Materials are separated into two categories: raw materials (the ore from which we extract product) and associated process materials (materials that are used in processing but are not part of the final product).
We extract ore from both open pit and underground operations. This ore is either processed through a mill or placed on a heap leach pad to extract the product.23 In 2015, we processed 70.7 million tonnes (Mt) of ore, compared with 75.8 Mt in 2014.
Raw Materials Processed24
Associated Process Materials
To process the ore and extract metals, we use materials such as lime and cyanide. The table below shows our main processing materials.
Associated Process Materials and Recycled Input Materials25
|Sodium metabisulphite (t)||3,300||4,000||3,900|
|Grinding balls (t)||36,400||28,500||39,800|
|Other reagents (t)||57,400||56,800||61,800|
Recycled Input Materials
Recycled input materials used at our mines include mainly waste oil, used grinding balls, fly ash, biosolids and used liners. All of these recycled materials are sourced internally.
Recycled input materials as a percentage of our total tracked input materials (excluding raw materials and fuel) was 4% in 2015.
|Recycled fly ash (t)||7,500||10,300||11,200|
|Used oil (t)||150||500||1,000|
|Used liner (t)||0||100||100|
|Other recycled materials (t)||1,200||2,200||4,900|
|Subtotal, recycled (t)||9,050||20,300||112,300|
|Total, all materials used (t)||220,500||218,900||424,900|
|Percent from recycled||4%||9%||26%|