Research from the Stocks and Flows (STAF) Project

Yale University is an academic research institution and its work is almost exclusively published in appropriate academic journals. As such, there are limits on what can be reproduced here although the links provided go to the sites where typically an abstract is available at no cost. Unless otherwise indicated below, downloading of the full article requires the payment fee to the publisher.

The following is an overview of STAF literature on nickel as of 2010:

Anthropogenic Nickel Cycle: Insights into Use, Trade, and Recycling, B.K. Reck et al. (2008)

The Reck paper is the building block for all that followed. It was in this paper that, using 2000 as the base year, nickel flows on country, region and global levels were comprehensively mapped and initial mass balances produced. Attention to the front end of the process - production and first-use - allowed a more precise basis for quantifying end-uses and recycling. Of greatest interest was the indication that 57% of end-of-life nickel was recycled within the nickel and (especially) the stainless steel industries. Another 14% was lost into other recycling loops such as copper and (especially) carbon steel. Thus, after one product cycle, 71% of nickel in discarded products remains in productive use or as a constituent of other recycled metals.

An update of this paper, using 2005 as the base year, is expected to be published in 2011. A variant of the paper, comparing different historic cycles of nickel production and use, is expected in 2012 and for that paper there will be an additional base year: 2010.

The Contemporary Nickel Cycle, B. Reck (2006), is a slide deck that draws work from the academic paper eventually published in 2008 and is available for free download from the website of the International Nickel Study Group (INSG). It provides, in addition to information on nickel flows, a very brief introduction to the entire STAF methodology.

"Bottom up" Study of In-use Nickel Stocks in New Haven, CT, K. Rostkowski et al. (2007)

New Haven Connecticut is an academic, medical research and cultural center with associated employment in a post-heavy industrial environment. This STAF project considered all the types of products by end-use sector (buidling and infrastructure, household appliances and electronics, etc.) that would include nickel, calculated the average nickel content of those products, and considered the frequency of those products in a city of 126,000 with a certain social and economic profile. While the numbers are of interest (an average of 2.6 kg on nickel in use for every inhabitant), the insights into distribution are important. If more end-of-life nickel material is going to be collected and recycled, it helps to know where to look for it. The full study is available without cost.

The energy benefit of stainless steel recycling, J. Johnson et al. (2008)

The simplest and most efficient way to make stainless steels is by using scrap stainless steel. This free paper calculates just what that can mean in terms of energy savings using three scenarios for the production of austenitic (nickel-containing) stainless steel: current ("early 2000s" for the study), production assuming 100% of the input material is scrap, and production assuming 100% virgin (new) material. This provides - using current technology -  the theoretical upper and lower limits of energy use... and the potential for savings as the availability and use of recycled material increases:

  • The 100% scrap scenario compared to 100% virgin material case gives a 67% reduction in total energy demand and a 70% reduction in CO2
  • The current (early 2000s) use of scrap compared to 100% virgin material case shows a 33% reduction in total energy demand and a 32% reduction in CO

Facility-level energy and greenhouse gas life-cycle assessment of the global nickel industry, M.J. Eckelman (2010)

As stainless steel is the destination for most nickel it is understandable that it is there that most of the research is directed: it is where nickel becomes most relevant to the economy. Moreover, the competitiveness and acceptability of stainess steels is determined by the price and environmental burdens of its constituent... and nickel is the most prominent of these. The Eckelman paper is a facility-level life-cycle assessment of energy efficiency and greenhouse gas potential of the global nickel industry. Cradle-to-gate results (including extraction, production, and fabrication) are presented for selected nickel and nickel alloy products. It also investigated the energy and carbon implications of secondary material use using the same three scenarios as Johnson: current (early 2000s) production, theoretical maximum recycle input, and all virgin material. A high volume austenitic (nickel-containing) stainless steel and two common ferritic stainless steels (low or very low nickel content) were examined.

Global stainless steel cycle exemplifies China's rise to metal dominance, B.K. Reck et al. (2010)

The middle years of the first decade experienced an enormous rise in the price of nickel. That the growth of Chinese production of stainless steel was driving this rise in price is well known. This paper shows that between the year 2000 (the base year for earlier research by Reck) and 2005 the global production of stainless steel ("flow-into-use") rose by more than 30%. Most of this increase came from China which tripled its production during this five year period and, in doing so, passed such traditional stainless steel producers and users as Japan, USA, Germany and South Korea. At the same time -  and underlining the strong developmental nature of China's growth - there was no significant stainless steel scrap of Chinese origin. As the stock of stainless steel in use continues to increase in China the flow of scrap of Chinese origin is expected to grow significantly during the period 2015-2020.


Eckelman, M.J. 2010. Facility-level energy and greenhouse gas life-cycle assessment of the global nickel industry. Resources Conservation and Recycling 54(4): 256-266

Graedel, T.E. and J. Cao. 2010. Metal spectra as indicators of development. Proceedings of the National Academy of Sciences of the United States of America 107(49): 20905-20910.

Graedel, T.E., D. Van Beers, M. Bertram, K. Fuse, R.B. Gordon, A. Gritsinin, A. Kapur, R.J. Klee, R.J. Lifset, L. Memon, H. Rechberger, S. Spatari, and D. Vexler. 2004. Multilevel cycle of anthropogenic copper. Environmental Science & Technology 38(4): 1242-1252.

Johnson, J., B.K. Reck, T. Wang, and T.E. Graedel. 2008. The energy benefit of stainless steel recycling. Energy Policy 36(1): 181-192.

Reck, B.K., D.B. Müller, K. Rostkowski, and T.E. Graedel. 2008. Anthropogenic nickel cycle: Insights into use, trade, and recycling. Environmental Science & Technology 42(9): 3394-3400.

Reck, B.K., M. Chambon, S. Hshimoto, and T.E. Graedel. 2010. Global Stainless Steel Cycle Exemplifies China's Rise to Metal Dominance. Environmental Science & Technology 44(10): 3940-3946.

Rostkowski, K., J. Rauch, K. Drakonakis, B. Reck, R.B. Gordon, and T.E. Graedel. 2007. "Bottom-up" study of in-use nickel stocks in New Haven, CT. Resources Conservation and Recycling 50(1): 58-70.