Canadian Process Technologies (CPT) has recently transported the first column flotation cells to Vale's Salobo Metais copper project in Brazil. At almost 400 m³, these are the world's largest flotation cells. Vale awarded CPT, a multi-million dollar contract for the supply of 14 flotation columns complete with sparging (gas bubbling) systems and instrumentation for Salobo. This is Vale's largest copper project with the potential to produce 200,000 t/y of copper and 5 t/y of gold over a 30 year period.

The first eight large flotation columns delivered (6 m in diameter and 14 m in height), feature CPT's hydro-dynamic external sparging system using ‘cavitation tube' spargers. Cavitation tube spargers were selected because of their excellent wear characteristics and ability to generate ‘pico' bubbles to enhance separation efficiencies, resulting in improved metallurgy.

The remaining six columns are 4.3 m in diameter and 14 m high and will use CPT's proprietary SlamJet sparging system. SlamJet spargers are regarded as the industry standard because they are; low maintenance, able to be removed or retro-fitted while the column continues to operate, automatically ‘slam shut' on loss of supply sparger gas and because they use a single large bore orifice plugging or fouling is virtually eliminated.

John Chadwick is editor/proprietor of International Mining Magazine -