JOM

Rapid solidification plasma deposition (RSPD) is a unique process for producing metallurgical structures. Homogeneous, nearly fully dense microstructures are achieved which have significantly improved mechanical behavior relative to the behavior of the same alloys in conventionally cast and heat-treated form, such as a 50% increase in tensile strength and a many-fold increase in thermal fatigue crack initiation resistance. Thin-walled structures can be produced in alloys which could not be cast or wrought to that size, while massive fine-grained structures can be produced in a fraction of the time of conventional processes.

Red mud based ceramic tiles were successfully fabricated by high-temperature sintering and the influence of the Fe2O3 content on their comprehensive performance, mineral phase, and microstructure were systematically investigated. The results indicate that iron is involved in the structural reorganization of mullite during the nucleating process. Adding 9% Fe2O3 elongated mullite crystals to an aspect ratio of 15.6 ± 2.1, and the crystals were successfully obtained at a sintering temperature of 1300°C for 2 h. In this case, the values for water absorption and compressive strength of the red mud based ceramics were 6.6% and 178.3 MPa, respectively, reaching the national standard for building materials. Putting the right amount of Fe2O3 into ceramics can not only promote the anisotropic growth of mullite crystals but can result in the formation of an interlocked network of mullite at lower temperatures. This work will contribute to a better understanding of the influence of Fe2O3 on basic material performance, such as structural, micro-analysis, and mechanical characteristics of ceramic tiles with iron-containing mullites.

This paper has shown the pattern of production and usage of zinc dust in Western Europe, and indicates that although the major source of this product is still via the old Horizontal Retort Distillation plant, suitably modified, that more sophisticated methods of production are in use for producing the higher grades of dust required by the surface coating industry. Undoubtedly, should the zinc production in Europe get out of phase with the demand for zinc dust, or the production of zinc via the Imperial Smelting Blast Furnace or by electrolytic processes increase, then these methods will be adopted to an increasing degree.

Operating experience for a unique hot-blast cupola — basic-oxygen jurnace steelmaking facility is described. The facility is unusual in that basic, hot-blast, water-cooled cupolas are used to produce a low-silicon hot-metal for the basic oxygen furnaces. The problems encountered in using low-silicon hot-metals are discussed. Because of the low silicon content of the cupola hot-metal, steelmaking operations at Acme are different than at other basic oxygen facilities. The various steelmaking techniques employed, including the use of an artificial slag, are described in detail.