| Aluminum pre-baked anode(also known as carbon anode) is the "heart" of the production of aluminum electrolysis. The quality of carbon anode has a great impact on the current efficiency, carbon Consumption and product levels in the aluminum electrolytic production. The pre-baked anode is made by petroleum C oke and Coal tar pitch as raw material. The percent of calcied Coke, made by petroleum Coke after calcinations is about 85% in pre-baked anode. So the quality of petroleum C oke directly determines the pre-baked anode performance.In this paper, 13 kinds petroleum Coke, Contained different sulfur and trace element Contents from Sinopec refinery production, were choose for studying the influence of S, V, Ni, Ca and other major and trace elements in petroleum C oke on the growth mechanism of carbon crystal and perfo rmance of calcied Coke during calcinations process. The mixed Cokes Contained s and trace elements C ontent were obtained by blending experiments in the laboratory. The microstructure development, Conductivity, CO2 reactivity and air reactivity of C okes calcied by different temperatures were tested.Through analyzing the petroleum element content and the performance differences of calcined coke, the research group found that increasing S value between 1.33 – 3.51 will enlarge the Lc value of calcined coke. For instance, under the 1100? condition of being burned, the Lc values of petroleum coke with S value of 1.33, 2.42, 3.51% are respectively 26.47, 27.00, 27.09( ?). Increasing V? Ni?Ca(within the set scope of experiment) will decrease the Lc value of calcined coke, among which Ca is the most obvious: when the content of Ca is 100, 200, 300 mg?g-1, the corresponding Lc values of calcined coke are 27.56, 26.06, 24.64( ?). Increasing S value will decrease true density and electrical resistivity, for instan ce, under the 1100? condition of being burned, the true density of petroleum coke with S value of 1.33, 2.42, 3.51% is respectively 2.065, 2.061, 2.052(g/ cm3), and the electrical resistivity is 453.5, 462.5, 481.5???m. Increasing V, Ni and Ca will enhance the true density and electrical resistivity of calcined coke and Ca has the biggest influence on true density: when Ca is 100, 200, 300 mg?g-1, the corresponding true density of calcined coke is respectively 2.053, 2.067, 2.081(g/m3); V has the biggest i nfluence on electrical resistivity: when V is 151, 251, 356 mg?g-1, the corresponding electrical resistivity of calcined coke is respectively 462.38, 482.88???m. Increasing S value will inhibit the reactivity of CO2, but due to the spill of volatile matter, the structure defect increases, which results in the high loss ratio of calcined coke with high S value under the condition of lower calcination temperature; with the increased calcination temperature, the active point disappears and the loss ratio reduce s, which reflects increasing S value inhibits the reactivity of CO 2. Increasing S value will reduce the reactive ignition temperature of air and increase the reaction rate of air, which is basically similar to the reactivity of CO 2. V, Ni(within the set scope of experiment) will inhibit the reactivity of CO 2, and Ca will enhance the reactivity of CO2. Increasing V, Ni and Ca(within the set scope of experiment) will promote the air reactivity of caicined coke and Ca exerts the biggest influence, for instan ce, under the 1100? condition of being burned, the air reaction rate of calcined coke is respectively 0.4, 0.46, 0.58 %/min.The above research provides theoretical basis for the rational blending of different S values and microelement petroleum coke raw m aterial, as well as the production of prebaked anode used for high-performance aluminium electrolysis. |
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