黄铁矿及毒砂中负氧化数金的发现及判定

DISCOVERY OF GOLD WITH NEGATIVE OXIDATION NUMBER IN PYRITE AND ARSENOPYRITE

作者在以突破金的氧化态（价态）为先导的研究中，使用光电子能谱对９个金矿区的黄铁矿与毒砂进行了研究。发现它们之中广泛出现有结合能为８３（８２．８～８３．２）ｅＶ的峰，经分析对比后，指认它为Ａｕ峰（４ｆ＿（７／２）。但它的结合能小于Ａｕ￣０（约８４ｅＶ），更小于Ａｕ￣（１＋）及Ａｕ￣（３＋）．根据结合能与氧化态的关系，判定８３ｅＶ峰为负氧化数金（负价金）所引起。即黄铁矿与毒砂中存在有负氧化数金。

Pyrite and arsecopyrite are the most important goldbearing minerals.There has been a great deal of arguement on the state of invisible gold in these twominerals.To determinc the valence of gold,the authors carried out photoelectronspectroscopy study on pyrite and arsenopyrite from nine gold deposits.A binding onergypeak at 83 eV(82.8～83.2 eV)was widely found in the samplea,whieh is assigned to bethat of gold. The binding energy is lower than that of Au￣0(about 84 eV),aswell asAu￣(1+) and Au￣(3+).The relationship between oxidation number and binding cnergy suggeststbat the 83 eV peak could be produced by negative valenced gold that exists in the pyriteand arsenopyrite. Such discovery is important to study of gold in various aspects.