抄録
The effects of inhibitors to iron-oxidizing bacteria (Thiobacillus ferrooxidans) on the dissolution of iron species from high sulfur coal refuse (5.75 db% S) were studied in acidic solutions with the bacteria, using sodium lauryl sulfate (SDS) and tannic acid as inhibitors. Flotation experiments of high sulfur coal (4.27 dafb% S) in leachates from the refuse were conducted to remove sulfur.
Compared with tannic acid, SDS inhibited the iron-oxidizing activity of Thiobacillus ferrooxidans more and dissolution of pyrite in high sulfur coal refuse, but SDS did not prevent dissolution of soluble iron species in the refuse even at high addition rates, and pH values of the leachates were very low. When adding CaO, CaCO3, and limecake (byproduct of sugar making), dissolution of iron was completely suppressed and the pH values were about pH 8.
Flotation of the high sulfur coal was conducted in the leachate of high sulfur coal refuse, which was prepared by Thiobacillus ferrooxidans to contain about 0.01 mol / dm3 soluble iron (almost all ferric ions) and adjusted to pH 2.5. Coal was selectively recovered as a froth product with high combustible recovery and high pyrite rejection.
