Dr Gavin M Mudd Environmental Engineering

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Dr Gavin M MuddEnvironmental Engineering

• Sustainability Metrics of Gold Mining
• February 2007

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Gold
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Gold Mining v Sustainability ?

• Define oxymoron sustainable gold mining
• Gold mining has been a critical aspect of
  economic and social development in many countries
• Gold mining has also left a legacy of impacts
  social, environmental, etc
• The application of sustainability principles to
  gold mining is, at first, counter-intuitive
• This paper attempts to compile such data !

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Gold Mining Sustainability Metrics

• Data Sources and Methodology
• Analysis of Sustainability Metrics
• Results Global Gold Production
• Results Energy, Water and Cyanide Consumption
• Results Greenhouse Emissions
• Discussion Deficiencies, Future Work
• Summary

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Analysis of Sustainability Metrics

• Some key issues for sustainability include
  energy, water and cyanide consumption and
  greenhouse emissions
• The eco-efficiency of various gold mines is
  compared using the unit consumption (/emission)
  per gold produced relative to ore grade and ore
  throughput
• kL water / kg Au t CO2 / kg Au GJ energy / kg
  Au
• kL water / t ore t CO2 / t ore GJ energy / t
  ore
• t cyanide / kg Au

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Global Historical Gold Production
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Global Historical Gold Ore Grades
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Unit Water Consumption v Grade
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Unit Water Consumption v Ore
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Unit Energy Consumption v Grade
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Unit Energy Consumption v Ore
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Unit Cyanide Consumption v Grade
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Unit Greenhouse Emissions v Grade
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Unit Greenhouse Emissions v Ore
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Discussions Debates ..

• Gold mining has occurred throughout the world,
  with main factors including
• new discoveries, prices, technology, social,
• The most recent gold boom (gt1980) has seen
  unprecedented global gold mining
• Fundamental trends for gold mining
• declining ore grades, open cuts, technology,
• Sustainability metrics, unit consumption/
  emissions, are highly grade dependent

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Sustainability Costs of Gold

• In general, based on data within this paper, the
  production of gold entails

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Summary Conclusions

• Gold Mining continues around the world
• Gold ore grades are in terminal decline
• Sustainability metrics are clearly linked and
  very sensitive to ore grade
• Due to the low grade, gold production entails
  significant unit costs for water, energy,
  cyanide, greenhouse emissions
• Future sustainability is difficult to predict