Development of gold deposits by underground method is the most profitable in comparison with open-pit mining. In addition, the underground mine produces less emissions into the atmosphere, experts from consulting companies say.
High gold prices have led to the construction and start-up of many new facilities, and with it increased concerns about their impact on climate change.
At the end of 2019, total emissions from all developed gold deposits averaged 0.8 tonnes of CO2 equivalent per ounce of gold mined, the report says. S&P Global…
Experts Wood mackenzie argue that over the next 20 years, emissions from precious metals production must be halved in order to meet the decarbonization targets set out in the Paris Agreement.
According to S&P, underground mines operate with higher gold grades, process less material, and generally have a lower carbon footprint (greenhouse gas emissions) than larger open pit mines.
“Open pit mines emit on average about twice as much CO2-equivalent per ounce of gold mined as underground mines: 0.85 tonnes versus 0.4 tonnes, respectively. The open pit mines also process about five times more ore with an average grade of about 1.05 g / tons of gold compared to 3.25 g / t for underground mines, “- noted in the S&P.
Open pit mining allows more idle cash to be generated in poorer mines, but their larger production base is associated with higher emissions.
“Underground mines have a clear advantage over open pit mines, and not vice versa, as was previously thought,” S&P analysts are convinced. tonne of CO2 equivalent. Thus, underground mines generate about 422 dollars of free cash flow per ounce of gold, versus 375 dollars per ounce from an open pit, and the scale of greenhouse gas emissions from the open pit is much higher. “
Most gold mines, on average, emit less than 70 tonnes of CO2 equivalent annually per thousand tonnes of ore processed, but volumes vary considerably across regions.
Enterprises in Australia have a relatively high intensity of greenhouse gas emissions – about the level of Russian ones.
Canadian production has the lowest greenhouse gas concentrations, in part due to the high proportion of underground mines with high precious metal grades. Another important factor here is the energy source – up to two-thirds of the country’s electricity is produced from renewable sources, and 82% – from sources not related to greenhouse gas emissions.
According to S&P calculations, the Russian gold industry generates significantly more free cash flow due to the ruble exchange rate and low fuel prices – an average of $ 991 per ounce, which is slightly higher than the $ 989 per ounce in the United States.
“When we compare free cash flows and emissions, we see that Canada, East and Central Africa are significantly ahead of other countries, while the latter jurisdiction has more underground mines,” says S&P Global… “Largely due to lower atmospheric emissions, Canadian enterprises generate on average $ 2609 per ton of CO2 equivalent emitted, in Russia high emissions reduce this factor to $ 1210.”
Gold Miner Bulletin