Australian-based lithium-boron mine developer Global Geoscience Ltd has appointed Amec Foster Wheeler as the engineering and design firm to complete the PFS for the Rhyolite Ridge lithium-boron project in Nevada, USA. The Amec technical team that will work on the Rhyolite Ridge PFS has extensive experience that is highly relevant to the project including:
- Extraction and processing of lithium and boron ores in Chile, Argentina, United States, China and Serbia from the full range of brine, spodumene and sedimentary deposits
- Processing and refining of lithium to produce battery-grade lithium carbonate and lithium hydroxide
- Production of sulphuric acid at mining operations
- Leaching, evaporation, crystallisation, purification and solvent extraction relating to lithium and other salts
- Open pit mining and financial analysis in Nevada
- Heap leach processing and tailings management in Nevada and elsewhere
A key aspect of Amec’s selection was its strong technical team and recent experience in lithium projects, including a sedimentary lithium-boron deposit like Rhyolite Ridge. The Amec team members for the Rhyolite Ridge PFS are based in Vancouver, Reno and Santiago.
Global Geoscience’s Senior Vice President of Engineering and Operations, Matt Weaver said: “Amec’s capabilities and strong technical team are an exceptionally good fit for the Rhyolite Ridge PFS. Amec has completed numerous studies for mining projects in Nevada as well as relevant studies for various lithium and boron projects globally.
Global Geoscience’s Managing Director, Bernard Rowe added: “Amec was chosen because of their capabilities, integrity and proven track record of delivering value. In December 2017, we announced the positive outcomes from the initial Rhyolite Ridge mining study and favorable heap leach results. This work to date provides the foundation for the PFS and confirms that the large, shallow Rhyolite Ridge lithium-boron deposit is amenable to low-cost open pit mining. Amec has the capability to rapidly progress the engineering and design work required to complete the Rhyolite Ridge PFS as targeted by mid-2018.”
Global Geoscience’s 100%-owned Rhyolite Ridge project is a large, shallow lithium-boron deposit located close to existing infrastructure in southern Nevada. The project lies 25 km west of Albermarle’s Silver Peak lithium mine (pictured) and 340 km from the Tesla Gigafactory near Reno.
Rhyolite Ridge is one of the largest known lithium and boron deposits in North America and has the potential to become a strategic, long-life and low-cost source of lithium and boron.
The outcropping deposit is amenable to open pit mining at low strip ratios. High-grade lithium-boron mineralisation is the focus of the Rhyolite Ridge PFS as it represents potentially the highest value material combined with a low-cost, simple processing route. This is due to the low-clay, low-carbonate and high-searlesite content of the rock, which make the mineralisation amenable to low-cost acid leaching at ambient temperature and pressure.
Lithium-boron mineralisation is hosted within two sedimentary basins located 4 km apart: South Basin (9 km²) and North Basin (20 km²). The minerals in the host rocks are dominated by the searlesite (boron-bearing), sepiolite (lithium-bearing), K-feldspar, calcite and dolomite.
At South Basin, high-grade lithium-boron mineralisation occurs in 20 to 50 m thick, sub-horizontal sedimentary layers. The upper-most layer is 20 to 30 m thick and outcrops along the western margin of South Basin over a strike length of approximately 3 km.
Drilling at South Basin has defined an Indicated and Inferred Resource of 460 Mt at 0.9% Li2CO3 and 2.6% H3BO3), containing 4.1 Mt of lithium carbonate and 11.9 Mt of boric acid. The resource is open in most directions and is likely to increase in size with additional drilling.
The Mineral Resource includes a high-grade lithium-boron zone of 137 Mt at 0.9% Li2CO3 and 7.2% H3BO3, with 75% in the Indicated category.
