Chemical Consumption in mining and mineral processing refers to the quantity of reagents and chemical substances used per unit of ore processed, concentrate produced, or metal recovered, and is a critical operating cost, process efficiency, and environmental impact metric. Managing and minimizing chemical consumption while maintaining process performance is a key objective for metallurgical and process engineers across bauxite, iron ore, gold, and diamond operations. In bauxite refining using the Bayer Process, the primary chemicals consumed include caustic soda (NaOH) for bauxite digestion, flocculants for red mud settling, lime (CaO or Ca(OH)₂) for scale control and liquor purification, and fuel for calcination. Caustic consumption is one of the most significant operating costs and is expressed in kilograms of NaOH per tonne of alumina produced. In gold mining, cyanide (NaCN) consumption per tonne of ore or per ounce of gold produced is a central operating parameter, influenced by ore mineralogy, grind size, dissolved oxygen levels, and the presence of cyanide-consuming minerals (such as pyrrhotite or copper minerals). Lime is also consumed for pH control in cyanidation circuits. In iron ore flotation, consumption of fatty acid collectors, depressants (such as starch or dextrin), and frothers is monitored closely. In diamond processing, dense media ferrosilicon consumption is tracked to manage losses through recovery circuits. Benchmarking chemical consumption against design targets and industry norms supports continuous improvement and identifies opportunities to recover, recycle, or substitute chemicals for cost and environmental benefit.
