Investigating possibility of replacing some chemical reagents used in sulfide copper flotation with halophilic bacteria

Flotation is the most important method for processing sulfide copper ores. Due to the high cost and environmental hazards caused by the chemical reagents used in this process (collectors, frothers, pH regulators, depressants, etc.), the possibility of replacing all these reagents or at least some of them are of special importance through environmentally friendly methods such as bio-flotation using halophilic bacteria. These bacteria have the ability of growth and proliferation in salty media and relatively neutral pHs such as sea salty water. In this research work, the four types of halophilic bacteria Halobacillus sp., Alkalibacillus almallahensis, Marinobacter sp., and Alkalibacillus sp. are studied to replace frothers (MIBC and F۷۲۴۰), depressant (sodium metabisulfite), and pH regulator (lime) in sulfide copper flotation using a Denver laboratory flotation cell. The results obtained indicate that each of the four types of bacteria mentioned above along with collectors (gasoil, Z۱۱, and C۷۲۴۰) as the only chemical reagents (bio-flotation + collector) can depress pyrite better than the bacteria-free mode (flotation + all chemical reagents). Iron recovery in tailings in the standard flotation test is ۴۶.۸%, which is, respectively, increased to ۹۱.۹%, ۷۴.۵%, ۷۰.۳%, and ۷۶.۹% using the halophilic bacteria of Halobacillus sp., Alkalibacillus almallahensis, Marinobacter sp., and Alkalibacillus sp. On the other hand, the recovery of chalcopyrite using the bio-flotation method is lower than its recovery using the flotation method. Copper recovery in the concentrate in the standard flotation test is ۸۹.۱%, which is reached to ۵۸.۸%, ۷۱.۴%, ۶۲.۵%, and ۶۹.۴%, respectively, using the above bacteria in the bio-flotation method.

کلیدواژه ها:

Sulfide copper flotation ، Bio-flotation ، Halophilic bacteria ، Chemical reagents ، Pyrite and chalcopyrite