A laboratory-scale galvanic deoxidation technology developed by earlier workers has been improved, with the aim of developing a prototype pilot-scale deoxidation unit. Each deoxidation cell consists of a one end-closed yttria-stabilized zirconia (YSZ) tube coated with a Ni-YSZ cermet anode on the inner walls. The YSZ tube is immersed, with its closed end in the metallic melt, and an oxygenchemical-potential gradient across the tube is established by passing a reducing gas through the tube. The melt is then deoxidized by short circuiting it with the anode. Through laboratory experimentation, the nature of the anode/electrolyte interface adhesion was identified to be an important factor in obtaining enhanced deoxidation kinetics. The kinetics of oxygen removal from the melt was increased by an order of magnitude with an improved anode/electrolyte interface. A pilot-scale refining unit consisting of 53 cells with the improved anode/electrolyte interface was manufactured, and a field evaluation of the galvanic deoxidation of copper was conducted. The deoxidation-process model was modified to include multiple deoxidation cells, which were required for the pilot-scale trials, and to analyze the effect of electrolyte/electrode adhesion on deoxidation kinetics. Preliminary studies on process component lifetimes were conducted by investigating the thermal cycling, corrosion behavior of the electrolyte, and stability of the cermet anode structure. Based on the results of the field trial and the analyses of the process component lifetime, future work needed toward commercializing the technology is discussed.

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DISCLAIMERThis report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof. nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any infomution, appamtus, product, or p m s s disclosed or represents that its use would not infringe privately owned rights. Reference Program OverviewThe production of high quality, cost competitive silicon and ferrosilicon alloys is vital to maintain a strong domestic siliconlferrosilicon industry. The methods of production currently used in the U.S. are too cost inferior in many cases to compete globally. The primary focus of this program was to prove the hypothesis that there are many advantages in using direct current (DC) power over alternating current (AC). The DC, submerged arc, open top, single electrode design should increase efficiency and result in significant specific energy savings. SCRA assembled a research consortium, known as the Silicon Technology CompetitiveCooperative (STCC), to advance the technology base of the U.S. Silicon and Ferrosilicon industry.A cost shared, cooperative research program was scooped and budgeted with funding via the U.S. Department of Energy (DOE), Industrial Waste Program (IWP). The program goal was to demonstrate energy savings, improve metal recovery, and reduce process emissions.An existing plasma arc 1.5 M W test facility, located in Charleston, S.C., was extensively modified and used for testing purposes. The program received strong support from the DOE, SKW Alloys, and the research consortium. The program began in March 1993 and concluded with the submission of this final report in February 1995. A draft report was submitted to DOE for review in September 1994, and comments were received back in December. The actual testing period ran from May 2, 1994 through August 6, 1994. Test FacilityThe test facility was originally constructed in 1990 for smelting studies as a result of the requirement to make the U.S. more competitive in the world ferrochromium market. These studies were conducted under a Department of Defense (DoD) Grant to SCRA and administered by the Defense Logistics Agency (DLA). This furnace was also previously used for taconite tailings testing to support a program with Dow Corning and DOE, with the cooperation of DLA. The furnace was originally constructed as a containment vessel of steel, refractory lined, with a closed roof. The furnace was modified extensively to carry out the objectives of the STCC program, which included removing the closed roof and replacing it w i t h a refractory-lined hood with sliding doors to permit stoking operations. The furnace sides were raised by 18 inches and relined with sidewall refractories. Two insulated ducts were added to the hood to remove the off gases and steel platforms were added to facilitate stoking. The furnace was relined once during the program when mak...

Corrugated stainless steel tubing (CSST) has become a common product installed in new and retrofitted older homes. The ease of installation due to its flexibility and the need for fewer joints significantly lowers labor costs. Despite the advantages of lower cost and ease of installation, however, the thin wall of CSST presents an increased risk of perforation by both mechanical puncturing and electrical arcing from either household current or lightning strikes. In the course of forensic investigations of household fires, perforated tubing is occasionally identified as a potential cause. The metallurgical features of the perforated area are capable of distinguishing the cause of the hole as being from either lightning current or household current.