SYNOPSIS Although carbon is typically considered a reductant in pyrometallurgical smelting processes, it can also be applied as refractory material in the furnace containment system. The paper introduces researchers, new to the field, to refractory materials and the role they play in the design of the furnace containment system. It also provides an overview of carbon-containing and carbon-based refractory materials and their respective applications, including the refractory lining of the furnace containment system. The industries discussed include iron and steel making, ferro-alloys (silicomanganese), and platinum group metals. Keywords: refractories, carbon-containing, carbon-based, graphite, carbon.

The effect of temperature and gas composition on the corrosion rate and corrosion byproduct of copper foil was studied by exposing it to sulphur (S 2 ), S 2 + hydrochloric acid (HCl) and hydrogen sulphide. The temperature was varied from 80 to 140 °C. Copper foil reacted with S 2 to form CuS, Cu 9 S 8 and Cu 1.8 S. Corrosion rates ranged from 9.6 µm/h at 110 °C to 0.5 µm/h at 140 °C. The presence of HCl caused pitting and enhanced the corrosion rate above 112 °C. Cu 2 S formed when copper was exposed to hydrogen sulphide gas. Sulphide scale that formed was friable and nonadherent.

About 80% of the worlds' reserves for platinum group metals (PGMs) are in South Africa's Bushveld Igneous Complex. Processing of PGM involves comminution, flotation, smelting, converting, base metals refinery and precious metals refinery. Due to increasing chrome content in the feed and the challenges associated with operating high chrome feed, alternative routes to smelting of PGM are being investigated. Some hydrometallurgical routes have been proposed. However, none of the reported potential routes have yet been commercialised.

Wear resistance of synthetic graphite against liquid industrial platinum group metals furnace matte (Cu-Fe-Ni-S) was investigated from 800°C to 1450°C at a contact time of 1 hour. Graphite resistance was measured by the extent of liquid-matte penetration through the graphite, using Xray microtomography. The matte was molten at 900°C, and it penetrated through cracks in the graphite wall. The matte penetration depth into the graphite did not increase with temperature. The matte loss in the gas phase increased with temperature. During melting, the volume of the industrial matte expanded. As the matte expanded, it pushed against the wall of the graphite and penetrated through cracks in the graphite wall. Where the crucible volume was large enough to accommodate the expanded matte, the matte did not penetrate through the graphite. Graphite exhibited poor resistance against penetration by the liquid industrial platinum group metals furnace matte.

Paper written on project work carried out in partial fulfilment of BTech (Metallurgical Engineering) degree SynopsisThe hypothesis that matte will only react with certain constituents of a refractory brick, as opposed to the entire brick, was tested by observing the extent of possible reactions between iron sulphide (FeS) and the refractory oxides silica and alumina. The main aim was to identify the components of the alumina-chrome refractory brick which are most reactive with the matte. Pellets comprised of FeS and either SiO 2 or Al 2 O 3 were enclosed in a graphite crucible and reacted in a horizontal tube furnace for one hour at 1200°C, 1350°C, or 1500°C in an argon atmosphere. The specimens were analysed with SEM and XRD to determine the extent of any reactions. Results showed that FeS penetration into the silica grain was more prominent with increasing temperature, while alumina was not penetrated by FeS at all temperatures. At 1200°C, no significant reactions were observed for both reaction couples; however, at 1350°C and 1500°C intermediate products were observed. For example, an FeS FeO mixture, SiS-O, and nonstoichiometric oxides with excess oxygen were detected in the products. SiO 2 was also more reactive towards FeS. Thus, the postulation that brick components may individually be reactive towards matte was proved to be true.

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<p>Wettability of SGL's RN-graphite by synthetic and industrial PGM (Platinum Group Metal)-furnace matte (CuFeNiS) was investigated using a sessile drop configuration. This work was done to determine the compatibility of a graphite refractory with liquid PGM-furnace matte. Direct measurements of interfacial contact angles were used to determine wettability. In inert conditions, graphite was poorly wetted by synthetic and industrial PGMfurnace matte (CuFeNiS), the contact angles were > 90° for all tested matte types. No correlation was observed between the sulphur content of the matte and its wetting behaviour. The granulated matte expanded by up to 25 volume % during melting.</p>