Sonora Project

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Mine TypeOpen Pit
  • Lithium
  • Sulfate of potash (SOP)
Mining Method
  • Truck & Shovel / Loader
Mine Life... Lock
SnapshotGanfeng Lithium Group Co., Ltd. (Company) has been developing the Sonora Project, an open-pit mine and lithium chemical product processing facility located in Sonora, Mexico. The Company’s ability to develop the Project is based on a series of concessions granted in accordance with Mexican law and held by three controlled subsidiaries of the Company incorporated in Mexico

In April 2022 and May 2023, the Mexican Government approved amendments to its Mining Law, which prohibited lithium concessions, declared lithium as a strategic sector, and granted the exclusive right to engage in lithium mining operations to a state-owned entity.

The General Directorate of Mines (“DGM”) has issued a formal decision notice to the Mexican Subsidiaries in August 2023, indicating that the nine lithium concessions held by the Mexican Subsidiaries, including the principal lithium concessions for the Sonora Project, were cancelled.


Ganfeng Lithium Group Co., Ltd. 50 % Indirect
Bacanora Lithium Plc. 50 % Indirect
Ganfeng completed its option to increase its stake in Sonora Lithium Ltd ("SLL") from 22.5% to 50% (the "Option") on 26 February 2021. On completion of the transaction, a revised 50:50 Joint Venture Agreement (“JVA”) came into force, whereby each party is responsible for their portion of the Project capex. After review of the provisions of the revised JVA, the Company has assessed that Bacanora now has joint control over SLL and its subsidiaries (the “Sonora Lithium Group”).



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Deposit type

  • Hydrothermal
  • Sedimentary


The Sonora deposit is believed to have formed by hydrothermal alteration as a result of alkaline volcanism effecting layers of volcaniclastic sedimentary rocks deposited in a basin environment. The origin and timing of the mineralised content remains unclear with regard to source and whether the alteration was essentially syn-genetic with deposition of the sedimentary rocks or whether the alteration is a post depositional event. Additional work is required to clarify the origin of these deposits.

Mineralisation on the concessions consists of a series of lithium-bearing clays that occur within two bedded sequences, the Upper and the Lower Clay units, which are separated by an ignimbrite sheet.

Bacanora understands there to be a number of lithium-bearing clay minerals, with polylithionite being the only one currently positively identified. The clay units are believed to have formed from supergene or diagenetic alteration of volcanic ash. The clay layers also contain relict quartz and feldspar crystal shards, lithic fragments and silica bands, and traces of other minerals. The layers are locally interbedded with reddish terrigenous beds composed of sand and silt-sized material.

Initial interpretation has indicated a high grade lithium core in the area covered by the La Ventana, El Sauz and Fleur concessions where the lithium grades are generally above 3,000 ppm Li. This high grade zone extends from the middle of La Ventana southward across Fleur and approximately a third of the distance south into El Sauz. The best grades of lithium are associated with elevated levels of calcium, caesium, magnesium, potassium, rubidium and strontium; however, the correlation (especially for magnesium) is not one-toone.

On La Ventana, the best grades of lithium are co- incident with elevated levels of potassium and caesium and are found in the southern part of the deposit. Magnesium appears to be irregularly distributed and does not follow lithium or the other alkalis. Mineralised intervals within the clay units vary for the Upper Clay Unit from 25% to 80% of the overall thickness and from 40% to 100% for the Lower Clay Unit, depending on the cutoff used.

Further mineralogical studies are recommended to determine what minerals host the various alkalis in the clay units. Results of such studies could have an impact on beneficiation of these minerals and recovery of the alkalis.



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Mining Methods


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Crushers and Mills


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Sulfate of potash (SOP) Crystals t 537,100

Operational metrics

Plant annual capacity 2.2 Mt *
Annual production capacity 35,000 t of lithium carbonate *
Annual production capacity 28,805 t of Sulfate of potash (SOP) crystals *
Stripping / waste ratio 3.42 *
Waste tonnes, LOM 126,672 kt *
Ore tonnes mined, LOM 37,058 kt *
Total tonnes mined, LOM 163,730 kt *
Tonnes processed, LOM 37,058,000 t *
* According to 2017 study.

Production Costs

Cash costs Lithium USD 3,910 / t *  
Cash costs Lithium USD 3,418 / t * **  
Assumed price Sulfate of potash (SOP) USD 550 / t *  
Assumed price Lithium USD 11,000 / t *  
* According to 2017 study / presentation.
** Net of By-Product.

Operating Costs

OP mining costs ($/t mined) USD 1.66 *  
* According to 2017 study.

Project Costs

MetricsUnitsLOM Total
Pre-Production capital costs $M USD  ......  Subscribe
Total CapEx $M USD  ......  Subscribe
OP OpEx $M USD  ......  Subscribe
Total OpEx $M USD  ......  Subscribe
Net revenue (LOM) $M USD  ......  Subscribe
Pre-tax Cash Flow (LOM) $M USD  ......  Subscribe
After-tax Cash Flow (LOM) $M USD  ......  Subscribe
Pre-tax NPV @ 0% $M USD  ......  Subscribe
Pre-tax NPV @ 10% $M USD  ......  Subscribe
Pre-tax NPV @ 8% $M USD  ......  Subscribe
After-tax NPV @ 0% $M USD  ......  Subscribe
After-tax NPV @ 10% $M USD  ......  Subscribe
After-tax NPV @ 8% $M USD  ......  Subscribe
Pre-tax IRR, %  ......  Subscribe
After-tax IRR, %  ......  Subscribe
Pre-tax payback period, years  ......  Subscribe

Heavy Mobile Equipment


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