Seminar concentrates on optimization of the cupola.

Cincinnati, OH, was the site of the second annual "Advances toward Control of the Cupola" conference held Sep 25-26. Organized by the American Coke and Coal Chemicals Institute (ACCCI) and the American Foundrymen's Society, this year's conference drew more than 200 attendees. The conference was chaired by Richard M. Frazier, Hickman Williams & Co, and William L. Powell, Waupaca Foundry, Inc. Among the topics was "Best Ways to improve Your Coke Ratio" by William Provis, Modern Equipment Co, in which he discussed the results from 45 respondents to an ACCCI questionnaire.

Respondents said the 1 0 best methods for improving coke ratios are: hotblast, coke size control, oxygen enriched blast, silicon carbide charge materials, high carbon charge materials, oxygen injection through tuyeres, charge material size control, removal of coke breeze, coke vendor selection and cupola operation scheduling.

Powell described the economic losses encountered in the mishandling of coke and how Waupaca Foundry maximized the return on its invested coke. This was accomplished by minimizing coke breeze generation through reduced handling, thereby minimizing labor and reducing overall maintenance.

"Too often good coke is broken, which creates nearly worthless breeze," Powell said. Implementation of a coke handling system can save a foundry hundreds of thousands of dollars per year. Even a partial implementation can provide significant savings. Powell urged foundries to observe their coke handling systems from unloading to charging-and estimate the annual dollar losses.

The environmental implications of cupola melting were addressed by Gary E. Mosher, AFS. "The increasing federal regulations, particularly in the area of air toxics, portend rough times for cupola operators in meeting compliance with air toxic provisions," he said.

Mosher also explained the new test procedures, waste treatment standards, clean air act amendments and reviewed the list of potential air toxics.

in keeping with the same subject, Dale A. Gilbert, Sloss industries Corp, and Mark T. Engle, ACCCI, gave a two-part presentation on the basics of coke making and an overview of the ramifications of the clean air act on coke production.

Frazier of Hickman, Williams & Co discussed the availability of foundry coke. "Despite the closing of several merchant plants that historically produced foundry coke, the productive capacity of the current foundry coke industry continues at almost twice the recent annual consumption," he stated. "Short of a total restructuring of the ferrous iron casting industry, the decade of the '90s should certainly have more than adequate supplies of quality foundry coke for the North American marketplace." The usage of slags in the manufacture of rock wool was discussed by William F. Porter, USG Corp. Since the mid-1940s the mineral wool industry in the U.S. has relied almost entirely on blast furnace slag. In slag wool manufacturing, slag is the primary component and other additives are used to make up for deficiencies in the raw material. The slag and additives can be melted in a cupola or electric or gas-heated furnace. The rock wool market has many diverse applications in addition to the ceiling tile industry. For example, it allows asphalt to remain more viscous. it is used as a plastic filler material; for clutches and brake aipplications-. as curtain wall insulation; fire protection for ceilings, walls and furniture; and in agriculture as a plant support and growth medium. Carl Curry, Detroit Coke Corp, presented a step-by-step quality control plan for foundry coke producers. The plan is an agreement on what characteristics are tested, how coke is tested and how often. In the 1970s only spec sheets were used and in the 80s production control plans were initiated.

The current plan details 1 1 areas of importance as a result of supplier/customer communication. "Better communication between the coke supplier and user is needed for a successful control plan to exist," Curry said.

Failure to have a control plan results in a customer ordering a load of foundry coke without full knowledge that it would work in his application.

An AFS/U.S. Dept of Energy research update on cupola modeling was presented by Daniel L. Twarog, AFS, covering the development of cupola furnace process models. The goals of the modeling program are to optimize process control and energy efficiency of the foundry cupola furnace.