Mines & Concentrator, Namibia
Mining operations will use conventional open pit methods for the deposits at Rubicon and Helikon 1 with particular emphasis on selective mining of high-grade ore zones. The footprint is designed to maximise the use of land disturbed by previous mining activities and thereby minimise environmental impacts.
A small fleet of one 50-tonne excavator and 35 tonne trucks can adequately support the mining schedule for the majority of the mine life. Ore will be blended before the concentrator to optimise concentrate production and quality.
The Helikon 1 deposit will be mined as a satellite pit located approximately 7km from the concentrator. The haul road from Helikon 1 to Rubicon is already developed and road trucks will be used for haulage.
Mine waste from the Helikon 1 pit will be placed into the Helikon 1 Waste Management Area (WMA), constructed immediately to the south of the open pit and up dip of the pegmatite structures to avoid sterilisation of any deposit extensions.
Rubicon mine waste will be placed in a separate WMA immediately to the east of the open pit. There it will be co- disposed with filtered benign mineral tailings from the concentrator and used to construct the walls and to cap the facility at closure. This approach minimises the land disturbance, water use and project closure costs leaving a stable structure that can be returned to agricultural land use.
The mineral concentrator will use conventional crushing, grinding, desliming and froth flotation processes followed by dewatering of concentrate and tailings streams.
The lithium principally occurs in lepidolite, amblygonite and lithian muscovite although modest quantities of zinnwaldite may also be recovered through the froth flotation process. The overall recovery of lithium to the lithium concentrate is 80-90%, at a concentrate grade of 2.9%-4.2% Li2O. These values vary according to the mineralogy.
Concentrate from the Karibib flotation plant will be bagged and containerised to prevent contamination during its journey to Abu Dhabi for chemical conversion. Five truck movements per day will be required to transport the concentrate containers 220km to the port of Walvis Bay. From here concentrate will be shipped to Khalifa Port, the main container terminal for Abu Dhabi. KIZAD, where the L-Max conversion plant will be built is a purpose built industrial free zone adjacent to the port. Abu Dhabi City is located approximately 70km to the southwest and is serviced by a well developed road network and in the future rail.