Sustainability

LIFE CYCLE ASSESSMENT: LCA Data

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(Last updated on 10 December, 2003)

Table R1a Overall Inventories and Potential Impacts: Ferronickel, Nickel Oxide, and Class I Nickel
NOTE: Baseline date for metallic nickel and oxidic nickel were revised on 6 May, 2003, and data on ferro-nickel removed on the same date. Revised baseline data for ferro-nickel was added on 31 October, 2003. See Guide to Nickel LCA for details.
Table R1b Overall Inventories and Potential Impacts: Ferronickel, Nickel Oxide, and Class I Nickel
NOTE: Baseline date for metallic nickel and oxidic nickel were revised on 6 May, 2003, and data on ferro-nickel removed on the same date. Revised baseline data for ferro-nickel was added on 31 October, 2003. See Guide to Nickel LCA for details.
Table R2 Class 1 Nickel Metal: Breakdown by Unit Process Stage
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R3 Class 1 Nickel Metal: Refining Gate-to-Gate Breakdown
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R4 Refining Transportation Breakdown
NOTE: No changes. Restated baseline values did not affect this table.
Table R5 Class 1 Nickel Metal: Primary Extraction Gate-to-Gate Breakdown
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R6 Nickel Oxide: Breakdown by Unit Process Stage
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R7 Nickel Oxide: Primary Extraction Gate-to-Gate Breakdown
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R8 Ferronickel: Breakdown by Unit Process Stage
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R9 Ferronickel: Primary Extraction Gate-to-Gate Breakdown
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R10 Beneficiation: Gate-to-Gate Breakdown
NOTE: Revised 5 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table R11 Surface and Underground Mining
NOTE: No changes. Restated baseline values did not affect this Table.
Table S1 Sensitivity: Class 1 Nickel Metal with and without Packaging
NOTE: No changes. Restated baseline values did not affect this Table.
Table S2 Sensitivity: Ferronickel with and without Packaging
NOTE: Revised 14 November, 2003, to reflect restated baseline values. See Guide to Nickel LCA for details.
Table S3 Sensitivity: Ammonium Sulfate Allocation Decisions
NOTE: No changes. Restated baseline values did not affect this Table.

Inventory Tables
Revised November 2003

Note: Many Tables have been revised because of adjustments made to baseline values in April and October 2003. For more background on these changes, go to "Baseline Revision: 2003".

Tables R1a and R1b present the overall product inventories for 1 kg nickel in each product, and per kg of product, respectively. The subsequent results discussions will focus on the results on a per kg of nickel basis. The overall inventory tables are more meaningful when broken into the main process stages, so the discussions on each nickel product are contained in sections below which highlight the process stages.

LCIA Results Presented with the Inventory Tables

Overall

The following potential impact assessments were performed:

Acidification potential
Eutrophication potential
Global warming potential
Photochemical ozone creation potential
Natural resource depletion potential
Land Alienation

(Table 2 on page 28 of the Final Report of November 2000) provides a summary of why the remaining categories [such as resource depletion] were not retained):

The methodology descriptions for these start on page 16. The Appendix section contains all weighting factors that were applied to each data category contained in the impact assessment, as well as a sample calculation.

The results of the impact assessments are found with the overall cradle-to-gate inventories (Table R1a and R1b) and for each nickel product's unit process breakdown tables (Tables R2, R5, and R7) which identify the contribution of the impact potential to each product's main unit process stage. Additionally, figures R15 through R18 present charts that contain the contribution of each impact category's flows.

The LCIA results, like the inventory results, are part of a baseline study. As such, since no comparisons or applications to nickel have been made, the LCIA results are relative values and can not be formally interpreted (except to assess the methodology and limitations).

Discussion on use of the LCIA results

Individual flows in an impact category can be put into perspective. Figures R15 through R18 provide in stacked charts the contribution of each impact category's flows. Taking Global Warming Potential (GWP) as an example (Figure R17), carbon dioxide is the main contributing flow for all three products. Therefore, if it is the nickel industry's goal to decrease its greenhouse gas release, it could focus its efforts on energy consumption, as CO₂ is for the most part a combustion-related emission. Whereas in another industry, N₂O could be the main contributor to the GWP, indicating to that industry that decreasing energy is not the solution, but instead trying to identify the contributor of the N₂O in the process.

Land Alienation

Page 27 describes the land alienation impact assessment, and the results for land alienation for surface mining and underground mining are found in the table below.

Table 16 Land Alienation Impact Assessment Results

	Surface Mining	Underground Mining
Land Actively Disturbed - Rehabilitated m2 Nickel in the Ore kg	0.0018	0.00076

It should be reminded that this calculation is based numbers from many facilities (with site-to-site variations and different rates of rehabilitation). Also, this represents a 1-year snapshot, whereas total cumulation numbers, which were not collected, might have provided a better picture.

Class 1 Nickel Metal

Table R2 presents the percent breakdown of each unit process stage of Class 1 nickel metal: mining, beneficiation, primary extraction, and refining. The first column contains the actual flow quantity in the appropriate units. The subsequent columns present the percent contribution of the unit process stages, with each row adding to 100%. The next few paragraphs discuss selected flows from the nickel metal production inventory. For the most part (including the LCIA results), the primary extraction and refining stages contribute most of the environmental inputs and outputs.

Figures R1 through R5 present total primary energy, CO₂, SO_x, NO_x, and (w) nitrogenous matter for each main unit process stage in Class 1 nickel metal. Primary extraction is the highest contributor for most of the flows, with refining second, for all of the flows except nitrogenous matter, from beneficiation. Mining emissions are negligible.

Figure R6 presents the three solid material categories in stacked graphs. It should be no surprise that the main source of "waste rock and backfill" comes from mining, and the "tailings and other process residue" comes from beneficiation. The primary extraction stage contains waste rock and backfill, which is not very intuitive, but it is because the primary extraction stage consumes other nickel-bearing inputs (which upstream processes contain waste rock and backfill (see Figure 42). Note: This is one aspect of the 2000 LCI that was very affected by the October 2003 baseline revisions.

There is a notably high water well water amount used, but this number was ascertained with the site (and no management methods [such as evaporation ponds] were claimed to be used).

Gate-to-gate detailed breakdown results

Table R3 presents the first of several gate-to-gate detailed breakdown tables. The gate-to-gate detailed breakdown tables and charts contain the following information for each flow:

Plant. This represents actual releases from the plant, which may include effluents from the plant and fugitive emissions. Note that the fuel combustion taking place at the plant (i.e., in a natural gas boiler) is accounted for in the energy consumption category (described below);
Electricity Consumption. This represents the electricity consumed at the plant. The inflows and outflows therefore represent production and combustion of the electricity grid components, all happening "upstream" from the facility;
Energy Consumption. This represents fuels consumed at the plant for energy. This category contains inputs and outputs of the production of those fuels plus their combustion emissions at the plant;
Upstream Materials. This represents the materials and consumables used at the plant. These materials have come to the plant from "upstream", and their production inputs and outputs are contained in this column; and
Transport. This represents the energy to transport all upstream materials and molybdenum-bearing materials to the plant. Inflows and outflows in this column are associated with all transportation distances and modes.

Figure 43 portrays what data are contained in the gate-to-gate breakdowns. Since these data represent only a "slice" of the inventory, flows specific to upstream or downstream processes will not be seen (e.g., nickel (ore) is only contained in the gate-to-gate breakdown of mining, as it is first produced there and not further downstream).

Figure 43 Gate-to-Gate Breakdown Concept

Table R3 demonstrates that most of the impacts from refining come from the plant itself and from electricity consumption.

Figures R7 through R10 break down the refining component of Figures R1 through R5 in order to understand the sources of some of its flows.

Figure R7 presents Total Primary Energy sources shared by electricity, energy, transportation, and to a lesser extent upstream materials. The actual plant release of SO_x and nitrogenous matter (Figures R8 and R10, respectively) overwhelm the other components. Transportation of upstream materials to refining sites seems to be a relatively important contributor to refining, evidenced most notably by NO_x (Figure R9), and also total primary energy. Most of this transportation is due to rail transport, as shown in Table R4. The modeling for sea, rail, and truck transportation is found in the Appendix section (page 97).

Table R5 demonstrates that most of the impacts from primary extraction come from upstream materials production. Figures R11 through R14 break down the primary extraction unit process stage in order to understand the sources of some of its flows. For all flows found in these figures (and also seen in the corresponding Table R5), the upstream materials production (which includes production of the upstream nickel flows) is the main contributing component.

Nickel Oxide

Table R6 presents the breakdown of the contribution of each unit process stage to produce nickel oxide. Most of the inflows, outflows, and impacts are due to the primary extraction unit process stage, and the gate-to-gate breakdown (Table R7) shows a broad distribution amongst the various components of nickel oxide primary extraction, including transportation: 13% of the fuel oil consumed and up to 36% of some of the combustion-related emissions (i.e., N₂O, NO_x...) come from transportation.

Ferronickel

Table R8 presents the breakdown of the contribution of each unit process stage to produce ferronickel. The main contribution for the most part is primary extraction to produce ferronickel, with some exceptions: the air emissions zinc, mercury, silver, and ammonia are the main contributors due to mining. This could, however, be due to lack of these air emissions reported in ferronickel primary extraction operations.

Table R9 presents a broad distribution amongst the various gate-to-gate components of the primary extraction of ferronickel.

Note: The 2003 revisions to baseline values had very significant impacts of ferronickel values, especially in energy use and greenhouse gas emissions.

Additional Results

The following tables are also provided for further analysis of some of the upstream stages:

The detailed breakdown of beneficiation per 1 kg of concentrate produced (Table R10);
The surface mining vs. underground mining unit process stages per 1 kg ore produced (Table R11).

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