At the hearing on October 9, 2018, the Supreme Court of India decided to liberalize import restrictions on carbon grade petroleum coke and calcined petroleum coke, while setting import quotas for carbon grade petroleum coke and calcined coke.
India's annual import quota is 500,000 tons of calcined coke and 1.4 million tons of carbon grade petroleum coke, but it is not allowed to be used as fuel. Petroleum coke is a sponge-like solid residue produced during the distillation of crude oil. Its calorific value is 1.5 times that of coal. It is usually used as fuel in electric power, glass, cement, and other industries. Because of the high calorific value of petroleum coke and the much cheaper price than coal, coupled with the loopholes in India's environmental protection tax, petroleum coke has become the most attractive raw material for Indian power stations and cement plants.
For India, petroleum coke is indeed cheap and easy to use, but it also costs a lot of use. India’s sulfur dioxide emissions have surpassed China in 2016 to become the world’s number one. At present, about 33 million people live in sulfur dioxide pollution. Area. To this end, the Modi government is determined to ban the use of petroleum coke as a fuel nationwide!
Petroleum coke market: The results of this hearing are also expected by all parties in the market. At present, Indian buyers are already in contact with Chinese petroleum coke and calcined coke suppliers. India’s two-month carbon-grade petroleum coke and calcined coke imports will soon recover.
China's petroleum coke price: For the current Chinese petroleum coke market, the impact is very limited. The export volume of petroleum coke from major manufacturers in the early stage was basically at the port level and did not enter the domestic market. The import restrictions on the release of petroleum coke in India are mainly to continue the previous export plan, which has little impact on the domestic petroleum coke market supply and demand.
Quota setting impact: The output converted to prebaked anodes is 165-1.7 million tons/year from the set limit. Compared with the demand for prebaked anodes in 2017, the demand for 1.7 million tons is basically the same.
For the Indian aluminum carbon market, the quota set this time basically meets the current demand. However, considering that India's electrolytic aluminum production has grown rapidly in recent years, the growth rate is basically 15%-20%, and the future demand is difficult to meet. There may be two situations in the future:
The first is that annual quotas are raised as demand for electrolytic aluminum increases;
The second is to still limit the current quota, or to increase the relative demand, and instead import more pre-baked anode products.
The second article above is relatively more in line with India's national environmental requirements. For the China Petroleum Coke Industry Chain, both of these situations can share the dividends generated by the development of the Indian electrolytic aluminum industry. Relatively speaking, if the second article is established, it will be more favorable to the domestic petroleum coke industry chain, which can boost the export of prebaked anodes, increase the utilization rate of prebaked anode capacity, and drive the demand for petroleum coke and calcined coke. Moreover, the recent domestic environmental protection policy is more rational, and it is also convenient for carbon enterprises to stabilize production.
Monday (October 8th) today is the first working day after the National Day. According to the understanding of the price of petroleum coke during the National Day, the price remains mainly stable, and the price after the holiday has been adjusted. The price of calcined petroleum coke is slightly raised, and the coke is burnt. The price of recarburizer is temporarily unchanged.
The three major groups of petroleum coke market:
Sinopec, during the National Day, Sinopec's Tahe and Maoming Petrochemical prices have been adjusted, and today, Tahe coke prices continue to increase, it is reported that Tahe petroleum coke cumulative increase of 60 yuan / ton, Maoming petrochemical coke price before the holiday cut significantly 120 yuan / Tons, mainly due to the high price in the previous period, coupled with the price adjustment of the National Day holiday, the current oil coke shipments of the factory are low. The price of petroleum coke in Yanshan Petrochemical Company of North China was lowered by RMB 60/ton today. The factory shipped poorly during the festival and there were fewer transport vehicles. Luoyang Petrochemical's shipment is still acceptable, and the price of Dongming is raised to support its shipment. The price of Tianjin Petrochemical Railway Transportation was raised by RMB 50/ton. The quality of petroleum coke in Anqing Petrochemical was slightly lower due to higher prices in the previous period. The Sinochem Quanzhou coking unit has been shut down during the National Day and there is currently no inventory in the plant.
In the case of PetroChina and CNOOC, Daqing and Fushun Petrochemical in Northeast China began to sell their petroleum coke in October, and the shipment is relatively stable. Liaoyang Petrochemical's price is lowered by 50 yuan/ton today, and the coking unit of the plant is expected to be shut down for one year from mid-October. The commencement of the Liaohe petrochemical coking unit has been postponed and it is expected that products will be available in the middle. The petrochemical coking unit in the northwest region started construction at the end of September. At present, it has been out of focus, and the price is raised by 50 yuan/ton. Wu Petrochemical and Dushanzi Petrochemical petroleum coke shipped well, among which the petrochemical index of Wujiang Petrochemical continued to improve in the near future. The sulfur content was all within 1.0%, and the price of Yumen Petrochemical Petroleum Coke was raised by RMB 50/ton from 10.1.
Refining petroleum coke:
As the first working day after the National Day, the price of refinery petroleum coke has risen in an all-round way, with a concentration of 30-130 yuan/ton. Before the holiday, due to the high cost performance of the refining petroleum coke, the refineries have signed a large number of contracts. At present, most of the refineries have no inventory and the shipments are smooth. In terms of refinery dynamics, Hengbang Petrochemical Co., Ltd. resumed production and still produces projectile coke; Zhenghe Petrochemical Coking Unit was shut down for maintenance on September 30, and petroleum coke has no inventory; Longhai Petrochemical and Qirun Chemical Coking have not yet started.
Calcined petroleum coke recarburizer market:
Today, the market for calcined coke recarburizers is stable, and corporate prices have not been adjusted. During the National Day of PetroChina Liaohe Petroleum Exploration Bureau Co., Ltd., the two rotary kiln have been started normally. However, since the refinery coking unit has not been out of focus, the plant is not yet fully loaded. At present, the plant is burning coke recarburizer. The price is maintained before the National Day, and the shipment is acceptable.
180925 China's petroleum coke prices are stable and downward, the short-term market petroleum coke prices will continue to be low, and the low-sulfur calcined petroleum coke recarburizer market will slow down this week.
The three major groups of petroleum coke market:
In terms of Sinopec, the price of petroleum coke in its refinery is stable today. Only the prices of petroleum refineries in individual refineries are slightly adjusted. Among them, the price of Huadong Petrochemical is lowered by RMB 20/ton, and the petrochemical of South China is lowered by RMB 50/ton. Stable, the National Day is approaching and near the end of the month, and the recent coking price is still in a downward trend, so Sinopec's refineries are also mainly shipped, the price is stable.
In the case of PetroChina and CNOOC, the price of petroleum coke in the northeast region is stable today. Daqing and Fushun low-sulfur high-quality petroleum coke continue to insured, and prices are expected to fall sharply at the end of the month. The petroleum coke shipments in the northwest region performed well, and the downstream carbon companies received positive products. In the case of CNOOC, Zhoushan Petrochemical Coking Plant started construction today to implement the latest price. Binzhou Zhonghai Bitumen Coking started to be sold tomorrow, and the Shandong Haihua Group coking unit was postponed.
Refining petroleum coke:
Today is the first working day after the Mid-Autumn Festival, and the price of refining petroleum coke is still “falling down”. Today, Rizhao Yanqiao Port petrochemical coking unit has been out of focus, and shipped according to 3#A. The National Day holiday is approaching, the downstream carbon companies are still enthusiasm for receiving goods, and the refinery shipments are eager. Today, the price of sulfur coke continues to decline. It is expected that the short-term price will continue to stabilize.
Calcined coke market:
Today, the market for calcined coke is stable and the price has not been adjusted. The market price of low-sulfur calcined coke is relatively stable. The performance of low-sulfur calcination coke is general. Some enterprises have obvious inventory. The market price of downstream graphite electrode has risen slightly this week, but the raw materials of enterprises are still purchased on demand, and the environmental protection is further Affected the operating rate is limited. Low-sulfur calcination coke recarburizer market coking is slowing down this week. On the one hand, the downstream purchasing enthusiasm has declined after the price rise. On the other hand, this week, the Liaohe Petroleum Exploration Bureau Co., Ltd. Petrochemical Branch has started a rotary kiln this week. The market share has shifted.
What is carbon additive? Carbon additive is a carbon or petroleum coke follow-up product of black or gray particles (or blocks) with high carbon content. The material is mainly coal and petroleum coke. The petroleum coke is divided into general calcined petroleum coke. (calcined coke or calcined coke) and graphitized petroleum coke. The carbon additive is used to reduce the oxygen content in the molten iron mainly during metal smelting and improve the mechanical properties of the casting. In the new synthetic cast iron smelting process, the amount of scrap steel used is greatly increased. By adding a carbon additive to adjust the carbon content of the molten iron, the production cost is greatly reduced while ensuring the quality of the molten iron.
Types of carbon additive
According to the existence form of carbon atoms, carbon additive can be divided into graphitized carbon additive and non-graphitized carbon additive. Graphitized carbon additive mainly includes graphitized petroleum coke and graphite electrode. Graphitized petroleum coke carbon additive is the most widely used in the foundry industry. The production process is to convert the raw material petroleum coke in a graphitization furnace through a high temperature of 2200-2600 °C, so that the carbon crystallization of the petroleum coke amorphous layer structure is transformed into The high-temperature heat treatment process of the three-dimensional ordered graphite crystal, that is, through the graphitization process, reaches the graphitization state. The non-graphitized carbon additive mainly includes: calcined petroleum coke, coal carbon additive, etc., calcined petroleum coke refers to petroleum coke heated at 1200-1500 ° C high temperature, the treatment temperature is low, and the crystal structure has not changed. Due to the high ash content and volatile matter, coal-based carbon additive is rarely used in electric arc furnace smelting. The indicators for measuring the quality of carbon additives are fixed carbon content, sulfur, volatile matter, ash, nitrogen content and water. After high temperature graphitization, the graphitized carbon additive has a much lower sulfur and nitrogen content than the non-graphitized carbon additive.
Carbon additive index: fixed carbon, ash, volatile matter
The fixed carbon of carbon additive is different from the carbon content. The fixed carbon value is calculated based on the moisture, volatile matter, ash and sulfur content of the sample, and the carbon content can be directly detected by the instrument. The fixed carbon content is high and the ash content is low, so the carbonization effect is better. The high ash content in the carbon additive generates a large amount of soot and slag during the smelting process, increases energy consumption, and increases the labor intensity of the slag.
Carbon additive index: sulfur
The sulfur content of ordinary calcined coke has a relatively high grade, generally less than 3% of sulfur to 0.1%, and the sulfur content of graphitized carbon additive is generally less than 0.05%. In ordinary cast iron, sulfur element has stable cementite and prevents the expansion of graphitization. In the production of ductile iron and vermicular graphite iron, a graphitized carbon additive with low sulfur content should be used. If the sulfur content is too high, the ball will be affected. The effect is to consume more spheroidizing agent and increase the production cost; the calcined petroleum coke carbon additive is used in the production of some gray iron castings because of the lower calcination temperature and higher sulfur content, generally less than 1%.
Carbon additive index: nitrogen content
Nitrogen content is an important indicator of the quality of carbon additive. In general, when the foundry purchases the carbon additive, the first is to pay attention to the price of the carbon additive; the second is the fixed carbon, sulfur, ash, volatile matter, and moisture content in the carbon additive, and less attention is paid to the nitrogen content. Ordinary calcined petroleum coke carbon additive, the calcination temperature is low, and the nitrogen and sulfur contents are high. When producing gray iron castings, the scrap steel itself will bring in a part of nitrogen. If the scrap is added in a large proportion, the amount of carbon additive will increase accordingly. If ordinary carbon calcined carbon additive with high nitrogen content is used, the molten iron is used in molten iron. The nitrogen content will increase significantly. Excessive dissolved nitrogen in the molten iron hinders graphitization, increases the stability of the carbide, promotes the formation of D-type graphite, improves the hardness, and deteriorates the processing properties of the casting.
For gray cast iron, the proper amount of nitrogen can shorten the length of the graphite sheet, increase the degree of bending, passivate the end, reduce the aspect ratio, stabilize the pearlite of the matrix, refine the grain structure and improve the tensile strength of the casting. And the role of hardness. According to the data, when the iron is N>0.012%, there is a possibility of nitrogen hole defects in the casting. Nitrogen pores are commonly found in the interior, surface or near surface of castings. They are round, rectangular and irregular in shape and are one of the common defects in casting production. The graphitized carbon additive is subjected to high-temperature desulfurization and denitrification treatment, and the content of nitrogen and sulfur is very low. The content of molten iron in the molten iron using graphitized carbon additive is generally low.
Factors affecting the absorption rate of carbon additive: The factors affecting the absorption rate of carbon additive are mainly the way of adding carbon additive, the chemical composition of molten iron, the temperature of molten iron, and the particle size of carbon additive.
In the process of iron and steel smelting, if the carbon content in the molten iron is not improved well, it will affect the quality of the steel and increase the cost of smelting and casting. In order to ensure the quality of steel casting, the quality of smelting can be improved by increasing the amount of smelted pig iron, but the raw iron of pig iron is relatively high. When using a recarburizer, it is not necessary to put too much pig iron. It is possible to increase the carbon content in the molten iron.
At present, there are many materials for cast iron recarburizers on the market. In general, coal quality recarburizers, petroleum coke recarburizers, calcined petroleum cokes, graphitized petroleum coke recarburizers and artificial graphite can be used as cast iron smelting. Recarburizer used. Although these products can be used as recarburizers, you must choose the right recarburizer when you buy them. If the quality of the products to be cast is high, you need to choose artificial graphitized petroleum coke recarburizer.
If the quality of the smelting metal is not high, you can choose a lower cost recarburizer. For example, in converter smelting, when high carbon steel is used, you can use petroleum coke with a lot of impurities as a recarburizer. However, the requirements for the recarburizer for the top-blown converter steelmaking are higher than the carbon of the fixed furnace recarburizer. The ash, volatiles, sulfur, phosphorus, nitrogen and other impurities are also required to be high in content, and are required to be dry, clean, and granular. Moderately, it is necessary to choose a calcined coke recarburizer and a graphitized recarburizer.
Among them, the most used mainstream carbonizers specifications are: fixed carbon C ≥ 98%, volatile matter ≤ 1.0%, sulfur content ≤ 1%, moisture ≤ 0.5%, particle size is more than 1-5mm, this recarburizer The indicator shows the calcined petroleum coke recarburizer, which is calcined petroleum coke. In the past, in the domestic smelting industry, relatively low-end non-graphitizing recarburizers were generally used. With the improvement of product quality and upgrading, more and more enterprises using graphitized petroleum coke in China will increase carbonization of graphitized petroleum coke. The indicators of the agent are: fixed carbon C ≥ 98.5%, volatile matter ≤ 0.5%, sulfur content ≤ 0.1%, moisture ≤ 0.5%, particle size between 0-5mm.
Different types of recarburizers are used differently. In the process of selecting a recarburizing agent for steel making, the particle size should be moderate, the particle size is too fine to be easily burned, and when it is too coarse to be added, it floats on the surface of the molten steel and is not easily absorbed by the molten steel. With the development of the market, the quality requirements of steelmaking refining agents are getting higher and higher, especially the conversion from coal quality carbonizers to calcined petroleum coke recarburizers, or graphitized petroleum coke recarburizers. .
The recarburizer is a material used to increase the carbon content. The main component is carbon. There are many materials that can be used as a recarburizer. Commonly used are coke and anthracite, calcined petroleum coke, graphitized petroleum coke, and graphite (artificial graphite). , natural graphite) and mixtures made from such materials.
1. Coke and anthracite
Coke is a type of solid fuel. It is obtained by dry distillation of coal under high temperature conditions of about 1000 °C. The main component is fixed carbon, followed by ash, and contains less volatile matter and sulfur. Silver-gray, metallic luster. Hard and porous. In addition to a large amount of coke and iron non-ferrous metal smelting (metallurgical coke), coke is also used in foundry, chemical, calcium carbide and ferroalloys, and its quality requirements are different. For example, for casting coke, it is generally required to have large particle size, low porosity, high fixed carbon and low sulfur content; coking for chemical gasification is not strict with strength, but requires good reactivity, high ash melting point, and coke requirement for calcium carbide production. Try to increase the fixed carbon content.
Anthracite is a hard, dense and high-gloss coal mine. The main applications of anthracite lump coal are chemical fertilizer (nitrogen fertilizer, synthetic ammonia), ceramics, manufacturing forging and other industries; anthracite coal is mainly used in the metallurgical industry for blast furnace injection (blast furnace coal mainly includes anthracite, lean coal, lean coal and gas coal) ).
2. Calcined petroleum coke (calcined coke or calcined coke)
Calcined petroleum coke is a widely used recarburizer, which is obtained by calcining petroleum coke. Petroleum coke is a by-product of refined crude oil. Residual oil and petroleum asphalt obtained by vacuum distillation or vacuum distillation can be used as raw materials for petroleum coke, and then coke is obtained to obtain raw petroleum coke. The annual production of American petroleum coke is about 30 million T. The raw petroleum coke has high impurity content and cannot be directly used as a recarburizer. It must be calcined first.
Raw petroleum coke has spongy, needle-like, granular and fluid states.
Sponge petroleum coke is produced by delayed coking. Because of its high sulfur and metal content, it is usually used as a fuel for calcination and as a raw material for calcined petroleum coke. The calcined plum cotton coke is mainly used in the aluminum industry and as a recarburizer.
The acicular petroleum coke is obtained by a delayed coking process using a raw material having a high content of aromatic hydrocarbons and a low impurity content. This coke has a needle-like structure that is easily broken, sometimes referred to as graphite coke, and is mainly used for the manufacture of graphite electrodes after calcination.
Granular petroleum coke is a hard granule. It is a raw material with a high content of sulfur and bitumen. It is produced by delayed coking and is mainly used as a fuel.
The fluid petroleum coke is obtained by continuous coking in a fluidized bed. It is in the form of fine particles, has no directional structure, high sulfur content and low volatile content.
The burning of petroleum coke is to remove sulfur, moisture, and volatiles. The raw petroleum coke is burned at 1200 ° C - 1350 t ° C to make it substantially pure carbon.
The largest user of smoked petroleum coke is the aluminum industry, 7 which is used to make anodes for the reduction of bauxite. The United States produces smoked petroleum coke, which accounts for about 6% of cast iron enhancers.
3. Graphitized petroleum coke
Graphitized petroleum coke refers to the high-temperature graphitization of petroleum coke. Under the high temperature of 3000 °C, the carbon molecular form in the petroleum coke is changed from an irregular arrangement to a hexagonal uniform arrangement. The agent is most easily decomposed in molten iron.
Characteristics of graphitized recarburizer
1) The low-sulfur graphitization recarburizer has a high decomposition rate and a high absorption rate, and can reach more than 90%.
2) High carbon, low sulfur, low nitrogen, and extremely harmful components.
3) Adding graphite nucleus to molten steel and molten iron, more uniform and finer distribution in molten steel and molten iron, so that the performance is more excellent and stable.
4. Graphite is an allotrope of elemental carbon. Each carbon atom is connected with three other carbon atoms (multiple hexagons arranged in a honeycomb shape) to form a covalent molecule by covalent bonding. . Graphite and carbon products have excellent performance, are increasingly used, and the production capacity and benefits are growing rapidly. There are more enterprises of graphite and carbon products above the scale of China, and the concentration is low. With the rapid development of China's metallurgy, chemical, machinery, medical equipment, nuclear power, automotive, aerospace and other industries, the demand for graphite and carbon products will continue to grow in these industries, and China's graphite and carbon products industry will maintain rapid growth. . Graphite is mainly divided into natural graphite and artificial graphite.
4.1. Natural graphite
Natural graphite can be divided into two types: flake graphite and microcrystalline graphite. Microcrystalline graphite has a high ash content and is generally not used as a carbon reinforcer for cast iron. There are many varieties of flake graphite. High-carbon flake graphite needs to be extracted by chemical methods, or heated to high temperature to decompose and volatilize the oxides. This flake graphite has low yield and high price, and generally does not act as a recarburizer; low carbon scales Graphite has a high ash content and should not be used as a recarburizer; it is mainly used as a carbon reinforcer for medium carbon graphite, but it is not used in large amounts.
4.2. Artificial graphite
Among the above various recarburizing agents, the best quality is artificial graphite. The main raw material for the manufacture of artificial graphite is powdered high-quality simmered petroleum coke, in which asphalt is added as a binder, and a small amount of other auxiliary materials are added. After the various raw materials are combined, they are press-formed and then treated in a non-oxidizing atmosphere at 2500 to 3000 ° C to be graphitized. After high temperature treatment, the ash, sulfur and gas contents are greatly reduced. Due to the high price of artificial graphite products, the artificial graphite breakers commonly used in foundries are mostly cut when manufacturing graphite electrodes.
Recycled materials such as chips, used electrodes and graphite blocks to reduce production costs. In the smelting of ductile iron, in order to make the metallurgical quality of cast iron superior, the carbon-reducing agent should be the first choice of artificial graphite. For this reason, it is better to purchase scrap electrodes from nearby companies that use electric arc furnace steelmaking or electrolytic aluminum production enterprises, and crush them to the required particle size. .
180909 This week, China's recarburizer market started to work stably and trading was good. Among them, the market price of recalcurizer (common calcined coal) is lower. The main reason is that the downstream steel mills are affected by many factors such as environmental protection and trade warfare. In general, recarburizer shipments are limited, and the company is basically stable in environmental protection. Most of the inventory, the market price will decline. The market price of calcined coke recarburizer (calcined petroleum coke) was stable overall. The company said that although the price is high, the supply and demand side is relatively balanced, and the market is stable; the graphitized rebcarburizer (graphitized petroleum coke) market is raised by individual companies, and the market is out. The goods are in good condition and the production situation of the company is relatively stable.
Calcined coal recarburizer:
This week, the mainstream price of China's general calcined coal rebcarurizer market was lowered. The production in the main producing area of Ningxia is stable overall, affected by the rain, and the transportation is slightly limited. The enterprises are mostly in the process of rectification and maintenance, preparing for the acceptance at the end of September. Due to the downstream receiving, the enterprises are more or less in stock, the market In general, the overall transaction is relatively light, and the mainstream market price is down. The overall market production in North China is relatively stable, but environmental protection pressure is still not small. The overall performance of the market is generally high, mainly depending on the poor start of the downstream steel mills.
This week, the mainstream price of the calcined coke recarburizer market remained stable and the market was stable. In the northeast and north China, the production of enterprises is stable, the price of calcined coke is rising, and the cost pressure of enterprises is increasing. However, in view of the high price in the downstream market, the price intention is weak, the production enterprises are still shipping, and the mainstream prices of the market have not yet fully fluctuated.
Graphitized petroleum coke recarburizer:
This week, the market price of China's graphitized petroleum coke recarburizer was stable, and the company's price intention was strong. The main reason was the increase in cost. The crude oil price of raw materials rose in the mainstream, and the high-end operation, individual companies raised product prices. Among them, the production of individual enterprises in Henan and Xinjiang was suspended due to environmental protection, and the operating rate fell. In addition, the graphitization enterprises of anode materials in the market will start construction in the second half of the year, and the output will be released. Graphitized rebcarurizer is highly concentrated in the Inner Mongolia region. Enterprises in Jiangsu Province have normal production, good shipments and smooth exports.
Recarburizer is mainly used in steel smelting process. Due to improper ingredients or improper loading and excessive decarburization, the carbon content in steel or iron sometimes fails to meet the expected requirements. At this time, carbon is added to steel or molten iron. The relationship between recarburizer and steel is also very close. Domestic steel prices have stabilized this week. Recently, the market turnover is weak, but the recent environmental protection inspection work in Shandong is in full swing. The inventory of various steel mills has decreased, and the market price support is strong. Steel mills have obvious willingness to price, and the market price on the weekend has also risen slightly, but the mainstream temporary stability has been comprehensively considered. It is expected that the short building materials market will be operated in a multi-country volatility with a range of 50 yuan/ton.
Forecast of the market outlook: the raw material price of raw calcined coal will rebound in September due to the limited price of environmental protection acceptance enterprises, and the price of the crude calcined recarburizer will develop in a stable-up mode. The price of the calcined recarburizer and the graphitized petroleum coke recarburizer is driven by cost, and the price is stable or slightly upward.
The use of recarburizers, as the name implies, is to increase the content of carbon. Its main purpose is to increase the carbon content lost during the steelmaking process. If the carbon content does not meet the expected requirements during the steelmaking process, a certain proportion is required. The recarburizer enhances the carbon content of the molten steel and smelts the ideal steel.
There are many kinds of raw materials for recarburizers, and the production process is also different. There are wood carbons, coal carbons, petroleum cokes, etc., while petroleum cokes are divided into calcined coke recarburizers and graphitized recarburizers. The current mainstream recarburizer.
The calcined petroleum coke recarburizer refers to the calcination of the raw material petroleum coke, and the temperature is controlled at 1250～1380°C. During the calcination process, the structure and element composition of the petroleum coke undergo a series of deep changes, thereby improving their physics. Chemical properties.
Why is petroleum coke calcined?
The purpose of calcination:
1. Eliminate volatiles and moisture in petroleum coke raw materials. After calcination, the volatile matter is 0.5% or less, and the water content is 0.3% or less.
The calcined volatiles and moisture represent the degree of calcination, which does not require secondary shrinkage and crack formation during calcination.
2. Improve the density and mechanical strength of petroleum coke raw materials. The true density is 2.00 g/cm3 or more.
The true density of the calcined coke affects the true density of the final product, and the mechanical strength is low. The bulk density is low, which affects the molding. The main performance is difficult to form. The height of the green block does not meet the requirements within the required time, which affects the operation of the aluminum electrolytic cell.
3. Improve the electrical conductivity of petroleum coke raw materials.
The calcined coke specific resistance affects the final product resistivity.
4. Improve the chemical stability of petroleum coke raw materials. Improved oxidation resistance.
Graphitized petroleum coke recarburizer is a process of treating petroleum coke into high temperature by graphite. This process is the process of energizing petroleum coke and then calcining at a high temperature of 3000 degrees, so that the carbon molecular form of petroleum coke is changed from irregular arrangement to hexagonal uniformity. In the way of arrangement, petroleum coke in this way can be better decomposed in molten iron to improve the effect of carbon absorption. Graphitized petroleum coke is the best refining agent for smelting. In the steelmaking industry, to produce good steel, there must be good raw materials, including good recarburizers, and graphitized petroleum coke is the best recarburizer. In the absence of graphitized petroleum coke, the graphite electrode has less scrap and higher price, which not only increases the cost of steelmaking, but also restricts the development of the steel industry. The appearance of graphitized petroleum coke breaks this bottleneck.
How much is a ton of recarburizer? The price of recarburizer depends on the specific indicators and particle size, such as the amount of fixed carbon, the amount of sulfur, the size of the grain, etc., in order to report the exact price, as well as the source of goods and freight, etc., Foshan Jitian Foundry Co., Ltd. mainly supplies calcined After the coke recarburizer and graphitization recarburizer, for Guangdong, Hunan, Guangxi, Jiangxi, Fujian and other provinces, customers are welcome to contact 2018 the most new carbon agent price, indicators and granularity!
Calcined coke recarburizer (petroleum coke): 2018.09.02 This week, the mainstream price of calcined coke recarburizer market remained stable, and individual companies offered slightly higher prices, and the market was stable. Raw materials: The price of domestic medium-high sulfur calcined coke has risen this week, with a concentration of 70-150 yuan/ton. The main reason for the increase in coke price is supply reduction and cost increase. In terms of raw materials, domestic petroleum coke prices are still rising mainly this week. The local refinery coke price has started to fall slightly on Wednesday. On the supply side, the supply of calcined coke in Shandong has decreased this week, mainly due to the impact of environmental supervision. Shandong this week The operating rate of Dongying calcined coke was significantly reduced. Most enterprises cut production by half and one was shut down. The production of calcined coke in other parts of Shandong has not been affected significantly. The fluctuations of calcined coke in Jiangsu and Hebei this week are not significant. Market outlook: It is expected that the market price of domestic medium and high sulfur calcined coke will be stabilized and stabilized next week.
Graphitized petroleum coke recarburizer (petroleum coke): 2018.09.02 This week, the price of graphitized petroleum coke recarburizer was stable, the market spot was abundant, and the shipment situation was general. Among them, the production of individual enterprises in Henan and Xinjiang was suspended due to environmental protection, and the operating rate fell. In addition, the graphitization enterprises of anode materials in the anode market will be put into production in the second half of the year. It is expected that the output will be released one after another, affecting the overall supply of graphitized recarburizer market. The concentration of negative electrode enterprises in Inner Mongolia is high, and the graphitization and recarburizer processing enterprises have also been transferred, and the market concentration has increased. The Jiangsu area is operating normally and the shipments are good. The orders are mainly for the old customers. The anode materials processing enterprises in Qinghai, Lanzhou, Ningxia, Inner Mongolia and other regions have higher activity and increased production.
Foshan Yoshida Casting Materials Co., Ltd. has long-term supply of various particle size indicators of recarburizers, calcined coke recarburizers and graphitized recarburizers. There are various indicators, and the particle size can be selected according to customer needs.
The calcined coke recarburizer is obtained by calcining petroleum coke, also called calcined coke, calcined petroleum coke. The main component is carbon. Its role is to increase carbon as its name suggests. However, the quality of different recarburizers is not the same. The higher the carbon content, the lower the basic impurities (basic impurities refer to ash, volatiles, moisture, etc.). Another one is the sulfur and nitrogen content in the composition. The role of sulfur is basically clear. The inclusion of a certain amount of sulfur in the cast iron can better improve the physical properties of the casting. In recent years, the nitrogen content has also been extensively studied. The nitrogen content is too high, nitrogen holes are generated, the nitrogen content is too low, the hardness of the castings is not high, and the ferrite is much.
The role of the calcined coke recarburizer is for casting cast iron and cast steel. Castings have a requirement for carbon, so the recarburizer is used to increase the carbon content of the molten iron. The common charge in smelting is pig iron, scrap steel, and recycled material. The carbon content of pig iron is high, but the purchase price is higher than that of scrap steel. Therefore, increasing the amount of scrap steel, adding high-quality recarburizer, reducing the amount of pig iron added, saving production costs and meeting the production needs. The recarburizer is slightly different for each batch. You have to be a specific percentage, which is not realistic. Other ingredients are ash, moisture, sulfur, phosphorus and the like.
Graphite recarburizer has high degree of graphitization, low sulfur, low nitrogen, less harmful impurities, very fast dissolution, no absorption, no residue, no floating, no residue, less added; low sulfur and low nitrogen, very graphitized High, very suitable for all (or most) use of shavings, cold-filled materials, briquettes, wire, particle steel as raw materials, smelting vermicular cast iron, ductile iron, gray cast iron. We will provide targeted recarburizers according to the characteristics of different customers' process castings, and it is not expensive to ensure that the products are easy to use!
Scope of application: It is used for carbonization of cast iron and cast iron in various electric furnaces. It is especially suitable for the ball mill cast iron industry with strict requirements on product quality and strict sulfur control. Compared with other types of recarburizers, it has an absolute price advantage. The intermediate frequency furnace of half a ton to 12 tons, the furnace temperature is controlled at about 1500 degrees. The absorption rate can reach up to 93%.
Particle size: 0-2mm, 1-2mm, 0-3mm, 1-3mm, 1-5mm...etc. (can be selected according to customer's needs)
1. Petroleum coke
Petroleum coke is a black or dark gray hard solid petroleum product with metallic luster and porosity. It is a carbonaceous material composed of tiny graphite crystals in the form of granules, columns or needles. The petroleum coke component is a hydrocarbon containing 90-97% carbon, 1.5-8% hydrogen, and nitrogen, chlorine, sulfur and heavy metal compounds.
Petroleum coke is a by-product of the delayed coking unit's feedstock oil cracking at high temperatures to produce light oil. The production of petroleum coke is about 25-30% of the feedstock oil. The low calorific value is about 1.5-2 times of coal, the ash content is not more than 0.5%, the volatile matter is about 11%, and the quality is close to anthracite.
2. The quality standard of petroleum coke
Delayed petroleum coke refers to the raw coke produced by the delayed coking unit, also known as ordinary coke. The current domestic production enterprises are mainly produced according to the industry standard SH0527-92 formulated by the former China Petrochemical Corporation. The standard is mainly classified according to the petroleum coke content:
No.1 coke is suitable for the production of ordinary power graphite electrodes in the steelmaking industry, and is also suitable for the aluminum industry for carbon for aluminum;
No. 2 coke is used as electrode paste and graphite electrode for electrolysis cell (furnace) in the aluminum smelting industry;
No. 3 coke is used to produce silicon carbide (abrasive material) and calcium carbide (calcium carbide), as well as other carbon products. It is also used in the manufacture of anode bottom blocks for aluminum-making electrolysis cells and for blast furnace carbon lining or furnace bottom construction.
3. The main use of petroleum coke
The main uses of petroleum coke are prebaked anodes and anode pastes for electrolytic aluminum, carbon generators for carbon industry, graphite electrodes, silicon for smelting industry, and fuels.
According to the structure and appearance of petroleum coke, petroleum coke products can be divided into four types: needle coke, sponge coke, projectile coke and powder coke:
(1) Needle coke, with obvious needle-like structure and fiber texture, mainly used as high-power graphite electrode and ultra-high power graphite electrode in steel making. Since needle coke has strict quality index requirements in terms of sulfur content, ash content, volatile matter and true density, there are special requirements for the production process and raw materials of needle coke.
(2) Sponge coke, with high chemical reactivity and low impurity content, mainly used in the aluminum industry and carbon industry.
(3) Projectile coke or spherical coke: The shape is spherical and the diameter is 0.6-30mm. It is generally produced from high sulfur and high asphaltene residue and can only be used as industrial fuel for power generation and cement.
(4) Powder coke: produced by fluidized coking process, its fine particles (0.1-0.4mm in diameter), high volatile content and high thermal expansion coefficient, can not be directly used in electrode preparation and carbon industry.
4. Calcined petroleum coke
In the case of a graphite electrode for steel making or an anode paste (melting electrode) for producing aluminum or magnesium, it is necessary to calcine the green coke in order to meet the requirements of petroleum coke (green coke). The calcination temperature is generally around 1300 ° C, in order to remove the petroleum coke volatiles as much as possible. This can reduce the hydrogen content of the petroleum coke rework, increase the degree of graphitization of the oil coke, thereby improving the high temperature strength and heat resistance of the graphite electrode, and improving the electrical conductivity of the graphite electrode. Calcined petroleum coke is mainly used in the production of graphite electrodes, carbon paste products, diamond sand, food grade phosphorus industry, metallurgical industry and calcium carbide. The most widely used graphite electrode. The raw coke can be directly used for calcium carbide as the main material of calcium carbide without calcination, and silicon carbide and boron carbide are produced as abrasive materials. It can also be used directly as coke or blast furnace wall lining carbon brick for metallurgical industry blast furnace, or as compact coke for casting process.
Name: Owen Zhang
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Add: Foshan, Guangdong, China