REFRACTORIES REVIEW: R&D Snapshot
The improved performance of refractories is clearly a major factor in the continually decreasing rate of consumption of refractories worldwide. The user industries have all realized benefits such as reduced downtime, the ability to use harsher processing conditions to improve their products, increased unit productivity, safer and more efficient operations, reduced maintenance needs, and more. Additional benefits will be realized as refractory researchers direct more attention to developments such as "functional" refractories (i.e., products that will serve more than a protective, containment function and actually contribute to the processing of products through enhanced purification, reduced contamination, etc.), more durable refractories, and further improving the refractory installation and repair process.
A representative view of the current refractory R&D topics and activities around the world was provided by two conferences in 2004_The Tehran International Conference on Refractories (TICR), Iran, May 3-6, and the World Refractories Congress (WRC '04), Singapore, June 27-29. These conferences, which each attracted multinational audiences, provided information and discussions on contemporary activities and needs in refractories.
TICR-New OpportunitiesTICR was reported to be the first international refractories meeting in the Middle East, where there has been a dramatic growth in the refractory consuming industries, and hence an increased need for locally manufactured and imported refractories. The program featured 74 papers, including many speakers who provided overviews of refractories activities and applications in Iran. The sessions focused on science and technology, iron and steel, non-ferrous, cement and glass, market and potential, and raw materials.
Prof. M. Rigaud, Canada, discussed trends and new refractory requirements in the steel industry, especially for electric arc furnaces and secondary metallurgy (ladles). He recommended that refractory companies should focus on value-added products for molten steel processing/transfer, such as slide gates, submerged entry nozzles, porous plugs, shroud tubes and others.
A paper by Prof. R. Moore (deceased), U.S., on the development of in-situ refractories for iron and steel applications, was presented by W. Headrick, Ph.D. In-situ refractories are materials that react with mix components/additives or with the furnace atmosphere, slag, and/or other components, resulting in enhanced performance. Examples mentioned were spinel-forming castables, castables containing microsilica, doloma-zirconia, and carbon-containing products. Some strategies for the future development of in-situ refractories were also outlined.
WRC '04-Challenges AheadProf. A. Yamaguchi, Japan, discussed the very interesting subject of self-repairing refractories. For carbon-containing refractories, additives serve mainly to inhibit oxidation, but they also contribute to mineralization (self-repair). Yamaguchi indicated that further research to identify and develop better additives will result in improved durability by self-repair, in-situ.
With the high interest in spinel-based refractories, there were two talks on the subject. Prof. R. Bradt, U.S., presented a tutorial overview of the fundamentals of spinel and highlighted the many benefits that are expected to result in further increased usage of typical and novel spinels in refractories. Mr. Liu, China, discussed the factors that have led to the resurgence in spinel materials. Research has been done to develop materials and mixes containing no microsilica, as these materials have low resistance to shear stresses for pumping for installation by wet gunning, in addition to improved high-temperature properties.
Ms. Tai, China, discussed the refractories activities and needs of Baoshan Steel Co. Boashan_s research on the maintenance technology for coke ovens has resulted in the development of a semi-dry gunning mix and a sealing material, based on the need to reduce/eliminate the escape of pollutants to the atmosphere. For steel ladles, the company is researching carbon-free bottoms, low carbon MgO-C bricks and MgO-CaO materials. Other R&D needs were mentioned, such as high-quality ladle purge plugs, longer life slide gates, and improved maintenance/repair refractories and associated procedures/equipment.