Water quality effects on flotation: Impacts and control of residual xanthates

For increasing the sustainability and cost effectiveness of their operations Boliden Kevitsa Mining Oy in collaboration with academic research partners aims to develop a holistic approach to water management in its mineral processing operation. This paper describes one of the first steps taken in this process, namely the monitoring and control of residual collectors in their flotation circuits. Boliden Kevitsa Mining Oy, a Cu-Ni-PGE concentrator recycles 90–95% of its water for use in the plant. The quality of recycled water tends to deteriorate as various elements and compounds such as Ca, Na, Mg, K, SO₄ ²⁻ and residual reagents accumulate. The accumulation shows seasonal cyclic variation that has an impact on flotation performance. UV/VIS Spectrophotometry was employed to measure residual xanthates in key process streams and process return water from the Tailings Storage Facility. This allowed the implementation of dosage monitoring and control strategy with the objective of performance control and optimization throughout the seasonal changes during the year.