graphitized petroleum coke(gpc)
Graphitized petroleum coke (gpc) material introduction
graphitized petroleum coke (gpc): Petroleum coke is a by-product of refining crude oil. Residual oil and petroleum pitch obtained from crude oil distillation or vacuum distillation can be used as raw materials for making petroleum coke. After coking, raw petroleum coke can be obtained. . The production of raw petroleum coke is less than 5*** of the amount of crude oil used. The raw petroleum coke has a high impurity content and cannot be used directly as a recarburizer. It must be calcined first. The calcination of petroleum coke is to remove sulfur, moisture, and volatiles. Calcining raw petroleum coke at 1200~1350°C can make it into substantially pure carbon. However, its sulfur content and nitrogen content still cannot fully meet the current production requirements of high-quality cast iron products. This requires a good petroleum coke recarburizer, which requires lower sulfur and nitrogen content under higher temperature conditions. It also makes the arrangement of carbon atoms show the microscopic morphology of graphite. It is more conducive to the improvement of the quality of cast iron molten iron. And this process of high temperature treatment is called graphitization
The role of graphitized petroleum coke (gpc):
As one of the main sources of graphite main elements in molten iron, recarburizer is not only to supplement the right amount of carbon. Other effects are often overlooked. In fact, adding a recarburizer is not simply “increasing C”, but an important measure to increase the graphitization ability of its cast iron products to achieve better matrix structure and mechanical properties. Not all recarburizers can achieve this effect. The production of qualified recarburizers must undergo strict selection of materials, and then undergo high-temperature graphitization. The process not only reduces impurities such as sulfur, gases (nitrogen, hydrogen, oxygen), ash, volatiles, and moisture, but also improves its purity and For graphitization, carbon atoms can change from the original disordered arrangement to an orderly arrangement, and most of the carbon atoms can become a very good driving force for graphitization. The carbon atoms can be quickly melted in the molten iron, and when the molten iron is solidified, it is adsorbed on the nucleation core produced by the nucleation and grows into graphite under the action of a strong driving force when the molten iron is solidified. If the selected recarburizer has not undergone high-temperature graphitization treatment, the graphitization driving ability of carbon atoms will be greatly reduced, and the graphitization ability will be weakened. Even if the same carbon content can be achieved, the quality of the product is completely different. Therefore, petroleum coke products that have undergone high-temperature graphitization treatment and graphite electrode fragments manufactured at high temperatures are currently very suitable for the production of high-quality cast iron products requiring recarburizer additives. It not only meets the requirements of product “C increase”, but also provides a good source of power for the production of cast iron products.
How to use recarburizer:
1. The recarburizer is added into the furnace along with the process
1) The feeding sequence of the cold furnace—in accordance with the method of “scrap steel + ferromanganese + recarburizer + scrap steel + recycle material + iron filings + pig iron + ferrosilicon”;
2) The feeding sequence of the hot furnace-there is about 300kg of molten iron left at the bottom of the furnace, which is added according to the method of “scrap + ferromanganese + recarburizer + scrap + recharge + iron filings + pig iron + ferrosilicon”;
3) If the scrap is briquetted from leftovers, it may not be practical to add it directly to the bottom of the furnace at the beginning. Therefore, according to the actual situation of the factory, it is added according to the method of “recycled charge + ferromanganese + recarburizer + scrap + recycled charge + ferrosilicon”;
2. The use process of recarburizer when fine-tuning
After the molten iron is melted, in the case of insufficient carbon content in the molten iron, it is necessary to fine-tune the carbon increase to meet the process requirements. At this time, it is generally hoped that the recarburizer can quickly achieve the recarburization effect, so as to avoid affecting the metallurgical quality of the molten iron due to the excessively long treatment time of the molten iron. At this time, the instant graphitized petroleum coke (gpc) should be added to the surface of the molten iron after being melted, and the iron can be tapped in 1 to 2 minutes after proper stirring.
①The recarburizer should avoid direct contact with the furnace bottom lining material to prevent the recarburizer from corroding the furnace lining;
②The recarburizer should be avoided to be added together with iron filings to prevent the recarburizer from agglomerating with other materials and affecting the absorption of the recarburizer;
③If the total scrap steel production process, the amount of recarburizer added is too large, it is not advisable to add all of it, and it should be added gradually in layers.