バクテリアによる酸化が黄鉄鉱の浮遊性におよぼす影響
1985 年 101 巻 1173 号 p. 719-724
詳細
1985 年 101 巻 1173 号 p. 719-724
As a fundamental study on utilization of microorganisms in the differential flotation of sulfide minerals, effects of oxidation by an iron-oxidizing bacterium (Thiobacillus ferrooxidans) on floatability of pyrite were investigated. In addition, some surface properties of oxidized pyrite were investigated in relation to the floatability.
The main results obtained are summarized as follows:
1) Bacterial oxidation and leaching behaviors of pyrite are much affected with the condition of previous culture of the bacterium. The previous culture using pyrite substrate reduces induction period for the oxidation.
2) Floatability of pyrite is remarkably depressed by bacterial pretreatment. The decrease in the floatability well corresponds to the degree of progress in the leaching based on the condition of previous culture.
3) The surface of pyrite changes into porous structure with the progress of bacterial leaching, while a notable decrease in the floatability of it begins before. Accordingly, in this case, it is apparent that the effect of surface structure on depression of the floatability of pyrite is not dominant.
4) By the bacterial oxidation, jarosite or a jarosite-like insoluble sulfate is formed on pyrite surface and wettability of the pyrite becomes larger. Consequently, it is inferred that the depression of the floatability mentioned above is due to the formation of a hydrophilic sulfate film on pyrite.
5) Besides, the effect of pH on the floatability of pyrite with various leaching stages was also discussed.
