As part of the FEED works relating to the wet harvesting equipment, Agrimin has now completed a comprehensive testwork programme within the pilot evaporation ponds located on Lake Mackay. During the Definitive Feasibility Study (DFS) phase, the pilot evaporation ponds were operated under steady-state conditions for a sufficient period of time to accumulate a thick bed (nominally 500 mm) of salt minerals in the ponds. These minerals provided a good quality, representative substrate to test the wet harvesting equipment design at a pilot scale as the mineralogy mix is comparable to that expected during commercial operations.
The testwork programme gathered critical data on the cutting forces required to break the potassium bearing salts under varying cutting depths and speeds. Importantly, this data has supported the key design parameters that were applied in DFS.
IHC will now complete and deliver detailed design drawings for all key areas of the equipment including cutting tools and propulsion, slurry transport systems, hydraulics, electrical and control system, field testing and a fixed cost for supply of the harvesting equipment.
The use of wet harvesting at the Mackay potash project can provide significant operating benefits, including:
- Significantly lower energy consumption to transfer raw potash salts from the evaporation ponds to the processing plant (i.e. raw potash salts will be transferred to the plant via pipeline as a slurry, thereby removing the requirement to truck dry salts);
- Reduced labour costs as wet harvesters will be automated;
- Increased overall potassium recovery with harvesting of two pre-concentration ponds to recover a portion of the potassium-bearing entrained brine; and
- Reduced pond sizes due to harvesting occurring earlier in the evaporation cycle and not having to take ponds off-line for harvesting.
The overall FEED phase for the Mackay potash project continues to advance well with multiple work streams underway, in parallel with finalising the project’s approvals, offtake and financing.
Image of the Auger Test Rig courtesy of Agrimin.
Read the article online at: https://www.worldfertilizer.com/project-news/18012022/feed-testwork-for-wet-harvesters-completed-at-mackay-potash-project/