Bioflotation of Sarcheshmeh copper sulphide ore.

The low-grade Iranian ore contains pyrite, which causes some problems in the flotation of chalcopyrite and other sulphide minerals. It was shown in experiments that selective flotation of the copper sulphides is possible when they interact with Acidithiobacillus ferrooxidans grown in the presence of either natural ferrous ion or sulphur. The bacteria did not adhere significantly to the chalcopyrite but could selectively adhere to the surface of pyrite, hindering its flotability and acting as a depressant. Cells strongly adsorbed on the pyrite surface may have hindered adsorption of xanthate, whereas the collector could be adsorbed on the copper sulphide minerals to promote their hydrophobicity. Development of the technology would not only result in reduced emissions of sulphur dioxide but would also solve the problem of pipelines becoming blocked by lime, resulting in considerable cost savings.
The low-grade Iranian ore contains pyrite, which causes some problems in the flotation of chalcopyrite and other sulphide minerals. It was shown in experiments that selective flotation of the copper sulphides is possible when they interact with Acidithiobacillus ferrooxidans grown in the presence of either natural ferrous ion or sulphur. The bacteria did not adhere significantly to the chalcopyrite but could selectively adhere to the surface of pyrite, hindering its flotability and acting as a depressant. Cells strongly adsorbed on the pyrite surface may have hindered adsorption of xanthate, whereas the collector could be adsorbed on the copper sulphide minerals to promote their hydrophobicity. Development of the technology would not only result in reduced emissions of sulphur dioxide but would also solve the problem of pipelines becoming blocked by lime, resulting in considerable cost savings.