The Mozambican Ministry for Coordination of Environmental Affairs gave BHP Billiton’s Mozal smelter at Matola, 17km from the capital Maputo, permission to bypass two fume treatment scrubbers at its carbon plant in May, up to November.
Scrubbers re-processes fumes and produces anodes for use in producing aluminium, reports IPS.
BHP had asked to rebuild and upgrade the scrubbers from November 2010 to April 2011.
Local civil society groups sued in September to gain more information and reverse the government decision on grounds of potential impacts to local human health and environment.
Fluroide and compounds
Anode production cause hazardous compounds from fluoride, like hydrofluoric acid and sulphur dioxide. The World Health Organisation sets recommendations for related exposure, but exposure calculation requires specific air dispersion and concentration information.
Objectors have collected 14 000 signatures in protest. Matola has a million residents, some living 2km from the 10 year old smelter.
Consultation about emissions
Mozal consulted residents at three meetings, with civil groups, media and residents, saying the operation meets international standards without filters.
Richards Bay smelter maintenance
BHP Billiton operates a similar aluminium smelter, Hillside, in South Africa at Richards Bay. A scrubber bypass of 72 hours here, met with local protest. Smelters are by nature continuous processes, and could not be turned off and on without incurring huge expense.
Mozal had commissioned an independent air dispersion model by two environmental consultants, but did not release the report, and gagged the consultants. SGS is hired to monitor emissions during the bypass.
The state’s own report found ‘no risk’, but cites that Mozal could not be held liable for public health or environmental damage, since the state had no health or environmental baseline in the local area.
PHOTO; Aluminium smelter emissions scrubber and anode retrieval diagram.