engleski

Electrochemical treatment of the acid mine drainage pretreated with CaO

The subject of this research was the characterization and the treatment of the acid mine drainage (AMD) originating from the sulfide ore mining and metallurgical activities in the Bor copper mining and smelting complex, Serbia. The AMD from the Bor mining complex (Bor-Krivelj-Cerovo) and smelting /refining of copper was characterized by low pH value (usually below 4) and high concentrations of heavy metals whose concentrations vary depending on the source. If entire complex was considered 7 different sources of the wastewaters could be defined. The treatment of the AMD included pretreatment/pH adjustment with CaO until pH 8 followed by electrocoagulation using iron (I = 50 A ; U = 10 V ; t =5 min.) followed by aluminum electrode sets (I = 50 A ; U = 10 V ; t =10 min.). Each electrode set contained of ten quadratic, one millimeter thick plates (75 x 250 mm) in the parallel arrangement, separated by an electro insulator. The distance between plates was 10 mm in both electrode sets. In the end of electrochemical treatment the suspension was recirculated in strong electromagnetic field for 10 minutes and subjected to slow mixing for another 15 minutes while the settlement time was 30 minutes. Waste sludge from the combined treatment process could be reused for another cycle of the pH adjustment/pretreatment of the acid mine drainage instead of CaO, and afterwards, due to its inertness, it could be used for overlaying layer of the flotation waste heap during its recovery work.

kisele otpadne vode ; elektrokemijski tretman ; CaO

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