REFRACTORIES REVIEW: Advancing Technology
Duell's 1899 report quoted President McKinley, "Our future progress and prosperity depend upon our ability to equal, if not surpass, other nations in the enlargement and advance of science, industry and commerce. To invention we must turn to accomplish such a result."1 Duell correctly foresaw that inventions (and the U.S. Patent Office) would be very important for the future growth and success of the U.S.
Fast ForwardAs written recently by C. Grahl, "Someone is always going to invent a better product, or find a better way to produce an existing product. Anyone who wants to stay in the game has to figure out how to play better than everyone else-and how to keep improving."2 This is certainly the case for the refractories industry, with countless improvements and advances in products, technologies and services over the decades since the late 1800s. Just a few examples of the many refractory advancements are synthetic raw materials, castables, plastics (moldables), direct-bonded magnesia-chrome bricks, fiber blanket, modules, solid-solution bonding, tar-bonded magnesia bricks, magnesia-carbon bricks, nitride- and oxynitride bonding, porous plugs, and wet gunning (shotcasting).
A refractory company will commonly conduct more than 100 R&D projects each year, based on internal or external ideas, actual or anticipated needs or problems, customers' requests, the success of competitive products, the cost or availability of raw materials, and published information (including patents). The associated advances typically result in refractories that perform better or longer in service, but the return on investment for the improvements frequently doesn't correlate with the true economic benefits realized by the user companies.
In reality, the annual production and market value for refractories has steadily decreased in recent years, so there are economic concerns associated with the ongoing improvement of products and technologies that are bringing in less revenue. The competitive pressures are intense in the global marketplace, but it seems that there should be an effort to develop and promote a "fair value" strategy wherever possible. The refractories industry has continued to make improvements, however, because of the constant hope of making a bonanza development, coupled with the pressures of maintaining and growing the business.
Recent PatentsIn many cases, it is considered important to protect refractory developments from infringement by patenting the technology. The public patent literature provides a valuable repository of detailed information that fully documents the many improvements and advances in refractories. Several examples of patents from the last six months, obtained from the U.S. Patent Office website (http://www.uspto.gov ), are mentioned below:
- Composite Materials for Use in High Temperature Applications by M. Rigali, et al, Tucson, Ariz.3 Fibrous composites have been developed with enhanced strength and resistance to corrosion and thermal cycling.
- Method of Fabricating Shaped Monolithic Ceramics and Composites by K. Sandhage and P. Kumar, Columbus, Ohio.4 A procedure for synthesizing a porous perform, infiltrating the preform, and causing a reaction to produce a dense body of a desired shape.
- Method for Making Aluminate Cement by G. Beauvent, et al, Ferques, France.5 A process and apparatus for making sulfoaluminate or ferroaluminate cement.
- Use of Phosphates to Reduce Slag Penetration in Cr2O3-based Refractories by K. Kwong, et al, Albany, Ore.6 A high-Cr refractory was developed for use in slagging gasifiers, with improved resistance to coal slag penetration, to increase the lining life and reduce the millions of dollars of lost revenue due to downtime for lining repair. The improved refractory consists of a suitable aggregate and a bonding matrix of Cr2O3, an inorganic oxide and a phosphate.
- Alumina Refractories and Methods of Treatment by R. Pavlik, Corning, N.Y.7 Methods for improving the strength of alumina refractories, including exposure to a halogen gas.
The FutureOngoing refractory improvements continue to be highly beneficial for the user industries, as indicated by the continuing decrease in the refractory consumption rate, increased online production time, reduced maintenance and repair, improved process operating efficiency, and reduced energy. History indicates that the progress will continue, through patented and unpatented refractory improvements. For example, the know-how is available to develop prescription (optimized) refractories for any process or application, which might possibly be an option where a "fair value" pricing concept could be implemented.