The Unsung Hero of Modern Steelmaking. Graphite electrodes are the lifeline of electric arc furnaces (EAFs), transforming scrap metal into molten steel at temperatures exceeding 3,000°C. For steel plants, rock wool producers, and glass manufacturers, electrode failure means costly downtime. Rongsheng Group solves this with electrodes engineered for extreme resilience, backed by rigorous quality control and adaptable sizing.
Using premium low-ash materials—petroleum coke, needle coke, and coal pitch—Rongsheng electrodes excel in critical areas:
Thermal shock resistance
Mechanical strength under load
Low electrical resistivity (as low as 5.5 μΩm for UHP grades)
Oxidation/corrosion resistance
The process is meticulous: calcining → kneading → forming → baking → graphitization → CNC precision machining. Every electrode is boutique-crafted, ensuring structural integrity.
Product Range & Technical Excellence
Rongsheng offers three industry-standard grades, each optimized for specific demands:
≤5.5 μΩm resistivity, 17 MPa strength, 1.75 g/cm³ density
Quality Assurance:
Surface defects are strictly controlled (≤2 holes/cracks per electrode)
Zero transverse cracks; longitudinal cracks ≤5% of circumference
Diameter tolerances as tight as ±3mm (e.g., 600mm electrode: 607–613mm)
Why Customers Choose Rongsheng
Longer Lifespan: Resists breakage and oxidation, reducing changeovers.
Cost Efficiency: Competitive pricing without sacrificing material quality.
High Qualification Rate: Rigorous testing ensures >99% compliance with specs.
Custom Sizing: Diameters from 300–800mm; lengths tailored to your furnace.
Proven Repurchase Rate: 78% of clients reorder within 12 months.
*“Our UHP electrodes reduced electrode consumption by 22% in a 550-ton EAF.”*
—Feedback from a Southeast Asian steel mill
Handling & Longevity Best Practices
Maximize electrode life with Rongsheng’s guidelines:
Storage: Keep dry, stack ≤4 layers, use waterproof covers outdoors.
Installation: Clean threads with oil-free compressed air; align centers precisely.
Operation: Avoid thermal shocks; follow current load recommendations (e.g., 18–28 A/cm² for HP 550mm electrodes).
Partner with Precision
Rongsheng graphite electrodes aren’t just components—they’re reliability engineered into carbon. With customizable dimensions, industry-leading durability, and a repurchase rate that speaks volumes, we power facilities where failure isn’t an option.
The global demand for Ultra-High Power (UHP) graphite electrodes, particularly the 600mm diameter variant, remains strong due to their critical role in electric arc furnace (EAF) steelmaking. As a leading manufacturer, Rongsheng Graphite closely monitors spot prices, which fluctuate based on raw material costs, supply chain dynamics, and shifts in steel production. This blog examines the latest UHP 600mm graphite electrode pricing trends, key influencing factors, and future market projections.
Graphite Electrode 600 for Steel Plant
Current Spot Price Trends of Graphite Electrodes
Recent market data indicates that UHP 600mm graphite electrodes are trading between 2,000–2,800 per ton, depending on quality, supplier, and regional demand. Prices have seen moderate volatility due to:
Supply constraints from major producers exiting key markets (e.g., Resonac’s shutdown of China/Malaysia plants).
Rising demand from EAF steelmakers, especially in Asia, where scrap-based steel production is expanding.
Raw material costs, including needle coke and petroleum coke, which impact production expenses.
The global steel sector is increasingly adopting EAF technology for its lower carbon footprint, driving demand for UHP electrodes. With China and India leading in steel output, their procurement strategies significantly affect spot prices.
Supply Chain Disruptions
Recent exits by major players have tightened supply, benefiting manufacturers like Rongsheng Graphite Electrode Manufacturer. Reduced competition in Asia could lead to higher price stability or increases.
Raw Material and Energy Costs
Needle coke prices (a key component) remain high due to limited suppliers.
Energy-intensive production (requiring 3,000°C+ graphitization) means electricity costs directly impact pricing.
Inventory and Logistics
Wooden packaging and shipping delays (e.g., from Chinese ports) add to costs.
Just-in-time purchasing by steel mills can cause short-term price spikes.
Future Market Outlook
Analysts predict UHP graphite electrodes will see 5–7% annual price growth through 2030, driven by:
Expanding EAF steelmaking (projected to reach 90% of electrode demand by 2034).
Geopolitical factors, such as trade policies affecting needle coke exports.
RS Graphite Electrodes Manufacturer
For steel producers and traders, tracking UHP 600mm graphite electrode spot prices is crucial for cost management. With supply tightening and demand rising, strategic sourcing from reliable manufacturers like Rongsheng Graphite ensures competitive pricing and consistent quality. Stay updated on market shifts to optimize procurement strategies in this dynamic industry.
For customized quotes or technical specifications, contact Rongsheng Graphite NOW!
In the world of industrial manufacturing, the production of yellow phosphorus stands out as a highly specialized and demanding process. This critical chemical compound is widely used in producing fertilizers, pesticides, and even semiconductors. However, the efficiency and success of yellow phosphorus manufacturing heavily depend on the quality of the equipment used, particularly graphite electrodes. For manufacturers looking to buy graphite electrode & nipple yellow phosphorus solutions, the EG-20 diameter 300 mm with nipples from Rongsheng Graphite Electrode Manufacturer is a game-changer.
Artificial graphite electrodes
The Role of Graphite Electrodes in Yellow Phosphorus Production
Yellow phosphorus is produced in electric arc furnaces, where raw materials like phosphate rock, coke, and silica are subjected to extremely high temperatures. Graphite electrodes play a pivotal role in this process by conducting the electrical energy required to generate the heat needed for the chemical reactions. The electrodes must withstand intense thermal and mechanical stress, making their quality and durability critical to the efficiency of the operation.
For yellow phosphorus manufacturers, the choice of graphite electrodes can significantly impact production costs, energy consumption, and overall output. This is where the EG-20 diameter 300 mm graphite electrodes with nipples from Rongsheng come into play.
RS Graphite Electrode with Nipples
Why Choose EG-20 Diameter 300 mm Graphite Electrodes with Nipples?
Rongsheng’s EG-20 graphite electrodes are specifically designed to meet the rigorous demands of yellow phosphorus production. Here’s why they are the preferred choice for manufacturers:
Superior Thermal Conductivity
The EG-20 electrodes are engineered to provide exceptional thermal conductivity, ensuring efficient heat transfer and consistent performance in high-temperature environments. This translates to lower energy consumption and reduced operational costs for yellow phosphorus manufacturers.
High Mechanical Strength
The diameter 300 mm size of these electrodes offers excellent mechanical strength, enabling them to withstand the physical stresses of the electric arc furnace. This durability minimizes the risk of breakage and extends the lifespan of the electrodes.
Precision-Engineered Nipples
The nipples included with the EG-20 electrodes are precision-engineered to ensure a secure and stable connection between electrode sections. This seamless integration reduces electrical resistance and enhances the overall efficiency of the furnace.
Cost-Effective Solution
By choosing Rongsheng’s EG-20 graphite electrodes, manufacturers can achieve significant cost savings in the long run. The combination of durability, efficiency, and performance ensures a high return on investment.
RS Graphite Electrode
The Rongsheng Advantage
As a leading graphite electrode manufacturer, Rongsheng has built a reputation for delivering high-quality products tailored to the needs of industrial clients. Our state-of-the-art manufacturing facilities and rigorous quality control processes ensure that every electrode meets the highest standards of performance and reliability.
For yellow phosphorus manufacturers, Rongsheng offers more than just products; we provide comprehensive solutions that address the unique challenges of phosphorus production. Our team of experts works closely with clients to understand their specific requirements and recommend the best graphite electrode options for their operations.
How to Buy Graphite Electrodes & Nipples from Rongsheng
If you’re looking to buy rp graphite electrode & nipple yellow phosphorus solutions, Rongsheng makes the process simple and hassle-free. Here’s how you can get started:
Contact Our Sales Team
Reach out to our experienced sales team to discuss your requirements. Whether you need EG-20 diameter 300 mm electrodes or customized solutions, we’re here to help.
Request a Quote
Provide details about your production needs, and we’ll prepare a competitive quote tailored to your budget and specifications.
Enjoy Fast Delivery
With a global distribution network, Rongsheng ensures timely delivery of your graphite electrodes, no matter where you’re located.
Benefit from Ongoing Support
Our commitment to customer satisfaction doesn’t end with the sale. We offer ongoing technical support to ensure your operations run smoothly.
Buy Graphite Electrodes from Rongsheng Company
For yellow phosphorus manufacturers, the choice of graphite electrodes is a critical decision that can make or break the efficiency of their operations. The EG-20 diameter 300 mm graphite electrodes with nipples from Rongsheng Graphite Electrode Manufacturer offer unmatched performance, durability, and cost-effectiveness. By partnering with Rongsheng, you can elevate your production process and achieve greater success in the competitive world of yellow phosphorus manufacturing.
Ready to buy graphite electrode & nipple yellow phosphorus solutions? Contact Rongsheng today and discover why we’re the trusted choice for industrial manufacturers worldwide.
This blog post highlights the benefits of Rongsheng’s EG-20 graphite electrodes while incorporating the specified keywords naturally. It also provides actionable steps for potential customers, making it both informative and engaging.
The Role of High-Power Graphite Electrodes in Modern Steelmaking. High-power (HP) graphite electrodes have become a cornerstone of steel production, especially in electric arc furnace (EAF) technology, which dominates modern steelmaking due to its efficiency and environmental benefits. With the ability to withstand intense temperatures and electrical currents, these electrodes play a pivotal role in melting scrap steel and other materials. As the demand for higher production capacities and improved furnace efficiency continues to grow, precision-engineered electrodes with specific dimensions have become more important than ever.
Graphite Electrodes for Sale
In this post, we will explore two key categories of HP graphite electrodes based on their dimensions: the dia 200mm (length 1800mm) variety and the HP graphite electrode, diameter: 352-357mm, length: 1800 (±100)mm. Each category is designed to meet specific industrial needs, balancing performance, durability, and cost-effectiveness.
High-Power Graphite Electrodes: A Brief Overview
Before delving into the technical specifications, it’s essential to understand what makes HP graphite electrodes different from other types. HP electrodes are made from fine coke, a high-quality raw material that is calcined, crushed, and molded into the required dimensions. The electrodes then undergo a series of processes, including baking and graphitization at temperatures of up to 3000°C, which imparts their superior electrical and thermal conductivity.
HP graphite electrodes are typically used in EAFs, ladle furnaces, and other equipment that require sustained high temperatures and significant electrical energy to melt and refine metals. Their ability to efficiently conduct electricity and maintain structural integrity in extreme conditions makes them indispensable in industries ranging from steelmaking to silicon production.
Graphite Electrode Price in RS
Key Dimensions: Dia 200mm (Length 1800mm)
Graphite electrodes with a diameter of 200mm and length of 1800mm are specifically designed for smaller or mid-sized furnaces. Despite their smaller diameter compared to larger electrodes, they deliver high electrical conductivity and can operate at power levels suitable for smaller-scale steel production.
Applications:
Smaller electric arc furnaces, typically used in facilities where steel production volumes are lower or where the furnace size is constrained by space or energy requirements.
Specialty steelmaking and refining processes, where the focus is more on precision rather than sheer volume.
Advantages:
Versatility: Smaller electrodes, like those with a 200mm diameter, can be easily replaced and maintained in facilities with lower production needs.
Cost-effective: For smaller operations, these electrodes provide a balance between performance and operational costs, ensuring that production is both efficient and sustainable.
Efficiency: Despite their size, these electrodes offer excellent performance in terms of heat and electrical conduction, making them suitable for prolonged operation.
HP Graphite Electrodes: Diameter 352-357mm, Length 1800 (±100)mm
On the other end of the spectrum, the HP graphite electrodes with a diameter of 352-357mm and length of 1800mm represent a more robust solution for larger furnaces and high-output operations. These electrodes are engineered to handle greater electrical currents and endure prolonged exposure to extreme temperatures, making them ideal for more demanding industrial applications.
Applications:
Large-scale electric arc furnaces: These electrodes are commonly used in facilities producing high volumes of steel, particularly in industries requiring a continuous, high-output process. The larger diameter allows for higher current-carrying capacity, leading to more efficient steel melting.
Ladle furnaces: In refining molten steel after the initial melting phase, larger HP graphite electrodes help maintain temperature and electrical flow in processes like secondary metallurgy.
Advantages:
High conductivity: These electrodes allow for higher amperage, which is essential in larger furnaces requiring sustained, intense electrical energy for longer periods.
Increased durability: The larger size enhances the electrode’s mechanical strength, ensuring it can withstand the extreme thermal and mechanical stresses in large-scale steelmaking environments.
Optimized efficiency: With their robust design, these electrodes contribute to faster melting times, increased furnace efficiency, and reduced downtime.
Precision in the dimensions of HP graphite electrodes directly influences their performance and durability. This is particularly true for the 352-357mm diameter, length 1800 (±100)mm variety, where even slight variations in size can impact the overall efficiency of the electrode in the furnace. Consistent electrode sizing ensures uniform heating, stable arcs, and reduced risk of breakage or premature wear.
Moreover, as furnace technology continues to evolve, the demand for electrodes that can meet the exacting standards of modern equipment has never been higher. Manufacturers of HP graphite electrodes must continuously innovate in both materials and production techniques to ensure they can meet these demands while adhering to stringent quality controls.
Sustainability and Efficiency
Another key factor driving the adoption of high-power graphite electrodes is their role in improving the overall sustainability of steelmaking operations. As the steel industry faces increasing pressure to reduce its carbon footprint, the use of electric arc furnaces powered by HP graphite electrodes represents a more eco-friendly alternative to traditional blast furnace methods.
EAFs not only emit fewer greenhouse gases, but they also enable the recycling of scrap metal, further reducing the environmental impact of steel production. By using high-performance graphite electrodes with optimized dimensions—such as those in the 200mm and 352-357mm categories—industries can achieve more efficient operations while lowering energy consumption and emissions.
The importance of high-power graphite electrodes
The importance of high-power graphite electrodes in modern industrial applications cannot be overstated. Whether it’s the dia 200mm (length 1800mm) variety for smaller, more precise operations or the HP graphite electrode, diameter 352-357mm, length 1800 (±100)mm designed for larger-scale production, these electrodes are critical components in driving efficiency, performance, and sustainability.
In an industry where every minute counts, having the right electrode size ensures optimal furnace performance, reduces energy consumption, and minimizes downtime. As advancements in electrode technology continue, the role of these precision-engineered components in steelmaking and other high-temperature industries will only become more significant, shaping the future of sustainable production.
The Role of HP Grade Graphite Electrodes from Fine Coke in Steelmaking. In the steelmaking industry, the electric arc furnace (EAF) process is widely used to produce high-quality steel. Central to the efficient functioning of these furnaces are graphite electrodes, which facilitate the melting of scrap steel through high-temperature electric arcs. Among the various types of electrodes available, those made from fine coke stand out for their superior performance, particularly in HP (High Power) grade variants.
In this blog post, we will explore graphite electrodes made from fine coke with HP grades and diameters of 400 mm and 300 mm. We will delve into their unique properties, applications, and the advantages they offer in modern steel production.
RS Graphite Electrode Supplier
What Are Graphite Electrodes from Fine Coke?
Graphite electrodes are primarily made from petroleum coke and needle coke, materials that undergo high-temperature treatments to form a solid carbon structure. Fine coke refers to the smaller grain size used in the production of high-performance electrodes. When subjected to additional refinement processes, fine coke leads to the creation of electrodes with enhanced electrical and mechanical properties, making them ideal for high-power applications.
In the case of HP grade graphite electrodes, fine coke is used to ensure the electrodes can handle the high currents and temperatures required in large-scale steel production. HP graphite electrodes are designed to withstand the rigors of the electric arc furnace process, where they play a crucial role in conducting electrical current and sustaining the intense heat needed to melt steel.
The two sizes we’ll focus on—400 mm and 300 mm diameter—are common in the steel industry, offering different benefits based on the specific needs of production.
RS Graphite Electrode
HP Grade Graphite Electrodes with 400 mm Diameter
HP graphite electrodes with a 400 mm diameter are typically used in large-scale steel production, where the demand for power and durability is at its peak. The larger diameter allows these electrodes to carry higher currents, making them suitable for furnaces that require intense and sustained arcs to efficiently melt scrap steel.
Key Characteristics of HP Grade 400 mm Electrodes:
High Electrical Conductivity:
The use of fine coke ensures that these electrodes offer exceptional electrical conductivity, a critical factor in minimizing energy loss during the steelmaking process. The larger surface area of the 400 mm diameter allows for a more stable flow of electricity, ensuring consistent furnace performance.
Durability and Strength:
Graphite electrodes in HP grades are built to withstand the mechanical stresses of the electric arc furnace. The 400 mm variant offers enhanced durability, reducing the frequency of electrode replacement and minimizing operational downtime.
Superior Arc Stability:
In EAF operations, maintaining a stable arc is essential for efficient melting. HP grade graphite electrodes with 400 mm diameter provide the robustness needed for continuous, stable arcs, even under high current loads. This stability translates into faster melting times and improved overall efficiency.
Applications in Steelmaking:
The 400 mm HP grade graphite electrode is commonly used in large electric arc furnaces where higher tonnage steel production occurs. These furnaces operate at higher voltages and demand greater energy input, making the 400 mm diameter ideal for such environments. The larger electrode can withstand high-energy conditions, ensuring efficient steel production while minimizing electrode wear.
RS HP Grade Graphite Electrodes 300mm for Sale
HP Grade Graphite Electrodes with 300 mm Diameter
Graphite electrodes with a 300 mm diameter offer a more versatile solution for medium-sized electric arc furnaces or processes requiring lower power input compared to their 400 mm counterparts. While they may be smaller in diameter, HP grade 300 mm electrodes still deliver excellent performance and durability.
Key Characteristics of HP Grade 300 mm Electrodes:
Efficient Conductivity:
The use of fine coke in HP grade electrodes ensures that even smaller diameter electrodes, like the 300 mm variant, provide high levels of electrical conductivity. This enables steelmakers to maintain efficiency while reducing the overall power consumption in medium-capacity furnaces.
Cost-Effectiveness:
HP graphite electrodes with a 300 mm diameter offer a balance between performance and cost. Their smaller size makes them less expensive than the 400 mm electrodes, while still offering the necessary power-handling capabilities for many steel production operations. This makes them an attractive option for steel mills focused on reducing operational costs.
Reliable Performance in Mid-Scale Operations:
While larger furnaces may demand the power of 400 mm electrodes, mid-scale EAFs benefit greatly from the reliability of 300 mm diameter HP graphite electrodes. These electrodes can handle moderate current loads while providing the arc stability needed for consistent melting.
Applications in Steelmaking:
HP graphite electrodes with 300 mm diameters are typically used in medium-sized EAFs or as complementary electrodes in large furnaces. Their ability to handle high temperatures and electrical currents while offering a cost-effective solution makes them ideal for steel mills that produce lower tonnage steel but still require high-performance electrodes.
The Advantages of Using Graphite Electrodes Made from Fine Coke
Graphite electrodes made from fine coke offer several advantages over those made from coarser materials. These benefits are particularly important in HP grade electrodes, where the need for durability, electrical efficiency, and arc stability is paramount.
Enhanced Electrical Efficiency:
Fine coke produces graphite electrodes with better electrical conductivity, which translates into lower energy consumption during the steelmaking process. This efficiency is crucial in modern steel production, where energy costs can represent a significant portion of overall expenses.
Improved Durability:
The fine grain structure of coke used in HP grade electrodes contributes to their structural integrity. This means that electrodes made from fine coke are more resistant to wear and tear, ensuring longer operational life in electric arc furnaces.
Better Arc Control:
HP grade graphite electrodes are known for their ability to maintain stable arcs, a critical feature in EAF operations. Fine coke enhances this capability, allowing for more precise control over the melting process, leading to improved steel quality and faster production times.
Conclusion: The Value of HP Grade Graphite Electrodes from Fine Coke
Graphite electrodes made from fine coke are a cornerstone of modern steel production. Their superior electrical conductivity, durability, and arc stability make them ideal for use in electric arc furnaces, where they help to optimize efficiency and reduce costs. The availability of HP grade electrodes in both 400 mm and 300 mm diameters provides steelmakers with the flexibility to choose the right electrode for their specific needs, ensuring that production remains efficient and cost-effective.
For steel manufacturers, investing in HP grade graphite electrodes from fine coke is a strategic choice that can enhance performance, minimize downtime, and support sustainable, high-quality steel production.
Understanding the Role of Ultra-High Power (UHP) Graphite Electrodes in Modern Industry. In the world of steel production and other high-temperature applications, graphite electrodes play a crucial role. These electrodes are indispensable in electric arc furnace (EAF) operations, where they serve as the conduits of electric current into the furnace, enabling the production of steel and other materials through the application of intense heat. Among the various types of graphite electrodes, those of ultra-high power (UHP) grade, particularly in the sizes ranging from Φ200～800mm, have become increasingly important. This blog post will explore the significance of UHP grade graphite electrodes, with a particular focus on the widely used sizes of 450 mm and 550 mm.
Graphite Electrodes are an Important Part of the Steelmaking Industry
The Importance of Graphite Electrodes
Graphite electrodes are essential components in the steelmaking process, particularly in electric arc furnaces (EAFs). These furnaces rely on the high electrical conductivity and heat resistance of graphite electrodes to generate the extreme temperatures necessary for melting scrap steel or direct reduced iron (DRI). Graphite electrodes are made from high-quality needle coke and are subjected to a series of manufacturing processes, including mixing, molding, baking, impregnation, graphitization, and machining. The final product is a high-purity graphite electrode capable of withstanding the demanding conditions within an EAF.
What is an Ultra-High Power (UHP) Graphite Electrode?
Ultra-high power (UHP) graphite electrodes represent the pinnacle of graphite electrode technology. These electrodes are designed to handle extremely high current densities, making them ideal for demanding applications in steel production. The UHP grade is characterized by its exceptional electrical conductivity, thermal shock resistance, and mechanical strength. This allows UHP graphite electrodes to operate at much higher temperatures and with greater efficiency than regular power (RP) or high power (HP) electrodes.
Φ200～800mm UHP Graphite Electrode
The Significance of Φ200～800mm UHP Graphite Electrodes
The diameter of graphite electrodes is a critical factor in determining their current-carrying capacity and suitability for different applications. UHP graphite electrodes are available in various sizes, typically ranging from Φ200 to 800mm. This wide range of sizes allows for flexibility in choosing the appropriate electrode for specific furnace operations.
Φ450mm UHP Graphite Electrode
The 450 mm diameter UHP graphite electrode is widely used in medium to large-sized electric arc furnaces. Its size strikes a balance between current-carrying capacity and operational efficiency, making it a versatile choice for many steel producers. The Φ450mm UHP graphite electrode is capable of handling high currents, making it suitable for high-output steel production facilities that require consistent performance and reliability.
Due to its UHP classification, the 450 mm electrode can operate under extreme conditions, withstanding high temperatures and minimizing electrode consumption. This reduces downtime and operational costs, contributing to more efficient steelmaking processes.
Φ550mm UHP Graphite Electrode
The 550 mm diameter UHP graphite electrode represents an even higher capacity option, often used in large-scale steel production facilities. This electrode size is particularly advantageous in ultra-high power furnaces where very large currents are required to melt significant quantities of scrap steel or other raw materials.
The Φ550mm UHP graphite electrode offers excellent performance in terms of electrical conductivity and durability. Its larger diameter allows it to carry more current, which is essential in EAFs with larger capacities. Additionally, the enhanced mechanical strength of this electrode ensures it can endure the physical stresses of the steelmaking process, including thermal cycling and mechanical wear.
Why Choose UHP Grade Graphite Electrodes?
Choosing UHP grade graphite electrodes for your electric arc furnace operations comes with several key benefits:
Higher Efficiency: UHP graphite electrodes allow for higher current densities, which translates into faster melting times and increased production efficiency.
Reduced Consumption: The superior thermal and mechanical properties of UHP electrodes result in lower consumption rates, meaning fewer electrodes need to be replaced over time.
Enhanced Durability: UHP electrodes are designed to withstand the harshest conditions within an EAF, including rapid temperature changes and mechanical stress, leading to a longer operational life.
Cost-Effectiveness: While UHP electrodes may have a higher upfront cost, their longer lifespan and reduced consumption make them more cost-effective in the long run.
Rongsheng Graphite Electrode Factory
In the competitive world of steel production, the choice of graphite electrodes can have a significant impact on the efficiency and cost-effectiveness of your operations. UHP grade graphite electrodes manufacturer, particularly in the sizes of Φ450mm and Φ550mm, offer unparalleled performance, making them the preferred choice for modern electric arc furnaces. Their ability to handle high currents and endure the rigors of steelmaking ensures that they remain a cornerstone of industrial operations, driving advancements in the production of high-quality steel.
Roasting is an important process for producing ultra-high-power graphite electrodes with excellent performance. By comparing the roasting furnace types and in-depth analysis of the heating mechanism of the green body during the roasting process. Understanding the effects of heating rate, binder pitch, temperature field and other factors on the quality of graphite electrodes can provide a reference for the production of high-quality graphite electrodes.
UHP Graphite Electordes
Ultra-high power graphite electrodes have the advantages of low resistivity, good oxidation resistance, and a small thermal expansion coefficient. It is widely used in arc steelmaking furnaces with high current density and harsh working conditions. Moreover, its bulk density and flexural strength also need to reach a high level. At the same time, its elastic modulus must be appropriate and matched with the performance of the matching electrode joint to demonstrate good thermal shock resistance during the electric furnace steelmaking process and not be easy to break. Therefore, it is necessary to strictly control the process parameters of each process of ultra-high power graphite electrode production to ensure that the product quality of each process is qualified and the internal structure of the product is uniform and stable. Therefore, continuously optimizing all aspects of process control is an effective means to obtain better quality products. The roasting process is the main factor affecting product quality.
Roasting Concept
Roasting means that the pressed green product (green body) is surrounded by air-isolating filler and continuously receives external heat to turn the binder asphalt in the product into asphalt coke. At the same time, it is combined with the carbon aggregate particles to form a strong integrated heat treatment process.
Comparison of Roasting Furnace Types
To adapt to the roasting of products of different sizes and varieties, different types of furnaces and control systems are designed. A wide variety of roasters have been developed based on improving productivity, reducing fuel consumption, controlling emissions, and improving quality. Up to now, the main furnace types of roasters include covered ring roasters, open ring roasters, car-bottom roasters, tunnel kilns, etc.
Currently, based on the traditional furnace type, the open ring roasting furnace has received new improvements. That is, a lightweight insulation cover is added to each furnace box, and the combustion nozzle structure is improved. This not only effectively solves the problem of unorganized exhaust gas emissions, but also achieves the low-nitrogen combustion effect of the combustion system.
Mechanism Analysis of the Whole Process of Roasting and Heating
For primary roasting, whether it is an externally fired ring roaster (open ring roaster), an internal combustion ring roaster (covered ring roaster), or a car-bottom roaster. They all conduct the heat generated after the fuel is burned to the refractory bricks or steel drums where the container is roasted. Then it is transferred to the filler by refractory bricks or steel drums. Finally, the filler transfers heat to the raw product. When the temperature felt by the green product itself exceeds the softening point of the binder asphalt, the green body first softens from the glassy state and then becomes a molten state. Just under the squeeze of the surrounding filler, it maintains its original geometric shape.
The selection and control of the roasting process is very important. Because it directly determines the structure, performance, and length of the product production cycle of the final product. During the roasting process, there are chemical reactions and transfers of mass, heat, and momentum. The three-phase system undergoes a series of continuous anisothermal phase transitions, making the study of the system very complicated.
The connection of graphite electrodes is realized through graphite electrode nipples. How to tighten the graphite electrode nipple? Graphite electrode manufacturers suggest that the torque required to screw the joint into the electrode screw hole to achieve a tight connection is well controlled.
RS Graphite Electrode with Nipples
The contact resistance of the graphite electrode with a smooth surface varies with the applied pressure. As the pressure increases, the contact resistance decreases. In order to reduce the contact resistance of the contact parts during electrode connection as much as possible, in addition to the two important conditions of graphite electrode material and processing accuracy, which must meet the technical standards, sufficient tightening torque must be applied when connecting electrodes in steelworks. If the tightening torque is insufficient when connecting, the contact resistance of the contact surface will increase significantly. Even high-quality electrodes will have redness and accelerated oxidation at the contact surface. Or loosening occurs in a strong vibration, increasing the chance of nipple breaking. The larger the electrode specification, the greater the tightening torque required. But the tightening torque is not as big as possible, but to reach a certain torque.
There are two main factors that affect the tightening torque not reaching the specified level. (1) The electrode processing quality is not good. If the processing surface is rough or the clearance of the thread is not well matched, it is difficult to screw into the joint, or it is still loose when it is screwed to the bottom of the screw hole, so it cannot be tightened. (2) The steel mill operator did not tighten the electrode and the joint when adding the new graphite electrode nipple, that is, the required tightening torque was not reached. In order to ensure that the required tightening torque can be achieved when connecting electrodes with different specifications, you can choose to use a graphite electrode wrench.
When tightening graphite electrodes in the smelting industry in some areas, the most common use is to clamp a graphite electrode with two iron clips for fastening operations, and there is also a “soil wrench” without a torsion structure. However, this type of tightening method not only needs to rely on the experience of master craftsmen but also faces the challenge of uneven quality of graphite electrodes from different manufacturers. A slight difference in the tightening force will make the current flow unstable. It leads to a series of problems such as the electrode is not tightened, the electrode is broken, and so on. Not only does it affect production, but it also consumes electricity, and the work efficiency and graphite electrode utilization rate are relatively low, which increases production costs.
The special graphite electrode wrench can perfectly solve these problems. It is widely used in the smelting industry in other regions. The special wrench for graphite electrodes is not only a tool for tightening graphite electrodes but also a kind of torque tool. Its appearance ended the smelting industry’s production history of relying on experience and technology when installing and replacing graphite electrodes. It provides a reliable guarantee for safe production, energy saving, and high efficiency, and cost reduction in the smelting industry.
Rongsheng graphite electrode manufacturer specializes in the production and sales of various types of graphite electrodes including graphite electrode with preset nipple products and can customize graphite electrodes and electrode nipples according to the actual needs of customers. Contact us for a free trial.
Vacuum furnaces process hard zinc and recover zinc metal. The normal working conditions of the vacuum distillation furnace are the vacuum degree of 500~2000Pa and the temperature of 950~1050℃. Under this condition, the vapor pressure of the graphite electrode is very low, and its volatilization loss is negligible, so its service life depends on its degree of oxidation and fracture caused by mechanical and electrical failures. Specifically, what are the reasons for the loss of graphite electrodes in vacuum furnaces?
Graphite Electrodes in RS Supplier
Oxidation loss of graphite
The oxidation of graphite is divided into dry oxidation (air, water, carbon dioxide gas) and wet oxidation (acid, alkali). Graphite is easily oxidized by air, water and carbon dioxide gas (CO2) at high temperature to form carbon monoxide or carbon dioxide. The product of its oxidation varies with the ambient temperature.
2C + O2 = 2CO (above 1 000°C)
C + O2 = CO2 (below 1000℃)
Graphite oxidation products are easy to escape and cannot form a dense oxide film protective layer like on some metal surfaces, so the oxidation reaction is continuous. The temperature and reaction speed at which graphite starts to oxidize are different in various cases. If the temperature at which 1% of the original weight is lost within 24 hours is set as the oxidation start temperature, the oxidation starts temperature of graphite is as follows.
In air: 420 ~ 460 ℃;
In carbon dioxide gas: about 900 °C;
In water vapor: about 700°C.
Generally speaking, graphite with a large porosity, especially a large open porosity, has a large surface area participating in the reaction, and of course the oxidation rate is also fast. The higher the degree of graphitization of graphite products, the better the oxidation resistance. The aggregate of graphite products also has an important influence on oxidation resistance. Graphite products made of aggregates such as petroleum coke and natural graphite with good graphitization properties have excellent oxidation resistance. The presence of trace metal impurities will obviously promote the dry oxidation of graphite.
In the production process of graphite, metals that are usually easy to exist in the form of impurities include sodium, potassium, magnesium, calcium, iron, vanadium, copper aluminum, titanium, etc. Among them, the existence of sodium, potassium, vanadium and copper can catalyze the oxidation reaction of graphite. As the oxidation reaction proceeds, these metal impurity particles move through the material and form defects or pores. This phenomenon is more obvious in the oxidation reaction at lower temperature. According to the data, when some metal impurities are artificially added, such as adding 20 ~ 40μg/g of sodium, potassium, vanadium or copper, the oxidation rate at 550 °C can be increased by 5 times.
Electrode short circuit or crushed
The vacuum furnace uses graphite electrodes as heating elements, and requires good contact between electrode components during installation. Keep the vertical direction horizontal, and reserve an expansion gap around the installation window at the end of the electrode nut. At the same time, both ends of the electrode assembly and the furnace shell maintain good insulation performance. Due to the poor sealing of the installation window, the zinc vapor in the feeding trolley enters the electrode nut or the electrode connection card through the gap of the sealing material, and condenses into a zinc block. With the continuous growth of the condensed zinc block, it will eventually contact with the iron shell of the furnace body, causing the electrode to short-circuit and damage the electrode. After the furnace shell and electrode support plate are deformed, the expansion gap at the end of the graphite electrode nut is usually insufficient. After the power is heated up, the electrode nut is squeezed by the furnace wall around the installation window to varying degrees, and the electrode is quickly broken.
The electrode processing quality and installation quality also have a very important influence on the service life of the electrode. The connection thread of the electrode and the electrode nipple is poorly processed or the tolerance matching does not meet the standard, which will cause the connection between the electrode and the joint to be too loose or too tight. Too loose will cause poor contact and arcing will burn the electrodes and nipples; too tight will easily damage the threads during assembly. When assembling the electrode, during the screwing process of the electrode and the electrode joint, the action is rude, which will also cause damage to the thread and cause the electrode to be scrapped.
In addition, when the water-cooled electrode is short of water, the heat of the electrode connection card cannot be taken away in time. It will also cause poor contact between the electrode and the card board, thereby burning the electrode connection card board. In severe cases, arcing will burn the electrode and the electrode connection card.
It can be seen that the graphite electrode is still easily worn out in the process of use. Therefore, it is helpful to purchase high-quality graphite electrode products and standardize the operation and installation procedures to reduce the loss of graphite electrodes.
Graphite electrodes are mainly used as conductive materials in electric smelting furnaces. Compared with other conductive materials, the biggest advantage of graphite electrode material is that it has good electrical and thermal conductivity and better toughness, can accept the impact of larger current and does not soften or melt at high temperatures. It is used as a conductive material in the steel-making electric arc furnace, and the heat energy is transferred to the charge through arc discharge to melt the steel scrap. In the submerged arc furnace for smelting yellow phosphorus and industrial silicon, the electric energy is transferred into the charge through the electrode, and the charge itself is melted by the electric resistance heating of the charge.
Graphite Electrodes Application
The Advantages of Electric Arc Furnace for Steelmaking
Compared with other steelmaking methods, electric arc furnace steelmaking has its unique advantages. Electric arc furnace steelmaking is heated by an electric arc, and its temperature can be as high as 2 000 ℃ or more. This exceeds the maximum temperature that other steelmaking furnaces can reach when burning and heating with general fuel. The thermal efficiency is higher than that of the open hearth and converter steelmaking methods. Heating with electric energy can also accurately control the temperature and can use various elements (including aluminum, iron, and other elements that are easily oxidized) to alloy steel. Various types of high-quality steel and alloy steel are smelted, such as ball-bearing steel, stainless acid-resistant steel, high-speed tool steel, electrical steel, heat-resistant steel and alloys, and magnetic materials.
At present, electric furnace smelting adopts the traditional alkaline electric arc furnace steelmaking method. The process consists of “refilling the furnace-charging-smelting (including melting period and oxidation period)-refining outside the furnace (reduction period)-tapping-continuous casting” and so on.
According to relevant data, with the continuous improvement of ultra-high power electric arc furnaces and related technologies, the electrode consumption dropped from 6.5 kg/t to 1.2 kg/t from 1965 to 2000. The power consumption is reduced from 630 kW. h/t to 290 kW. h/t and the tapping time is reduced from 180 min to 40 min.
High-Quality Graphite Electrodes for Steelmaking
Characteristics Requirements of Graphite Electrode Materials for Steelmaking Electric Arc Furnaces
When investigating the adaptability of graphite electrodes to steel-making electric arc furnaces, the physical and chemical properties of the materials, the matching accuracy of the electrode and the joint, the reliability of the connection, and the length of the adaptable equipment (the up and down stroke of the electrode) should be analyzed one by one. Among them, the pear blossom properties of graphite electrode materials include mechanical properties, electrothermal properties, electrical conductivity, and oxidation resistance. In addition, it is necessary to understand and master the power transmission mode, smelting method, and process of the equipment.
It is very important to correctly understand the basic characteristics of graphite electrode materials. The characteristics of different grades of graphite electrodes are basically determined by the raw materials and manufacturing methods used.
Graphite electrodes should have at least the following properties on the smelting furnace. (1) Must be able to withstand the arc current required by the steelmaking process. (2) Continuous arc generation must be maintained.
In addition, the electrode should be able to be used in a wide temperature range (that is, it can be used in a state of rapid cooling and rapid heating). In the comprehensive evaluation of the performance of the graphite electrode, the thermal shock resistance index is used as the basic standard to measure the resistance of the electrode tip.
Thermal shock resistance refers to the ability of a material to resist damage under rapid cold and rapid heat. It is a comprehensive reflection of the performance of graphite electrodes.
Compared with other conductive materials, graphite electrodes have some excellent or irreplaceable characteristics under high-temperature conditions. Graphite electrodes can be used at relatively high temperatures (sublimation temperature of 3650°C), and are the only high-temperature conductive materials that can withstand high temperatures. There is no other material that can replace them in actual use. The strength of graphite increases as the temperature rises at high temperatures. Compared with other metals, graphite has the lowest coefficient of thermal expansion. When studying the characteristics of graphite electrodes, especially the thermal stress and vibration of the connection part, the coefficient of thermal expansion and the electrical resistivity is regarded as one of the most important indicators. Therefore, it is very important to choose petroleum coke with a low CTE value to produce graphite electrodes.
Graphite Electrodes in RS Supplier
The Influence of Steelmaking Technology Progress on the Consumption of Graphite Electrodes
With the large-scale and ultra-high power of steelmaking electric arc furnaces, many improvements have been made to domestic UHP electric arc furnaces. For example, molten steel is reserved at the bottom of the furnace, and long-arc bubble slag submerged arc operation is used for drainage (the power transmission system is low current and high voltage). The foaming slag operation mainly reduces the radiation of the electric arc to the furnace wall and creates conditions for the long arc operation. The long-arc operation can effectively utilize power, that is, increase power factor, increase thermal efficiency, shorten smelting time and reduce electrical energy consumption. The improvement of thermal efficiency shortens the time for melting scrap steel and smelting. The use of long arc operation increases the vibration caused by the arc but can basically avoid the collapse of the electrode during the good penetration. After the current is reduced, the tip consumption of the electrode can be reduced. In addition, shortening the smelting time in an oxidizing atmosphere means that the side consumption of the electrode is also reduced. Coupled with the auxiliary electrode spray cooling, the electrode consumption of the UHP arc furnace is greatly reduced. From the level of over 2kg/t at the end of the last century to the level of 1.5 kg/t. Sometimes, it even reaches the level of 1.2~1.3 kg/t, which is especially in line with the characteristics of high production and low consumption in China’s steel industry in recent years.
In addition, the application of technologies such as out-of-furnace refining, scrap preheating, and addition of molten iron has contributed to the reduction of electrode consumption. The automatic control of electrode lifting protection makes the phenomenon of electrode breakage caused by human operation less and less.
The advancement of steelmaking technology has brought about a substantial reduction in electrode consumption, making imported electrodes of uniform material competitive advantage. It is a top priority for domestic carbon companies to break through the quality of large-size ultra-high-power electrodes as soon as possible and strive to reduce steelmaking consumption. To learn more about graphite electrodes for steelmaking electric arc furnaces, please contact us.
