graphite scrap is a kind of apparently defect product of carbon electrode after baking and before graphitization. It’s physical and chemical index belongs to the normal range, but there are defects such as apparent cracks. It has the characteristics of very low sulfur content and low ash content.
Because of the above characteristics, electrode scraps can be used together with cast cokes as fuel in the smelting of scraps of copper, aluminum, lead, zinc and other metals. Compared with the carbon anode butts, this product has the following characteristics:
The sulfur content of the carbon anode butts is usually difficult to be controlled under 1%. In some areas with very high environmental standards, carbon anode butts are unsuitable to be used for fuel, and then electrode scraps can be selected for fuel ;
The graphite scrap has high fixed carbon content and relatively low fuel consumption, thus reducing the labor intensity of workers, which can actually reduce the operating costs of factories in those countries, such as European countries and the United States, where human wages are relatively high. At present, the electrode scrap has been popularized and used in Japan, South Korea and Germany. According to end users’ feedback, 1 ton of electrode scraps is equivalent to 1.5-2.0 tons of cast cokes ;
The graphite scrap is more resistant to burning than the casting coke since the ash content and porosity ratio of it is lower than that of the latter. Although the ash content of carbon anode scrap is also lower than that of the casting coke, the ash content of carbon anode scrap is rich in trace elements such as sodium and calcium, which will sharply accelerate the activity of carbon ;
Although the graphite scrap is more resistant to burning, its ignition temperature is relatively high, so it must be used with the cast coke for the relatively low ignition temperature of the latter ;
From the point of view of performance-price ratio, the current price of the electrode scrap is about 1.3 times that of the foundry coke.
Fuel-purpose electrode scraps are surely replacing carbon anode butts in some areas.