Luca Reports Successful Metallurgical Test Work For New Copper Concentrate At Campo Morado

4 May 2024

Luca Mining Corp. is pleased to report that the metallurgical test work on the copper-lead separation process at Campo Morado has been successfully completed. The test work was primarily carried out by ALS-Kamloops and in parallel with Luca's onsite lab.  Currently, two concentrates are produced, namely, zinc and a bulk concentrate (made up of copper-lead-gold and silver). The result from the metallurgical testing provides confirmation to move forward with the Company's objective to produce three separate, higher value concentrates: copper (with precious metals), zinc and lead.

The Company has established a successful track record of identifying, testing, and implementing ongoing improvements at Campo Morado:

The ALS test work has provided a pathway to a copper-lead separation process that can be implemented at Campo Morado by re-configuring existing plant equipment.

Open circuit, bulk rougher results returned copper recovery of between 80 and 93%.

Testing indicates that copper grades as high as 28% Cu are achievable compared to current grades of 15-18% Cu in the bulk concentrate.

The separation results in the lab have been positive with improved grades of gold and silver in the copper concentrate. The work has shown that there is additional upside, and development of a new flowsheet and reagent optimization program has already begun.
Ramon Perez, President, and interim CEO, commented, "A key milestone we have stated for Luca is to increase cash flow at Campo Morado by producing three high-quality concentrates of copper, zinc, and lead, instead of two concentrates (zinc and a bulk concentrate). Given the results from ALS, we are moving forward to implement the copper-lead separation process and are on track to deliver results in 2H 2024. We are also pleased with the potential of improved grades of gold and silver into the concentrate."

Copper-Lead Separation
The copper concentration test work was conducted at ALS, utilizing parent samples sourced from each ore body in the production plan. A composite blend was formulated from these parent composites. The tests conducted were bench-scale open circuit flotation tests. A flowsheet was developed utilizing the pre-flotation and bulk roughing circuits in operation in the Campo Morado plant.

Understanding the mineralogy and the mineral associations has been a critical part of the test work to date. The test work results have guided modifications to the plant, identifying grinding target size and predicting flotation performance. Campo Morado already has sufficient installed grinding capacity that will be utilized to meet target throughput and adequate liberation of copper and lead minerals to achieve the objective of producing three salable concentrates of copper, zinc, and lead concentrates in H2 2024.

Open circuit, bulk rougher results returned copper recovery of between 80 and 93%. The testing indicates improvements to overall recovery and concentrate grades as high as 28% Cu are achievable.    

Precious Metal Recovery
The test work has shown that gold and silver behave similar to galena and chalcopyrite in the flotation process with preferential recovery to the copper and lead concentrates. Gold recovery of between 35% and 65% was achieved in open circuit copper rougher circuit testing, depending on ore body mineralogy. The key conclusion is that increasing copper and lead recovery will increase the recovery of gold and silver.

Campo Morado Optimization Plan
In conjunction with Ausenco, formally kicked-off the optimization project, internally called the Campo Morado Improvement Project (CMIP). The CMIP incorporated opportunities identified between the mine and mill. Mine planning, modelling, ore blending, metallurgy, reagent dosing and modernization were all incorporated into the CMIP. The metallurgy program with the external lab (ALS) provided a training opportunity for site metallurgists while at the same time confirming the expected benefits from the project and improving knowledge of the ore body. The metallurgical test work focused on future mining areas to improve both short-range and long-range planning and used to develop an integrated mine-to-mill production plan.   In addition, new procedures for ore blending and optimized reagent dosing for improved recoveries were rolled out at site. For the past 6 months equipment upgrades for the mine and mill have been implemented in phases and are ongoing.  The result of these changes includes higher metallurgical recoveries and concentrate grades, particularly for copper in the bulk concentrate where recovery increased from less than 48% at the beginning of the year to over 70% by year end, a 69% increase during Q4 2023.

Investor Relations Agreement
The Company has entered into an agreement with Triomphe Holdings Ltd. (dba Capital Analytica) ("Capital Analytica") for investor relations and communication services (the "Consulting Agreement"). The Consulting Agreement has an initial term of six months, commencing May 1, 2024, under which the Company will pay to Capital Analytica an aggregate of $120,000 at a rate of $20,000 per month, and has an option to renew the Consulting Agreement for an additional 6 months at a rate of $10,000 per month, unless terminated earlier in accordance with the Consulting Agreement. The Company has granted Capital Analytica incentive stock options to purchase 200,000 common shares at an exercise price of $.45 per share for a period of 2 years. The stock options will be subject to standard IR vesting provisions.

Pursuant to the terms of the Consulting Agreement, Capital Analytica will provide ongoing capital markets consultation, ongoing social media consultation regarding engagement and enhancement, social sentiment reporting, social engagement reporting, discussion forum monitoring and reporting, corporate video dissemination, and other related investor relations services.