The Indiana Clean Manufacturing Technology and Safe Materials Institute
2655 Yeager Road, Suite 103, West Lafayette, Indiana 47906-1337
JUPITER COIL COATING DIVISION
JUPITER ALUMINUM CORP.
POLLUTION PREVENTION PROJECT REPORT
Jupiter Coil Coating Division (Jupiter) initiated a project with the Indiana Clean Manufacturing Technology and Safe Materials Institute (CMTI) to identify methods to reduce or eliminate the need to replace their cleaning solution on a monthly basis. Jupiter also wanted to assure that their water effluent met their National Pollution Discharge Elimination System (NPDES) permit limits with the ultimate goal of zero water discharge. Eliminating the need to replace the cleaning solution on a monthly basis will save time and money as well as reduce the use of chemicals used in the process. Meeting the NPDES permit limits, or eliminating the effluent entirely, will eliminate the risk of violations and possible fines levied by The Indiana Department of Environmental Management or EPA.
Jupiter coats high quality, painted, aluminum coils for the appliance industry. The company is located in Fairland, Indiana, and employs approximately twenty people.
Jupiter coats aluminum coils. The coils of aluminum are shipped to the Fairland facility where they are placed on a coating process line. The coils continuously unwind as the aluminum is fed through the process. The first stage of the process is the cleaning stage. The aluminum is sprayed with a cleaning solution, with a spray rinse immediately following. After the spray rinse, the aluminum goes through a squeegee to remove excess water and is air-dried prior to being coated with a chromate conversion coating for corrosion protection. The chromate coating is also dried prior to the painting stage. After the aluminum exits the paint stage, it is oven-dried, cooled, and re-coiled. The finished product is then shipped off-site to Jupiter's respective customers.
The aluminum cleaning process removed (etched) small amounts of aluminum from the coil. The removed aluminum was transferred to a rinse tank and, subsequently, left the facility in its effluent. The aluminum remaining in the cleaning solution greatly reduced its cleaning capacity. In order to maintain proper cleaning efficiency, Jupiter had to dispose of the cleaning solution every month by shipping it off-site for treatment prior to disposal. Additionally, etched aluminum contaminated the chromate conversion bath through transfer, causing the bath to be discarded on a weekly basis.
Removing the etched aluminum from the cleaning solution would not only extend the life of the solution, but would also prevent the transfer of aluminum into the rinse tank and chromate conversion solution. Determining how to eliminate or minimize the aluminum was the challenge.
The CMTI/Jupiter team tackled the challenge by exploring options to remove the aluminum. Filtration was considered, but there was concern that the aluminum would be in solution and, therefore, could not be filtered out. The team decided to contact the Illinois Waste Management and Research Center (WMRC) to help answer this concern. WMRC has had considerable experience in filtration methods and has assisted CMTI with projects in the past. After receiving samples of the cleaning material contaminated with aluminum, WMRC confirmed that ultrafiltration (UF) would remove the aluminum. Jupiter set up a pilot project with a UF system on their cleaning solution, and found that it did, indeed, remove the aluminum and extended the cleaning solution bath life as well as the chromate conversion bath life. The Jupiter/CMTI team is currently working on a project to efficiently achieve zero discharge at the Fairland facility.
POTENTIAL ENVIRONMENTAL AND COST BENEFITS
By reducing the aluminum in the cleaning solution, Jupiter eliminated the need to dispose of the solution on a monthly basis. The UF of the cleaning solution also dramatically reduced the transfer of etched aluminum into the rinse tank and subsequent chromate conversion solution. The life of the chromate conversion solution has been extended from one week to six weeks, and through a UF and Reverse Osmosis (RO) units on the rinse tank, Jupiter currently discharges no water through their NPDES permit. Jupiter is compliant with their NPDES permit and has greatly reduced disposal of hazardous and special wastes.
Estimated hazardous waste
reduction (yearly): ... 11 tons
Estimated special waste
Reduction yearly ......... 55 tons
Estimated savings (yearly): . $47,000
Jupiter’s process of cleaning aluminum coils contaminated the cleaning and chromate conversion solutions with aluminum. The subsequent waste effluent generated from the process exposed the company to potentially exceeding NPDES permit limits. By installing the UF unit, Jupiter extended the life of the cleaning and chromate conversion solutions and met their NPDES limits by eliminating their discharge. Jupiter has reduced their chemical usage and hazardous waste production by removing the etched aluminum from their cleaning process solutions—thereby, accomplishing cost and waste reduction through pollution prevention.