Study On Electrolytic Aluminum Carbon Anode Preparation With Low-cost Materials

With the fast economic development of our country, carbon products increaserapidly and a large number of petroleum coke are required as raw materials, which leadto the tight supply of superior petroleum coke and price rising. On the contrary, fuelgrade petroleum coke fines that don’t apply to produce carbon materials become more,more than sixty percent of the total petroleum coke, and the price of fuel gradepetroleum coke fines are hundreds of yuan cheaper than that of superior petroleumcoke. Furthermore, as the oil resources gradually decrease, all kinds of petroleum cokewill be in the shortage of supply. Coal tar pitch gas which generate in the process ofcarbon anode baking and aluminum electrolysis harm the human health andenvironment. In addition, the coal tar pitch has been lack of standard and wholemeasuring means in our country, so the performance of pith fluctuate, which contributeto quality instability of anode.As a result, how to effectively use fuel grade petroleum coke fines and look forother materials to replace calcined petroleum coke and coal tar pitch partially or totallyto prepare carbon anode with low cost and high performance is urgent in aluminum andcarbon industry.In this paper, with raw materials with high quality, called secondary material,made by low-cost fuel grade petroleum coke fines or calcined petroleum coke as themain material, anthracite, artificial graphite, charcoal, material Y, green coke and shellcarbonized materials as auxiliary raw materials, coal pitch as binder,by the processesas following: mixing, kneading, shaping, baking, carbon anode with low-cost and goodchemical and physical properties used for electrolytic aluminum would be producedsuccessfully. In the meantime, on the basis of the basic formula, waste plastics,phenolic resin and inorganic binder exploratively substituted for pitch partially ortotally. Then comprehensive performance of carbon anode samples with differentformulas were tested and analysed. The result showed that the fourth sample whichwas prepared with secondary material as the main material, anthracite and artificialgraphite as auxiliary materials, coal pitch as binder achieves better performance,specific performance indexes as follows: bulk density is1.51g/cm~3, true density is2.06g/cm~3, ash content is0.58percent, volume resistance is58.71μ·m, compressivestrength is35.7MPa, air reaction residue is91.78percent. These main indicators have reached the requirements of national announced new standard YS/T285-2007.Thesample H that was added Z carbonized material also has excellent properties, specificperformance indexes as follows: bulk density is1.55g/cm~3, true density is1.98g/cm~3,rockwell hardness is97.7, compressive strength is34.0MPa, ash content is0.42percent, volume resistance is56.51μ·m and the microstructure is compact. Make useof Z carbonized material can receive obvious economic benefits. Besides, green cokereplacing calcined petroleum coke and waste plastics and phenolic resin substitutingfor pith were feasible, but the properties of anode should be improved through furtherstudy.