The requirement for petroleum coke recarburizer is that the higher the fixed carbon content, the lower the content of harmful impurities such as ash, volatile matter and sulfur, the better, so as to avoid polluting the molten iron. Recarburizers are the main products of our company. There are different types and a wide range of applications. However, there are still some people who don't know much about recarburizers, which has affected the development of recarburizers. In order to break this state, our company will summarize the knowledge of carbonizing agents over the years, and give you a brief talk about the selection and use of carbonizing agents. Recarburizer: A product of black or gray particles that is added to a metal smelting furnace to increase the carbon content in the molten iron. On the one hand, it can reduce the oxygen content in molten iron; on the other hand, it is more important to improve the mechanical properties of molten metal or castings. In the smelting process, the content of steel or iron cannot meet the expected requirements due to improper ingredients and excessive decarburization. Carbon should be added to the steel or iron solution. The main substances used to increase carbon are anthracite powder, carbonized pig iron, electrode powder, petroleum coke powder, pitch powder, charcoal powder and coke powder. Carbon fiber spun pitch

Under normal circumstances, do not add carbon agent, add in batches. After the calcined coke is melted, add a part, put a part of the molten iron (about a bag) into the bag, and then return to the furnace to add the carbon agent 1-2 times, then slag and add the alloy. The adding method is wrong, and the layer-adding carbon agent is used. Avoid adding too much slag to the molten iron mirror, and try not to use too much rust material. The foundry made a mistake in choosing the recarburizer. For example, there is confusion between the fixed carbon content and the carbon content of the carbonizer. The fixed carbon value is calculated based on the moisture, volatile content, ash and sulfur content of the sample, and the carbon content can be obtained by a direct carbon meter. Some recarburizers have high ash content and large carbon content, but their fixed carbon content is not ideal. There are also some foundry workers who judge whether the fixed recarburizer is qualified unilaterally from the carbon content of the fixed recarburizer and its material properties. The result may be biased, making the choice of recarburizer unworthy. In summary, the above is that the so-called recarburizer of Henan Shengchi New Material Technology Co., Ltd. can increase the carbon content of the molten iron after being added. Therefore, the fixed carbon content of the recarburizer cannot be too low, or to achieve certain carbon content, it is necessary Increase the amount more than the high-carbon recarburizer, so there is no doubt that the increase in the recarburizer, other harmful elements in the liquid iron can not achieve good returns.

Sulfur compounds and oxides have high stability, fine particle size, and are difficult to float in molten iron. In addition, the mismatch between these compounds and the graphite lattice is very small, and can be used as a heterogeneous core for graphite precipitation. Magnesium oxide MgO, a spheroidizing agent, has a high melting point, good stability, low solubility in molten iron, but a slightly larger particle size. It can rise to the surface and become scum, or it may involve slag inclusions inside the casting. At the same time, the density of magnesium sulfide (MGS) is very low and it is easy to float on the surface of molten iron, but its stability is poor. After contact with oxygen, magnesium oxide will be formed. Sulfur will be released back to molten iron and react with molten magnesium iron again. The continuous occurrence of this reaction is one of the main reasons why the spheroidization rate decreases when magnesium is used alone as a spheroidizing agent. When rare earth (cerium) is used as a spheroidizing agent, the fading phenomenon is not obvious, and the tendency of the formation of inclusions is also small. From the point of view of the free energy of elements reacting with sulfur and oxygen to form sulfides and oxides, rare earth (cerium) and calcium have better desulfurization and deoxidation capabilities than magnesium. However, when the boiling point of magnesium is 1107°C, it vaporizes quickly after entering the molten iron and has a strong stirring effect on the molten iron. At the same time, the gas dissolved in the molten iron easily diffuses and precipitates in the bubbles, and thus is taken out by the bubbles. The oxides and sulfides contained in the molten iron are also easily absorbed and discharged by the bubbles. From the viewpoint of reaction kinetics, the deoxidation and desulfurization effect of magnesium in molten iron is actually stronger than that of rare earth (cerium) and calcium.

Carbonization is a measure to prevent or reduce the tendency to shrink. Due to graphitization and expansion during the solidification of molten iron, good graphitization will reduce the tendency of molten iron to shrink. In order to obtain high-strength gray iron castings under high carbon content conditions, the smelting process uses scrap steel and recarburizers to make the molten iron more pure and produce castings with high material properties. When smelting, clean materials that are not contaminated should be used to avoid leakage or excessive scum.