Stockpiling, reclaiming and blending

Stockpiling
To stay on top of production demand, we send 30 truckloads of magnesite ore from QMAG’s Kunwarara mine to Parkhurst every single day. When the ore reaches Parkhurst, 70 kilometres away, it is stored in stockpiles of several thousand tonnes.

We manage and grade stockpiles based on differing grades of chemical purity, analysed during and after beneficiation. This means we can blend different ore to the right chemical requirements.

There are eight stockpile zones, with the capacity to store 30,000 tonnes of magnesite serviceable by the stacker. There are three additional zones not serviced by the stacker, where trucks can dump directly onto the stockpile storage area.

When the trucks arrive at Parkhurst, they deliver ore into the dump hoppers. A travelling, luffing stacker then moves along railway lines and works with a conveyor running through the centre of the stockpile area to deliver product to the specified zone.

Reclaiming
Front end loaders ‘reclaim’ magnesite from the stockpiles and deliver to any one of three ‘reclaim hoppers’. From there, our conveyor transfer systems deliver the material to each multiple-hearth furnace (MHF) feed bin ready for processing.

To meet the specific magnesite chemical composition for each MHF, we calculate a ratio of bucket loads from various stockpiles. These loading instructions are issued to the loader driver, to ensure the correct blend is being used for each MHF.

Blending
With the magnesia analysed and separated into twelve silos, we use high accuracy weigh-feeders to blend the product and discharge from the silos at exact chemical specifications, depending on what we need for downstream processing.