Dr' Subodh K' Das

1
Dr. Subodh K. Das
President CEO Secat, Inc. Designing Aluminum
Alloys for a Recycling Friendly World Presented
ToAluminum Association Sheet and Plate
Division Spring Meeting Montreal, Canada April
24th, 2006
2
Outline of Presentation

• Recycling advantages and incentives
• Recycled aluminum is the new Urban Mine
• Secondary is the new Primary
• Opportunities to maximize recycling
• Aluminum alloy design for recycling
• Rationales
• Opportunities
• Recommendations
• Looking to the future

3
Number of Primary Smelting Plants in the U.S.
2003 Fourteen (14) Smelters Operating

• SMELTERS OPERATING - 2003
• 8 Alcoa
• 2 Century
• 1 Alcan
• 1 Norandal
• 1 Ormet
• 1 Columbia Falls

?
SOURCE LIGHT METAL AGE
4
U.S. Trends of Re-Melting vs. Smelting(000
Metric Tons)
SOURCE SECAT, INC.
5
Why Recycling?
1 change in recycling rate has an economic
impact of approximately 12 million
Trashed cans contribute about 600 million to the
nations trade deficit each year
National Aluminum Beverage Can Recycling Rate
Trends.
6
Impact of Recycled Automotive Aluminum

• Two largest areas are cans and autos
• Can recovery reached 67 in early 1990s now
  at 50 cultural, societal and technical issues
• Auto metal recovery gt90 aided by regulations,
  shredders and lack of individual choice.
• Recovery of Al from autos has exceeded all other
  scrap sources since 2005
• We have to learn to make as much new aluminum
  products as technically possible from recycled
  automotive aluminum in the US

7
Advantages of Aluminum Recycling

• Recycling aluminum provides metal for 5 of
  energy invested in new primary aluminum and only
  5 of CO2 produced
• Economic savings to municipalities supports
  creation of new or enlarged recycling facilities
• Domestic recycling reduces trade deficit and
  minimizes dependence on overseas metal sources
• The price of alloying elements such as Cu, Mn,
  Mg, etc are rising at equal or higher rate than
  Al

8
Characteristics of the Recycling Friendly World

• Ecology Recycling and Consumption
• Advanced Processing and Technology
• Recycling Friendly Alloy Systems
• High Value, Recycling Friendly Products
• Good Public Awareness of Recycling

9
Challenges in Achieving the Recycling Friendly
World

• Improve efficiency of metal recovery
• Increase effectiveness of shredding and sorting
  technology
• Identify useful byproducts available through use
  of secondary scrap
• Broaden range of alloys readily produced from
  recycled metal
• Retain domestic aluminum scrap in US and lower
  exports to China and India

10
Recycling Successes to Recognize

• Automotive Aluminum recovery and part pre-sorting
• Laser induced breakdown spectroscopy (LIBS) for
  finer sorting after shredding
• Alternative products such as de-ox, Fe-bearing
  aluminum for de-oxidizing steel

11
New Focus for Discussion Optimizing Alloy
Design for Recycling

• Focuses on properties rather than chemistry
• Requires careful consideration of challenges from
  higher impurity contents of recycled metal
• Requires testing and qualification of new
  compositions for important applications
• Revisits applicability and commercialization of
  the unialloy concept for packaging

12
Compositions of Recycled Aluminum (ref Gesing,
HVSC)
13
Difficulties Utilizing Recycled Al Scrap Directly

• Higher impurity levels
• Fe buildup from equipment
• Si levels from cast components
• Others levels exceed AA limits
• Special handling called for
• Segregate wrought and cast alloys when practical
• Target alloys for reusing recycled metal
• To optimize use of recycled metal, new alloy
  options would be desirable

14
Design New Wrought Aluminum Alloys For Use of
Recycled Metal

• Useful preliminary rationale
• Select compositions from each series
  representative of their strong points
• Adjust limits on impurities to higher levels,
  potentially acceptable for many applications
• Recognize implications of increased levels of
  impurities, and need to reset new limits based
  upon performance and not chemistry

15
Some Potential Candidates for Recycled Aluminum
Alloys
16
More In-Depth Evaluation of Recycling Friendly
Alloys Needed

• Gain more specific information on the volume and
  compositions of aluminum alloy recycled from
  specific markets
• Fine-tune candidate compositions of
  recycle-friendly alloys based upon findings
• Critically evaluate wrought products made from
  proposed recycle-friendly alloys

17
Critical Evaluation of Recycling Friendly Alloys

• Determine, among others
• Toughness
• Formability
• Corrosion resistance
• Relate results to design requirements of intended
  applications, e.g.,
• Building highway structures
• Industrial piping tanks
• Consumer durables
• Refine compositions as needed to obtain
  required performance

18
Conclusions

• Advantages of recycling aluminum justify
  maximization of potential
• Some successes to report in shredding, sorting,
  and alternative products
• Inadequate attention given to optimizing alloy
  design for a recycle-friendly environment
• Proposals put forth as to how such alloy design
  optimization might be approached
• Evaluation testing to match performance
  requirements proposed

19
The Next Steps?

• Establish recycling alloy optimization leadership
  team
• Generate financial support
• Phase 1 Analyze volumetric recycling content by
  market
• Phase 2 Optimize new alloy compositions for use
  of recycled metal
• Phase 3 Evaluate properties and performance
  of new alloys, and adjust chemistry accordingly
• Results will be published in Light Metals 2006
  and presented at the annual TMS meeting in San
  Antonio in 2006
• Future research will be published in Light Metal
  Age (June 2006), International Aluminum Alloys
  Conference (July 2006) and Journal of Metals
  (August 2006)