Columns

Refractories Review: Refractories Papers at the ACerS Annual Meeting

June 1, 2001
/ Print / Reprints /
ShareMore
/ Text Size+
The Refractory Ceramics Division (RCD) program at the recent 2001 American Ceramic Society (ACerS) meeting and exposition in Indianapolis, Ind., included 18 papers and several posters. Eight of the papers dealt with monolithic refractories, with others on various technical topics such as testing, post-mortem studies and raw materials. Refractory-related talks were also given in other multi-disciplinary sessions/symposia. Highlights included:

V. Pandolfelli and R. Pileggi of Federal University of Sao Carlos, Brazil, discussed the development of multifunctional and high performance castables. For a study of high alumina castables, Pandolfelli reported that the correct particle sizing is very important. In fact, if the particle sizing and dispersant are correct, it is not necessary to include micro-silica in the mix, which has been typical in the majority of high-tech castables despite the potential for some decrease in refractoriness. Thorough mixing is essential for realizing the optimum properties, and he suggested adding the water in two steps, i.e., 75% initially, with the remainder at the “turning point” (where the rheology changes).

Pileggi discussed the rheology and particle sizing of pumpable castables. He indicated that a castable must be pseudo-plastic to be pumpable, and that the aggregate and matrix constituents must flow together and not segregate. The pumpability of a castable must be evaluated by a rheometer and not a flow table because of the segregation of components that can occur. Regarding high performance castables, Pileggi discussed the importance of controlling the aggregate (3 to 45 mesh) and matrix content of castables.

Based on the need for MgO-graphite castables in steelmaking, H. He of CIREP, Ecole Polytechnique, Canada, described several different methods—including extruded, coated and granulated—of including graphite in such castables. An extruded form of graphite plus carbon and antioxidant showed promise with a higher temperature of initial oxidation (800°C) than flake graphite (600°C), but evaluation of the slag resistance is still to be done.

B. Headrick, University of Missouri-Rolla, discussed the measurement of modulus of elasticity (MOE) of a range of self-flowing castables, including measurements at elevated temperature. He determined that MOE decreased as the amount of bond decreased, and that it was slightly higher for white fused alumina mixes than tabular alumina mixes.

C. Schacht, consultant, discussed the use of finite element analysis in evaluating the stress state of a brick and mortar lining in steelmaking ladles. And J. Kwong of the U.S. Department of Energy (DOE) Albany Research Center described the development of a model that uses phase equilibrium data to optimize the MgO saturation of slag for electric arc furnaces.

A post-mortem study of used MgO-Cr2O3 refractory from a Zn-containing environment, by G. Oprea, University of British Columbia, revealed the contribution of spinel formation (ZnFe2O4, expansion and ZnCr2O4, shrinkage) to the cracking and spalling of the hot face.

R. Chinn of the DOE Albany Research Center summarized the evaluation of refractories from a slagging gasifier. Based on the deterioration mechanisms determined, a microstructural modification was developed to minimize slag penetration (patent pending).

P. Kleven, Energy & Environmental Research Center, N.D., reported the results of work to compare refractories for use in a slagging gasifier. It was confirmed that (a) a dynamic slag test gave a better indication of service performance than a static cup test, (b) lowering the temperature 100 degrees to 1500°C reduced the refractory corrosion by half, and (c) slag additives (e.g., 3% alumina) can reduce the refractory corrosion up to 60%. She also indicated that an improved slag test furnace had been designed and would be used in further tests to compare candidate refractories.

D. Ellerby, Sandia Labs, Albuquerque, N.M., described the tile (and high-emittance coatings) used on the NASA space shuttle. Conditions on the space shuttle surface vary from 300 to 1650°C, so several tile compositions and coatings have been developed that allow the surface protection to be zoned. Based on the tile and other developments, the number of tiles on the space shuttle has been reduced from 30,000 to 24,000.

Next year, the RCD spring program will be held in conjunction with the St. Louis Section meeting in March, instead of at the spring ACerS meeting. Further information about the 2002 spring RCD meeting can be obtained from Patty Smith, psmith@umr.edu.

Did you enjoy this article? Click here to subscribe to Ceramic Industry Magazine.

Recent Articles by Charles Semler

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

In-Depth Features

These articles detail innovative advanced ceramic and glass materials and technologies.

Podcasts

Sapphire: An Extreme Performer

Ian Doggett of Goodfellow and CI Editor Susan Sutton discuss the benefits and opportunities provided by industrial sapphire.

More Podcasts

THE MAGAZINE

Ceramic Industry Magazine

CI April 2014 cover

2014 April

Our April issue features details on advanced materials such as ceramic matrix composites and piezoelectric ceramics, among many others. Be sure to check it out!

Table Of Contents Subscribe

THE CERAMIC INDUSTRY STORE

M:\General Shared\__AEC Store Katie Z\AEC Store\Images\Ceramics Industry\handbook of advanced ceramics.gif
Handbook of Advanced Ceramics Machining

Ceramics, with their unique properties and diverse applications, hold the potential to revolutionize many industries, including automotive and semiconductors.

More Products

Clear Seas Research

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications,Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

Directories

CI Data Book July 2012

Ceramic Industry's Directories including Components, Equipment Digest, Services, Data Book & Buyers Guide, Materials Handbook and much more!

STAY CONNECTED

facebook_40px twitter_40px  youtube_40pxlinkedin_40