RE:Market ResponseThis is from the last two pages & page 58 ,59 & 61 of CYP's PFS
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25.0 INTERPRETATION & CONCLUSIONS:
The information within this report supports the presence of economic lithium mineralization and further work on the project.
The mineralization occurs within a large lithium-bearing clay deposit. The estimated Mineral Reserves for the project are large and capable of supporting a mine life of more than 40 years.
26.0 RECOMMENDATIONS
The recommendations to advance the project are:
• Processing—Additional test work is needed to confirm the process flowsheet and determine recoveries and reagent consumptions at the pilot stage. Critical information includes,
o confirm steps and equipment in leaching and filtration
o conduct further work to enhance solid-liquid separation and reduce acid consumption
o determine lithium and acid losses in the processing plant, if any
o optimize solution handling in the plant and determine if bleed streams or additional treatment are needed to recycle solutions
o determine whether K, Mg, REEs, and other elements have commercial value.
• Mining—Drilling or limited test mining is required to obtain material for metallurgical testing.
• Permitting—A field program is required to determine if any species of concern are present and to gather data to prepare a Plan of Operations.
• Infrastructure—Feasibility-level designs for the mine, plant and tailings storage areas can begin. Further determination of project power and water supply are needed.
Program Costs:
Although the project uses off-the-shelf equipment and design, a pilot plant will be required to ensure all the processes work together as a single unit and to identify any scale-up or operational issues.
The pilot plant is projected to operate at approximately one tonne/day, and parts of the plant will be able to operate 24 hours/day for an entire month. The plant will be designed to ensure proper interaction of components. The estimated cost of the pilot plant study is $6.75 million and covers the capital, sample procurement, construction, and operation for six months, and includes a contingency allowance of 25%.
Large Leach Tests:
To provide slurry for rheology, filtration, and lithium recovery testing, two large samples were prepared from the composites and leached at CMS (Table 13-2). Sample L-1was a 92 kg composite prepared from GCH-06 grading 1,380 ppm Li. Sample L-2 was a 41 kg composite prepared from GCH-06 and DCH-15 grading 1,330 ppm Li.
The two samples were leached in a heated 75-gallon jacketed stainless-steel leach vessel. The leach vessel used a high shear, variable speed impeller mixed in a baffled stainless-steel tank. Leaching was conducted at time, temperature and acid concentrations identified by CMS. The leaching conditions are the same as used in the process design and simulate the actual processing conditions.
Filtration:
During the large leach tests, it became apparent the resulting leach slurries were problematic to filter by conventional means. Extensive testing was conducted at Pocock Industrial and Andritz (Andritz, 2019); the tests included:
• Sample Characterization
• Flocculent Screening and Evaluation
• Static and Dynamic Thickener Tests
• Pulp Rheology (FANN Viscosity—Pre-sheared Measurement Only)
• Vacuum and Pressure Filtrations Studies • Centrifuge Screening
Studies Results from the above tests are:
• The leached slurry does not thicken well, the material settles very slowly and does not compress. The results rule out the use of conventional and high efficiency thickeners.
• Addition of polymer flocculant aides in the flocculation of the slurry. • Vacuum belt filtration tests produced filtration rates that are uneconomic for the production rate required.
• Filter presses and centrifuges initially appeared viable, but further tests concluded they were uneconomic for the production rate required. • Specific conditions and equipment were ultimately identified to achieve economic filtration rates for the project.
Solids from filtration tests simulating the final circuit were generated containing a cake moisture of 70 to 75% moisture and were readily washable. The solids generated were suitable for handling by conveyor to a dry-stack tailings facility.
Lithium Recovery :
The process flowsheet in the 2018 PEA (GRE, 2018b) was based on purification-evaporationcrystallization, an approach common to the processing of lithium concentrates from hardrock mines. For the PFS, CMS worked with NORAM Engineering and Constructors Ltd. to develop an alternate approach to more efficiently concentrate the lithium, remove impurities without high reagent consumptions, and recycle sulfuric acid and water back into the leaching circuit. The flowsheet was developed in consultation with vendors. Critical key elements were tested at NORAM’s subsidiary company, BC Research Inc., from December 2019 to March 2020.
Conclusions & Interpretation:
• The processing methods are projected to effectively recover lithium from the project’s mineralized materials.
• Lithium extractions of 85-87% were achieved in large sample leach tests.
• An overall recovery rate of 83% is used in the economic analysis to allow for possible losses of lithium in the recycle streams from the lithium recovery plant.
• Acid consumptions averaged 126.5 kg/tonne in the large leach test. Recovery and recycling of unused acid is expected within the processing flowsheet.
• To advance the project to the feasibility level, further test work is needed. Test work should include a pilot plant study conducted at a continuous production of at least one tonne per day (tpd) of claystone.
BTW, much more is included in CYP's PFS. I recomend looking at all of it. Most of us waited over a year to see the PFS. Some may like to see all that was done for us during that year and to learn why we had to wait so long. All the answers are in the PFS.