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采用密度泛函理论计算含有砷、硒、碲、钴或镍等杂质的黄铁矿的结构和电子性质,并采用前线轨道理论讨论含杂质黄铁矿与氧气和黄药的反应活性。杂质的存在使黄铁矿晶胞体积膨胀。钴和镍主要对费米能级附近的能带产生影响,而砷杂质主要对黄铁矿浅部和深部价带产生影响,硒和碲主要影响深部价带。电荷密度分析结果表明,所有的杂质原子都与其周围的原子形成较强的共价相互作用。前线轨道计算表明,砷、钴和镍杂质对黄铁矿的 HOMO 和 LUMO 的影响比硒和碲杂质大。此外,含砷、钴或镍的黄铁矿比含硒或碲的黄铁矿更容易被氧气氧化,而含钴或镍的黄铁矿与黄药捕收剂的作用更强。计算结果与观察到的黄铁矿实际情况相符。
The structure and electronic properties of pyrite containing arsenic, selenium, tellurium, cobalt or nickel impurities were calculated by density functional theory. The frontier orbital theory was used to discuss the reactivity of the pyrite with oxygen and xanthate. The presence of impurities expands the unit cell volume of pyrite. Cobalt and nickel mainly affect the energy band near the Fermi level, while arsenic impurities mainly affect the shallow and deep valence bands of pyrite, while selenium and tellurium mainly affect the deep valence band. Charge density analysis shows that all the impurity atoms form strong covalent interactions with the surrounding atoms. Frontier orbital calculations show that the effects of arsenic, cobalt and nickel impurities on the HOMO and LUMO of pyrite are greater than those of selenium and tellurium impurities. In addition, pyrite containing arsenic, cobalt or nickel is more easily oxidized by oxygen than pyrite containing selenium or tellurium, whereas pyrite containing cobalt or nickel is more effective than xanthate collector. The calculated results are consistent with the actual observed pyrite conditions.