The gas stream exiting the kiln via the preheater is passed through a venturi water scrubber. This system removes particulate matter from the gas as well as several non-metal oxides such as sulfur dioxide. The remaining wet gas (28% carbon dioxide, 20% water vapour and the remainder mainly nitrogen) from the scrubber is then vented to the air via a 30 m chimney. As the wet gas cools, water condenses, forming a visible cloud of steam.
The wastewater is channelled to an on-site settling pond, and the solid material that collects is removed and placed in waste cells at the quarry.
Careful monitoring of the waste management systems is enacted to ensure that the calcination plant’s operation meet all of the national and local requirements for air, water and waste discharge.
McDonald’s Lime Limited
United States Environmental Protection Agency