Carbon Dioxide (CO2) Emissions Model for World Base Metals and Iron Ore Mines

These reports are no longer available because the data is now three years out of date and because progress on international carbon taxation and emissions trading schemes has stalled.

But the carbon emissions models which produced all the data and tables in the reports remains current and are available for download. The copper model covers 133 copper mines owned by 56 companies in 22 countries producing some 80% of western world copper in 2010. Similar carbon emissions models are available for zinc (74 mines operated by 37 companies in 18 countries), lead (57 mines operated by 32 companies in 13 countries)and nickel (62 mines operated by 35 companies in 18 countries). The nickel carbon models also contain data for downstream metallurgical processing. Earlier editions of the models generated the data published in recent SME Annual Meeting technical papers, one of which was reprinted in the April 2009 issue of Mining Engineering.

A similar model is also available for iron ore. The iron ore emissions model covers 66 iron ore mines operated by 30 companies and producer groups in 11 countries producing upwards of 90% of western world iron ore in 2010. Virtually all iron ore production in Australia, Brazil, Canada, Sweden, the USA and South Africa is included.

The carbon emissions models run in standard Microsoft Excel and is based on minecost's detailed engineering-based spreadsheet models of world mining operations. All minecost models are peer-reviewed by analysts and through strategic alliances with CHR Metals, Bloomsbury Mineral Economics, GFMS and Metalytics.

The minecost carbon emissions model collates all fuel, power and explosives consumption at each minesite using minecost's road-tested engineering based models of each mining operation and the identified source of electricity. This information is used to estimate onsite carbon dioxide emissions using known energy and emissions factors for all fuels and electricity generation sources.

Operating results for each minesite are based on minecost's mine models which are audited by comparing estimated results with reported costs and consumables, consistent with published sustainability statements and company publications. For mines with onsite smelter complexes we add in smelting and refining energy and emissions, but selectable by the user. These complexes are for Bingham Canyon, Chuquicamata, El Teniente, Salvador, Flin Flon, Kidd Creek, Mufulira, Mt Isa, Vale Inco, Xstrata Sudbury, Olympic Dam and Ray/Hayden. The zinc and lead carbon emissions models are much the same, however the nickel carbon models also include metallurgical processing at all smelters and refineries treating all nickel mine products. For iron ore we include the pellet plants supplied by the iron ore mines.

The Carbon Emissions Models for Copper, Zinc, Lead and Nickel and a similar Carbon Emissions Model for Iron Ore are now available for download. The models are based on actual 2009 and estimated 2010 production data and the latest available electricity generation information. The models tabulate fuel and power consumption and carbon emissions data are shown in the form of emissions curves that rank mines by their site direct and indirect carbon emissions, consistent with each producer's sustainability reporting requirements and GRI. This allows each producer to be meaningfully compared with its competitors.

The models generate data tables and charts ranked on energy, carbon dioxide and cash costs showing the results for each mine, for each producer company and for each country (there are no country tables in the iron ore model, but can be added if needed). All model calculations and input assumptions are available for inspection - there are no black boxes in minecost models. All tables can be re-sorted on any variable and all charts dynamically re-draw themselves according to the assumptions and rankings chosen by the user.

All major energy and carbon input variables are editable by the user. Users can change the power generation mix for each mine and the energy and carbon content for all fuels, and whether or not to include offsite transport and associated smelters, or pellet plants for iron ore. Users may also input a country-specific carbon tax to see the impact on cash operating costs. The model gives users extensive control over how the charts are displayed - you can display some or all mines, companies and countries with or without credits and/or a carbon tax. All charts and tables automatically re-calculate and display according to user-selected input assumptions.

The emissions models resembles the minecost dynamic cost curves models and the minecost mine models with multiple sheets containing tables and charts which re-calculate after changes to the Edit sheet. In this screenshot you can see the beginning of the copper model Edit sheet with each mines's power generation matrices and the row of tabs containing the data tables and charts along the bottom of the screen. In all, the emissions models for copper, zinc, lead and nickel have thirty tabbed sheets containing data tables and charts. The emissions model for iron ore has twenty-two tabbed sheets with data and tables.

The copper, zinc, lead and nickel models generates tables and matching charts for:

• Energy inputs - diesel, electricity and electricity supplier generation matrix for each mine, company and country;
• Total carbon dioxide emissions for diesel and electric power by mine, company and country;
• Carbon emissions per unit ore milled for diesel and electric power by mine, company and country;
• Carbon emissions per unit metal for diesel and electric power by mine, company and country (where for multi-product mines emissions are allocated by metal weights);
• Carbon emissions per unit metal for diesel and electric power by mine, company and country (where for multi-product mines emissions are allocated by metal values);
• Energy consumption in gigajoules per unit metal by major departments mine, onsite smelter and offsite transport for mines, companies and countries;
• Carbon emissions by major departments mine, onsite smelter and offsite transport for mines, companies and countries;
• Cash Costs and carbon taxes for mines, companies and countries presented by process (mine, mill, TC/RC and shipping, royalties, less credits plus carbon taxes) and by inputs (labor, energy, reagents, other onsite, offsite costs, less credits plus carbon taxes). The corresponding charts may be set to display cash costs by process or by inputs, with or without credits and carbon taxes.

This chart shows a carbon dioxide emissions curve for the major copper mining companies. Both direct and indirect emissions are shown for all site activities plus offsite transport. In this chart Codelco smelter emissions are included as they are effectively part of site activities in each Codelco division, plus for BHP Billiton we include the Olympic Dam smelter.

Model users have the option of excluding co-located smelters so that all mines can be compared on the same basis, as below, where Codelco unit emissions are now below Freeport.

For the same producers we now show the impact of a $100/ton carbon tax on cash operating costs. The uncolored stacked bars show mining, milling and TC/RC and shipment costs - royalties are not normally included in C1 cash costs.

Underpinning the carbon emissions curves and carbon tax estimates are modelled energy consumption estimates for each mine. Here we show energy in kWh equivalents per ton of ore milled, however the model also generates charts showing energy consumption in gigajoules per unit copper.

Here we show total carbon dioxide emissions from copper mining for some of the big producers. Clearly Codelco is the biggest emitter with close to 6 million tonnes in 2009

And here we show the impact of a $100 carbon tax on the major mines before byproduct credits. Chuqui includes the onsite smelter, while some of the other big concentrate producers such as Escondida are carrying the carbon cost of shipping concentrate to Asian markets.

And for completeness we show the same information, but this time after byproduct credits. In this chart the byproduct credits are shown "below the line" with the same stacked bars for labor, fuel and power, plus other plus carbon taxes. This way of showing credits is very useful because the contribution of byproduct credits to overall cash cost is immediately apparent. For clarity we have coloured each cost component.

The Carbon Emissions Model for Iron Ore has very similar tables and charts.

This chart shows a carbon dioxide emissions curve for the major iron ore producers. Both direct and indirect emissons are shown for all site activities plus offsite transport to the pellet plant or port, and pelletizing where relevant. In this chart the biggest emitter with over 3 million tons of carbon dioxide is Cleveland Cliffs because all product is pelletized. Second is Kumba with the Sishen mine which uses coal-fired power, and then the Australian majors and the three main Vale systems. But considered as one producer, Vale would be the biggest emitter, with virtually all emissions coming from diesel at the mines and natural gas at the pellet plants - practically all Vale electricity comes from hydro power.

And here we show the impact of a $100 carbon tax on the major iron ore mines, including pelletizing. The stacked bars are for activities and the carbon cost is shown in the top bar. Among the majors, the Sishen mine would carry the highest carbon tax because of the indirect emissions from coal fired power, compared with the Pilbara mines with gas fired power plants and Vale's hydro plants.