Carbon black is a type of industrial carbon products used mainly in the production of rubber as a filler that enhances its useful performance properties, polymers, master butches. Unlike coke and pitch, it consists of almost one carbon, either in its standard version or in an allotropic form and resembles soot in appearance.
Scope of application
Approximately 70% of the world's carbon black output is used for the manufacture of tires, 20% – for the production of rubber products. Also, technical carbon is used in the paint and varnish production and the production of printing inks, where it acts as a black pigment. Another area of application is the production of plastics and cable sheaths. Here the product is added as a filler and giving the products special properties. Carbon black is also used in other industries in small volumes.
For the nanoindustry, less than 1.5% of carbon black is used for the production of carbon nanomaterials and other forms of carbon black-based nanocarbon.
Scope of application
Approximately 70% of the world's carbon black output is used for the manufacture of tires, 20% – for the production of rubber products. Also, technical carbon is used in the paint and varnish production and the production of printing inks, where it acts as a black pigment. Another area of application is the production of plastics and cable sheaths. Here the product is added as a filler and giving the products special properties. Carbon black is also used in other industries in small volumes.
For the nanoindustry, less than 1.5% of carbon black is used for the production of carbon nanomaterials and other forms of carbon black-based nanocarbon.
CARBON BLACK IS A UNIQUE MATERIAL OF THE XXI CENTURY
Characteristic
Carbon black is a product of a process that includes the latest, modern, high-tech, engineering technologies and control methods. Due to its purity and a strictly defined set of physical and chemical properties, it has nothing to do with soot, which is formed as a contaminated by-product as a result of burning coal and fuel oil, or when operating unregulated internal combustion engines. According to the generally accepted international classification, carbon black is designated as - "Carbon Black" (black carbon) or soot. That is, these concepts are currently not mixed in any way.
Reinforcing properties
The improvement of the physical properties of the material due to the introduction of a filler is called reinforcement or reinforcement, and such fillers are called amplifiers or hardeners (carbon black, precipitated silicon oxide). Among all amplifiers, technical carbon has truly unique characteristics. Even before vulcanization, it binds to rubber, and this mixture cannot be completely divided into "carbon black" and rubber using solvents or other destructive compounds.
Carbon black significantly affects the tensile strength of rubbers, the properties of resistance to abrasion and abrasion. Similar fine powders, or similar dispersed compositions used in rubber mixtures to give the desired color or reduce the cost of the mixture - chalk, kaolin, talc, iron oxide and others do not have reinforcing properties.
Carbon black production
There are three technologies for the production of industrial technocarbon, which use a cycle of incomplete combustion of hydrocarbons:
- furnace soot;
- channel soot;
- lamp blade;
- plasma carbon black.
There is also a thermal method in which acetylene or natural gas decomposes at high temperatures.
Numerous grades of carbon black produced by various technologies have a wide variety of characteristics; but the most expensive and high-quality derivatives are nanotubes and fullerenes.
Alternative carbon black manufacturing technology
Theoretically, it is possible to obtain carbon black by all of the above methods, but more than 90% of the product produced is obtained by the furnace method from liquid raw materials. The method allows to obtain various grades of carbon black with a certain set of properties. For example, in this case, more than 20 grades of carbon black are produced using this technology. The general technology is as follows. The reactor, lined with highly refractory materials, is supplied with natural gas and air heated to 800 °C. Due to the combustion of natural gas, products of complete combustion with a temperature of 1820-1900 °C containing a certain amount of free oxygen are formed. Liquid hydrocarbon raw materials, previously thoroughly mixed and heated to 200-300 °C, are injected into high-temperature products of complete combustion. Pyrolysis of raw materials occurs at a strictly controlled temperature, which, depending on the brand of carbon black produced, has different values from 1400 °C to 1750 °C. At a certain distance from the feed site, the thermo-oxidative reaction is stopped by water injection. The carbon black powder and reaction gases formed as a result of pyrolysis enter the air heater, in which they give part of their heat to the air used in the process, while the temperature of the carbon-gas mixture decreases from 950-1000 °C to 500-600 °C. After cooling to 260-280 °C due to additional water injection, a mixture of carbon black and gases is sent to the bag filter, where carbon black is separated from gases and enters the filter hopper. The extracted carbon black powder from the filter hopper is fed through the pipeline of the gas transmission line by a fan (turbo blower) to the screening and granulation department.
Carbon Black Manufacturers
The global production of carbon black exceeds 10 million tons. Such a great need for the product is explained, first of all, by its unique reinforcing and modifying properties. The locomotives of the industry are:
Aditya Birla Group (India) – about 15% of the market.
Cabot Corporation (USA) – 14% of the market.
Orion Engineered Carbons (Luxembourg) – 9%.
Carbon black is a product of a process that includes the latest, modern, high-tech, engineering technologies and control methods. Due to its purity and a strictly defined set of physical and chemical properties, it has nothing to do with soot, which is formed as a contaminated by-product as a result of burning coal and fuel oil, or when operating unregulated internal combustion engines. According to the generally accepted international classification, carbon black is designated as - "Carbon Black" (black carbon) or soot. That is, these concepts are currently not mixed in any way.
Reinforcing properties
The improvement of the physical properties of the material due to the introduction of a filler is called reinforcement or reinforcement, and such fillers are called amplifiers or hardeners (carbon black, precipitated silicon oxide). Among all amplifiers, technical carbon has truly unique characteristics. Even before vulcanization, it binds to rubber, and this mixture cannot be completely divided into "carbon black" and rubber using solvents or other destructive compounds.
Carbon black significantly affects the tensile strength of rubbers, the properties of resistance to abrasion and abrasion. Similar fine powders, or similar dispersed compositions used in rubber mixtures to give the desired color or reduce the cost of the mixture - chalk, kaolin, talc, iron oxide and others do not have reinforcing properties.
Carbon black production
There are three technologies for the production of industrial technocarbon, which use a cycle of incomplete combustion of hydrocarbons:
- furnace soot;
- channel soot;
- lamp blade;
- plasma carbon black.
There is also a thermal method in which acetylene or natural gas decomposes at high temperatures.
Numerous grades of carbon black produced by various technologies have a wide variety of characteristics; but the most expensive and high-quality derivatives are nanotubes and fullerenes.
Alternative carbon black manufacturing technology
Theoretically, it is possible to obtain carbon black by all of the above methods, but more than 90% of the product produced is obtained by the furnace method from liquid raw materials. The method allows to obtain various grades of carbon black with a certain set of properties. For example, in this case, more than 20 grades of carbon black are produced using this technology. The general technology is as follows. The reactor, lined with highly refractory materials, is supplied with natural gas and air heated to 800 °C. Due to the combustion of natural gas, products of complete combustion with a temperature of 1820-1900 °C containing a certain amount of free oxygen are formed. Liquid hydrocarbon raw materials, previously thoroughly mixed and heated to 200-300 °C, are injected into high-temperature products of complete combustion. Pyrolysis of raw materials occurs at a strictly controlled temperature, which, depending on the brand of carbon black produced, has different values from 1400 °C to 1750 °C. At a certain distance from the feed site, the thermo-oxidative reaction is stopped by water injection. The carbon black powder and reaction gases formed as a result of pyrolysis enter the air heater, in which they give part of their heat to the air used in the process, while the temperature of the carbon-gas mixture decreases from 950-1000 °C to 500-600 °C. After cooling to 260-280 °C due to additional water injection, a mixture of carbon black and gases is sent to the bag filter, where carbon black is separated from gases and enters the filter hopper. The extracted carbon black powder from the filter hopper is fed through the pipeline of the gas transmission line by a fan (turbo blower) to the screening and granulation department.
Carbon Black Manufacturers
The global production of carbon black exceeds 10 million tons. Such a great need for the product is explained, first of all, by its unique reinforcing and modifying properties. The locomotives of the industry are:
Aditya Birla Group (India) – about 15% of the market.
Cabot Corporation (USA) – 14% of the market.
Orion Engineered Carbons (Luxembourg) – 9%.
As shown by the research carried out by the authors of various patents and employees of various world laboratories, the treatment of a graphite electrode with a glow discharge in an inert gas (helium) before feeding it into the electric arc zone and the movement of the formed products by an annular flow of inert gas directed perpendicular to the axis of the electrodes outside the fullerene formation zone allows a continuous process of obtaining fullerene soot with a high content of fullerene fractions in it, since it is possible to continuously feed a graphite electrode into the reactor, remove soot particles with fullerenes formed in the gas-flame jet, without disturbing the process of fullerene formation.
This continuous process of obtaining fullerene soot allows us to implement the design of the FSM machine developed by our specialists, equipped with a chamber for removing the gas of a mobile graphite electrode by a glow discharge, an inert gas circulation system with a slit nozzle placed perpendicular to the mobile graphite electrode, and a carbon black capture device equipped with a fine filter with a cleaning system installed at the outlet of the inert gas circulation system, which indicates a certain unique level of the claimed developments.
The equipment for the production of fine carbon black powder FSM has a sealed cylindrical chamber (reactor chamber) with an inert gas circulation system (mainly helium) consisting of a gas supercharger (vortex pump or booster pump) connected by a pipeline in the form of hermetically welded metal pipes, or bending bellows that allow connecting equipment components and assemblies into a single circuit through standardized vacuum flanges.
CARBON BLACK POWDER PRODUCTION TECHNOLOGY
Tank-containers that capture and store the produced carbon black during the carbon synthesis period contain two filters – a fine filter (bag filter) and a coarse filter (cover). Technically, tank-containers are cyclones, which are designed according to all standards of gas dynamic conditions, minimize the loads of vortex flows of inert gas.
The fine filter is connected by a pipeline (outlet pipe of the reactor chamber – carbon synthesis). The fine filter is connected to the inlet of the vortex pump by an outlet flange. Graphite is fed along the axis of the carbon black synthesis chamber through standardized seals of the electrode supply chamber (see, for example, Danilin B.S., Minaichev V.E. Fundamentals of Vacuum System Design. - M., Energia, 1971, p.221). Graphite electrodes are usually installed statically, passing through the electrode insertion chamber, being clamped by a current collector (which has its own cooling) and practically resting against the cathode electrode. The graphite electrode is installed with the possibility of translational movement in a cooled current collector connected to another output of the arc power source. The outputs of the arc power supply are isolated from the ground. The carbon synthesis chamber is grounded, and the anode and cathode contactors are isolated from the ground using textolite insulators, excluding voltage from entering the chamber body and other equipment catches.
The fine filter is connected by a pipeline (outlet pipe of the reactor chamber – carbon synthesis). The fine filter is connected to the inlet of the vortex pump by an outlet flange. Graphite is fed along the axis of the carbon black synthesis chamber through standardized seals of the electrode supply chamber (see, for example, Danilin B.S., Minaichev V.E. Fundamentals of Vacuum System Design. - M., Energia, 1971, p.221). Graphite electrodes are usually installed statically, passing through the electrode insertion chamber, being clamped by a current collector (which has its own cooling) and practically resting against the cathode electrode. The graphite electrode is installed with the possibility of translational movement in a cooled current collector connected to another output of the arc power source. The outputs of the arc power supply are isolated from the ground. The carbon synthesis chamber is grounded, and the anode and cathode contactors are isolated from the ground using textolite insulators, excluding voltage from entering the chamber body and other equipment catches.
1. A method for producing fullerene soot, including the evaporation of graphite in an electric arc between coaxial graphite electrodes placed in an inert gas atmosphere, the movement of products formed in an electric arc with an inert gas and their subsequent deposition in the form of fullerene soot, characterized in that the graphite electrode supplied to the electric arc zone is passed through the glow electric discharge zone, and the movement of the said products is carried out by an annular flow of inert gas directed parallel to the axis of the said electrodes through area, spaced at a distance of 30-40 mm. from the axis of the mentioned electrodes.
THE FORMULA OF THE INVENTION OF FSM MACHINES
2. The device is distinguished by the fact that an annular flow of inert gas is simultaneously twisted around the mentioned electrodes, without increasing the resistance in the line during continuous operation.
3. The device is distinguished by the fact that the graphite electrode supplied to the electric arc zone is supplied with an electric voltage alternately of positive polarity for more than 24 hours and negative polarity for 0.5-1 min.
4. A device for producing fullerene soot, including a reactor in the form of a sealed cylindrical chamber with an inert gas circulation system with a means of capturing fullerene-containing soot with two graphite rod electrodes placed along the axis of the chamber, one of which is fixed in a cooled contactor with a provided translational displacement system, and the other is installed in a second cooled contactor with the possibility of axial translational displacement, characterized in that, that the mentioned reactor is additionally equipped with a decontamination chamber of a mobile graphite electrode with a glow discharge, the inert gas circulation system is equipped with an annular slit nozzle placed perpendicular to the electrodes, and the fullerene-containing soot capture device is equipped with a fine filter with an autonomous cleaning system installed at the outlet of the inert gas circulation system.
5. A device characterized in that the inner radius of the said nozzle is not more than 15 mm.
6. A device characterized in that the outlet of the said nozzle is located at a distance of 30-40 mm. from the plane passing through the center of the interelectrode gap.
7. A device characterized in that an asbestos-based cooling insulator is installed in the cathode electrode mounting unit to prevent sintering and destruction of the cathode electrode.
8. A device characterized in that in order to supply voltage to the contactors of the reactor chamber, respectively to the movable electrode anode and fixed cathode, the supply is made from a 600A power source.
9. A device characterized in that in order to organize the continuous operation of the reactor and the cleaning of the fine filter, it is not necessary to stop the device by switching on an additional, small circulation circuit.
10. A device characterized in that the polarity of the movable electrode anode and the stationary cathode is changed without first stopping the supply system of the movable electrode anode and turning off the power source.
11. A device characterized in that, in order to exclude a rapid increase in the cathode deposit on a stationary cathode electrode, the cold start mode provided for by the technological design of the developed power supply is activated by the operator at the first start.
The graphite electrode, at the moment of its movement into the reactor chamber (carbon black synthesis chamber), passes through the vacuum degassing chamber, where it is cleaned of oxygen. The supplied graphite electrode - anode is completely isolated from the body of the FSM machine, as well as from the ground thanks to polymer and textolite insulators. The current collector of the anode (movable electrode) is connected to the positive terminal of the power supply. The negative terminal of the power supply is connected to a static graphite electrode. Both outputs (positive and negative) of the power supply are isolated from the equipment housing and from the ground, which makes it possible to stabilize the arc in the reactor chamber during the production of carbon black.
The general gas dynamic system of the FSM machine is pumped out by a pre-vacuum pump or pumping station to the required values – the readings of the vacuum gauge sensor; after which the degassed volume is filled with inert gas (preferably helium) through a needle reducer.
The electrode is moved into the carbon black synthesis chamber by a rod feed device in which the pusher rollers are isolated from the electrode by a gummed silicone material. And the electrode supply unit itself to the synthesis chamber is isolated from the base of the FSM shelf by fiberglass insulators, at the base of the feeding device.
To avoid excessive deposition of soot dust on the cathode electrode formed in an arc discharge, it is surrounded by a conical cooled screen. For these purposes, a conical cooling screen is provided, mounted on the lid of the reactor chamber. The chamber itself also has its own cooling circuits for both the coaxial part and the end part, excluding local overheating of the carbon black synthesis chamber body. Connection of the external cooling system of the reactor chamber is carried out through the refrigerant inlet/outlet fittings installed on the outer part of the reactor chamber shell.
The electrode is moved into the carbon black synthesis chamber by a rod feed device in which the pusher rollers are isolated from the electrode by a gummed silicone material. And the electrode supply unit itself to the synthesis chamber is isolated from the base of the FSM shelf by fiberglass insulators, at the base of the feeding device.
To avoid excessive deposition of soot dust on the cathode electrode formed in an arc discharge, it is surrounded by a conical cooled screen. For these purposes, a conical cooling screen is provided, mounted on the lid of the reactor chamber. The chamber itself also has its own cooling circuits for both the coaxial part and the end part, excluding local overheating of the carbon black synthesis chamber body. Connection of the external cooling system of the reactor chamber is carried out through the refrigerant inlet/outlet fittings installed on the outer part of the reactor chamber shell.
The gas-dynamic nozzle, which serves as an element for the introduction of inert gas into the reactor chamber, the general gas circulation system, can be equipped with a special deflector that allows to twist the annular flow of inert gas, which maximally cleans the inner surface of the chamber. The deflector can be made in the form of guide vanes or in the form of plates mounted at an acute angle to the nozzle axis.