RACA Journal I May 2026 www. refrigerationandaircon. co. za 25
MINE VENTILATION FEATURE SERIES
For Shaft 2, CO2 concentrations exhibited more variation, also averaging around 800ppm, with some peaks linked to blasting periods. The net CO2 from Shaft 2 was approximately 200ppm.
These concentration values were then converted to total annual emissions by multiplying them by the ventilation quantities( cubic meters per second) flowing through each fan, assuming 360 working days per year, and converting gas volumes to mass. The IPCC ' s figure for CH4 was used for methane calculations.
The total annual fugitive greenhouse gas emissions were calculated as follows: Shaft 1: CO2: Between 3 000 and 3 500 tons per year. CH4: Between 42 and 50 tons per year. Shaft 2: CO2: Between 11 800 and 13 200 tons per year. CH4: Between 76 and 92 tons per year. Cook noted that these figures, particularly for CO2, often seem " low " when compared to global-scale emissions, which are typically discussed in millions of tons. However, when aggregated across all shafts and mines, they become more substantial. The ranges provided reflect statistical plus / minus deviations from the average, as advised by CSIR for South Africa ' s national inventory.
Part of the presentation.
COMPARATIVE ANALYSIS AND REPORTING IMPLICATIONS
To contextualise these findings, Cook compared them with data from other South African mines:
Platinum Mines( for example, Rustenburg Platinum, 2008 data): Individual shafts emitted between 150 and 23 000 tons of CO2 per year, and 5 to 145 tons of CH4 per year. The gold mine ' s emissions, therefore, fall within a comparable range.
Underground Coal Mines( 2005 & 2012 data): Individual shafts typically emit between 100 and 600 tons of CH4 per year( some significantly more), and 500 to 5 500 tons of CO2 per year. Total methane emissions for South African coal mines were estimated between 70 000 and 80 000 tons per year, a substantial reduction from previous international model estimates of up to 2 million tons per year, underscoring the value of direct measurement. mine ventilation
RACA Journal I May 2026 www. refrigerationandaircon. co. za 25