LIFE CYCLE ASSESSMENT
Executive Summary
This Executive Summary was prepared by the Nickel Institute and does not constitute part of the peer-reviewed Life Cycle Assessment of Nickel Products (LCA) authored by Ecobalance Inc. It is based on the original report prepared by Ecobalance Inc and has not been updated. For a current overview of the nickel LCA, this summary should be read with the Guide to the Nickel Institute LCA pages.
The Life Cycle Assessment of Nickel Products (LCA) provides the only complete and recent measures of environmental inputs and outputs associated with the cradle-to-gate production of one kilo of nickel in metallic nickel, nickel oxide and ferro-nickel.
The nine companies that participated in the LCA produce approximately 55% of the world's nickel from primary sources and the three products covered by the LCA constitute approximately 98% of their collective nickel production.
There are many values provided in the tables attached to the report for the two parts of the LCA: the life cycle inventory (LCI) and the life cycle impact assessments (LCIA). The LCI is the most rigorous part of the LCA and the greater part of this Executive Summary deals with the LCI.
The LCIA is more subjective and the participating companies and Nickel Institute do not always agree with the methodologies used to generate the LCIA values. The weaknesses of some LCIA methodologies are well understood in the LCA community. Nonetheless, they represent the best that is currently available and most of the LCIA categories are included in the LCA for purposes of completeness and transparency.
In printed form the LCA is 144 pages: 108 pages of text and 36 pages of data.
The Results
The inputs required and the outputs resulting (products plus emissions including wastes) are recorded by the LCI. Little meaning can or should be assigned in isolation to these inventory numbers. Firstly, the numbers are for a kilo of 'constructed' nickel -- averages derived from numbers gathered from different process routes, ore types and energy grids. Secondly, and more importantly, the size of a number may not be indicative of the potential environmental importance of the number.
Using examples for 1 kilo of nickel in metallic (99.3%) nickel -
| Total lead: | 0.037 grams |
| Sulphur dioxide: | 959 grams |
| Carbon dioxide emissions: | 15.4 kilos |
| Primary energy consumption: | 160 mega joules |
| Water use: | 1903 liters |
one cannot conclude that the CO2 emissions are more significant than the lead emissions. That requires a larger picture which a full LCA (i.e., cradle-to-grave as opposed to this cradle-to-gate LCA) for a kilo of nickel could attempt. The full LCA would, inter alia, consider the consequences -- positive and negative -- associated with the use of that kilo of nickel, and what happened to that kilo at the end of its service life compared to alternative materials.
That is beyond the scope of this LCA but without these data, any further investigations would not be possible, or worse, would be based on questionable assumptions and inappropriate data.
The Process
The LCA, including the contractor selection and contract negotiation, took two years.
The Steering Group, composed of representatives of the participating companies and Nickel Institute, agreed from the start that the objective was a fully ISO compliant, peer-reviewed study. This was achieved.
As required, the Steering Group met with the Contractor, and the Contractor met three times with the Critical Review Panel (the peer review mechanism).
The Decisions
An LCA is possible only because certain limits are imposed. The limitations for this LCA are:
Boundaries: The LCA covers four major cradle-to-gate unit process stages:
- underground and surface mining
- ore preparation and/or beneficiation
- primary extraction to matte, ferro-nickel and nickel oxide
- refining to final nickel products
No nickel chemicals (e.g., nickel chloride, nickel sulphate) are included; no further processed specialty products such as nickel wire or nickel foam are included.
Cutoff: The LCA had as its goal the accounting for 99.5% of the mass of the inputs through all four unit processes. This was achieved.
Product packaging: The packaging of final nickel products is not included. The sensitivity analysis confirmed this decision.
Capital equipment: Capital equipment is not included. This was at the recommendation of the Contractor who provided citations showing that capital investments such as found in the nickel industry have a negligible impact over the life cycle of the total volume of nickel produced by that equipment.
Human activities: Calculating the impact of human activities (travel to and from work; production, packaging, transportation, preparation of the food eaten by workers; etc.) adds enormously to the complexity of a LCA and for no benefit.
Inventory data categories: Of the literally thousands of possible inputs and emissions, some will be particularly relevant to environmental impacts and only some will be expected to be associated with the production of primary nickel products. The nickel products LCA includes 13 ìelementalî inputs (nickel, oil, coal, water, etc.); 27 emissions to air (CO2, NOx, CH4, etc.); 28 emissions to water (metals, Biological Oxygen Demand, acids, etc.), and 3 solids (waste rock and backfill, tailings and process residues, other solid materials).
Allocation
Allocation is a vital aspect of LCA: decisions on allocations directly affect outcomes. Two basic allocation decisions were made for this LCA:
- Allocations are made on a mass basis, not on the economic value of the co- products. This was dictated by
the nature of the process paths, and was tested in the sensitivity analysis.
- Allocations were made by partitioning, not substitution. The distinctions between these choices and their importance are complex and subject to debate within the LCA community. This is explained further in the body of the LCA.
In general, the Steering Group directed the Contractor to make the most conservative allocation decisions, that is, decisions that would tend to keep environmental burdens on the nickel production rather than shift those burdens to co-products or by-products.
Modeling
Over the century of nickel production, different companies have exploited different ore types using different metallurgical routes. This means that there is a very significant range of processes that had to be accurately modeled so that all relevant inputs and outputs would be captured. There were also associated allocation decisions because co- products and by-products were different. What might be a pollution abatement process at one location (a plant that fixed sulphur from off-gases into sulphuric acid) could be an economic activity in another where the production of sulphur was maximized to allow the production of ammonium sulphate for fertilizer.
This was a difficult task and required much attention on the part of the Contractor and the Steering Group.
Data Quality Evaluation
Next to the modeling of the different process routes, the greatest challenge for the Contractor was the checking of the data quality. In this, the LCA shows both strengths and weaknesses. The LCA provides a good representation of more than half of the world's production of nickel products.
Within that, however, different companies with different plants in different parts of the world with different regulatory regimes do not record the same kind of data to the same degree of reliability. This required a great deal of consultation and verification by the Contractor, as described in the LCA. These variations in data collection will be a persistent challenge for the nickel industry.
