A mathematical model of the nickel converter: Part I. Model development and verification

TLDR: In this paper, a mathematical model of the nickel converter was developed, where the primary assumption of the model is that the three phases in the converter are in thermal and chemical equilibrium, and the overall predicted mass balance was shown to be close to that seen in actual practice.

Abstract: A mathematical model of the nickel converter has been developed. The primary assumption of the model is that the three phases in the converter are in thermal and chemical equilibrium. All matte, slag, and gas in the converter is brought to equilibrium at the end of each of a series of short time steps throughout an entire charge. An empirical model of both the matte and slag is used to characterize the activity coefficients in each phase. Two nickel sulfide species were used to allow for the modeling of sulfur-deficient mattes. A heat balance is carried out over each time step, considering the major heat flows in the converter. The model was validated by a detailed comparison with measured data from six industrial charges. The overall predicted mass balance was shown to be close to that seen in actual practice, and the heat balance gave a good fit of converter temperature up to the last two or three blows of a charge. At this point, reactions in the converter begin to deviate strongly from “equilibrium,” probably due to the converter reactions coming under liquid-phase mass-transfer control. While the equilibrium assumption does work, it is not strictly valid, and the majority of the charge is probably under gas-phase mass-transfer control.