after heating;

[0021] and / or, the melting point of the heat transfer medium in the heating and cooling unit (12) is lower than 80 °C, and the temperature can reach above 1000 °C after heating.

[0022] In some embodiments, the lubricant is selected from one or more of asphalt, resin, grease, and paraffin;

[0023] and / or, the roasting medium is molten salt, and the molten salt is selected from one or more of fluoride salts, nitrate salts, chloride salts, carbonate salts, and sulfate salts;

[0024] and / or, the heat transfer medium is molten salt.

[0025] The second aspect of the present invention provides an integrated impregnation and roasting method based on the above device, including the following steps:

[0026] Preparation: Heat and melt the impregnating agent in the impregnating agent storage tank and the roasting medium in the roasting medium storage tank through the heating and cooling unit, and preheat the integrated impregnation and roasting tank and the green body after roasting therein;

[0027] Vacuum pumping: Vacuum pump the integrated impregnation and roasting tank through the vacuum pressurization unit;

[0028] Primary impregnation: The molten impregnating agent is pumped into the integrated impregnation and baking tank. After reaching the set liquid level, nitrogen is pressurized through the vacuum pressurization unit until the impregnation process is completed.

[0029] Secondary baking: The excess impregnating agent in the integrated impregnation and baking tank is discharged, and the baking medium is pumped into the integrated impregnation and baking tank for heating and baking.

[0030] Subsequent impregnation and baking are carried out according to the steps of the above primary impregnation and secondary baking respectively.

[0031] Compared with the prior art, the technical effects achieved by the present invention are as follows:

[0032] (1) The present invention realizes that both the impregnation process and the baking process can be completed on the same device. The baking includes not only atmospheric baking but also pressure baking, greatly reducing the manual operations of frequent loading and unloading. It can very efficiently carry out multiple impregnation and multiple baking processes, or pressure baking process to prepare high-performance graphite (mainly high-strength and high-density graphite), and the production plan is flexibly adjustable.

[0033] (2) When baking in the present invention, the blank is directly immersed in the baking medium, effectively utilizing heat energy and avoiding processes such as yellow sand heat preservation in the traditional process. The baking process is not only simpler but also more efficient, greatly simplifying the baking device and saving a large amount of manpower and material resources for loading and unloading the cylinder during the baking process in the prior art.

[0034] (3) In the traditional process, atmospheric baking is often used during baking. The vacuum pressurization system of the present invention can not only be used for impregnation pressurization but also for baking pressurization. By setting a set of vacuum pressurization systems, both pressure impregnation process and pressure baking can be carried out. During baking pressurization, since the integrated impregnation and baking tank contains liquid baking medium, at this time, the system indirectly pressurizes through the liquid baking medium using protective gases such as nitrogen, which is simpler and more reliable than the current high-pressure baking device with direct nitrogen pressurization. Description of the Drawings

[0035] Figure 1 is a block diagram of the connection relationship of each unit of the device in Embodiment 1 of the present invention;

[0036] Figure 2 is a schematic structural diagram of the device in Embodiment 1 of the present invention;

[0037] Description of the Reference Numerals

[0038] 11 - Impregnating agent storage and melting unit;

[0039] 111 - Impregnating agent storage tank; 112 - First heating coil;

[0040] 12 - Heating and cooling unit;

[0041] 121 - Heating furnace; 122 - Heat exchanger; 1221 - Cooling water return port; 1222 - Cooling water inlet port; 123 - Heat transfer medium circulation pump; 124 - Heat transfer medium filter;

[0042] 13 - Integrated impregnation and roasting unit;

[0043] 131 - Integrated impregnation and roasting tank; 132 - Second heating coil;

[0044] 14 - Roasting medium circulation unit;

[0045] 141 - Roasting medium storage tank; 142 - Third heating coil; 143 - Roasting medium circulation pump; 144 Roasting medium filter;

[0046] 15 - Vacuum pressurization unit;

[0047] 151 - Vacuum pump; 152 - Vacuum filter; 153 - Pneumatic pressurization device;

[0048] 16 - Flue gas treatment unit;

[0049] 161 - Fan; 162 - Flue gas treatment device. Detailed implementation manners

[0050] The technical solutions of the present invention are described below with reference to the accompanying drawings through specific embodiments. It should be understood that one or more steps mentioned in the present invention do not exclude the existence of other methods and steps before and after the combined steps, or other methods and steps can be inserted between these clearly mentioned steps. It should also be understood that these examples are only used to illustrate the present invention and not to limit the scope of the present invention. Unless otherwise specified, the numbers of each method step are only for the purpose of identifying each method step, rather than limiting the arrangement order of each method or defining the implementation scope of the present invention. The change or adjustment of their relative relationship can also be regarded as the scope in which the present invention can be implemented under the condition of no substantial change in technical content.

[0051] There is no specific limitation on the sources of the raw materials and instruments used in the embodiments, and they can be purchased in the market or prepared according to the conventional methods well-known to those skilled in the art.

[0052] Example 1: An integrated impregnation and roasting device

[0053] As Figure 1 and Figure 2 shown, an integrated impregnation and roasting device includes: an impregnating agent storage and melting unit 11, a heating and cooling unit 12, an integrated impregnation and roasting unit 13, a roasting medium circulation unit 14, a vacuum pressurization unit 15, and a flue gas treatment unit 16.

[0054] Among them, the impregnating agent storage and melting unit 11 is used for melting and storing the impregnating agent, which is generally asphalt. The softening point temperatures of different types of asphalt are different, and heating is carried out according to the softening point temperature of the asphalt to reach a flowing state. The impregnating agent storage and melting unit 11 includes an impregnating agent storage tank 111, in which a liquid level gauge and a temperature measuring gauge (not shown in the figure) are provided. In order to keep warm, the impregnating agent storage tank 111 is coated with a heat preservation layer. A first heating coil 112 is wound outside the impregnating agent storage tank 111, and the first heating coil 112 is heated by the heating and cooling unit 12, so as to realize the heating and melting of the impregnating agent.

[0055] The heating and cooling unit 12 includes a heating system and a cooling system. The heating system is a set of heat transfer medium circulation heating system, which is used to heat the impregnating agent storage and melting unit 11, the integrated impregnating and roasting tank unit 13, and the roasting medium molten salt circulation unit 14; Molten salt is used as the heat transfer medium, and the molten salt can be fluoride salt, nitrate salt, chloride salt, carbonate salt, sulfate salt, etc., or a mixed molten salt of various molten salts; Since the molten salt is easy to oxidize, the molten salt circulation heating system is protected by nitrogen; The heating system is composed of a heating furnace 121, a heat transfer medium circulation pump 123, a heat transfer medium filter 124, and heating coils outside each tank body. Among them, the heating furnace 121 is heated and melted by a high-pressure steam heating pipe or an electric heating pipe installed in the molten salt storage tank. The heating temperature of the heating furnace is stable, the temperature can be accurately adjusted, and the thermal efficiency is high. The cooling system realizes the cooling water circulation by the heat exchanger 122 taking in water from the cooling water inlet 1222 and flowing out from the cooling water return port 1221, so as to cool the heat transfer medium and thus cool the corresponding connection unit.

[0056] The integrated impregnating and roasting tank unit 13 is provided with an inlet and outlet asphalt interface to connect the impregnating agent storage and melting unit 11, a second heating coil 132 is provided on the outside to connect the heating and cooling unit 12, a molten salt circulation interface is provided to connect the roasting medium circulation unit 14, an interface is provided at the top to connect the vacuum pressurization unit 15, an interface is also provided at the top to connect the flue gas treatment unit 16, and a liquid level gauge and a temperature measuring gauge (not shown in the figure) are also provided.

[0057] The roasting medium circulation unit 14 includes a roasting medium storage tank 141 and a third heating coil 142 wound outside the roasting medium storage tank 141. The roasting medium storage tank 141 is communicated with the integrated impregnating and roasting tank 131 through an outlet pipeline and an inlet pipeline respectively. Among them, a roasting medium circulation pump 143 is provided on the outlet pipeline of the roasting medium storage tank 141 to increase the power of the roasting medium, and a roasting medium filter 144 is provided on the inlet pipeline; The third heating coil 142 is connected to the heating and cooling unit 12, and there is an interface at the top of the roasting medium storage tank 141 to connect the flue gas treatment unit 16.

[0058] The vacuum pressurizing unit 15 includes a vacuum pump 151, a vacuum filter 152, a pneumatic pressurizing device 153, and corresponding pipelines and valves. The pneumatic pressurizing device 153 and the vacuum filter 152 are respectively connected to the inlet and outlet of the integrated impregnation and roasting tank through pipelines, and can evacuate or increase pressure in the integrated impregnation and roasting tank unit 131 during impregnation or roasting. The vacuum pump 151 can be a rotary vane pump or a Roots pump, and the vacuum degree can reach -0.1 Mpa. The pneumatic pressurizing pipe device uses nitrogen or other inert gases as the pressurizing gas.

[0059] The flue gas treatment unit 16 consists of a fan 161 and a flue gas treatment device 162 and valve pipelines. The flue gas treatment device 162 can be an activated carbon adsorption device or an electrostatic purification device, etc. It absorbs various flue gases through pipelines connected to the impregnating agent storage tank 111, the heating furnace 121, the integrated impregnation and roasting tank 131, and the roasting medium storage tank 141.

[0060] Example 2: An integrated method for impregnation and roasting

[0061] (1) Preparation of the primary roasted blank: Grind petroleum calcined coke and knead it with asphalt with a softening point of 90°C. After processing the paste, press it into a square blank of 500 mm * 500 mm * 500 mm under a pressure of 120 Mpa on a molding press.

[0062] (2) Preparation of the heating and cooling unit: Prepare a molten salt mixture with a melting point below 80°C and a high temperature reaching 1000°C by mixing high-temperature fluoride salts and low-melting-point nitrate molten salts in a certain ratio. Put the powdered molten salt into the molten storage tank in the heating furnace, start the heating furnace, and heat it through the high-pressure steam heating pipes installed in the heating furnace. After reaching 90°C, start the heat transfer medium circulation pump to start the roasting medium circulation unit and maintain the temperature at 90°C.

[0063] (3) Preparation of the roasting medium circulation unit: Heat the powdered molten salt in the roasting medium storage tank to 90°C through the started heating and cooling unit, start the roasting medium circulation pump, and pump the roasting medium molten salt into the integrated impregnation and roasting tank and circulate.

[0064] (4) Conduct primary atmospheric roasting: Put the formed green blank into the integrated impregnation and roasting tank, increase the temperature at a rate of 5°C / h to a maximum temperature of 840°C. At this time, the heating rate can be set by adjusting the power of the molten salt heating furnace in the heating and cooling unit. After reaching the maximum temperature of 840°C, start to cool down at a rate of 15°C / h. The cooling rate is jointly controlled by the circulating water flow rate of the cooling system in the heating and cooling unit and the power of the heating furnace. When the temperature drops to 300°C, drain the flowing molten salt in the integrated impregnation and roasting tank into the roasting medium storage tank.

[0065] (5) Prepare before impregnation: The impregnating agent is asphalt with a softening point of 90°C. The asphalt in the impregnating agent storage and melting unit is heated to 110°C by molten salt in the first heating coil, while the integrated impregnation and roasting tank is kept at 150°C. The roasted product in the integrated impregnation and roasting tank is evacuated to -0.1 MPa by the vacuum pump of the vacuum pressurization unit and maintained for 6 h. Among them, flow valves are respectively provided on different heating coils, and the temperature control of different heating coils is achieved by adjusting the opening degree of the flow valves.

[0066] (6) Perform pressure impregnation: The molten asphalt in the impregnating agent storage tank is pumped into the integrated impregnation and roasting tank. After reaching the set liquid level, nitrogen pressure is applied by the pneumatic pressurization device of the vacuum pressurization unit at a pressure of 2 Mpa. After the pressure is maintained for 24 h, the pressure is released. At this time, the impregnated asphalt is re-discharged into the impregnating agent storage tank of the impregnating agent storage and melting unit to complete the impregnation process.

[0067] (7) Perform secondary atmospheric roasting: Start the roasting medium circulation pump, and pump the roasting medium molten salt into the integrated impregnation and roasting tank. At this time, the temperature in the integrated impregnation and roasting tank is more than 100°C. The temperature is raised at a maximum temperature of 700°C and a heating rate of 7°C / h. At this time, the heating rate can be set by adjusting the power of the heating furnace of the heating and cooling unit. After reaching the maximum temperature of 700°C, the temperature starts to decrease at a cooling rate of 20°C / h. The cooling rate is jointly controlled by the flow rate of the circulating cooling water in the cooling system of the molten salt heating and cooling unit 12 and the power of the molten salt heating furnace. When the temperature drops to 300°C, the flowing molten salt in the integrated impregnation and roasting tank is discharged into the roasting medium storage tank.

[0068] (8) Perform secondary impregnation: After the integrated impregnation and roasting tank is evacuated, the molten asphalt in the impregnating agent storage and melting unit is pumped into the integrated impregnation and roasting tank. After reaching the set liquid level, nitrogen pressure is applied by the pneumatic pressurization device of the vacuum pressurization unit at a pressure of 2 Mpa. After the pressure is maintained for 18 h, the pressure is released. At this time, the impregnated asphalt is re-discharged into the impregnating agent storage tank of the impregnating agent storage and melting unit to complete the impregnation process.

[0069] Perform three atmospheric pressure calcinations: Start the calcination medium circulation pump, pump the molten salt of the calcination medium into the integrated impregnation and calcination tank. At this time, the temperature in the integrated impregnation and calcination tank is over 100 °C. Heat up at a maximum temperature of 650 °C and a heating rate of 7 °C / h. At this time, the heating rate can be set by adjusting the power of the heating furnace of the molten salt heating and cooling unit. After reaching the maximum temperature of 650 °C, start to cool down at a cooling rate of 20 °C / h. The cooling rate is jointly controlled by the circulating water flow rate of the cooling system of the heating and cooling unit and the power of the heating furnace. When the temperature drops to 300 °C, drain the flowing molten salt in the integrated impregnation and calcination tank into the calcination medium storage tank. After the temperature drops to 100 °C, open the lid of the integrated impregnation and calcination tank and lift out the product to complete the integrated impregnation and calcination process.

[0070] Graphitize the above-mentioned three calcined products at a maximum temperature of 2500 °C and a heating rate of 50 °C / h to prepare a high-performance graphite product with a bulk density greater than 1.86 g / cm 3 , a flexural strength reaching 35 Mpa and a compressive strength reaching 75 MPa.

[0071] Example 3: An integrated method for impregnation and calcination

[0072] (1) Preparation of the primary calcined blank: Grind the pitch calcined coke powder and knead it with pitch with a softening point of 130 °C. After processing the paste, press it into a cylindrical blank Φ500 mm * 500 mm on an isostatic press at a pressure of 150 Mpa.

[0073] (2) Preparation of the heating and cooling unit: Prepare a mixed molten salt with a melting point below 80 °C and a high temperature reaching 1000 °C by mixing high-temperature fluoride salt and low-melting-point nitrate molten salt in a certain ratio. Put the powdered molten salt into the melting storage tank in the heating furnace, start the heating furnace, and heat it through the high-pressure steam heating pipe installed in the heating furnace. After reaching 90 °C, start the circulation pump to start the heating of the calcination medium molten salt circulation unit and maintain the temperature at 90 °C.

[0074] (3) Preparation of the calcination medium circulation unit: Heat the powdered molten salt in the calcination medium storage tank to 90 °C through the started heating and cooling unit. Start the calcination medium circulation pump, pump the calcination medium molten salt into the integrated impregnation and calcination tank, and circulate it.

[0075] (4) Conduct atmospheric pressure roasting once: Put the formed green body into an integrated impregnation roasting tank, heat it up at a maximum temperature of 900°C and a heating rate of 6°C / h. At this time, the heating rate can be set by adjusting the power of the molten salt heating furnace of the heating and cooling unit. After reaching the maximum temperature of 900°C, start to cool down, and the cooling rate is 18°C / h. The cooling rate is jointly controlled by the circulating cooling water flow rate of the cooling system of the heating and cooling unit and the power of the molten salt heating furnace. When the temperature drops to 300°C, drain the flowing molten salt in the integrated impregnation roasting tank into the roasting medium storage tank.

[0076] (5) Prepare before impregnation: The impregnating agent selects pitch with a softening point of 130°C. Heat the pitch in the impregnating agent storage and melting unit to 150°C through the molten salt of the first coil, while the integrated impregnation roasting tank is kept at 180°C. Use the vacuum pump of the vacuum pressurization unit to evacuate the roasted product in the integrated impregnation roasting tank to -0.1 MPa and maintain it for 6 h. Among them, flow valves are respectively arranged on different heating coils, and the temperature control of different heating coils is realized by adjusting the opening degree of the flow valves.

[0077] (6) Conduct pressure impregnation: After the integrated impregnation roasting tank is evacuated, pump the molten pitch in the impregnating agent storage and melting unit into the integrated impregnation roasting tank. After reaching the set liquid level, conduct nitrogen pressurization through the pneumatic pressurization device of the vacuum pressurization unit, with a pressure of 2.5 Mpa. After the pressure is maintained for 24 h, relieve the pressure. At this time, the impregnating pitch is re-drained back into the impregnating agent storage tank of the impregnating agent storage and melting unit to complete the impregnation process.

[0078] (7) Conduct secondary high-pressure roasting: Start the roasting medium circulation pump, pump the roasting medium molten salt into the integrated impregnation roasting tank. At this time, the temperature in the integrated impregnation roasting tank is more than 100°C. Heat it up at a maximum temperature of 750°C and a heating rate of 9°C / h. When reaching 200°C, conduct nitrogen pressurization through the pneumatic pressurization device of the vacuum pressurization unit, with a pressure of 1.8 Mpa. This pressure is maintained until the maximum temperature. The heating rate can be set by adjusting the power of the molten salt heating furnace of the heating and cooling unit during the heating process. After reaching the maximum temperature of 750°C, start to cool down, and the cooling rate is 22°C / h. During the cooling process, the pressure drops to 1.2 Mpa. The cooling rate is jointly controlled by the circulating cooling water flow rate of the cooling system of the heating and cooling unit and the power of the molten salt heating furnace during the cooling process. When the temperature drops to 300°C, drain the flowing molten salt in the integrated impregnation roasting tank into the roasting medium storage tank. After the temperature drops to 100°C, open the lid of the integrated impregnation roasting tank and lift out the product.

[0079] Graphitize the above-mentioned roasted product at a maximum temperature of 2500°C and a heating rate of 50°C / h to prepare a product with a bulk density greater than 1.92 g / cm 3, high-performance graphite products with a flexural strength of 40 Mpa and a compressive strength of 90 MPa.

[0080] The foregoing description of specific exemplary embodiments of the invention has been presented for purposes of illustration and example. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is apparent that, in light of the above teaching, many modifications and variations are possible. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize the various different exemplary embodiments of the invention, as well as various different selections and modifications. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. An integrated impregnation and roasting device, characterized in that, Comprising: An integrated impregnation and roasting unit (13), which includes an integrated impregnation and roasting tank (131); An impregnating agent storage and melting unit (11), which includes an impregnating agent storage tank (111), and the impregnating agent storage tank (111) is communicated with the integrated impregnation and roasting tank (131); A roasting medium circulation unit (14), which includes a roasting medium storage tank (141), and the roasting medium storage tank (141) is communicated with the integrated impregnation and roasting tank (131); A heating and cooling unit (12), which is used to heat or cool the integrated impregnation and roasting tank (131), the impregnating agent storage tank (111), and the roasting medium storage tank (141) respectively; A vacuum pressurization unit (15), which is communicated with the integrated impregnation and roasting tank (131).

2. The integrated impregnation and roasting device according to claim 1, wherein The heating and cooling unit (12) includes a heating furnace (121), a heat exchanger (122), and heating coils connected in sequence at the head and tail.

3. The impregnation and calcination integrated device according to claim 2, wherein, The heating coils include a first heating coil (112), a second heating coil (132), and a third heating coil (142), and the first heating coil (112), the second heating coil (132), and the third heating coil (142) are arranged in parallel.

4. The impregnation and roasting integrated device according to claim 3, wherein, The first heating coil (112) is wrapped around the outer wall of the impregnating agent storage tank (111), the second heating coil (132) is wrapped around the outer wall of the integrated impregnation and roasting tank (131), and the third heating coil (142) is wrapped around the outer wall of the roasting medium storage tank (141).

5. The impregnation and calcination integrated device according to claim 2, wherein The heat exchanger (122) is also respectively provided with a cooling water inlet (1222) and a cooling water return port (1221).

6. The integrated impregnation and calcination device according to claim 2, characterized in that The integrated impregnation and roasting unit (13), the impregnating agent storage and melting unit (11), the roasting medium circulation unit (14), and the heating and cooling unit (12) are respectively provided with driving devices.

7. The integrated impregnation and calcination device according to claim 2, wherein, It further includes a flue gas treatment unit (16), and the flue gas treatment unit (16) is respectively communicated with the integrated impregnation and roasting tank (131), the impregnating agent storage tank (111), the roasting medium storage tank (141), and the heating furnace (121).

8. The integrated impregnation and roasting device according to claim 1, wherein The impregnating agent is a lubricant; And / or, the melting point temperature of the roasting medium is below 100 °C, and the temperature can reach above 900 °C after heating; And / or, the melting point of the heat transfer medium in the heating and cooling unit (12) is lower than 80 °C, and the temperature can reach above 1000 °C after heating.

9. The integrated impregnation and roasting device according to claim 8, wherein The lubricant is selected from one or more of asphalt, resin, grease, and paraffin; And / or, the roasting medium is molten salt, and the molten salt is selected from one or more of fluoride salts, nitrate salts, chloride salts, carbonate salts, and sulfate salts; And / or, the heat transfer medium is molten salt.

10. An integrated impregnation and roasting method based on the device according to any one of claims 1-9, comprising the following steps: Preparation: Heat and melt the impregnating agent in the impregnating agent storage tank (111) and the roasting medium in the roasting medium storage tank (141) through the heating and cooling unit, and preheat the integrated impregnating and roasting tank (131) and the green body after roasting therein; Vacuum pumping: Vacuum pump the integrated impregnating and roasting tank (131) through the vacuum pressurizing unit (15); Primary impregnation: Pump the melted impregnating agent into the integrated impregnating and roasting tank (131). After reaching the set liquid level, perform nitrogen pressurization through the vacuum pressurizing unit (15) until the impregnation process is completed; Secondary roasting: Drain the excess impregnating agent in the integrated impregnating and roasting tank (131), pump the roasting medium into the integrated impregnating and roasting tank (131), and raise the temperature for roasting; Subsequent impregnation and roasting are carried out according to the steps of the above primary impregnation and secondary roasting respectively.

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