Method for preparing high-structure-degree carbon black by plasma sintering

Abstract

The invention belongs to the technical field of carbon black post-treatment, and particularly relates to a method for preparing high-structure-degree carbon black through plasma sintering. In order to solve the problem that the structural degree of furnace-process carbon black is limited by a reaction furnace in the prior art, the invention provides the method for preparing the high-structural-degree carbon black by utilizing plasma sintering, and the structural degree of the carbon black is improved by utilizing a two-step method. Part of the aromatic hydrocarbon compound is left at the contact part of the carbon black to provide a carbon source for the next step of micro-sintering; in the second step, high-temperature plasma is adopted for heating, the carbon source can be rapidly carbonized in a short time, the micro-sintering phenomenon is generated among the carbon black, the size of a carbon black aggregation structure is increased, and therefore the structural degree is improved, and compared with traditional high-temperature heat treatment, the method can reduce energy consumption and consumed time in the treatment process to a greater extent.

Description

Technical Field

[0001] The present application belongs to the technical field of carbon black post-processing, and in particular relates to a method for preparing high-structure carbon black by plasma sintering. Background Art

[0002] Carbon black is a black powdery substance formed by incomplete combustion or pyrolysis of hydrocarbons in the gas phase under strictly controlled process conditions. Its main component is carbon, and contains a small amount of elements such as oxygen, hydrogen and sulfur. Carbon black particles are approximately spherical, with a particle size between 10 and 500 μm. Many particles often fuse or agglomerate into three-dimensional bonded dendrites or fibrous aggregates. Furnace carbon black is carbon black generated by incomplete combustion or pyrolysis of natural gas or high aromatic oil in a reactor. The degree of sintering or agglomeration of furnace black particles can be adjusted according to different uses, so furnace black in the same particle size range is divided into several derivatives with different structures. The structure of carbon black depends on the size and shape of the aggregates, as well as the number and average mass of each aggregate. All of the above characteristics affect the stacking state of the aggregates and the void volume of the powder. Usually, the structure of carbon black is expressed by the DBP oil absorption value. The oil absorption value is a numerical expression of the amount of DBP that the carbon black structure can absorb. From a practical point of view, carbon black with a high oil absorption value can accommodate more resin molecules in the structure, forming a stable resin-carbon black combination, which provides higher mechanical properties for the composite system. At the same time, the highly branched carbon blacks in the resin-carbon black combination are in contact with each other to form a developed electronic pathway network. As the structural degree of the carbon black used increases, the unit mass of carbon black can form a more developed network structure, and the conductivity of the system will also increase accordingly. As a commonly used resin conductive agent, the structural degree of carbon black greatly affects the electrical properties of the composite system, so it is of great significance to develop a carbon black with a high structural degree.

[0003] Furnace carbon black is currently the most common and largest-volume type of carbon black, but the production of furnace black is currently greatly limited by the reactor. Since the size and structure of the carbon black reactor are fixed during design and manufacturing, all carbon black original particles generated by the same reactor under the condition that the production parameters remain unchanged can be considered to be the same in size, shape, quantity and collision probability, and the properties of the finished carbon black are also very uniform. Although the carbon black structure is controlled by changing the reaction temperature, feed ratio and reaction termination time during the production process of furnace carbon black, a fixed reactor can only achieve carbon black structural changes within a certain range by adjusting process parameters, and this method is extremely risky. Inappropriate parameter adjustment will lead to a significant decrease in the performance of carbon black products. At present, the production of carbon black with great structural differences can be achieved by replacing the reactor, but replacing the reactor means huge costs in manpower, material resources and time.

[0004] The structure of carbon black is largely limited by the reactor, but it does not mean that the structure of carbon black can be increased indefinitely by changing the reactor. At present, there are limits to the method of improving the structure of furnace-processed carbon black by improving the reactor, and a large number of difficult technical problems also need to be faced in the process of improving the reactor. At present, there is a method of post-treating furnace-processed carbon black at high temperature to improve the structure of carbon black, but because high temperature is required to change the microscopic composition of carbon black during the treatment process, the process is difficult to implement and has poor stability. At the same time, because the treatment process needs to maintain high temperature for a long time, this method has high energy consumption, long time consumption, low output, and cannot be used on a large scale in the industry.

[0005] In summary, the problem that the structural degree of furnace-process carbon black is limited by the reaction furnace cannot be changed for the time being. At the same time, the means to improve the structural degree of carbon black are very limited. The technology of improving the structural degree of carbon black through high-temperature post-treatment is feasible, but there are still many problems. At this stage, there is no technology that can efficiently improve the structural degree of carbon black. Summary of the invention

[0006] In order to solve the problem in the prior art that the structure of furnace carbon black is limited by the reaction furnace, the present application provides a method for preparing high-structure carbon black by plasma sintering, and uses a two-step method to improve the structure of carbon black. In the first step, powdered carbon black is mixed with aromatic compounds in the gas phase, and part of the aromatic compounds are retained in the contact area between the carbon blacks to provide a carbon source for the next micro-sintering; in the second step, high-temperature plasma is used for heating, which can quickly carbonize the carbon source in a short time, produce micro-sintering between the carbon blacks, increase the size of the carbon black aggregation structure, and thus improve the structure. Compared with traditional high-temperature heat treatment, this method can reduce the energy consumption and time consumption of the treatment process to a greater extent.

[0007] The present application provides a method for preparing high-structure carbon black by plasma sintering, comprising the following steps:

[0008] S1. Preheating the non-oxidizing gas, mixing it with the powdered carbon black and then passing it into a mixer from one side; mixing the aromatic compound with the solvent and atomizing it through an atomizer, and then passing it into the mixer from the same side and heating it, and obtaining the powdered carbon black through a collector;

[0009] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor and heat it at 1500-2000° C. to obtain high-structure carbon black.

[0010] Furthermore, in step S1, the non-oxidizing gas is one or more of nitrogen, argon, and helium.

[0011] Furthermore, the non-oxidizing gas preheating temperature in step S1 is 200-300°C.

[0012] Furthermore, in step S1, the flow rate of the non-oxidizing gas is 0.1-2 L / s.

[0013] Furthermore, the aromatic compound in step S1 contains an aromatic hydrocarbon compound with 3-5 benzene rings, including but not limited to one of anthracene, phenanthrene, pyrene, tetracene, pentacene, and benzopyrene.

[0014] Furthermore, the solvent in step S1 is one or more of benzene, toluene, xylene, ether, and acetone.

[0015] Furthermore, the concentration of the aromatic compound solution in step S1 is 5 g / L-20 g / L.

[0016] Furthermore, in step S1, the mass ratio of the aromatic compound to the carbon black is 1:20-200.

[0017] Furthermore, the carbon black used as the raw material is powdered furnace carbon black that has not been granulated or compressed, and the oil absorption value of the carbon black should be between 80-220×10 -5 m 3 / kg range.

[0018] Furthermore, in step S1, the atomizer, the mixer, and the collector are sequentially connected, the mixer is a tubular container, and includes a heating zone, an insulation zone, and a heat preservation zone in sequence according to the gas flow direction, and a feed pipe and a discharge pipe are respectively provided at both ends of the container, and the feed pipe includes a feed pipe A and a feed pipe B, which are symmetrical about the axis of the tubular container, and the angle is 30-60°, the atomizer is connected to the feed pipe A, and the discharge pipe is connected to the collector. The tubular container is made of quartz, corundum or high-temperature resistant stainless steel, with a length of 3-10m, an inner diameter of 10-30cm, and good sealing of the container. The heating zone adopts electric heating with a heating jacket, the heating temperature is 350-600℃, and the length of the heating zone is 0.5-9m; the insulation zone adopts an external air circulation system to achieve temperature control, and the external gas is cooled or heated by a temperature control device. The outlet temperature is kept greater than the boiling point of the solvent and lower than the boiling point of the aromatic compounds through dynamic temperature control. Normally, the temperature should be maintained in the range of 150-200℃, and the length of the insulation zone is 1-9m; a 30-100cm long insulation zone should be reserved between the container heating zone and the insulation zone, and the insulation zone is covered with an insulation layer.

[0019] Furthermore, the plasma thermal processor includes a heating medium, an electrode, a sealed air chamber, and a hollow cylindrical container. The heating medium is arranged on both sides of the hollow cylindrical container, and the electrodes are arranged at the top and bottom of the inner side of the sealed air chamber respectively. The hollow cylindrical container and the heating medium are located inside the sealed air chamber. The bottom diameter of the hollow cylindrical container is 1-10 cm, the height is 1-20 cm, and the outer shell of the cylinder is a graphite medium; the amount of carbon black added should be within the range of 80-90% of the container volume, and the high-temperature plasma heating is carried out in a mixed gas environment of one or more of non-oxidizing gases such as nitrogen, argon, and helium. The heating medium is selected from one or more of carbon fiber paper, carbon fiber cloth, carbon black paper, and graphite film. During the heat treatment process, the temperature of the high-temperature plasma is controlled at 1500-2000°C, and the high-temperature plasma is heated by pulse heating. The duration of the pulse heating is 1-10s, the cumulative time of the pulse heating is 1-30s, the heating rate is 1000-5000K / s, and the time interval between adjacent pulses during heating is 10s to 30s.

[0020] The present application uses a non-oxidizing gas to disperse powdered carbon black, preheats the non-oxidizing gas for dispersing powdered carbon black in advance, and passes it into a long tubular container from one end of the container after mixing with powdered carbon black. The aromatic compound is dissolved by a solvent, the solution is atomized by an atomizer and quickly passed into the above-mentioned container from the same end, and steam is generated by heating the heat in the container, and the two gases are mixed evenly by air flow collision. During the gas mixing process, the heating section of the long tube container will continue to heat to keep the temperature in the container constant. The mixed gas in the long tubular container is transported to the other end of the container by air pressure, and a temperature control device is added outside the wall of the outlet section of the tubular container to cool and keep warm, so that the temperature of the mixed gas at the outlet is maintained above the boiling point of the solvent and lower than the boiling point of the aromatic compound. The outlet of the container is connected to a collector, and the powdered carbon black in the gas is intercepted and collected by a filter bag, and the remaining gas will be cooled and separated. The collected powdered carbon black will be used as a raw material for the high-temperature plasma treatment step after cooling. The purpose of the raw material mixing step is to evenly mix the carbon black and aromatic compounds. Aromatic compounds can provide a carbon source in the high-temperature treatment stage. The solution containing aromatic compounds is vaporized by heating. At this time, the aromatic compounds will also exist in the form of gaseous molecules. When the temperature of the mixed gas is reduced in the insulation section, the aromatic compounds will preferentially condense and precipitate in the pores where the carbon blacks are in contact under the action of additional pressure. These pores are exactly the sites that need to be micro-sintered. In the stage of high-temperature treatment using high-temperature plasma, the aromatic compounds in the pores will be quickly carbonized and glue the carbon black that was originally only physically adsorbed into a whole, thereby achieving the growth of the carbon black structure.

[0021] High-temperature plasma has the advantages of high temperature, high power density, and concentrated heat, and can complete high-temperature heat treatment of target samples in a short time. In order to achieve high-temperature plasma treatment of carbon black, the powdered carbon black obtained in the above steps needs to be placed in a container, and the container is placed in a non-oxidizing gas environment. The container and the carbon black therein are heated by high-temperature plasma, so that the carbon black in the container reaches a high temperature of more than 1500°C and is continuously heated for a period of time. After the heating is completed, micro-sintering is formed between the obtained carbon black, and the structural degree is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the atomizer, mixer, and collector of this application.

[0023] Figure 2 This is a schematic diagram of a plasma thermal processor according to the present application.

[0024] In the figure: 1. atomizer; 2. mixer; 201. heating zone; 202. insulation zone; 203. heat preservation zone; 204. feed pipe A; 205. feed pipe B; 206. discharge pipe; 3. collector; 4. plasma thermal processor; 401. heating medium; 402. electrode; 403. closed gas chamber; 404. hollow cylindrical container. DETAILED DESCRIPTION

[0025] Example 1

[0026] The present application provides a method for preparing high-structure carbon black by plasma sintering, comprising the following steps:

[0027] S1, the selected oil absorption value is 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:100. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0028] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0029] like Figure 1-Figure 2 As shown, in step S1, the atomizer 1, the mixer 2, and the collector 3 are connected in sequence. The mixer 2 is a tubular container, which includes a heating zone 201, an insulating zone 202, and a heat preservation zone 203 in sequence according to the gas flow direction. A feed pipe A, a feed pipe B, and a discharge pipe 206 are respectively provided at both ends of the container. The feed pipe A and the feed pipe B are symmetrical about the axis of the tubular container, and the angle is 45°. The atomizer 1 is connected to the feed pipe A, and the discharge pipe 206 is connected to the collector 3; the tubular container is 5m long and has an inner diameter of 20cm. It is made of high-temperature resistant stainless steel. The heating zone 201 of the tubular container is 2m long, and the heat preservation zone 203 is 2.5m long. A 50cm transition zone with a heat insulation layer is left in the middle. The heating zone 201 adopts a heating sleeve electric heating method, and the heat preservation zone 203 adopts an external air circulation system to achieve temperature control.

[0030] Step S2: The plasma thermal processor 4 includes a heating medium 401, an electrode 402, a sealed air chamber 403, and a hollow cylindrical container 404. The heating medium 401 is arranged on both sides of the hollow cylindrical container 404. The electrodes 402 are respectively arranged at the top and bottom of the inner side of the sealed air chamber 403. The hollow cylindrical container 404 and the heating medium 401 are located inside the sealed air chamber 403. The bottom diameter of the hollow cylindrical container 404 is 5 cm and the height is 10 cm. The powdered carbon black filling amount is 90% of the container. The heating medium 401 is made of carbon fiber paper. The hollow cylindrical container 404 is placed in a nitrogen environment for heating.

[0031] Example 2

[0032] S1, the selected oil absorption value is 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 2g / s, the nitrogen flow rate is 2L / s, and the preheating temperature of the mixed gas is 280℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:20. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 2mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0033] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0034] The apparatus used is the same as that in Example 1.

[0035] Example 3

[0036] S1, the oil absorption value is selected to be 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.1g / s, the nitrogen flow rate is 0.1L / s, and the preheating temperature of the mixed gas is 240℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:200. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.1mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0037] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0038] The apparatus used is the same as that in Example 1.

[0039] Example 4

[0040] S1, the oil absorption value is selected to be 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:100. The aromatic compound and the solvent are prepared into a solution at a ratio of 5g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0041] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 2000°C, the pulse heating duration to 10s, the cumulative heating to 30s, the pulse heating heating rate to 4000K / s, and the time interval between adjacent pulses during heating to 30s, to obtain high-structure carbon black.

[0042] The apparatus used is the same as that in Example 1.

[0043] Example 5

[0044] S1, the selected oil absorption value is 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 10g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, the amount ratio of benzopyrene to carbon black is 1:100, the aromatic compound and the solvent are prepared into a solution at a ratio of 20g / L, and the rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0045] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1800°C, the pulse heating duration to 5s, the cumulative heating to 10s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0046] The apparatus used is the same as that in Example 1.

[0047] Example 6

[0048] S1, the selected oil absorption value is 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:100. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 400℃, and the gas temperature at the outlet is controlled at 150℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0049] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0050] The apparatus used is the same as that in Example 1.

[0051] Example 7 (It is suggested to add different types of aromatic compounds and solvents, such as pentacene and tetracene)

[0052] S1, the selected oil absorption value is 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Pyrene is selected as the aromatic compound, xylene is used as the solvent, the amount ratio of pyrene to carbon black is 1:100, and the aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0053] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s, to obtain high-structure carbon black.

[0054] The apparatus used is the same as that in Example 1.

[0055] Comparative Example 1

[0056] S1, the oil absorption value is selected to be 140×10 -5 m 3 / kg of powdered carbon black is used as the raw material carbon black, and nitrogen is used to disperse the carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B and heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector.

[0057] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s to obtain carbon black.

[0058] Comparative Example 2

[0059] S1, the oil absorption value is selected to be 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:100. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature of the heating zone is 600℃, and the gas temperature at the outlet is controlled at 170℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0060] S2. The powdered carbon black obtained in S1 is placed in a high-temperature tubular furnace and calcined at 1200° C. for 6 hours to obtain carbon black.

[0061] Comparative Example 3

[0062] S1, the oil absorption value is selected to be 140×10 -5 m 3 / kg of powdered carbon black is used as raw material carbon black, and nitrogen is used to disperse carbon black. The amount of carbon black is 0.5g / s, the nitrogen flow rate is 0.2L / s, and the preheating temperature of the mixed gas is 260℃. After the two are mixed, they are passed into the mixer from the feed pipe B. Benzopyrene is selected as the aromatic compound, toluene is used as the solvent, and the amount ratio of benzopyrene to carbon black is 1:100. The aromatic compound and the solvent are prepared into a solution at a ratio of 10g / L. The rate of passing the solution into the atomizer is 0.5mL / s. The solution is atomized by the atomizer and passed into the mixer from the feed pipe A and then heated. The heating temperature is 600℃. The powdered carbon black in the gas is collected by the collector, and the remaining gas is cooled and processed.

[0063] S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor, control the high-temperature plasma heating temperature to 1600°C, the pulse heating duration to 5s, the cumulative heating to 15s, the pulse heating heating rate to 2500K / s, and the time interval between adjacent pulses during heating to 10s to obtain carbon black.

[0064] Step S1: an atomizer, a mixer, and a collector are connected in sequence. The mixer is a tubular container. A feed pipe A, a feed pipe B, and a discharge pipe are provided at both ends of the container. The feed pipe A and the feed pipe B are symmetrical about the axis of the tubular container, and the angle is 45°. The atomizer is connected to the feed pipe A, and the discharge pipe is connected to the collector. The tubular container is 5 m long and has an inner diameter of 20 cm. It is made of high-temperature resistant stainless steel. The tubular container is electrically heated by a heating jacket.

[0065] Step S2: The plasma thermal processor includes a heating medium, an electrode, a sealed air chamber, and a hollow cylindrical container. The heating medium is arranged on both sides of the hollow cylindrical container. The electrodes are arranged at the top and bottom of the inner side of the sealed air chamber, respectively. The hollow cylindrical container and the heating medium are located inside the sealed air chamber. The bottom diameter of the hollow cylindrical container is 5 cm and the height is 10 cm. The powdered carbon black filling amount is 90% of the container. The heating medium is carbon fiber paper. The hollow cylindrical container is placed in a nitrogen environment for heating.

[0066]

[0067]

Claims

1. A method for preparing high-structure carbon black by plasma sintering, characterized in that: The following steps are involved: S1, preheating the non-oxidizing gas, mixing it with the powdered carbon black and then passing it into a mixer (2) from one side; mixing the aromatic compound with the solvent and atomizing it through an atomizer (1), passing it into the mixer (2) from the same side and heating it, and obtaining powdered carbon black through a collector (3); S2. Place the powdered carbon black obtained in S1 into a plasma thermal processor (4), and perform pulse heating at 1500-2000°C. The pulse heating duration is 1-10s, the cumulative time is 1-30s, the heating rate is 1000-5000K / s, and the time interval between pulses is 10s to 30s, so as to obtain high-structure carbon black.

2. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: In step S1, the non-oxidizing gas is one or more of nitrogen, argon and helium.

3. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: The non-oxidizing gas preheating temperature in step S1 is 200-300°C.

4. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: In step S1, the non-oxidizing gas flow rate is 0.1-2 L / s, and the addition rate of powdered carbon black is 0.1-10 g / s.

5. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: The aromatic hydrocarbon compound in step S1 contains aromatic hydrocarbon compounds with 3-5 benzene rings.

6. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: The solvent in step S1 is one or more of benzene, toluene, xylene, ether and acetone.

7. The method for preparing high-structure carbon black by plasma sintering according to claim 5, characterized in that: The concentration of the solution of the aromatic compound in step S1 is 5 g / L-20 g / L.

8. The method for preparing high-structure carbon black by plasma sintering according to claim 1, characterized in that: The mass ratio of the aromatic compound to carbon black in step S1 is 1:20-200.

9. The method for preparing high-structure carbon black by plasma sintering according to any one of claims 1 to 8, characterized in that: The plasma thermal processor (4) comprises a heating medium (401), an electrode (402), a sealed air chamber (403), and a hollow cylindrical container (404); the heating medium (401) is arranged on both sides of the hollow cylindrical container (404); the electrode (402) is respectively arranged at the top and bottom of the inner side of the sealed air chamber (403); and the hollow cylindrical container (404) and the heating medium (401) are located inside the sealed air chamber (403).

10. The method for preparing high-structure carbon black by plasma sintering according to claim 9, characterized in that: In step S1, the atomizer (1), the mixer (2), and the collector (3) are sequentially connected, the mixer (2) is a tubular container, and includes a heating zone (201), an insulation zone (202), and a heat preservation zone (203) in sequence according to the gas flow direction. A feed pipe and a discharge pipe (206) are respectively provided at both ends of the container. The feed pipe includes a feed pipe A and a feed pipe B, which are symmetrical about the axis of the tubular container and have an angle of 30-60°. The atomizer (1) is connected to the feed pipe A, and the discharge pipe (206) is connected to the collector (3).

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