CLEANER 3 UPGRADE PROJECT

1. CLEANER 3 UPGRADE PROJECT Flotation circuit cleaners has been upgraded purposely to increase the final concentrate grade from Cleaner flotation. Previously the cleaners cells arrangement allowed four main stages of upgrade but the new set-up have 5 stages to upgrade the rougher concentrate. Consider the flow sheet describing the old and new set up respectively for cleaners concentrate feed arrangements in the next slide The difference between the old set up and the new set up is that the cleaner 3 bank 1 & 2 are working as separate upgrading banks Previously the cleaner 2 conc. was pumped to both cleaner 3 bank 1 and 2 with cleaner 4 tails feed to clnr3b1 while cleaner 3b1 tails feed to cleaner 3b2. That set up had an impact on diluting the combined cleaner 3 concentrate grade due to the feed from cleaner bank2 being diluted by tails from cleaner 3 bank 1. The new set-up system gives more retention time due to the split of feed to each bank being separate. The cleaner 2 concentrate feeds Cleaner 3b2 (Cleaner 3) Cleaner 3b2 concentrate feeds cleaner 3b1 (Cleaner 4) Cleaner 3b1 concentrate feeds cleaner 4 (Cleaner 5) In the new flotation flow sheet there are 5 cleaners. The new installed tank-pump is special for the new cleaner 4 concentrate which feeds to the new cleaner 5. In case of any problem with the tank-pump, the flow configuration could be changed to the old configuration by opening and closing valves. A pH of 11 needs to be maintained and adequate CMC needs to be dosed in order to obtain the desired final concentrate grade. In addition, also refer to the mass pull strategy. The idea is now to increase the mass pull on the roughers since the upgrading ability in the cleaners appears to be adequate. Composite Samples will be taken daily with the operating parameters on the cleaner 3 to 5, to finally establish the optimum operating conditions

2. Cleaner 1 Cleaner Scav. Regrind Cyclone Pump-Box OLD FLOTATION CLEANERS SET UP Cleaner 2 Cleaner 4 Cleaner 3 NEW CLEANERS SET UP FLOWSHEET Cleaner 1 Cleaner Scav Cleaner 2 Recycled Tails Conc. Feed Flow Cleaner 4/5 Cleaner 3B1/4 Cleaner 3B2/3 Final conc

3. Back Ground • Bulyanhulu Flotation Circuit produces copper concentrate from three main streams which are flash flotation, contact cell and cleaners flotation cells. • Final concentrate grade target are 17% Cu, 250g/t gold & 200 g/t Silver. • Flotation cleaners was designed to have 4 cleaning stages. • With 4 cleaning stages the Cleaners Cu grade was up to 18% Cu, 180g/t silver and 220g/t gold. • The survey conducted around cleaners flotation lead to the objectives of upgrading the cleaners flotation cells in order to improve the final concentrate grade. • After the diversion and re-arrangement of cleaners concentrate streams, the resulted cleaners concentrate grade have improved up to 28% Cu. • The upgrade of cleaners grade have resulted to the increase of final concentrate grade which is reflected into the finished goods concentrate grade.