Bottom Blown Copper Smelting Process Research Articles

Effects of Matte Grade on the Distribution of Minor Elements (Pb, Zn, As, Sb, and Bi) in the Bottom Blown Copper Smelting Process

With increasing impurity contents in concentrates, the control of the minor elements is an important issue for the oxygen bottom blown copper smelting process (Shuikoushan process or SKS process). In this work, the distribution behaviors of the minor elements (such as Pb, Zn, As, Sb, and Bi) among the matte, slag, and gas phases as a function of matte grades was investigated by adjusting the ratios of oxygen/ore in the SKS process. With a matte grade around 70%, about 82% As and 70% Bi enters the gas phase, and about 70% Sb and 64% Zn reports to the slag phase, while 55% lead enters the matte phase. The tendency of changes in the distribution of the minor elements in the SKS process is different from that in the Isasmelt process and the Flash smelting process. It may be concluded from this study that the distributions of the minor elements could be optimized to reduce adverse effects in the SKS process by regulating the matte grade.

Development and Application of SKSSIM Simulation Software for the Oxygen Bottom Blown Copper Smelting Process

The oxygen bottom blown copper smelting process (SKS process) is a newly developed intense smelting process, which has been widely applied to copper production in China. A multiphase equilibrium model for the SKS process was established based on its mechanism characteristics and the principle of Gibbs energy minimization, and an efficient simulation software—SKSSIM (SKS Simulation)—was developed based on the model. Industrial data from the SKS process were used to compare with the calculated data from the SKSSIM software. The calculated data on the compositions of slag and matte as well as the distribution ratios of minor elements (such as Pb, Zn, As, Sb and Bi) among the slags, mattes and off-gases were in good agreement with the actual plant data. Accordingly, the SKSSIM simulation software has the potentail to be used for the prediction of smelting production and for optimizing the operating parameters of the SKS process.

Reaction Mechanism and Distribution Behavior of Arsenic in the Bottom Blown Copper Smelting Process

The control of arsenic, a toxic and carcinogenic element, is an important issue for all copper smelters. In this work, the reaction mechanism and distribution behavior of arsenic in the bottom blown copper smelting process (SKS process) were investigated and compared to the flash smelting process. There are obvious differences of arsenic distribution in the SKS process and flash process, resulting from the differences of oxygen potentials, volatilizations, smelting temperatures, reaction intensities, and mass transfer processes. Under stable production conditions, the distributions of arsenic among matte, slag, and gas phases are 6%, 12%, and 82%, respectively. Less arsenic is reported in the gas phase with the flash process than with the SKS process. The main arsenic species in gas phase are AsS (g), AsO (g), and As2 (g). Arsenic exists in the slag predominantly as As2O3 (l), and in matte as As (l). High matte grade is harmful to the elimination of arsenic to gas. The changing of Fe/SiO2 has slight effects on the distributions of arsenic. In order to enhance the removal of arsenic from the SKS smelting system to the gas phase, low oxygen concentration, low ratios of oxygen/ore, and low matte grade should be chosen. In the SKS smelting process, no dust is recycled, and almost all dust is collected and further treated to eliminate arsenic and recover valuable metals by other process streams.