中文摘要：

对主元素活度项法优势相图计算机绘制过程作了改进，利用QBasic软件和Origin制图系统计算和绘制了Fe—S—O体系的lgPs2-lgPo2优势区相图和lgPs2-lgPso2优势区相图，并利用这些优势区相图分析了黄铁矿合成时残余氧气杂质对黄铁矿材料的影响，结果表明：（1）使用流动的高纯惰性气体携带硫化气体（如S2）与加热的Fe或其氧化物起硫化反应制备二硫化铁时，为了保证合成黄铁矿的纯度，合成反应发生前必须让残余氧与硫充分反应去除残余氧；（2）硫磺与Fe或其氧化物一起密封于石英容器中。在573-773K加热处理从理论上可以制备高纯的FeS2。

英文摘要：

The predominance area diagrams of lgPs2-lgPo2 and lgPs2-1gpso2 for Fe-S2-O2 were drawn by the improved component activity term method of base element. And the influences on the purity of pyrite by the residual oxygen impurity in the process of synthesis have been characterized according to these drawn predominance area diagrams. The results showed that： （1）While the pyrite is prepared by heat- treatment of iron or iron oxides in flowing high-purity inert gas with gaseous sulfur to ensure the purity of pyrite, the residual oxygen must be removed by complete reaction of oxygen with sulfur before synthesis pyrite. （2）The high-purity pyrite can be prepared by heat-treatment of iron or iron oxides with sulfur in sealed quartz reactor.