It was designed and built for an annual capacity of eight million tonnes of ore, with three stage ore crushing and two stage grinding in three identical sections. Three years later, the Copper Institute of Bor performed redesigning and the Krivelj Concentrator started implementing the collective flotation instead of selective in 1985. Since the beginning of production in 1983 until today, the Concentrator has produced 2,765,063 tons of dry copper concentrate with an average Cu content of 19.68% and recovery of 81.6%, totaling 544,112 tons of copper in the concentrate.
On the basis of verified ore reserves, mining operations and equipment, the “Veliki Krivelj” open pit should be the holder of mass production of the high quality copper concentrate which from the year 2014 will be processed in the new pyrometallurgical plant. According to the project of reconstruction of a new smelter and building of a new sulfuric acid plant, 300 to 350 thousand tons of copper concentrate from our own resources will be processed.
Given the fact that the installed machinery and engines are technologically outdated and that after 30 years of operation can achieve only unsatisfactory technological parameters along with high operating costs, a comprehensive reconstruction of the existing smelter and an acquisition of new equipment for the Veliki Krivelj Concentrator was imposed as a necessary solution at the end of 2010.
Contract on the reconstruction of the Veliki Krivelj Concentrator was entered into in March of the following year with Metso Minerals Company and it is anticipated that by the end of 2011 new flotation machines will have been installed there. It is envisaged also that the entire production process will be automated, with reconstructed milling and grading units with additional milling and filtering sections repaired.
Investment objectives are to repair and refurbish the equipment that can still be used with minimum interruption and investement, but also to enable the system to annually process 10.5 million tons of ore per year. Reconstruction of the Krivelj Concentrator will enable better technological parameters of processing, with recovery rates of 96%, technological recovery of 87% with the quality of the concentrate of 21% and the maximum recovery of precious metals and moisture in the concentrate of nine percent.
Introduction of the new and reconstruction of the existing flotation equipment, improvement of the flotation processing cycle from the „Veliki Krivelj“ ore, with already commenced repair and replacement of equipment for the crushing and screening of the ore, will be “rounded up” in technical and technological terms.
- Nebojša Videnović – Manager