ALUMINUM ALUMINUM ALUMINUM ALUMINUM ALUMINUM 
Project Fact Sheet 
DETECTION AND REMOVAL OF MOLTEN SALTS 
BENEFITS 
year 
FROM MOLTEN ALUMINUM ALLOYS 
• improved metal casting quality, recovery, 
and reliability 
• elimination of melt rejection and recast 
due to salt contamination, with a potential 
annual energy savings of 40 billion 
British thermal units (Btu) 
• estimated reduction in chlorine use and 
release of about 71,000 cubic feet per 
APPLICATIONS 
The implementation of this technology will 
improve the metal quality of the aluminum 
casting industry through the detection and 
removal of impurities and inclusions from 
molten aluminum. 
NEW PROBE AND FILTER WILL IMPROVE METAL QUALITY 
THROUGH DETECTION AND REMOVAL OF IMPURITIES 
Commercialization has begun on a new probe and filter technology to detect and 
reduce chloride salts in molten aluminum. These salts have been shown to 
initiate defects when they agglomerate and migrate to the surface of an ingot or a 
casting. The salts are liquid at aluminum casting temperatures and pass through 
conventional filter systems that are designed to capture solid inclusions. 
Moreover, the salts tend to reduce the efficiency of conventional filters by causing 
the release of solid inclusions. 
Project partners have developed a simple electrical probe that detects the 
presence of salts in molten aluminum. This probe is used with a filter that 
selectively removes liquid salts from liquid metal. Together, the probe and filter 
ensure better quality casting. The efficiency and capacity of the probe and filter 
have been demonstrated under commercial casting conditions. Demonstration 
trials are continuing at commercial plant sites. In addition, Selee Corporation is 
developing a more robust and portable version of the data acquisition system for 
the salt probes and has manufactured additional probes. 
This project addressed research needs identified in the Aluminum Industry 
Technology Roadmap. These needs include improved metal quality, increased 
reliability of manufacturer operations up to 95 percent, and real-time measurement 
of molten metal composition. 
SALT PROBE 
Microporous coated electrical probe. 
Conductive Silicon Carbide Rod 
Microporous Coating 
OFFICE OF INDUSTRIAL TECHNOLOGIES 
ENERGY EFFICIENCY AND RENEWABLE ENERGY • U.S. DEPARTMENT OF ENERGY
Project Description 
Goals: The goal of this project was to develop a new probe and filter technology 
for detecting and removing molten salts from aluminum alloys. This goal has 
been met. Project partners recently began commercializing the filter and sensor 
probe technology. 
Progress and Milestones 
Completed Tasks 
• Completed the first and second set of experimental trials of the filter and 
sensor probe at the Alcoa Technical Center by the Summer of 1999. 
• Exposed the sensor probe and the filter to various levels of chlorine and metal 
flow rates using commercial alloys at Alcoa Technical Center's experimental 
casting facility. 
• Analyzed melt inclusions using a Liquid Metal Cleanliness Analyzer (referred 
to as the LiMCA II). 
• Characterized the melt using a vacuum filtration technique to provide metal 
cleanliness data. 
• Collected and analyzed samples of the melt to provide an independent 
determination of the chlorine level. This way, the response of the probe was 
correlated with chlorine levels over a wide range of conditions. 
• Assessed the efficiency of the salt filter. By monitoring the efficiency of the 
filter as a function of chlorine and time in casting, the adsorptive capacity of 
filter media was determined. 
• Developed a more robust version of the data acquisition system for the salt 
probes. 
• Manufactured additional salt probes. 
On-Going Tasks 
• Conducting demonstration testing of the salt probes and filter media at 
commercial sites. 
• Fabricating extra portable data units. Engineers will carry these extra portable 
units with them whenever they travel to an aluminum cast shop. The units will 
become part of the engineers' routine trouble shooting gear. 
Commercialization Plan 
Selee Corporation has a clear and direct interest in implementing the technologies 
developed in this project. Demonstration trials of the probes and filters are being 
conducted at commercial plant sites. Full commercial implementation by the 
domestic aluminum industry will soon follow. 
PROJECT PARTNERS 
Selee Corporation 
Hendersonville, NC 
Alcoa Technical Center 
Alcoa Center, PA 
FOR ADDITIONAL INFORMATION, 
PLEASE CONTACT: 
Project Information 
Kenneth Butcher 
Selee Corporation 
Phone: (828) 693-0256 ext. 359 
Fax: (828) 697-7960 
kbutcher@selee.com 
Aluminum Program 
Office of Industrial Technologies 
Clearinghouse 
Phone: (800) 862-2086 
clearinghouse@ee.doe.gov 
http://www.oit.doe.gov/clearinghouse/ 
Please send any comments, 
questions, or suggestions to 
webmaster.oit@ee.doe.gov. 
Visit our home page at 
www.oit.doe.gov 
Office of Industrial Technologies 
Energy Efficiency 
and Renewable Energy 
U.S. Department of Energy 
Washington, D.C. 20585 
November 2000