Problem/Challenge:
An existing vanadium ore processing plant located in Emalahleni within the Highveld Priority Area—a region already burdened with poor air quality—posed potential air pollution concerns due to emissions from its operations. These included particulate matter (PM10 and PM2.5), sulphur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), ammonia (NH₃), and dustfall. Historical monitoring showed exceedances of national ambient standards for several of these pollutants, raising concerns over compliance with environmental regulations and the plant’s atmospheric emission licence conditions.
Solution/Approach Taken:
To assess and address these issues, a comprehensive Atmospheric Impact Report (AIR) was prepared. This included:
- A baseline assessment of local air quality and meteorological conditions.
- An emissions inventory for operational activities.
- Air dispersion modelling under two scenarios: the actual emissions from current stack operations and a future scenario aligned with national Minimum Emission Standards (MES).
- Comparison of modelled pollutant concentrations with South African National Ambient Air Quality Standards (NAAQS), National Dust Control Regulations (NDCR), and international guidelines (for ammonia).
- Identification of sensitive receptors such as residential areas, schools, and healthcare facilities within a 20 km radius.
The results revealed localised exceedances of standards for dustfall, PM10, PM2.5, and SO₂ near the plant’s active stacks, especially Kiln 1, but compliance was maintained beyond a 330–670 m radius from the plant. Most pollutants at nearby receptors were within acceptable limits. The report recommended further emission reduction measures, particularly for PM and SO₂, such as installing additional abatement equipment (e.g., scrubbers).
Role of Rayten Engineering:
Rayten Engineering Solutions acted as the air quality specialist responsible for conducting the entire assessment. Their role included:
- Designing and managing a site-specific dustfall monitoring network.
- Analysing historical and current ambient air quality data.
- Compiling a detailed emissions inventory and conducting air dispersion modelling.
- Interpreting the modelled impacts and identifying areas of non-compliance.
- Recommending operational and technological improvements to reduce emissions.
- Supporting regulatory compliance through documentation for the plant’s postponement application.
Rayten’s expertise ensured a scientifically robust evaluation of air quality impacts and provided actionable guidance to align operations with environmental regulations.
