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Since the second part of the twentieth century, Chile has become the largest copper producer in the world, being the pyrometallurgical processing of sulfides concentrates a central part of it.Since the introduction of the Peirce-Smith and later the Hoboken converters in Chilean smelters, some modifications were made to these reactors, including feeding of copper concentrate and intensive oxygen enrichment utilisation to increase their productivity. These modifications, and the use of bone dry concentrates, later became part of the new Teniente technology to smelt concentrates. All these innovations also influenced other processes, such as slag and gas treatment.This paper shows how pyrometallurgical processing of copper concentrates has been developed in Chile and how the Teniente reactor was conceived and implemented. Also, a comparison between nonferrous and ferrous technologies in terms of instrumentation and control, and some new processes being developed at laboratory and scale are shown.

The kinetics and reaction mechanism of the flash oxidation of +35/-53 lm molybdenite particles in air, as well as in 25, 50, and 100 pct oxygen higher than 800 K, has been investigated using a stagnant gas reactor and a laminar flow reactor coupled to a fast-response, twowavelength pyrometer. The changes in the morphology and in the chemical composition of partially reacted particles were also investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA), and electron microprobe. High-speed photography was also used to characterize the particle combustion phenomena. The effects of oxygen concentration and gas temperature on ignition and peak combustion temperatures were studied. The experimental results indicate that MoS 2 goes through a process of ignition/combustion with the formation of gaseous MoO 3 and SO 2 with no evidence of formation of a molten phase, although the reacting molybdenite particles reach temperatures much higher than their melting temperature. This effect may be a result of the combustion of gaseous sulfur from partial decomposition of molybdenite to Mo 2 S 3 under a high gas temperature and 100 pct oxygen. In some cases, the partial fragmentation and distortion of particles also takes place. The transformation can be approximated to the unreacted core model with chemical control and with activation energy of 104.0 ± 4 kJ/mol at the actual temperature of the reacting particles. The reaction was found to be first order with respect to the oxygen concentration. The rate constant calculated at the actual temperatures of the reacting particles shows a good agreement with kinetic data obtained at lower temperatures. The ignition temperature of molybdenite shows an inverse relationship with the gas temperature and oxygen content, with the lowest ignition temperature of 1120 K for 100 pct oxygen. Increasing the oxygen content from 21 to 100 pct increases the particle combustion temperature from 1600 K to more than 2600 K. A high oxygen content also resulted in a change of the reaction mechanism from relatively constant combustion temperatures in air to much faster transient combustion pulses in pure oxygen.

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