Dr. Jamil Sader reports

MONUMENTAL MINERALS BEGINS DRILLING AT THE JEMI HEAVY RARE EARTH ELEMENT PROJECT, MEXICO

Monumental Minerals Corp. has commenced drilling at the Jemi rare earth element (REE) project in Coahuila, Mexico, about 40 kilometres south of the Texas, United States, border.

A diamond drill rig from Globexplore Drilling SA is now aligned on the first drill target, on the Veladora North prospect area within Monumental's claims. The drilling will test areas with high concentrations of REE-mineralized dikes and sills at the surface, and the company's REE deposit model for Jemi. The model was developed based on detailed geological mapping, regional stream sediment sampling, ground radiometric geophysical surveys and lithogeochemical sampling (see the company's news release dated April 4, 2023) and suggests a mineralized REE-layered intrusion (source of the dikes and sills) exists at a depth of less than 300 metres. Monumental is planning to test a total of six drill targets to approximately 300 m each during this maiden campaign.

The Jemi project is characterized by broad areas of peralkaline intrusion-related REE mineralized dikes and sills at the margins of the La Vasca igneous complex. These intrusive bodies contain high grades of heavy rare earth elements (HREEs) dysprosium (Dy) and terbium (Tb), and light rare earth elements (LREEs) neodymium (Nd) and praseodymium (Pr), all critical to permanent magnets for electric vehicles. Additionally, samples contain high concentrations of niobium (Nb) and tantalum (Ta).

Dr. Jamil Sader, chief executive officer and director, comments: "Drilling at the Jemi REE project is under way, and we are optimistic that it will be able to validate the source of the mineralized dikes and sills, and the model we developed through extensive and pragmatic exploration activities in 2022 and 2023. Jemi has similar characteristics to other well-defined hard-rock peralkaline REE systems globally and has the added benefit of being on the doorstep of Texas, a fast-growing hub for REE processing, refinement and consumer goods manufacturing."

Rare earth element value and the global energy transition

Because of their unusual physical and chemical properties, REEs have diverse energy, industrial and military technology applications. It is projected that rare earth magnets will maintain dominant market share, powering EVs as well as other types of electric motors (such as wind turbines, water pumps) this decade, as there is minimal to no substitution risk. Significant demand growth is therefore expected for key magnet rare earths (Nd, Pr, Dy and Tb) and is likely to continue. The strongest magnets are neodymium-iron-boron (NdFeB) and are used when space and weight restrictions are present. The addition of terbium and dysprosium to NdFeB magnets can double their optimal operating temperature from 80 degrees to 160 degrees. In addition, dysprosium with praseodymium increases a magnet's coercivity (the resistance of a magnetic material to change in magnetization).

The four key REEs (Nd, Pr, Dy, Tb) represent 94 per cent of the REE market by value, all of which are significantly elevated at Jemi. Concentrations of Nb and Ta are also present that are potentially economically significant.

Qualified person

The scientific and technical information contained in this news release has been reviewed and approved by Kristopher J. Raffle, PGeo (British Columbia), principal and consultant of Apex Geoscience Ltd. of Edmonton, Alta., a director of the company, and a qualified person as defined in National Instrument 43-101 -- Standards of Disclosure for Mineral Projects. Mr. Raffle verified the data disclosed which include a review of the sampling, analytical and test data underlying the information and opinions contained therein.

About Monumental Minerals Corp.

Monumental Minerals is a mineral exploration company focused on the acquisition, exploration and development of mineral resource properties in the critical and electric metals sector. The company's flagship asset is the Jemi HREE project located in Coahuila, Mexico, near the Texas, U.S., border which the company has an option to acquire 100 per cent of the 3,650-hectare project. The company has an option to acquire a 75-per-cent interest and title to the Laguna cesium-lithium brine project located in Chile and a 50.01-per-cent interest in the Salar De Turi lithium project in Chile.

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