次生紫硫镍矿氧化膜成分的研究及意义

紫硫镍矿(Ni,Fe)₃S₄往往是镍黄铁矿表生蚀变作用的产物,分布在氧化带以下到潜水面附近。由于它易于氧化、淋失,故不易形成有工业价值的矿床,但在气候干燥地区,如我国甘肃金川地区,氧化速度减慢,特别是化学风化作用微弱,表面氧化膜隔离硫化镍与空气的连系,从而得以保持成为矿床。

STUDY OF THE OXIDIZED FILMS OF SECONDARY VIOLARITE AND ITS SIGNIFICANCE

In Jinchuan, Gan Su Province sulfide deposit from oxidation zone to groundwater level is characterised by the wide spread development of oxidized films. Therefore, the study of the composition and properties of oxidized films is helpful to the study of the oxidation process of sulfide minerals.Violarite is the easiest one to oxidize in all sulfide minerals.By means of the Electronic spectroscopy, EPMA, IMMA, X-ray analysis and other techniques, the following results have been attained:1. The thickness of the oxidized films is 0.2-1μ;2. Oxidized films are distributed both in the surface and the cleavege plane of the mineral;3. Nearly half of the nickel in oxidized films exist in the form of nickel vitrol(NiSO₄. 7H₂O), and the rest are associated with iron. It was probably absorbed by colloform fer-rhydite or displaced as within the mineral.Except for existence with nickel vitrol(NiSO₄·7H₂O), sulfur has not correlation to iron and nickel in oxidized films.