emissions

Measuring the diameter of a habitat tree in the Ravensworth State Forest, as part of the ongoing flora monitoring programme

Air emissions are produced from mining and metal production. At Xstrata, we monitor and manage sulphur dioxide (SO2), lead, zinc, arsenic and cadmium emissions from our metal production facilities, and methane, carbon dioxide (CO2) and dust from our mining operations. We are committed to effectively managing the environmental impacts of our operations and continually improving our environmental performance. As a result, we have initiated a number of projects aimed at addressing our emissions.

In 2004, our Commodity Businesses focused on installing equipment to further reduce emissions, optimising the use of air pollution prevention equipment, and improving monitoring.

Mount Isa Mines

The majority of Xstrata's emissions are produced from the copper-lead-zinc mining and processing complex at Mount Isa. Five years ago, Western Mining Corporation Fertilizers (WMCF) installed an acid plant at Mount Isa which uses sulphur dioxide emissions from Xstrata's Mount Isa copper operations to produce sulphuric acid, dramatically reducing the amount of sulphur dioxide and particulates emitted. In 2004, 218,500 tonnes of sulphur dioxide were emitted from the copper and lead smelter stacks, a 3% reduction from 2003. The installation of continuous in-stack monitoring in the lead smelter is improving the monitoring of sulphur dioxide point source emissions. Similar monitoring will be installed in the copper smelter in 2005. We have reduced fugitive emissions by permanently decommissioning several major areas that have been used for open-air loading, unloading, blending and stockpiling of mineral concentrates.

Annual emissions 1 July - 30 June.

The graph below illustrates the significant reduction in air emissions during the last five years since the acid plant was commissioned in 2000. It shows emissions have decreased due to the improved integration of the acid plant and copper smelter operations. The number of complaints about sulphur dioxide fumes have fallen over the same period.

A series of studies examining the environmental impacts of sulphur dioxide similar to those carried out in the Panel Assessment Study prior to 2001 will start in 2005. Negotiations are continuing with the Environment Protection Authority to determine the panel terms of reference and how the panel process is to be coordinated.

The Mount Isa copper operations are also working on enhancing the interface between the copper smelter and the WMCF acid plant to maximise off-gas collection and treatment by the acid plant.

Greenhouse gas emissions

Refer to climate change section on page 45.

Other emissions

At Alumbrera, a new in-pit water spray system is being trialled to maximise the suppression of airborne dust generated by haul ramp traffic. The water is sourced directly from pumping lines that are part of the in-pit dewatering infrastructure. Trials have proven to be very effective.

At Rustenburg chrome smelter in South Africa, we installed extraction hoods over all tapholes to contain fugitive emissions, replaced the standard fibreglass bags at Baghouse 2 with lined fibreglass bags, and fitted cyclones with scavengers. We also reduced air pollution equipment down-time at the Wonderkop chrome smelter.

Rhovan vanadium plant replaced an old 55-metre kiln stack with a new 90-metre stack, improving pollution dispersion, resulting in lower ambient air concentrations. Due to the success of a pilot scrubber at Rhovan - where sulphur dioxide scrubbing efficiency was as high as 95% and particulate removal from the already 'cleaned' gas was 80% - a full-scale series scrubber and sulphur dioxide removal plant has been designed. A capital application will be made in 2005. Particulate emissions from the new system will be less than 2 mgm/m3, compared with the level of 50 mgm/m3 required by July 2005. At Xstrata Coal, we focused on minimising our dust, methane and spontaneous combustion emissions. In South Africa, a dust fallout monitoring assessment was conducted across all sites and a monitoring network installed across 80% of the sites. We have also introduced Envirogen's electricity generators to utilise methane from our mining operation at Teralba in New South Wales and it is expected that the technology will be implemented next at Oaky Creek in Queensland. Xstrata Zinc's Spanish operations are updating their particulate matter monitoring instruments to meet new EU legislation on air quality control.

Northfleet upgraded its bag filter continuous monitoring system and replaced filter bags in the silver refinery process baghouse. The improvement in bag filter performance has made a major contribution to achieving the 2004 target of a reduction to 1 µg/m3 boundary lead in air emission levels, and together with other improvements, will contribute towards reducing these levels further towards the 2005 target of 0.5 µg/m3. In 2005, Xstrata Zinc's operations will concentrate on improving management plans, reducing fugitive emissions, improving monitoring and continuing their recycling efforts.