Patent ID: 11286425

Abstract:
A method for preparing needle coke for ultra-high power (UHP) electrodes from heavy oil is provided. In this method, heavy oil is used as a raw material. The size exclusion chromatography (SEC) is conducted with polystyrene (PS) as a packing material to separate out specific components with a relative molecular weight of 400 to 1,000. The ion-exchange chromatography (IEC) is conducted to remove acidic and alkaline components to obtain a neutral raw material. The neutral raw material is subjected to two-stage consecutive carbonization to obtain green coke, and the green coke is subjected to high-temperature calcination to obtain the needle coke for UHP electrodes. The needle coke has a true density of more than 2.13 g/cm3 and a coefficient of thermal expansion (CTE) of ≤1.15×10−6/° C. at 25° C. to 600° C.