Improved Cleaner Circuit Design for Better Performance Using the Jameson Cell

In today’s operating environment many conventional cleaner circuits struggle to produce final grade concentrate with acceptable levels of non-sulfide gangue and/or penalty elements. This is primarily due to poor selectivity and the entrainment of gangue, and is further exacerbated by the processing of lower grade ores with more complex mineralogy that require finer grinding for liberation. In new concentrators, the standard approach to cleaner circuit design is to define the number of stages of mechanical cells required to achieve the desired concentrate grade. Residence time is the primary factor to size cells and to determine the number of cells required to attain target recovery. While it is required for recovery, a bank of mechanical cells is not the ideal solution to maximise concentrate grade. Relatively coarse bubble size means slow flotation of fines, requiring long residence times. The combination of long residence times and no froth washing means higher entrainment as the pulp becomes more barren and froth stability decreases down a bank. In recent years, the Jameson Cell technology has been retrofitted into a number of concentrators around the world to solve both cleaner circuit capacity and concentrate grade issues. Jameson Cells have been installed at the head of conventional cleaner circuits to produce final grade concentrate in a single step of flotation using a single cell (referred to here as ‘cleaner scalping’ duty). The experience gained from these installations has provided the platform for the design of improved and simpler cleaner circuits that will perform better and be more robust to operate. This paper analyses traditional cleaner circuit designs and explains the philosophy behind new hybrid cleaner circuits, which use Jameson Cells to produce final concentrate and mechanical cells for a ‘cleaner scavenger’ duty. The advantages of the new cleaner circuit design are demonstrated by a case study from an operating plant. Engineering studies show that the better metallurgical performance can be achieved with less equipment than conventional cleaning designs, reducing capital cost, operating cost, and with more than 30 per cent energy savings. Finally, the paper describes simple modifications to the standard laboratory flotation test procedures which accurately simulate this new cleaner circuit using routine equipment. 1. MAusIMM, Flotation Manager, XT Pty Ltd, Level 10, 160 Ann Street, Brisbane Qld 4000. Email: [email protected] 2. Process Engineer, XT Canada, 10th Floor, 700 West Pender Street, Vancouver BC V6C 1G8, Canada. Email: [email protected] 3. MAusIMM, Principal Metallurgist, Newcrest Mining Ltd, 193 Great Eastern Highway, Belmont WA 6104. Email: [email protected] 4. FAusIMM(CP), Process Manager, AMEC Mining and Metals, Level 14, 144 Edward Street, Brisbane Qld 4000. Email: [email protected] 5. FAusIMM, Senior Principal Consulting Engineer, Mineralurgy Pty Ltd, Unit 2, 42 Morrow Street, Taringa Qld 4068. Email: [email protected]