Angel Island Mine

Century Lithium owns 100% of the Angel Island Mine (“Project”) totalling 5,585 acres in west central Nevada, USA. Exploration and development by Century led to the discovery of an extensive resource of lithium-bearing claystone, immediately adjacent to the lithium brine basin in the valley. The lithium resource is exposed at surface, sheltered from erosion by Angel Island, an outcrop of Cambrian metavolcanic and clastic rocks, protruding through the Pliocene lakebed sediments. At present, the Company is actively processing material from its lithium-bearing claystone deposit at its lithium extraction facility (“Pilot Plant” or “Plant”) in Amargosa Valley, Nevada. While moving toward the completion of a Feasibility Study and subsequent permitting, with the goal to become a domestic producer of lithium for the growing electric vehicle and battery storage market.

Pre-Feasibility Study for Angel Island Mine, Nevada, March 2021

A Pre-Feasibility study (“PFS”), NI 43-101 Pre-Feasibility Study Technical Report for Angel Island Mine, March 2021 by Global Resource Engineers and Continental Metallurgical Services was completed on the Company's Project in March 2021.

Highlights of Pre-Feasibility Study: 

• Average mine production rate of 15,000 tonnes per day to produce 27,400 tonnes lithium carbonate equivalent (“LCE”) annually over a 40-year mine-life.
• Lithium carbonate price of $9,500 per tonne.
• Capital cost estimate of US$493 million and a pre-production and operating cost estimate average of US$3,387 per tonne LCE.
• An after-tax net present value of US$1.03 billion at 8% discount rate, a 25.8% internal rate of return, and a capital cost payback of 4.4 years.
• Production is based on a Probable Mineral Reserve of 213 million tonnes (“Mt”) averaging 1,129 parts per million (“ppm”) Li (1.28 Mt LCE) using a cut-off grade of 900 ppm Li.
• Reserves and production plan derived from an Indicated Mineral Resource of 1,304 million tonnes averaging 905 ppm Li (6.28 Mt LCE) based on cut-off grade of 400 ppm Li.

All resources and reserves are pit-constrained by property and geologic boundaries.

The lithium mineralization of the resource at the Project occurs within montmorillonite and illite clays throughout the sediments to a depth of 467 feet. Metallurgical testing on Project material indicates low-cost processing can be achieved with conventional tank leaching and counter current decantation, resulting in low acid consumption and high lithium recovery of over 85% of total lithium. These high extraction rates of lithium from Project material further demonstrates the predominant lithium-bearing minerals are not hectorite, a common clay species found in many lithium-rich sedimentary deposits, which requires roasting and/or high acid use to liberate the lithium from.

Favourable geologic aspects of the Project’s resource include its large, flat-lying nature and surface exposure of the lithium-bearing claystone units. These characteristics led to a mine plan design with a low strip ratio of 0.29:1, due to minimal overburden and no interbedded waste. Surface mining will not require drilling or blasting for excavation.

In March 2021, based on recommendations in the PFS, Century Lithium announced the development of a lithium extraction facility at del Sol Refining, 125 miles south of the Project in Amargosa Valley, Nevada. The operation of the Pilot Plant is providing essential data for the ongoing Feasibility Study and allow Century Lithium to produce marketing samples to support negotiations with potential offtake and strategic partners.

The Company is using a chloride-based (hydrochloric versus sulfuric acid) approach in the configuration of the Pilot Plant. Following the release of the PFS, which was based on sulfuric acid, results from an internal scoping study demonstrated major benefits in the areas of economy, process, and environmental stewardship when to using a chloride-based leach method to liberate the lithium from the claystone.

A Feasibility Study on the Project began in February 2022, led by Wood PLC (Wood), supported by Global Resource Engineers, Continental Metallurgical Services, WSP USA Environment & Infrastructure Inc., and Century.

Progress on the Feasibility Study is proceeding as planned. Wood and the supporting groups have completed or are near completion of several key items, including resource and reserve estimates, mine plan, processing plant design, and tailings and waste storage, and ancillary facilities.

Century Lithium achieved a significant milestone in September 2022, with the production of 99.94% lithium carbonate (“Li₂CO₃”) made from lithium-bearing claystone from the Project. The Li₂CO₃ was derived from intermediate concentrated lithium solution produced at Century Lithium’s Pilot Plant. Following direct lithium extraction (“DLE”) at the Plant, Saltworks Technologies Inc. (“Saltworks”) completed the processing system design and pilot work to make the Li₂CO₃.

All processing is completed with material from the Project in an end-to-end automated Pilot Plant that represents full scale production. Independent analyses of product samples were completed by SGS Canada Inc., with the results showing greater than 99.9 weight-percent purity in a scalable representative process.

The lithium carbonate product produced using material from the Project surpassed industry basis for standard battery grade Li₂CO₃ (99.5% purity) and has achieved select industry basis for enhanced battery grade Li₂CO₃ for electric vehicle use. These results are general in nature, and lithium battery manufactures will have specific requirements for Li₂CO₃ used in their products dependent on application.

Saltworks completed a second phase of testing which examined the production of lithium from the blowdown-brine stream collected during the lithium carbonate concentration in the first stage of testing. This step has the potential to significantly reduce the volume of material required to be recycled back to the upstream direct lithium recovery (DLE) plant and potentially reduce size and capital cost of the DLE plant. Based on the results, Li₂CO₃ will be the end-product for the Feasibility Study and Saltworks will provide the engineering and design for the final stage for production of Li₂CO₃.

Century Lithium expects the Feasibility Study to be completed in the second half of 2023 following receipt of the major components design and cost analysis. With thyssenkrupp nucera USA, Inc leading the design and engineering for the chlor-alkali plant, the largest component remaining to be finalized.

NI 43-101 Technical Report on the Feasibility Study of the Angel Island Mine Esmeralda County, Nevada, April 24, 2024

  Feasibility Study

Daniel W. Kalmbach, CPG, Manager, Geology & Technical Services of Century Lithium Corp. is a Qualified Person as defined by National Instrument 43-101 and has approved the technical information on this website.