Our Altonorte copper smelter, near the Antofagasta port in northern Chile, has been implementing an improvement programme for its environmental performance since 2011, starting with a series of short-term actions to optimise operations. In total, the programme has cost around $150 million.
We took a phased approach to developing an integrated stack emissions management system, which included creation of a centralised control room to improve operational efficiency. During the annual plant maintenance shutdown, we took the opportunity to determine the most efficient type of catalyst for use in the last phase of the process at our acid plants.
Implementing these measures in 2011 and 2012 allowed us to reduce SO2 emissions by about 10%.
A new initiative
During 2012, we initiated one of our key improvement projects, Technological change for reducing SO2 emissions. This initiative was approved by the region’s environmental authorities in 2012 and began implementation in 2013 with the replacement of a rotary dryer for a steam-driven one. The new dryer began operation in
early 2014. The next stage was constructing a double absorption acid plant, which was completed in May 2015.
This initiative led to a further 40% decrease in emissions compared to 2010; as of December 2015, the plant now captures 96.8% of all SO2 emissions.
In addition to that initiative, we are improving our primary gas management system; we expect this to give us robust control of the acid plants. We have implemented a continuous emission monitoring system, which includes self-assessment and external audits. We are also developing a project to determine improved processes to increase the efficiency of copper treatment.
Compliance with our policies and external standards
All these initiatives are part of the process for implementing Altonorte’s sustainable development policy. The policy encompasses Chile’s new standards for foundries and smelters, and helps us position ourselves as one of the nation’s leaders in environmental performance. The initiatives comply with Chile’s new standards, which come into effect in December 2016.