What is Carbon Black?
Carbon black, also known as carbon black, is an amorphous carbon. A light, loose and extremely fine black powder, which can be imagined as pot bottom ash in a simple image. It is the product of incomplete combustion or thermal decomposition of carbon containing substances (coal, natural gas, heavy oil, fuel oil, etc.) under insufficient air conditions.
Carbon black is the earliest developed, applied, and currently the largest production of nanomaterials by humans. It is listed as one of the 25 basic chemical products and fine chemical products in the international chemical industry. The carbon black industry is of great significance for the tire industry, dyeing and chemical industry, and improving the quality of civil life products.
White carbon black and black carbon black
2. What are the classifications of carbon black?
Carbon black is classified according to manufacturing methods: contact method carbon black, furnace method carbon black, new process carbon black, hot cracking method carbon black, spray method carbon black, trough method carbon black, etc.
Carbon black is classified according to its function: it is divided into hard carbon black and soft carbon black; The particle size of hard carbon black is below 40nm, while the particle size of soft carbon black is above 40nm.
Carbon black is classified according to its use: it is divided into rubber carbon black, pigment carbon black, conductive carbon black, and special carbon black. Among them, pigment carbon black can be divided into many types, such as carbon black for ink, carbon black for coating, and carbon black for Color Masterbatch
Carbon black is classified into super wear-resistant carbon black, medium and super wear-resistant carbon black, high wear-resistant carbon black, fine particle furnace black, fast pressing furnace black, universal furnace black, high elongation furnace black, semi reinforced furnace black, fine particle hot cracking carbon black, medium particle hot cracking carbon black, easy to mix tank black, and mixed tank black according to its performance.
Types of white carbon black: White carbon black mainly refers to synthesized silica, which is not a product of carbon black. White carbon black is divided into gas-phase white carbon black and precipitated white carbon black.
Conductive carbon black can be divided into conductive groove black (cc), conductive furnace black (CF), superconducting furnace black (SCF), and special conductive furnace black (XCF) based on its conductivity and manufacturing method. Acetylene carbon black (ACEF) is also a carbon black with good conductivity.
Carbon black is classified according to ASTM standards, and China began using the American ASTM 1765-81 classification and naming in the 1980s. This naming system consists of four digits, with the first symbol being N or S, representing the vulcanization rate. Where N represents the normal vulcanization rate; And S represents slow vulcanization speed. The N or S symbol is followed by three numbers, with the first number indicating the average particle size range of carbon black; The second and third digits have no clear meaning and represent the differences between different brands in each series.
3. What are the uses of carbon black
3.1 Carbon black
carbon black
Carbon black is an indispensable chemical raw material, and it has a great application in our daily life. It is reflected in the raw materials such as car tires, ink, coatings, batteries, etc. around us. Carbon black is usually divided into pigment carbon black, rubber carbon black, conductive carbon black, and specialized carbon black.
Carbon black application field:
rubber
Carbon black is an important reinforcing agent in rubber products, which can improve the wear performance of tires and increase the tensile strength and tear strength of rubber materials. About 75% of carbon black used in rubber is used to make tires, while the rest is used to make rubber hoses, tape, and so on.
printing ink
Carbon black is mainly used in black pigments, and ink mainly uses pigment carbon black because the blackness and color phase of pigment carbon black are much stronger than ordinary carbon black.
plastic
Carbon black can mainly play a role in preventing ultraviolet aging and conducting electricity in plastics.
In addition, carbon black plays an important role in synthetic leather, coatings, batteries, printing and dyeing, gunpowder, and other fields.
3.2 White carbon black
White carbon black (modified silica)
White carbon black refers to modified silicon dioxide. White carbon black is the general term of white powder X-ray amorphous silicic acid and silicate products, mainly referring to precipitated silicon dioxide, fumed silicon dioxide and ultra-fine silicon dioxide gel, as well as powder synthetic aluminum silicate and silicate.
In fact, white carbon black and carbon black are completely different substances, and they are named white carbon black mainly because they have great similarities in reinforcing functions with carbon black. The main component of white carbon black is silicon dioxide, but it is also different from ordinary silicon dioxide. White carbon black is physically and chemically modified to add active silicon dioxide.
White carbon black has a wider range of uses. The chemical formula of white carbon black is SiO2nH2O, which is named after its similar use to carbon black and its white color. It is mainly used as a filling and reinforcing agent in rubber and plastic products, as a carrier for adding drugs and nutrients in feed processing and drug processing, and in salt processing, chili noodle processing, etc To prevent product clumping during processing, and to increase friction when used in toothpaste. The specific application areas are as follows:
3.2.1 Tire Industry
Tire production line
The use of white carbon black, especially highly dispersed precipitated white carbon black, in the tire tread compound in combination with coupling agents can simultaneously increase tire life (improve wear resistance) and safety (improve wet slip resistance), reduce fuel consumption (reduce rolling resistance). In addition, precipitated silica can be used in the tire carcass and belt layer to improve the adhesion between the rubber material and the steel cord; Replacing carbon black with white carbon black in the sidewall compound of tires can significantly improve the durability of the compound, as well as improve its flexibility and impact resistance.
3.2.2 Rubber shoes and other rubber products
Shoe making workshop
White carbon has high black and white color and fine particles. The vulcanizate made from white carbon has high transparency and can improve the comprehensive physical properties of the compound. Therefore, white carbon black is widely used as a main reinforcing filler in rubber shoe production, especially in transparent and semi transparent sole compounds.
In the production of adhesive tape, in order to improve its wear resistance, a large amount of white carbon black is added. At the same time, the silane alcohol on the surface of white carbon black plays a role in improving the wetting degree of the adhesive and fabric, which is conducive to the diffusion and penetration of the adhesive. In addition to the above products, white carbon black is also used on rubber rollers, rubber tubes, rubber plates, wires and cables, as well as rubber components in household appliances and cultural and sports products.
3.2.3 Plastic modification and products
In the plastic industry, using white carbon black for transparency and small particle size can make plastics more dense. It not only improves its transparency, strength and toughness, but also significantly improves its waterproof performance, anti-aging performance, hardness and smoothness.
3.2.4 Silicone rubber
The application of silicone rubber began with the emergence of white carbon black. Silicone rubber has high heat resistance and excellent cold resistance, ozone resistance, aging resistance and atmospheric aging resistance, as well as excellent electrical insulation. Due to the aforementioned characteristics, silicone rubber is widely used in industries such as aerospace and electronics. The price of fumed silica is high, and using relatively inexpensive precipitated silica instead of fumed silica can be used for the production of low-grade silicone rubber.
3.2.5 Pharmaceutical Industry
White carbon black has physiological inertness, high absorption, dispersibility, and thickening properties, and is widely used in pharmaceutical preparations. For example, quasi biotic E powder now uses white carbon black as a carrier in large quantities, as well as additives such as toothpaste.
3.2.6 Pesticide industry
White carbon black is mainly used as a carrier in the pesticide industry to improve fluidity and prevent agglomeration. Currently, white carbon black is mainly used in various wettable powders.
3.2.7 Application in Ink
White carbon black mainly plays a thickening role in ink and is used to control the flow rate of printing ink. It is also used to control the flow rate of printer ink, so that it cannot flow or hang freely, in order to achieve clear printing.
3.2.8 In the pigment and dye industry
Color masterbatch
White carbon black can overcome the shortcomings of organic pigments (dyes) that have bright colors and strong coloring power, but generally have poor light resistance, heat resistance, solvent resistance, and migration resistance. The surface modification of organic pigments (dyes) by adding nano silica not only greatly improves the anti-aging performance of pigments (dyes), but also improves the brightness, hue, saturation and other indicators to a certain extent, greatly expanding the grade and application range of organic pigments (dyes).
Carbon black is a rubber reinforcing filler, second only to raw rubber as the raw material. At the same time, carbon black can be used as a colorant, UV shielding agent, anti-static agent, or conductive agent, widely used in many industries such as plastics, chemical fibers, inks, coatings, electronic components, leather chemicals, and dry batteries. As a high-purity carbon material, carbon black can also be used in metallurgy and carbon material industries.
4. The industrial chain of carbon black
4.1 Carbon black upstream industry
The main raw materials for carbon black production are coal tar, ethylene tar, and other raw materials. Coal tar is a byproduct generated from coking; Ethylene tar is a byproduct of petroleum refining to produce ethylene. Therefore, the upstream of the carbon black industry is the coal chemical industry and the petrochemical industry.
According to statistics, the main components of carbon black raw materials in China are coal tar, anthracene oil, and ethylene tar, accounting for 49.2%, 34.2%, and 16.6% of the total raw materials, respectively. Among them, coal tar and anthracene oil account for more than 80% and are the most important raw materials. Therefore, the domestic carbon black industry is greatly influenced by the coal chemical industry.
The impact of upstream industries on the carbon black industry is mainly manifested in the price of raw oil. As anthracene oil is a downstream product of coal tar, its price mainly depends on the price of coal tar. Therefore, the price of coal tar largely determines the production cost of carbon black, with the most significant impact on carbon black production. The production and market concentration of China's coal tar industry is relatively low, but the scale of coal tar processing by a single company is constantly expanding.
Formula for the price relationship between carbon black and coal tar:
Coal tar price * 1.65+1000 yuan/ton=basic price of carbon black
The traditional main production areas of China's coal tar processing industry are concentrated in the north, with Hebei Province, Shanxi Province, and Shandong Province accounting for a total of 53.4%. In addition, the regional production capacity of provinces such as Henan, Xinjiang, and Inner Mongolia is over one million tons; It is worth noting that with the continuous construction of new devices in Guangxi, the southwest region will also become an important production area for the coal tar processing industry in the future.
Affected by the distribution of raw materials, the regions for deep processing in China are mainly concentrated in North China and East China. Therefore, the demand for coal tar is also mainly concentrated in these two regions, with East China mainly distributed in Shandong, accounting for 18%, while North China mainly concentrated in Shanxi and Hebei, accounting for 24% and 16% respectively.
According to market research data, from January to May 2020, the domestic coal tar deep processing production capacity was 10.34 million tons, including 4.54 million tons in North China (44%), 2.26 million tons in East China (22%), 980000 tons in Northwest China (9%), 1.27 million tons in Central China (12%), 620000 tons in Southwest China (6%), 530000 tons in Northeast China (5%), and 160000 tons in South China (2%).
Carbon black is the downstream product with the largest consumption of coal tar, accounting for approximately 26% of its total consumption.
4.2 Carbon black downstream related industries
Carbon black (excluding white carbon black) is mainly used as a reinforcing agent and filler for rubber, accounting for about half of the rubber consumption in the entire rubber product. Carbon black for rubber accounts for 94% of the total carbon black, of which about 60% is used in tire manufacturing.
At present, the overall development pattern of China's tire industry is characterized by rapid development throughout the industry, accompanied by structural adjustment and industrial upgrading. Radial tires, as the development direction of the tire industry, will gradually replace traditional diagonal tires. With the continuous improvement of the meridianization rate in China's tire industry, a large number of high-quality carbon black with high grade and stable quality are needed. Large carbon black manufacturers with scale and technological advantages in China will benefit from the industrial structure adjustment.
With the development of China's tire industry, the concentration of tire enterprises is gradually increasing, which is beneficial for carbon black enterprises to leverage their marketing advantages. At present, domestic carbon black consumption is mainly concentrated in the Bohai Bay and Yangtze River Delta regions. In the future, carbon black production enterprises with scale and technological advantages will be able to share the achievements of industrial upgrading in the tire industry.
In addition to rubber products, carbon black is also used as a colorant for inks, coatings, and plastics, as well as a UV shielding agent for plastic products. It is also an important additive in many other products, such as electrodes, dry batteries, resistors, explosives, cosmetics, and polishing pastes.
4.3 Domestic carbon black production capacity
Statistical data shows that the growth rate of the global carbon black industry market size in the first three quarters of 2015 to 2020 was between -30% -25%, with significant fluctuations. The global carbon black industry market size in 2015 was 69.7 billion yuan. In 2019, the global carbon black industry market size reached 94.1 billion yuan, a year-on-year increase of 2.9%.
Data shows that in 2018, the sales revenue of China's carbon black industry was 32.2 billion yuan, and in 2019, the sales revenue of China's carbon black industry was 33.5 billion yuan, a year-on-year increase of 3.8%. It is predicted that in the next few years, as the downstream demand situation in the industry improves, the industry market size will also show an upward trend. It is predicted that the market size of China's carbon black industry will reach 37.4 billion yuan by 2026.
5.1 Current main production methods of carbon black
The carbon black industry has a history of about 100 years to this day. The specific process can be summarized as follows:
(1) The initial period of carbon black industry: using natural gas as raw material, the main production method was the trough method. The equipment has a large volume and low production capacity.
(2) In the 1940s, furnace method carbon black was produced, including oil furnace method and gas furnace method. This production method reduces the volume of equipment and increases production, but the quality is not as good as that of tank method carbon black.
(3) In the 1950s, China first began producing trough process carbon black in Fushun and Sichuan, and in the 1960s, it began producing furnace process carbon black. In the 1980s and 1990s, Tianjin Carbon Black Factory introduced 15000 tons of carbon black hard wire from the mainland of the United States in 1985. In the future, Tianjin Carbon Black Factory, Fushun Chemical Factory, and Carbon Black Research Institute carried out absorption and transformation of the introduced production line.
5.2 The current mainstream production method for carbon black is the furnace method.
The characteristics of furnace process carbon black: Furnace process carbon black has high elongation, low heat generation, high elasticity, and good aging resistance of rubber materials, and is mainly used for matrix buffer rubber and various rubber products for cord fabric rubber. Mainly used in rubber materials such as tire fabric layer, lower layer of tread, sidewall, and inner tube. The furnace method is also divided into oil furnace method and gas furnace method. The production process of carbon black in the oil furnace method involves spraying liquid hydrocarbon raw materials such as coal tar, onion oil, anti-corrosion oil, and ethylene tar into a specially designed reaction furnace under controlled conditions, and generating a type of carbon black through incomplete combustion and cracking in an appropriate amount of air. After generation, carbon black is suspended in the flue gas, cooled, collected, refined, and granulated to obtain the finished product. The production process of carbon black using gas furnace method: Under controlled conditions, gaseous hydrocarbon raw materials such as natural gas and oilfield gas are sprayed into a specially designed reaction furnace, and a type of carbon black is generated through incomplete combustion and cracking in an appropriate amount of air. After generation, carbon black is suspended in the flue gas, cooled, collected, refined, and granulated to obtain the finished product.
The comparative characteristics of gas furnace method carbon black and oil furnace method carbon black are: oil furnace method carbon black has a large output, low cost, multiple varieties, low energy consumption, and high yield, making it the most important carbon black production method.
5.3 Carbon black granulation
Carbon black finished products are extremely fine powders, which are inconvenient for packaging, transportation, and processing. Therefore, most of the carbon black products currently sold on the market, except for a few coloring pigments such as carbon black, require the powder to be processed into granules. There are currently two granulation processes, one is dry granulation and the other is wet granulation. Dry granulation is the process of continuously passing carbon black through a rotating cylinder, causing powdered carbon black to become spherical particles due to its physical adhesion. The equipment for dry granulation is simple, the granulation cost is low, but the particle strength is low, and carbon black particles are easily broken during bulk transportation.
Wet granulation is the process of mixing carbon black with a certain proportion of granulation water, and in a stirring tooth type wet granulation machine, it is mixed, wetted, and stirred to form particles, which are then dried to form granular carbon black products. This method has good particle firmness and can be transported in bulk.
6. Factors affecting the price of carbon black
The price of carbon black is mainly influenced by upstream raw material prices and the supply and demand situation of the carbon black market. Currently, in China, the main upstream raw material is coal tar, and the price of coal tar has a decisive impact on the production cost of carbon black, followed by the price of petroleum. In terms of supply and demand, it is mainly influenced by the demand of the domestic tire industry.
