Process Stewardship
Our standard operating approach is to reduce by-products where possible and improve the production rate of quality product. A number of our operations implement programs to reuse and recycle by-products where applicable to their processes.
For example, at our Alumar aluminium operation (Brazil, 40% BHP Billiton ownership), coal fines from the refinery boilers are being reused as a substitute for the coke burned in the cement kilns at a nearby cement plant. This replacement of traditional fossil fuels in cement production has eliminated fugitive emissions generated during ash handling and removed the need to construct new storage areas for coal fines.
Read more: Environmental Case Studies>Waste Recycling and Reuse.
A R34-million environmental project at our Metalloys site near Meyerton (South Africa) has developed a process to convert hazardous manganese sludges and dusts into manganese alloy pellets, providing a unique alternative to the traditional industry method of storing sludges in lined dams, which is environmentally unacceptable and expensive.
With no precedent anywhere in the world, the team's development of the recycling process for the sludge broke new ground. The solution had to accommodate several waste streams that had accumulated over time, while being flexible enough to cater for future changes in the composition of contaminants. It also had to be environmentally responsible and acceptable to the local communities, the authorities and the Company.
After abandoning several options suggested by external consultants and suppliers, the team set about developing their own process, utilising a mothballed plant on the site for pilot studies. After three years of testing, all the hurdles were overcome, and a revolutionary new process was developed to recycle hazardous manganese sludge into manganese ore pellets, with significant advantages environmentally and economically.
Not only was the new process acceptable to all the stakeholders, but it offered significant economic benefits in that the pellets produced by the conversion process could be made into high-value manganese alloys, which are sold into the market. In addition, no further land would be required for storage dams, and the old dams could be reclaimed and recycled into valuable real estate on site to be used for other projects. This will also lead to further savings by minimising clean-up costs at the time of site closure.
