高温热处理石油焦中金属微量成分的变化

ALTERNATION OF METALLIC MICROCONSTITUENTS IN PETROLEUM COKE BY HIGH TEMPERATURE TREATMENT

用于石墨电极、建筑材料、碳化物和其它产品生产的石油焦含有一定的金属微量成份,从“碳质材料”中释出金属的方法之一是高温热处理(HTT)。本文报道了石油焦在2400℃高温热处理前后的微量成分及其化合物的含量的试验结果。本试验的一个目的是研究由热处理引起的金属释出的动力学。试验结果表明:所分析的焦炭中金属微量成分主要以氧化物、硅酸盐、硫酸盐、硫化物、磷酸盐和碳化物的形式存在。石油焦中存在的金属微量成分的种类不仅与加热的时间和温度有关,而且还与原料有关,与原料中微量成分的种类和浓度有关。在高温热处理时,一些化合物转变成热的不稳定形态,从而促使金属微量成分的部分或完全分离。所有发现的微量成分(Si,Al,K,Ca,Fe,Ni,Ti,V,Na,S,P,Cu,Gr)除铁、钛、钒外,都可用2400℃高温热处理的办法部分地或全部释出。

Petroleum coke, which is used as a feedstock for the production of graphite electrodes, construction meterials, carbides and other products, may contain a limited amount of metallic microconstituents. One of the procedures for separating metals from “carbonaceous materials”is high temperature treat- ment (HTT). The paper deals with the results of investigation of the content of microconstituents and their chemical compouds in petroleum cokes hefore and after the high temperature treatment up to 2400℃. One aim of the inves- tigation was to study the kinetics of metal separation induced by HTT. Experimental results show that metallic microconstituents in the analysed cokes are mainly present as oxides, silicates, sulphates, sulphides, phosphates and carbides. The types of chemical compounds of the metallic microconsti- tuents present in petroleum coke depend not only on the temperature and time of heating but also on the feedstock and on the type and concentration of microconstituents. During high temperature treatment some compounds are transformed to thermally more or less unstable forms thus facilitating partial or complete separation of matallic microconstituents. Of the identified micro- constituents, Si, Al, K, Ca, Fe, Ni, Ti, V, Na, S, P,Cu and Cr, all except iron, titanium and vanadium were separated partially or completely by means of the high temperature treatment up to 2400℃.