Potential copper plant Vanyukov furnace gas desulphurization capacity

To enable maximum disposal of Vanyukov furnace flue gas, the authors of this paper examined the spare capacity of the Elemental Sulphur Site at the Copper Plant of Nornickel’s Polar Division. Thus, the paper considers an optimized three-stage flue gas treatment process (which also includes a thermal reduction stage) and the possibility to skip the stage of preliminary condensation of sulphur from reduced gas. To estimate how it will affect the overall recovery of sulphur (desulphurization factor), a series of calculations was carried out to compare the Elemental Sulphur Site’s performance during two different treatment processes: a complete process that includes preliminary condensation of sulphur from thermally reduced gas; and a short process, i.e. without preliminary condensation of sulphur. In both cases, the concentration of sulphur dioxide in the Vanyukov furnace gas was [SO2] = 28 vol %. The results of the calculations were verified through experiments conducted on a pilot unit owned by Gipronikel Institute with the gas flow reaching ~1.2 nm3/h, and they confirm the possibility of implementing the three-stage treatment process using the available plant space and reaching the capacity of 40,000 nm3/h and the sulphur recovery of ~89 %. The obtained data on the specific consumption rates of natural gas, oxygen and boiler water can be used for a feasibility study to justify the adoption of the short treatment process at the Elemental Sulphur Site of the Copper Plant of Nornickel’s Polar Division.

Looking at the changing composition of blister copper obtained through continuous converting

Conventional converting of nickel-bearing copper mattes in horizontal Peirce – Smith converters does not conform with the current environmental regulations. A general global trend includes a transition from conventional batch converting to a continuous converting process producing running slags. The main purpose of the continuous matte converting process is to obtain commercial blister copper that would not require oxidation during further anode refining. To achieve this, rational process parameters should be strictly maintained. The existing method of monitoring the Vanyukov furnace process that is based on the product analysis is a prerequisite but cannot ensure real-time process control. The blister copper obtained through continuous converting differs from the one obtained through the conventional technology in terms of oxygen and nickel concentrations. That’s why its composition should be constantly monitored. The authors looked at how the composition of blister copper obtained through continuous converting of matte tends to change. Samples of blister copper of different compositions were synthesized that are typical of the start-up mode. When the process temperature rises, the required product characteristics can only be obtained if the oxidation potential is higher. This results in a higher concentration of oxygen in blister copper. Mathematical dependencies were derived between the concentrations of nickel and sulphur in the product at various temperatures and the concentration of oxygen. A technique is proposed that enables a real-time monitoring of impurities in blister copper.