Ultra-Dynamics Pty Ltd supplied on-conveyor Magnasat magnetic susceptibility meters to the Karara Iron Ore Project in Western Australia.
Located 200km east of Geraldton in Western Australia, the Karara Iron Ore Project is being developed by Karara Mining Limited (KML), which is a 50:50 joint venture between Gindalbie Metals and Chinese steel producer, AnSteel. Karara will take low-grade magnetite iron ore and produce a high-grade premium concentrate for use in steel making.
Karara is the first major project in Western Australia’s mid-west region to develop a long-life magnetite concentrate operation with the potential to produce over 30mtpa for more than 30 years as well as a smaller scale haematite operation based on a number of high-grade haematite deposits. The project includes construction and operation of a large open pit mine, a wet and dry processing plant to produce magnetite concentrate, and all associated infrastructure.
Budgetary constraints required the project to consider more economical solutions for process control compared to the more expensive on-line elemental analysis technologies. The plant consists of two main parts: the dry plant and the wet plant. The former consists of crushing and screening while the latter includes High Pressure Grinding Rolls (HPGRs), magnetic separation followed by a ball mill circuit. Magnasat magnetic susceptibility meter technology has been selected for installation in the dry plant and the wet plant.
Dry Plant - Metallurgical accounting
A Magnasat magnetic susceptibility meter has been installed on the crushed ore stockpile and will be used to monitor the actual magnetite content of the mined ore as extracted from the crushed ore stockpile. This information will provide metallurgical accounting reconciliation information to the management.
Wet Plant - On-line monitoring of high pressure grinding rolls feedgrade
Process control requirements in the wet plant included maintaining a constant magnetite feed rate to the HPGRs, and a constant feed to the ball mill circuit (as determined by the magnetic separation process).
Prevailing economic conditions dictated that, in the first instance, the feed rate to the HPGRs should be monitored and controlled. Subsequent operational experience will then indicate whether further control action is required to even out the ball mill feed-rate, the performance of which can be susceptible to significant feed rate variation. This will be based on the actual feed magnetite content variation and the effect of the magnetic separation on the ball mill feed.