Kinetics of As, Sb, Bi and Pb volatilization from industrial copper matte during Ar+O2 bubbling

Abstract

A kinetic study on minor elements removal during copper matte oxidation was designed under the presumptions of low FeO activity and of no fayalite slag formation. Copper matte with a mass fraction of Cu of 59 pct was mixed by Ar gas blowing during preheating. The matte was oxidized at 1523 and 1673 K by bubbling Ar ϩ O 2 gas through a submerged nozzle. The effects of melt temperature and input oxygen content on the oxidation rate of matte and the volatilization rate of minor elements in copper matte are discussed. The competition reaction composed of the oxygen dissolution into matte and SO 2 gas evolution rate results in the preferential oxidation of FeS in copper matte. The desulfurization rate of matte and the volatilization of minor elements in copper matte were primarily controlled by the mass-transfer rate through the gas film boundary layer around rising gas bubbles. The As, Pb, and Bi were significantly removed during Ar gas blowing with the volatilization rates of Bi and Pb markedly increasing with the melt temperature. However, the dependences of the volatilization rates on the input oxygen partial pressure were affected in a complicated way by the effects of the melt temperature and the reduced amount of exhaust gas.

A Kinetic Comparison between Laboratory and Industrial Scales in the Copper Blowing Process

“…The same negligible influence of the temperature was reported by Alyaser and Brimacombe starting from experiments in a top blowing reactor [3]. A constant slope (x S /t) was found by Ajersch and Toguri [2], Asaki et al [5], and Sohn et al [6], during the desulfurization of mattes or copper sulphide, in the same trend that our results show up to very high conversions. …”

“…Results concerning the desulfurization of copper sulfide at laboratory scale have been previously reported, with different conclusions. This is not surprising at all, given the change in hydrodynamic conditions resulting from the devices where experiments were carried out: capillary tubes [2], top lancing [3,4], bubbling gas through a submerged nozzle [5,6], or thermobalance [7]. In general, the data were explained by accepting the control of the gas-side resistance, which has been considered consistent with the high oxygen utilization efficiency of the copper converter.…”

Desulfurization Rate during the Copper Blow in a Peirce–Smith Converter

“…The usual method to estimate k L [36] has been applied to the penetration model. Because both u G and d b are constant, the coefficients calculated by this theory do not depend on conversion.…”

Phase equilibria studies of zinc-containing copper smelting slags

“…Validation of the Larouche [101] investigated the removal of As through volatilization in the copper smelting processes based on the industrial operation data from personal visit to the smelters and also those reported in literatures. As shown in -oxygen enrichment [101] Sohn et al [102] investigated the kinetics of As volatilization by blowing varied oxygen and argon gas mixture into industrial copper matte at 1250 and 1400 °C in a gas tight vertical furnace tube, of which the results are shown in Figure 2.36. In can be seen that the As content in the matte phase substantially decreases with blowing time.…”

“…A higher blowing temperature somewhat benefit the As volatilization, while the impact by input oxygen partial pressure appears to be rather small. [102] Acuna and Sherrington [91] investigated the As fractional distribution behaviour during smelting in Teniente Converter by applying a thermodynamical model similar to that reported by other researchers [96,103,104] . Using the developed model, they evaluated the effect of operating parameters on the As fractional distribution behaviour.…”